(ISSN 0015-4040)
FLORIDA ENTOMOLOGIST
(An International Journal for the Americas)
Volume 76, No. 3 September, 1993
TABLE OF CONTENTS
DENMARK, H. A.-An Overview of the History of the Florida Entomological
Society on its Diamond or Seventy-Fifth Anniversary [1916-1992] ......... 407
Research Reports
ATKINSON, T. H.-A New Species of Trischidias (Coleoptera: Scolytidae) From
Southern Florida With a Key to the Species of the Southeastern United
States ........................................................................................... 416
NOTESTINE, M. K.-Function of Gills and Mesonotal Shield of Baetisca rogersi
Nymphs (Ephemeroptera: Baetiscidae) ...................................... 423
TSAI, J. H., AND J. L. PERRIER-Morphology of the Digestive and Reproductive
Systems of Peregrinus maidis (Homoptera: Delphacidae) .................... 428
LABATTE, J. M.-Within-Plant Distribution of Fall Armyworm (Lepidoptera:
Noctuidae) Larvae on Corn During Whorl-Stage Infestation ................ 437
HERNANDEZ-ORTIZ, V., AND R. PEREZ-ALONSO-The Natural Host Plants of
Anastrepha (Diptera: Tephritidae) in a Tropical Rain Forest of Mexico .. 447
HALLMAN, G. J., AND R. J. KNIGHT, JR.-Hypocala andremona (Lepidoptera:
Noctuidae) Development on Eight Species of Diospyros (Ebenaceae) ....... 461
WHITE, W. H.-Movement and Establishment of Sugarcane Borer (Lepidoptera:
Pyralidae) Larvae on Resistant and Susceptible Sugarcane ................. 465
ESCHER, R. L., AND L. P. LOUNIBOS-Insect Associates of Pistia stratiotes
(Arales: Araceae) in Southeastern Florida ....................................... 473
SCHEFFRAHN, R. H.-Cryptotermes chasei, A New Drywood Termite (Isoptera:
Kalotermitidae) from the Dominican Republic ................................... 500
MEAGHER, R. L., JR., S. W. WILSON, H. D. BLOCKER, R. V. W. ECKEL, AND
R. S. PFANNENSTIEL-Homoptera Associated with Sugarcane Fields in
Texas ............................................................................................ 508
Scientific Notes
COLLINS, H. L., T. C. LOCKLEY, AND D. J. ADAMS-Red Imported Fire
Ant (Hymenoptera: Formicidae) Infestation of Motorized Vehicles 515
SILVA, J. G., AND A. MALAVASI-The Status of Honeydew Melon as a
Host of Anastrepha grandis (Diptera: Tephritidae) ...................... 516
ORREGO, C., AND F. AGUDELO-SILVA-Genetic Variation in the
Parasitoid Wasp Trichogramma (Hymenoptera: Trichogrammatidae)
Revealed by DNA Amplification of a Section of the Nuclear
Ribosomal Repeat .................................................................. 519
Continued on Back Cover
Published by The Florida Entomological Society
FLORIDA ENTOMOLOGICAL SOCIETY
OFFICERS FOR 1992-93
President ..................................................... J. E. Pefia
President-Elect ...................................... ...................... .... E. M. Thorns
Vice-President ...................... ............ ................. J. A. Coffelt
Secretary ........ ...... ......................... ............................. D. G. Hall
Treasurer .............................................................. ................... A. C. Knapp
Other Members of the Executive Committee
D. F. Williams N. D. Epsky L. A. Wood C. L. Bloomcamp
C. S. Lofgren M. Lindsey R. Goodson
PUBLICATIONS COMMITTEE
C. S. Lofgren, USDA/ARS (Retired), Gainesville, FL ............................... Editor
Associate Editors
Agricultural, Extension, & Regulatory Entomology
James R. Brown-Disease Vector Ecology & Control Center, NAS, Jacksonville, FL
Richard K. Jansson-Tropical Res. & Ed. Center, UF/IFAS, Homestead, FL
Michael F. Hennessey-Subtropical Horticulture Res. Lab., USDA/ARS, Miami, FL
Geoffrey Zehnder-Auburn University, Auburn, AL
Apiculture
Stephen B. Bambara-North Carolina State University, Raleigh, NC
Biological Control & Pathology
Ronald M. Weseloh-Connecticut Agricultural Experiment Sta., New Haven, CT
John M. Brower-Stored Products Insect Res. Lab., USDA/ARS, Savannah, GA
Book Reviews
J. Howard Frank-Dept. of Entomology, UF/IFAS, Gainesville
Chemical Ecology, Physiology, Biochemistry
Louis B. Bjostad-Colorado State University, Fort Collins, CO
Ecology & Behavior
Sanford D. Porter, Insects Affecting Man Res. Lab., USDA/ARS, Gainesville, FL
Gregory S. Wheeler-Ft. Lauderdale Res. & Ed. Cent. UF/IFAS, Ft. Lauderdale, FL
Forum & Symposia
Genetics & Molecular Biology
Sudhir K. Narang-Bioscience Research Laboratory, USDA/ARS, Fargo, ND
Medical & Veterinary Entomology
Arshad Ali-Central Florida Res. & Ed. Center, UF/IFAS, Sanford, FL
Resumen
F. W. Howard-Tropical Res. & Ed. Center, UF/IFAS, Homestead, FL
Systematics, Morphology, and Evolution
Michael D. Hubbard-Florida A&M University, Tallahassee, FL
Gary J. Steck-Florida State Collection of Arthropods, Gainesville, FL
Willis W. Wirth-Florida State Collection of Arthropods, Gainesville, FL
Business M manager .................................................................. A. C. Knapp
FLORIDA ENTOMOLOGIST (ISSN 0015-4040) is published quarterly-March,
June, September, and December by the Florida Entomological Society, 391 Escambia
Drive, S.E., Winter Haven, FL 33884-1588. Subscription price to non-members is $30
per year in advance, $7.50 per copy; Institutional rate is $30 per year. Full Membership
in the Florida Entomological Society is $25 with $20 allocated to member services and
$5 may be allocated toward FES publication, FLORIDA ENTOMOLOGIST and stu-
dent membership is $15 with $10 allocated to member services and $5 may be allocated
toward FES publication, FLORIDA ENTOMOLOGIST. Second Class Postage paid at
Winter Haven, FL and at additional mailing offices. POSTMASTER: Send address changes
to the FLORIDA ENTOMOLOGIST; P.O. Box 7326, Winter Haven, FL 33883-7326.
Inquiries regarding membership and subscriptions should be addressed to the Busi-
ness Manager, P. O. Box 7326, Winter Haven, FL 33883-7326.
Manuscripts from all areas of the discipline of entomology are accepted for consider-
ation. At least one author must be a member of the Florida Entomological Society.
Please consult "Instructions to Authors" on the inside back cover.
This issue mailed September 30, 1993
Denmark: History of the Society on Its Diamond Anniversary 407
AN OVERVIEW OF THE HISTORY OF THE
FLORIDA ENTOMOLOGICAL SOCIETY ON ITS
DIAMOND OR SEVENTY-FIFTH ANNIVERSARY [1916-1992]
H. A. DENMARK
Florida Department of Agriculture and
Consumer Services/Division of Plant Industry
P.O. Box 147100
Gainesville, FL 32614-7100
Seventy-five years ago, on January 5, 1916, 11 men interested in forming an en-
tomological society met in Science Hall on the campus of the University of Florida. The
name Florida Entomological Society was adopted and at the next meeting on January
17, 1916, Professor Watson was elected President; Wilmon Newell, Vice President; R.
N. Wilson, Secretary-Treasurer; and H. S. Davis, member of the Executive Committee.
The objectives, as set forth in the constitution, were to promote the study of entomology,
to distribute knowledge pertaining to insects, and to publish an entomological journal.
The annual dues were set at 50 cents per member. Professionals as well as amateur
entomologists were encouraged to accumulate information about insects. Charter mem-
bers included all persons who affiliated with the Society during the first 5 monthly
meetings. These included E. W. Berger, T. N. Bradford, K. E. Bragdon, H. S. Davis,
H. L. Dozier, J. C. Goodwin, Fritz Hatcher, S. P. Ham, A. C. Mason, Wilmon Newell,
F. M. O'Bryne, W. E. Pennington, Frank Stirling, T. Van Hyning, Shirley B. Walker,
J. R. Watson, and R. N. Wilson.
The Florida Entomological Society was the first entomological society organized in
the South, and it is the 12th oldest in the United States. By the end of 1917 the Society
had over 100 active members and 20 associate members. Monthly meetings were held
on the campus, except during the summer. Special meetings were held when distin-
guished entomologists visited the University of Florida. Occasionally, joint sessions
were held with the Florida Academy of Sciences, with whom the Society was an affiliate,
and the Horticultural Seminar, when their meetings were in Gainesville. Florida was
infested with citrus canker at that time, and the Society met with the citrus canker
inspectors when they met in Gainesville. Topics of current interest on insects, review
of new publications and events of entomological interest were discussed under the heading
of "Brief and Timely Notes." Some examples of these topics were: some methods of
hatching, rearing, and shipping insects; some Florida aphids; the dictyospermum scale;
color forms of the lubber grasshopper; the molting of mayflies; bug hunting as a pastime;
beekeeping in Florida; controlling pumpkin bugs in citrus groves; and artificial rearing
of vedalia lady beetles. The State Plant Board, housed in Anderson Hall, now Language
Hall, reared and sold 10 adult vedalia beetles for $1.00 to citrus growers to control their
cottony cushion scale infestations in the 1920's and early 1930's. Meetings continued to
be held on the University campus until December 1948 when the Society held its 31st
annual meeting in the San Juan Hotel in Orlando. Most of the entomologists at that
time lived fairly close to Orlando.
The enthusiasm of the Society was contagious, and in 1918 the Lee County Entomolog-
ical Society at Fort Myers, with a membership of 12, affiliated with The Florida En-
tomological Society as a branch society. In December 1938, the Society petitioned the
American Association of Economic Entomologists for affiliate membership in that organi-
zation. The petition was granted by action of the Executive Committee at the Richmond,
Virginia meeting. At the 39th annual meeting in Tallahassee, the Sub-tropical En-
tomologists of Florida presented a petition requesting affiliation as a branch of the
408 Florida Entomologist 76(3) September, 1993
Florida Entomological Society. The Society accepted the branch as an affiliate at the
40th annual meeting in Orlando in 1957. There are no active branches affiliated with
the Society today; however, in 1961, the Society became an affiliate of the Entomological
Society of America.
At the April 1917 meeting, Dr. E. W. Berger recommended that the Society publish
a periodical to be known as the Florida Buggist. Three volumes were published under
that name. On February 23, 1920, the Society voted to change the name of its publication
to The Florida Entomologist, at the recommendation of Dr. J. H. Montgomery. The
name of the journal was changed to Florida Entomologist (An International Journal for
the Americas) with volume 63 in 1980.
The Editors and the Associate Editors of the journal have all played an important
role in the development and the quality of the journal which has contributed greatly to
the prestige of the Society. Professor J. R. Watson was elected the first Editor in April
1917 and continued to serve as Editor until his death on June 6, 1946. In the 1930's,
Professor Watson had to request Pepper Printing Company of Gainesville to extend
credit to the Society for the publication costs. He also issued personal checks during
that period to help pay for the printing costs. The Tobacco By-Products and Chemical
Corporation carried a full page advertisement which also helped with printing costs.
Due to shortages of funds and manuscripts, it was sometimes necessary to combine 2
numbers in a volume. Twice during the history of the journal, the Editors (Professor
Watson, 1943 and Dr. H. K. Wallace, 1947) published non-entomological papers on
armadillos and crayfishes, respectively. Since 1947, the editors have had sufficient en-
tomological manuscripts to publish 4 numbers annually.
In 1958 at the 41st annual meeting, the Society voted to encourage the dissemination
of nematological information at annual meetings and to accept manuscripts for publica-
tion. An attempt was made in the early 1950's to meet jointly with the state pathologists.
In 1954, it was decided that there were too many conflicting events in both Societies to
allow such a meeting. In 1981, the Committee on a Florida Congress of Entomology
met in Orlando. Several associations and institutions were contacted by Chairperson A.
G. Selhime. It soon became apparent that some major problems would have to be
overcome before the membership of the various organizations could join together for a
meeting. To date, the task has not been accomplished.
Mr. G. B. Merrill, Associate Editor, served as Editor from June through the remain-
der of 1946 following Professor Watson's death. Dr. H. K. Wallace was elected Editor
beginning with vol. 29, no. 1, 1947 and served through vol. 32, no. 4, 1949. Dr. Lewis
Berner was elected Editor beginning with vol. 33, no. 1, 1950 and served through vol.
46, no. 4, 1963. In 1950, a cover was added to vol. 33. Until this time the lead article
began on the front page.
The field of entomology developed rapidly in the early 1950's due to the nation's
improved economy and to the production and the widespread use of chlorinated hydro-
carbon and phosphatic insecticides. The number of entomology students increased, and
the research by the University of Florida, Florida Department of Agriculture, the
USDA-ARS, and industry increased many fold. With the increased number of en-
tomologists publishing in the journal (including some from foreign countries), the editorial
responsibilities increased. Despite this, manuscripts were often published within 6
months, which attracted more manuscripts from out-of-state. By 1960, 55 libraries in
the United States and 29 in foreign countries were subscribing to the journal, in addition
to domestic and foreign exchanges. There are now 137 libraries in the United States
and 59 in foreign countries subscribing to the journal.
Dr. T. J. Walker, Jr. was elected Editor beginning with vol. 47, no. 1, 1963 and
served through vol. 49, no. 4, 1966. Dr. S. H. Kerr was elected Editor beginning with
Denmark: History of the Society on Its Diamond Anniversary 409
vol. 50, no. 1, 1967 and served through vol. 61, no. 2, 1978. Dr. C. A. Musgrave became
Editor beginning with vol. 61, no. 3, 1978 and served through vol. 62, no. 4, 1979. After
her marriage, Dr. C. A. Musgrave Sutherland served through vol. 63, no. 1, 1980, and
jointly with Dr. J. R. McLaughlin for vol. 67, no. 3 and no. 4, 1984. Dr. J. R. McLaughlin
has served as Editor beginning with vol. 68, no. 1, 1985 through vol. 75, no. 4, 1992.
Dr. E. W. Berger became the first Associate Editor and served in that capacity until
his death in 1944. G. B. Merrill served as Associate Editor from 1945 through 1949, Dr.
H. K. Wallace from January through December 1950, Dr. A. N. Tissot for the year of
1951, W. P. Hunter for the year of 1952. Dr. L. C. Kuitert served as Associate Editor
from 1953 through October 1955, N. C. Hayslep from September 1955 through September
1962, Dr. T. J. Walker from October 1962 through December 1963, Dr. S. H. Kerr from
1964 through 1966, Dr. J. L. Nation from 1967 through September 1969 and Dr. R. E.
Woodruff from October 1969 through September 1974. In 1973, Drs. H. V. Weems, Jr.
and R. C. Wilkinson were appointed Associate Editors with Dr. Woodruff and served
until June 1974.
Associate Editors who have served for varying periods of time from 1974 until the
time of this address are as follows: R. E. Woodruff (1969-1974), H. V. Weems, Jr.
(1973-1992), J. E. Lloyd (1974-1981), E. E. Grissell (1975-1977), R. M. Baranowski
(1975-1978), Carol A. Rolfs Kay (1975), Carol A. Musgrave (1977-1978), A. B. Hamon
(1978-1980), C. W. McCoy (1978-1982), J. R. McLaughlin (1978-1983), A. R. Saponis
(1981-1983), F. W. Howard (1981-1984), D. C. Herzog (1983-1984), M. D. Hubbard
(1983-Present), J. R. Heppner (1984-1989), O. Sosa (1984-1991), W. D. Adlerz (1984-
1985), A. D. Ali (1984-Present), C. S. Barfield (1986-1992), W. W. Wirth (1984-Present),
L. S. Osborne (1987-1989), R. H. Cherry (1987-1991), J. Sivinski (1988-1989), M. G.
Waldvogel (1989-1992), S. B. Bambara (1989-Present), R. M. Weseloh (1989-Present),
W. H. Frank (1989-Present), L. B. Bjostad (1989-Present), T. E. Burk (1989-1992), S.
K. Narang (1989-Present), J. R. Brown, (1991-Present), and R. K. Jansson (1991-Pres-
ent). Dr. H. V. Weems Jr. is to be commended for serving as an Associate Editor for
20 years.
The Journal now has 12 scientific subject editors in 8 subject areas. There are several
out-of-state editors. A new type of article, the Forum, was instituted to attract high
visibility articles. The color of the cover was changed, and the name of the journal,
year, volume and number are now printed along its spine so that a particular issue can
be found easily. The Long Range Planning Committee recommended and the Society
approved the inclusion of an abstract of each paper in Spanish, Portuguese, French or
some other appropriate language.
The practice of publishing the president's address in its entirety began with President
Homer Hixon in 1941. This practice continues today. In 1955 at the 38th annual meeting,
the Society voted to publish supplements to the journal. The first supplement published
was Egg types among moths of the Pyralidae and Phycitidae, by Dr. Alva Peterson
and The genus Galendromus Muma, 1961, by M. H. Muma in 1963. In 1970, the Society
published Sunshine State Entomology to help promote entomology in Florida and as a
reference source for visiting entomologists attending the Entomology Society of America
Meeting in Miami Beach the same year. The different Centers, Universities, State
Offices, USDA, and Industry were listed with their personnel. In 1980, the Society
published a Handbook of Florida Entomologists that included names and addresses of
active and retired professional entomologists, including amateurs who participated seri-
ously in entomology. This served as a reference source for the entomologists attending
the Entomological Society of America meeting in Miami Beach that year.
Beginning in 1986, a newsletter for the Florida Entomological Society has been
published quarterly. The first pre-meeting "Bull Session" was held at the 43rd annual
Florida Entomologist 76(3)
September, 1993
meeting in 1960 to allow the membership to informally discuss topics of entomological
interest not covered in the regular meeting.
In 1956, President Herman S. Mayeux appointed a committee, with Dr. Milledge
Murphey, Jr. as chairman, to design an exhibit to interest students in the field of
entomology. An exhibit, "Entomology in Action," received favorable attention at the
1957 and 1958 annual meetings of the Entomological Society of America. Mr. Lewis M.
Wright, Jr. gave an illustrated talk with a series of color slides depicting entomology
in action at the Society's annual meeting in 1957.
An Honors and Awards Committee was appointed in 1960 by President A. J. Rogers
at the 43rd annual meeting for the purpose of honoring and presenting appropriate
awards to entomologists who had made outstanding contributions to science and to the
public. A Public Relations Committee was established in 1963 at the 45th annual meeting
as a permanent committee with 3 members. Talks were given to various groups explaining
entomology as a science and profession and its contribution to society.
A legislative liaison was established in 1963 in order to introduce or support bills
before the Florida Legislature regulating or effecting our profession. Such an item of
interest in 1963 was support for establishing a laboratory on the Florida Gulf Coast to
study the biology and control of stable flies, deer flies, and other arthropods of public
health importance. To cite another example, regulation of pesticides by the Florida
Commissioner of Agriculture was supported by this committee.
Beginning in the 1970's the Executive Committee placed more emphasis on scholar-
ships and public relations. Symposia were encouraged that attracted many excellent
speakers whose papers were published in the journal beginning with a Fall Armyworm
Symposia. Dr. J. E. Lloyd has chaired several Symposia on Insect Behavioral Ecology.
These additional papers generated more income for the Society, as well as enhancing
the scientific status of the journal.
In 1977, the Society established a Florida Entomological Society Woman's Auxiliary
to be called the Florida Entomology Society Lovebugs. Its purpose was to aid in the
planning and operation of the annual meeting. In 1981 the Long Range Planning Com-
mittee recommended special emphasis be placed on the following: stimulating increased
participation, particularly by students, developing the Florida Congress of Entomology,
and continuing support for research mini-grants and 4-H programs. The committee
recommended that the chairperson of the Long Range Planning Committee be added
to the Executive Committee.
It is almost impossible to describe in detail the activities of all those who have
generously given time and energy in service to the Society. However, activities of the
presidents are a major factor in any organization's progress. Therefore, in recognition
of the contributions made by presidents of the Florida Entomological Society, their
names are listed here:
1916 J. R. Watson (deceased)
1917 E. W. Berger (deceased)
1918 H. S. Davis (deceased)
1919 F. M. O'Byrne (deceased)
1920 G. B. Merrill (deceased)
1921 J. R. Watson (deceased)
1922 F. Stirling (deceased)
1923 G. B. Merrill (deceased)
1924 G. B. Merrill (deceased)
1925 J. S. Rogers (deceased)
1926 J. Gray (deceased)
410
Denmark: History of the Society on Its Diamond Anniversary 411
1927 W. W. Others (deceased)
1928 E. D. Ball (deceased)
1929 E. F. Grossman (deceased)
1930 R. D. Dickey (deceased)
1931 C. F. Byers (deceased)
1932 A. N. Tissot (deceased)
1933 P. Calhoun (deceased)
1934 (No record of an election of officers for 1934 is available, so it is presumed that the
officers for 1933 also served during 1934.)
1935 W. L. Thompson (deceased)
1936 W. L. Thompson (deceased)
1937 R. L. Miller (deceased)
1938 W. V. King (deceased)
1939 J. H. Montgomery (deceased)
1940 H. Spencer (deceased)
1941 H. Hixon (deceased)
1942 K. E. Bragdon (deceased)
1943 T. H. Hubbell (deceased)
1944 A. H. Madden (deceased)
1945 A.C. Brown (deceased)
1946 H. K. Wallace, Apt. 2D Sycamore, 1717 NW 23rd Ave., Gainesville, FL 32605
1947 M. R. Osburn (deceased)
1948 E. G. Kelsheimer (deceased)
1949 M. C. Van Horn (deceased)
1950 J. A. Mulrennan (deceased)
1951 W. G. Bruce (deceased)
1952 J. W. Wilson (deceased)
1953 J. T. Griffiths, Rt. 1, Box 655, Winter Haven, FL 33880
1954 D. 0. Wolfenbarger, 29220 SW 187th Ave., Homestead, FL 33030
1955 F. G. Butcher (deceased)
1956 H. S. Mayeux (Address unknown)
1957 M. Murphey, Jr. (deceased)
1958 I. H. Gilbert, 531 Orange St., Altamonte Springs, FL 32701
1959 W. P. Hunter (deceased)
1960 A. J. Rogers, Rt. 4, Box 793, Panama City, FL 32405
1961 L. Berner, 7081 NW 23rd Ave., Gainesville, FL 32606
1962 W. C. Rhoades (Address unknown)
1963 H. J. True, Apt. 105, 5911 NE 14th Ln., Fort Lauderdale, FL 33334
1964 G. W. Dekle, 3600 NW 12th St., Gainesville, FL 32605
1965 N. C. Hayslip, 289 Bermuda Beach Dr., Fort Pierce, FL 33450
1966 J. R. King, Sun Coast Nursery, 802 Texas Ct., Fort Pierce, FL 33450
1967 J. E. Brogdon, 324 NW 30th St., Gainesville, FL 32607
1968 L. A. Hetrick, 1614 NW 12th Rd., Gainesville, FL 32605
1969 J. B. O'Neil, American Cyanamid Co., 2997 Gant Pl., Marietta, GA 30067
1970 H. A. Denmark, Division of Plant Industry, FDACS, P.O. Box 147100, Gaines-
ville, FL 32614-7100
1971 L. C. Kuitert, 2842 SW 1st Ave., Gainesville, FL 32607
1972 W. B. Gresham (deceased)
1973 A. G. Selhime, USDA/ARS, 2120 Camden Rd., Orlando, FL 32803
1974 W. G. Genung (deceased)
1975 R. M. Baranowski, AREC, UF, 18905 SW 280th St., Homestead, FL 33031
1976 H. V. Weems, Jr., P.O. Box 760, Hawthorne, FL 32604
Florida Entomologist 76(3)
September, 1993
1977 C. S. Lofgren, 1321 NW 31st Dr., Gainesville, FL 32605
1978 J. B. Taylor, Ciba-Geigy Corp., 1032 N Blvd., DeLand, FL 32720
1979 R. F. Brooks, AREC, UF, P.O. Box 1088, Lake Alfred, FL 33850
1980 N. C. Leppla, Development Centers, Science & Technology, APHIS, USDA,
Hyattsville, MD 20782
1981 E. C. Beck, 1621 River Bluff Rd. N., Jacksonville, FL 32211
1982 W. L. Peters, Fla. A&M Univ., Tallahassee, FL 32307
1983 A. C. White, White Consulting Service, 817W Fairbanks Ave., Orlando, FL 32804
1984 C. W. McCoy, AREC, UF, 700 Experiment Station Rd., Lake Alfred, FL 33850
1985 M. L. Wright, Jr., Wright Pest Control, Winter Haven, FL 33880
1986 D. H. Habeck, Dept. of Entomology & Nematology, UF, Gainesville, FL 32611
1987 D. J. Schuster, AREC, UF, 5007 60th St. E, Bradenton, FL 34202
1988 J. L. Taylor, P.O. Box 1893, Sanford, FL 32771
1989 R. S. Patterson, USDA/ARS, Insects Affecting Man & Animal Laboratory,
Gainesville, 1600 SW 23rd Dr., FL 32611
1990 J. E. Eger, Jr., Dow Chemical USA, 5100 W Kennedy Blvd., Suite 450, Tampa,
FL 33609
1991 J. F. Price, AREC, UF, 5007 60th St. E, Bradenton, FL 34203
1992 J. Knapp, CREC, UF, 700 Experiment Station Rd., Lake Alfred, FL 33850
On January 21, 1921, the Florida Entomological Society initiated the practice of
recognizing distinguished entomologists by conferring honorary membership upon Dr.
Herbert Osborn. In subsequent years, the Society has continued the practice. The
bylaws state that the Society may have up to 10 honorary members at any one time.
Presently there are 8 honorary members. The list of those honored in this manner include:
Dr. H. Osborn, 1921
Dr. W. M. Barrows, 1927
Dr. H. T. Fernald, 1927
Dr. L. O. Howard, 1928
Dr. E. M. Patch, 1940
Dr. C. T. Brues, 1948
Dr. J. T. Needham, 1948
Mr. W. W. Others, 1952
Dr. O. A. Johannsen, 1952
Mr. K. E. Bragdon, 1954
Mr. A. C. Brown, 1954
Dr. W. V. King, 1954
Mr. G. B. Merrill, 1957
Dr. A. Peterson, 1964
Dr. A. N. Tissot, 1964
Dr. J. W. Wilson, 1966
Dr. C. N. Smith, 1970
Dr. M. H. Muma, 1972
Mr. W. B. Gresham, 1974
Dr. D. O. Wolfenbarger, 1975
Dr. L. A. Hetrick, 1975
Dr. J. A. Mulrennan, Sr., 1976
Dr. W. G. Eden, 1976
Dr. A. J. Rogers, 1979
Dr. L. C. Kuitert, 1983
Mr. A. G. Selhime, 1987
Dr. H. V. Weems, Jr., 1991
Denmark: History of the Society on Its Diamond Anniversary 413
In addition to the presidents and the honorary membership, the Entomologists of
the Year are recognized here with brief comments. It is considered one of the highest
honors bestowed on a member by the Society. Space will not permit the listing of
members who have been singled out by our Society for special recognition in other areas
over the years. At the present time the Honors and Awards Committee has the following
areas for consideration each year:
1. Entomologist of the Year
2. Achievement Award for:
a. Teaching
b. Research
c. Extension
d. Industry
3. Certificates of Appreciation for Special Services to the Society
4. Certificates of Merit for Service to the Field of Entomology
5. Special Awards for Research Teams, Laboratories, Agencies, etc.
6. Honorary Memberships
The Entomologist of the Year was proposed by Dr. Andrew J. Rogers for the purpose
of recognizing individuals who have made outstanding contributions to science and to
the public. The individuals were first referred to as The Man of the Year and later The
Entomologist of the Year.
The first person to be recognized was Dr. Loren F. Steiner, ARS, USDA in 1959
at the 43rd annual meeting for his outstanding work on the biology of fruit flies and the
development of attractants for these insects. In 1962 the Society honored Dr. Archie
N. Tissot, 1925-1964, for his outstanding and meritorious service to science and to the
public. He served as the Florida Agriculture Experiment Station Entomologist in Gaines-
ville for 37 years and as Head for 15 years. His entomological interest was primarily
the taxonomy and biology of aphids.
In 1963, the Honors and Awards Committee recommended Drs. Carroll N. Smith
and Germain C. La Brecque of the Insects Affecting Man Research Laboratory, ARS,
USDA in Gainesville for their contribution in developing a method of controlling certain
insects by the sterile-male technique through the use of chemosterilants.
In 1965, the Society honored William Walters Yothers. He was employed by the
USDA and was transferred to Orlando to work on citrus insects in 1907 after working
on cotton insects for 3 years in Texas. He remained in charge of the laboratory until he
retired in 1935. He studied the life cycle of the citrus rust mite. In 1915 he published
the first insect and mite control program for citrus growers in Florida. He developed
early recommendations for the use of oil for scale insect control.
In 1966, the Society honored Charles P. Kimball for a compilation of Florida Lepidopt-
era beginning in 1946. His work was published in 1965, Volume 1, Arthropods of Florida
and Neighboring Land Areas, Florida Department of Agriculture.
In 1968, the Society honored George B. Merrill, who was an associate editor for 5
years and the only person to serve 3 terms as president. His early work included the
control of the gypsy moth and browntail moth in Massachusetts and sugarcane insects
in Puerto Rico. He joined the State Plant Board of Florida in 1916 and served as an
entomologist until 1943 and Chief Entomologist from 1943 until his retirement in 1956.
He was primarily interested in the Coccidae and published a revision of The Scale Insects
of Florida.
In 1969, the Society honored William Louden 'Tommy" Thompson for his contributions
to science and the public. He specialized in the control of citrus insects from 1927 until
1962. He was the first entomologist at the UF Lake Alfred Citrus Experiment Station.
Florida Entomologist 76(3)
September, 1993
In 1970, the Society honored Dr. Martin H. Muma, who joined the staff at the Lake
Alfred Experiment Station in 1951 and served through 1971. He was an instructor in
entomology and assistant entomologist at the University of Maryland 1940-1945, and
extension entomologist (1945-1951) at the University of Nebraska. His work included
research on the taxonomy, biology, and natural control of citrus mites, and the natural and
ecological control of injurious citrus insects. He was an authority on mites, spiders, and
Solpugida (wind scorpions).
In 1972, the Society honored Dr. Stratton H. Kerr, a member of the teaching staff
of the University of Florida in Gainesville from 1953 to 1991. His teaching assignments
included toxicology and his research was on turfgrass insects.
In 1973, the Society honored Dr. Andrew J. Rogers, who joined the teaching staff
of the Entomology Department, University of Florida in 1946. He was a research scientist
with the Florida Division of Health at Vero Beach until retirement in 1979. His interest
was insects affecting man and animals. His research was on ticks and mosquitoes.
In 1974, the Society honored Dr. D. O. Wolfenbarger, who joined the staff at the
Subtropical Research Station, Homestead, (TREC) in 1945 and retired in 1974. He
worked on vegetable insects and helped develop controls for the winter vegetables
grown in South Florida.
In 1975, the Society honored Dr. Maurice W. Provost, research scientist and director
of the Florida Medical Entomology Laboratory, Vero Beach from 1954 until his death
in 1977. He coordinated studies of the ecology, biology, behavior, and physiology of
mosquitoes and sand flies in the field and laboratory. It was in large part through his
work that man has been able to inhabit many parts of Florida that once abounded with
high mosquito and sandfly populations.
In 1976, the Society honored Dr. William G. Eden, who was chairman of the Entomol-
ogy and Nematology Department, University of Florida 1965-1975. Earlier, he was
employed by Auburn University for 20 years as an economic entomologist, working with
cotton insects.
In 1976, the Society honored George W. Dekle, who joined the staff of the State
Plant Board in 1942 and worked primarily with ornamental plant pests, scale insects,
mealybugs, whiteflies, and immature stages of insects. He also was interested in insect
control and was always ready to help the growers. He published the Armored Scales
of Florida.
In 1977, the Society honored Dr. Milledge Murphey, Jr., who served on the entomol-
ogy teaching staff of the University of Florida from 1947 to 1977. He taught economic
entomology, biological control, vocational entomology, apiculture, and insect morphol-
ogy. The students voted him a Professor of the Year, which was a first in the College
of Agriculture. He died in 1977.
In 1981, the Society honored James E. Brogdon and Dr. Frank W. Mead as Co-En-
tomologists of the year. Mr. Brogdon began work with the UF Agricultural Extension
Service in 1953, with the responsibility for all phases of Extension Entomology except
apiculture. He developed an Extension Safety Kit and Training Guide for agricultural
chemicals, and organized the County Chemical Educational Groups. He received the
1980 Entomological Society of America Distinguished Achievement Award for Extension
Entomology. He retired in 1980.
Dr. Mead began work with the USDA in Ohio in 1950 in the Bureau of Entomology
and Plant Quarantine, Division of Forest Insects. He joined the State Plant Board of
Florida on September 15, 1953. His area of responsibility included Diptera: suborders
Brachycera and Nematocera; Homoptera: Auchenorrhyncha, plus Psyllidae; Hemiptera
(Heteroptera). Dr. Mead is recognized for his many years of service to entomology and
his dedication to the Florida Entomology Society.
414
Denmark: History of the Society on Its Diamond Anniversary 415
In 1984, the Society honored Howard V. Weems, Jr., who joined the State Plant
Board in 1953 as an insect taxonomist. He became the head curator of the Florida State
Collection of Arthropods (FSCA) and developed the Research Associates Program of
over 300 members who have donated approximately 200,000 specimens annually to the
FSCA, now the 5th largest collection in the USA. He retired in 1991.
In 1985, the Society honored Dr. James A. Reinert, a member of the UF staff at
Fort Lauderdale from 1970 to 1984. He worked on the control of ornamental and sod
insects. He became chairman of the Entomology Department at Texas A&M in Dallas
in 1984.
In 1986, the Society honored Dr. Daniel L. Shankland, Chairman of the Entomology
and Nematology Department, University of Florida from 1980 until 1986. Upon retire-
ment he became Director for the Center of Environmental Toxicology. He also worked
with the Cameroon Project.
Five histories of the Florida Entomological Society have been published. The first
was prepared by Dr. A. N. Tissot in recognition of the twentieth anniversary, although
this celebration took place three years after the anniversary. It was published in The
Florida Entomologist 22(1): 8-9, 1939. The Silver Anniversary (25th Annual Meeting)
was held in Gainesville on December 13 and 14, 1940. Dr. H. Harold Hume, as toastmas-
ter, honored Professor Watson, the first president and editor of The Florida En-
tomologist. The second very brief history was included in "A Brief History of Entomology
in Florida" by Drs. A. N. Tissot, M. Murphey, Jr., and R. E. Waites that was published
in vol. 37(2): 51-57, 1954. The third report was presented on the fortieth anniversary
by Dr. John W. Wilson and published in The Florida Entomologist 40(2): 39-44, 1957.
Dr. Elwood C. Nance, former President of the University of Tampa, requested that
this historical report be included in the History of Florida he was preparing at that
time. The fourth report was prepared by Drs. A. N. Tissot, L. A. Hetrick, and A. J.
Rogers and was published in The Florida Entomologist 44(1): 1-9, 1961. The fifth report
was prepared by Dr. J. W. Wilson and published in 1967 as a separate of The Florida
Entomologist commemorating the golden or fiftieth anniversary of our Society. These
histories, particularly the fifth one, summarize the various activities of our Society
during the first 50 years.
The dedication to the purpose of our Society to promote entomology and to encourage
the younger generations by our members has been tremendous. The years from 1967
to 1992 showed a growth in membership, an improvement in the quality of papers
published in the journal, an improvement in the Florida Entomology Society's relation-
ship to the general public, and encouragement of international relationships through
scheduling meetings in Ocho Rios, Jamaica in 1985 and Cancun, Mexico in 1990. The
decision to hold meetings in other countries every 5 years should encourage greater
exchange of science and technology between the USA and Latin America.
The Society has encouraged students to attend meetings by providing incentives
such as travel support and mini-grants. The Americas Committee has recommended
development of a recruitment kit and posters with our Society's logo. In 1983, 23 appli-
cations were received from students for mini-grants. Ten students were awarded $50.00
each. The Scholarship Committee awarded two $500.00 scholarships to students in 1983
at the 66th annual meeting.
The economy worldwide has caused a "down sizing" or "right sizing" of government
and industry. Personnel that are forced to leave these positions often are not replaced
because reorganization, or "right sizing", results in changes in the emphasis or needs
of a company or government. These changes are bound to impact on all fields of science.
The field of taxonomy has already been curtailed in North America and Europe where
most taxonomists live and work. There is a need for our Society to let our congressmen
416 Florida Entomologist 76(3) September, 1993
both in Florida and in Washington know the importance of entomology and how we as
entomologists relate to the rest of our Society. The future is ours only if we make it
ours. The present trend to do a better job of promoting entomology will be even more
important in the future in order to attract bright young students. Our Society's financial
status is sound at this time. We have placed our Society in the hands of good leadership
and I have faith that we as members of the Florida Entomological Society have a bright
future, but it can only be as good as the visions of our leadership and the support they
receive from the membership. Thus, this is not only a tribute to our past leaders, it is
also a reminder to the present and future leaders to steer a course that will continue
to attract fertile minds that are dedicated to the promotion of the study of entomology,
the wide distribution of knowledge pertaining to insects, and continuing efforts to make
our journal the very best of its kind.
This address was presented by H. A. Denmark at the Florida Entomological Society
Meeting, August 11, 1992.
A NEW SPECIES OF TRISCHIDIAS
(COLEOPTERA: SCOLYTIDAE) FROM
SOUTHERN FLORIDA WITH A KEY TO THE
SPECIES OF THE SOUTHEASTERN UNITED STATES
T. H. ATKINSON
Entomology & Nematology Department
University of Florida, Gainesville, FL 326111
ABSTRACT
Five species of Trischidias are known from the southeastern United States. Tris-
chidias striata, new species, is described from southern Florida. Descriptions, distribu-
tions, and hosts are presented for all species, as well as a key to the females.
Key Words: Trischidia striata, ascomycetous fungi, beetles.
RESUME
Se conocen 5 species de Trischidia en el sureste de los Estados Unidos. Trischidia
striata, especie nueva, se describe del sur de Florida. Se presentan descripciones, distri-
buciones, y plants hospederas para todas las species, ademAs de una clave para hembras.
The genus Trischidias Hopkins includes the smallest known Scolytidae with females
ranging in length from 0.65-1.1 mm. As is the case with other inbred polygynous genera
in the Cryphalini, males are even smaller than females and flightless (metathoracic
wings not developed). Species in the genus are poorly known because of their very small
size and tropical distributions. Wood's (1982) monograph on the Scolytidae of North and
'Current address: Department of Entomology, University of California, Riverside, California 92521.
Atkinson: New Trischidias from Southern Florida
417
Central America included 3 species of Trischidias. Trischidias exigua Wood was sub-
sequently described from the Yucatan Peninsula of Mexico and Florida (Wood 1986,
Deyrup 1987). Trischidias atoma (Hopkins) is widely distributed, though seldom col-
lected, in the southeastern United States. Trischidias exigua, known from southern
Florida and the Yucatan Peninsula is the only species previously reported outside the
United States. The remaining southeastern species are known only in Florida and south-
eastern Georgia. Recently Wood & Bright (1992) expanded the genus to include species
from Africa and South America that had previously been described in other genera.
These and other species will probably be found over a wider area. Given the generally
poor state of knowledge of the largely uncollected tropical Scolytidae, the absence of
records of these tiniest of scolytids probably reflects a lack of field work by trained
collectors.
The genus Trischidias is unusual in the Scolytidae in that adults and larvae feed on
fruiting bodies of ascomycetous fungi on branches or on wood invaded by the hyphae
of these fungi (Deyrup 1987). Consequently, they are likely to be overlooked even by
experienced collectors of scolytids because they are in host material that would appear
"too old" or "too dead." Most scolytids either feed on the undegraded phloem of their
hosts (true bark beetles) or on ectosymbiotic fungi introduced into their tunnels in the
sapwood (ambrosia beetles). The biology of T. exigua in Florida and notes on the feeding
habits of T. atoma and T. minutissima Wood were discussed in detail by Deyrup (1987).
Recently, I had the opportunity to examine a very large number of Scolytidae (>2,500
specimens) collected by S. B. Peck and associates as part of a survey of the insect fauna
of tropical southern Florida (Peck 1989). Included were specimens of T. atoma, T.
exigua, and many specimens of a new species described here. As preparation of a
monograph of the Scolytidae and Platypodidae of the southeastern United States, I have
examined numerous specimens in institutional and private collections and found many
previously unpublished distribution and host records. A key to all of the currently
described species is included, as well as descriptions, locality data, and host information.
The following abbreviations are used for collections (from Arnett and Samuelson
1986): Archbold Biological Station, Lake Placid, Florida (ABSC), Canadian Museum of
Nature Collection, Ottawa, Ontario (CMNC), Canadian National Collection, Ottawa,
Ontario (CNCC), Department of Forestry and Environmental Science, State University
of New York, Syracuse, New York (DFEC), S. L. Wood private collection, Provo, Utah
(SLWC); Texas A&M University, College Station, Texas (TAMU), T. H. Atkinson
private collection, Riverside, California (THAC), University of Georgia at Athens,
Athens, Georgia (UGCA), U.S. National Museum, Washington, D.C. (USNM).
GENUS TRISCHIDIAS HOPKINS
Trischidias Hopkins. 1915. U.S. Dept. Agric. Rep. 99: 12. (Type species: Trischidias
georgiae Hopkins, original designation).
This genus is characterized by minute body size (length 0.6-1.1 mm), rotund body
shape (2.0-2.3 times as long as wide), the 3-segmented antennal funicle, and entire
margin of the eye. It is most closely related to Hypothenemus Westwood, from which
it is doubtfully distinct. This genus may eventually be treated as a species group of
Hypothenemus. Like many genera of the tribe Cryphalini, males of Trischidias are
smaller than females, flightless (metathoracic wings not developed), and found in much
lower numbers than females. Presumably females mate with siblings prior to emergence
from the parental gallery.
Florida Entomologist 76(3)
September, 1993
Key to females of Trischidias of the southeastern United States
1. Interstriae wider than striae (Figs. 1, 3); anterior margin of pronotum with 4
teeth (outer pair smaller than inner pair) ............................................ 2
Interstriae narrower than striae (Fig. 5); anterior margin of pronotum with 2 or
4 teeth ............................................. ............................................ 3
2 (1). Body 2.3 times longer than wide; erect interstrial setae on declivity short and
stout, almost as wide as long (Fig. 1). Southeastern U.S. 0.65-1.0 mm
............................................................................... atom a (H opkins)
Body 2.1 times longer than wide; erect interstrial setae on declivity long and
slender, more than 5 times as long as wide (Fig. 3). Southern Florida, Campeche.
0.8-0.9m m .......................................................................... exigua W ood
3 (1). Strial punctures increasing conspicuously in size posteriorly; declivital interstriae
less than 1/2 width of striae. Georgia. 1.1 mm .................. georgiae Hopkins
- Strial punctures not increasing conspicuously in size posteriorly; declivital in-
terstriae sub equal in width to striae. Southern Florida. 0.6-0.8 mm .......... 4
4 (3). Striae not impressed; scales about 1-2 times longer than wide minutissima Wood
- Striae deeply impressed; scales on declivity 4 times longer than wide (Fig. 5)
.......... ........ ............. ....................................... striata new species
Trischidias atoma (Hopkins)
(Figs. 1-2)
Hypothenemus atomus Hopkins 1915:15.
Trischidias atoma: Wood 1954:1068.
Hypothenemus impressifrons Hopkins 1915:15.
Hypothenemus marylandicae Hopkins 1915:15.
Hypothenemus robiniae Hopkins 1915:15.
Hypothenemus toxicodendri Hopkins 1915:15.
Diagnosis. This is the most widely distributed species in the genus and the only one
known to occur outside of Florida and southeastern Georgia. It can be distinguished
from other species in the genus by the more slender body form, short setae on the
elytra, and 4 marginal teeth on the pronotum.
Female. Length 0.75-1.00 mm, 2.3 times as long as wide. Frons convex with trans-
verse impression just above epistoma, shallowest in middle; convex above with median,
longitudinally-oriented impression (appears as a groove in some specimens) from epi-
stoma to upper level of eyes. Anterior margin of eye entire. Antennal club rounded,
longer than scape, with 3 short sutures indicated externally by rows of setae.
Pronotum 0.9 times longer than wide, anterior margin produced anteriorly with 4
(rarely 5-6) subcontiguous teeth, the middle pair distinctly larger. Summit at middle,
posterior and lateral area coarsely denticulate, with scattered granules; hair-like pubes-
cence mixed with short erect scales (length subequal to width).
Elytra glossy; striae slightly impressed, punctures fine, distinct, shallow, separated
by distance greater than diameter, with recumbent, hair-like strial setae, length slightly
greater than diameter of puncture; interstriae 1.5 times width of striae, punctures small,
uniseriate, granulate, with erect, stout, scale-like setae, these longer on declivity (twice
as long as wide on declivity). Declivity convex.
Male. Length 0.49-0.53 mm. Similar to female but smaller.
Distribution. Eastern U.S., east of the Great Plains; southern part of Great Lakes
states southward to the Florida Keys. United States: D.C.: Washington (Wood 1982);
Florida: Collier Co.: Copeland, 12-IX-86, M.A. Deyrup, Ficus aurea (ABSC); Dade
418
Atkinson: New Trischidias from Southern Florida
Figs. 1-2. Trischidias atoma. 1, female, dorsal view. 2, male, dorsal view.
Figs. 3-4. T. exigua. 3, female, dorsal view. 4, female, lateral view.
Figs. 5-6. T. striata. 5, female, dorsal view. 6, female, lateral view. White lines =
0.5 mm in Figs. 1, 3-6, 0.05 mm in Fig. 2.
Co.: Everglades Natl. Pk., Long Pine Key, 28-V to 8-V-86, 31-VII to 9-XII-86, S. & J.
Peck, flight intercept trap (CMNC); Flagler Co.: Relay, X-78, T.H. Atkinson, window
trap (THAC); Highlands Co.: Archbold Biol. Sta., 30-III-86, M.A. Deyrup, Cestrum
nocturnum (ABSC); 3-VI-86, M.A. Deyrup, Ilex opaca (ABSC); Sebring (Wood 1982);
Monroe Co.: No Name Key, 28-VIII to 13-XII-86, S. & J. Peck, flight intercept trap
(CNCC); Sugarloaf Key, 4-VIII to 19-XI-85, S. & J. Peck, flight intercept trap (CMNC);
Georgia: Barrow Co.: Winder, III-75, R.H. Turnbow, Carya illinoensis (Wangenh.)
420 Florida Entomologist 76(3) September, 1993
K. Koch (UGCA); Indiana: Jackson Co. (Deyrup 1981); Tippecanoe Co. (Deyrup 1981);
Kansas: Douglas Co.: Lawrence (Wood 1982); Louisiana: St. Tammany Par.: Covington
(Wood 1982); Maryland: Montgomery Co.: Chevy Chase (Wood 1982); Mississippi:
Oktibbeha Co.: Trimcane Swamp, 29-III-20, M.W. Blackman (DFEC); Warren Co.:
Vicksburg (Wood 1982); North Carolina: Polk Co.: Tryon (Wood 1982); Swain Co.:
Cherokee (Wood 1982); New Jersey: Gloucester Co.: Westville (Wood 1982); South
Carolina: Dorchester Co.: Pregnall (Wood 1982); Tennessee: Sevier Co.: Gatlinburg
(Wood 1982); Texas: Sabine Co.: 9 mi E Hemphill, 3-16- IV-89, Anderson & Morris,
flight intercept trap (TAMU); West Virginia: Monongalia Co.: Morgantown (Wood 1982).
Hosts. Aceraceae: Acer rubrum L. (Wood 1954), Anacardiaceae: Toxicodendron
radicans (L.) Kuntze (Hopkins 1915), Annonaceae: Asemina triloba (L.) Dunal (Wood
1954), Aquifoliaceae: Ilex opaca, Ericaceae: Rhododendron sp. (Wood 1954), Fagaceae:
Castanea dentata (Marsh.) Borkh. (Wood 1954), Quercus marilandica Muenchh. (Hop-
kins 1915), Juglandaceae: Carya spp. (Wood 1954), C. illinoensis, Leguminosae:
Robinia pseudoacacia L. (Hopkins 1915), Magnoliaceae: Liriodendron tulipifera L.
(Deyrup 1981), Moraceae: Ficus aurea L., Rhizophoraceae: Rhizophora mangle L.
(Wood 1982), Salicaceae: Salix nigra Marsh. (Hopkins 1915), Salix sp. (Hopkins 1915),
Solanaceae: Cestrum nocturnum, Ulmaceae: Ulmus americana L. (Wood 1954), U.
rubra Muhl. (Deyrup 1981).
Biology: This species breeds in wood of a variety of hardwood species that is invaded
by a black-staining fungus. It apparently feeds on the fungus-infested wood, rather than
sound tissues (Deyrup 1987). A relatively small brood is produced in each gallery system.
Comments. The types of Hypothenemus atomus, H. impressifrons, H. marylan-
dicae, H. robiniae and H. toxicodendri (USNM) were examined.
Trischidias exigua Wood
(Figs. 3-4)
Trischidias exigua Wood 1986:273.
Diagnosis. This species can be distinguished from all other species in the genus by
the long, extremely slender, hairlike setae on the pronotum and elytra. This species is
stout-bodied and usually has 4 submarginal teeth on the anterior margin of the pronotum.
Female. Length 0.8-0.9 mm, 2.1 times as long as wide. Body black. Frons with
strong transverse impression above slightly elevated epistomal margin, impression di-
vided in center by glossy area; concave above, with shallow central fovea in some
specimens; surface reticulate with sparse punctures and setae. Anterior margin of eye
slightly notched to depth slightly greater than one facet. Antennal club rounded, subequal
in length to scape, with 3 sutures marked externally by rows of setae.
Anterior margin of pronotum narrowly produced with 4 teeth, middle pair definitely
larger; summit at middle, posterior and lateral areas sparsely granulate, all setae hair-
like.
Elytra glossy; strial punctures small, shallow, separated in row by distance subequal
to diameter; striae not impressed, recumbent hair-like setae twice as long as diameter
of puncture, becoming longer and semi-erect on declivity; interstriae flat, twice as wide
as striae, uniseriately punctate-granulate, bearing slender scales (length 4 times width)
becoming longer posteriorly (length 5 times width on declivity). Declivity convex.
Male. Length 0.6 mm, 2.0 times as long as wide. Similar in appearance to female.
Distribution. Southern Florida, Yucatan Peninsula of Mexico (State of Campeche).
United States: Florida: Dade Co.: Everglades Natl. Pk., Long Pine Key, 31-VII to
9-XII-86, S. & J. Peck, flight intercept trap (CMNC); Old Cutler Hammock, 15-XI-86,
S. & J. Peck, flight intercept trap (CMNC); Monroe Co.: Big Pine Key, 17-XI-85 to
25-II-86, S. & J. Peck, flight intercept trap (CMNC); Big Torch Key, 19-XI-85 to 26-II-86,
Atkinson: New Trischidias from Southern Florida 421
S. & J. Peck, flight intercept trap (CMNC); Key Largo, 16-XI-85 to 24-II-86, S. & J.
Peck, flight intercept trap (CMNC); Sugarloaf Key, 4-XI-84 to 3-III-85, 4-VIII to 19-XI-
85, 19-XI-85 to 26-II-86, S. & J. Peck, flight intercept trap (CMNC); Highlands Co.:
Archbold Biol. Sta., M.A. Deyrup (ABSC); Mexico: Campeche: Escarcega (SLWC).
Hosts. Tiliaceae: Belotia campbelli Sprague (Wood 1986); Carbonaceous ascomycete
fruiting bodies on branches of Carya (Deyrup 1987).
Biology. Deyrup (1987) presented a detailed discussion of the biology of this species.
In central Florida it was found in raised carbonaceous ascomycete fruiting bodies on
branches of Carya floridana Sarg., but not other trees. Numerous specimens were
collected in flight intercept traps in southern Florida by S. & J. Peck where this tree
does not occur. This species is remarkable for the small brood sizes (6 or less) and the
large size of the egg with respect to the female's body size (nearly 1/3 of her size)
(Deyrup 1987).
Comments. The holotype and 6 paratypes were examined (SLWC), as well as other
specimens indicated above.
Trischidias georgiae Hopkins
Trischidias georgiae Hopkins 1915:12.
Diagnosis. This is the largest known species of the genus. Interstriae are narrow
and strial punctures noticeably increase in size posteriorly. The anterior prothoracic
margin has 2 teeth.
Female. Length 1.1 mm, about twice as long as wide.
Frons convex, with weak transverse impression above epistomal margin, concave
above, with shallow central fovea; surface reticulate with sparse punctures and setae.
Anterior margin of eye entire. Antennal club rounded, slightly longer than scape, with
3 sutures marked externally by rows of setae.
Anterior margin of pronotum narrowly produced with 2 marginal teeth; summit at
middle, posterior and lateral areas coarsely reticulate, sparsely granulate; hair-like
pubescence intermixed on posterior half with scale-like setae.
Elytra glossy; striae slightly impressed, punctures large, deep, separated in row by
half their diameters, becoming larger and closer toward declivity, with recumbent hair-
like setae; interstriae narrower than striae, uniseriately punctate-granulate, bearing
dark scale-like bristles (about as long as wide) becoming longer posteriorly (length 1.5
times width on declivity). Declivity convex.
Male. Unknown.
Distribution. United States: Georgia: Brunswick. Known only from the type locality.
Hosts. Unknown.
Comments. The unique type (USNM) was examined.
Trischidias minutissima Wood
Trischidias minutissima Wood 1954:1069.
Diagnosis. This is a stout-bodied species with narrow interstriae, with strial
punctures not impressed. The anterior margin of the pronotum has 2-4 marginal teeth.
Unlike most other species, the scales are dark, not pale-colored.
Female. Length 0.65-0.80 mm, 2.0 times as long as wide. Frons convex, transverse
impression above epistoma weak or inapparent, with longitudinally impressed area of
varaible length and depth in central area; surface coarsely reticulate with few inconspicu-
ous punctures and associated fine hairs. Anterior margin of eye entire. Antennal club
rounded, length greater than scape, with 3 sutures marked externally by rows of setae.
422 Florida Entomologist 76(3) September, 1993
Pronotum 0.8 times as long as wide; anterior margin narrowly rounded with 2 sub-
contiguous teeth (some specimens with an additional pair of smaller teeth on either
side); summit at middle, posterior and lateral areas coarsely reticulate with scattered
granules; hair-like pubescence intermixed with short erect setae (length equal to width).
Elytra glossy, striae slightly impressed, punctures large, deep, separated by distance
equal to diameters, strial setae recumbent, hair-like, length approximately equal to
diameter of puncture; interstriae narrower than striae, punctures fine, uniseriate, granu-
late, with erect scales (length equal to width), becoming slightly longer (length 1.5 times
width) on declivity.
Male. Unknown.
Distribution. United States: Florida: Monroe Co.: Sugarloaf Key, 3-VII-51, Price,
Beamer, Wood, Rhizophora mangle (SLWC); Sarasota Co.: Siesta Key, 24-XI-85, M.A.
Deyrup, Avicennia germinans (L.) L. (ABSC).
Hosts. Fungal pustules on bark of aerial roots of red mangrove, Rhizophora mangle
(Wood 1982), and black mangrove, Avicennia germinans (Deyrup 1987).
Comments. Ten paratypes (USNM, SLWC) were examined.
Trischidias striata Atkinson, new species
(Figs. 5-6)
Diagnosis. This species can be recognized by the combination of deeply impressed
striae with very large strial punctures and long, blunt-tipped interstial setae.
Female. Length 0.6-0.8 mm, 2.0 times as long as wide. Body black, setae pale.
Frons convex, not impressed above slightly elevated epistomal margin; weak median
longitudinal carina extending from middle of frons to epistoma; frons reticulate, sparsely
punctured with sparse setae. Anterior margin of eye slightly notched in middle to depth
of 2 facets. Antennal club large, rounded, slightly longer than scape, with 3 transverse
sutures marked externally by rows of setae.
Pronotum 0.7 times as long as wide, anterior margin slightly produced with 4 subcon-
tiguous teeth, the middle 2 larger; summit at middle; posterior and lateral areas coarsely
reticulate, with coarse punctures and associated granules; hair-like pubescence inter-
mixed with scale-like setae of similar length.
Elytra glossy; striae deeply impressed, punctures large, deep, separated in row by
distance less than their diameters, with hair-like recumbent setae; interstriae narrower
than striae, with uniseriate, very coarse granules, each with an erect scalelike seta
(length subequal to width), becoming longer on declivity (length 4 times width).
Male. Unknown.
Type Material. Holotype. Female. Sugarloaf Key, 19-XI-85 to 26-II-86, S. & J. Peck,
flight intercept trap (U.S. National Museum of Natural History (USNM), red holotype
label); 17 female paratypes deposited in the FSCA, CNCC, CMNC, and THAC.
Distribution. United States: Florida: Dade Co.: Everglades Natl. Pk., Long Pine
Key, 28-VIII to 5-IX-82, S. & J. Peck, flight intercept trap (CMNC); Monroe Co.: Big
Pine Key, 17-XI-85 to 25-II-86, S. & J. Peck, flight intercept trap (CMNC); Big Torch
Key, 19-XI-85 to 26-II-86, 1-IX to 15-XII-86, S. & J. Peck, flight intercept trap (CMNC);
Cudjoe Key, 21-XI-85 to 26-II-86, S. & J. Peck, flight intercept trap (CMNC); Key
Largo, 1989, S. & J. Peck, flight intercept trap (CMNC); No Name Key, 3-VI to 27-VIII-
86, S. & J. Peck, flight intercept trap (CMNC); Sugarloaf Key, 4-VIII to 19-XI-85,
19-XI-85 to 26-II-86, 26-II to 6-VI-86, 6-VI to 29-VIII-86, 29-VIII to 14-XII-86, S. &
J. Peck, flight intercept trap (CMNC).
ACKNOWLEDGEMENTS
Travel to Provo, Utah to visit the S. L. Wood collection was supported by a grant
from the American Philosophical Society. Scanning electron microscopy was done with
Notestine: Mesonotal Shield of Baetisca Nymphs 423
the facilities of the Electron Microscope Core Facility, IFAS ICBR, University of
Florida, and the assistance of associated staff. This is Florida Agricultural Experiment
Station Journal Series No. R-02748.
REFERENCES CITED
ARNETT, R., AND P. A. SAMUELSON. 1986. The insect and spider collections of the
world. Brill/Flora & Fauna Publications. Gainesville, Florida.
DEYRUP, M. A. 1981. Annotated list of Indiana Scolytidae (Coleoptera). Great Lakes
Entomol. 14: 1-9.
DEYRUP, M. A. 1987. Trischidias exigua Wood, new to the United States, with notes
on the biology of the genus. Coleopterists Bull. 41: 339-343.
HOPKINS, A. D. 1915. Classification of the Cryphalinae with descriptions of new genera
and species. U.S. Dept. Agric. Rep. 99: 1-75, 4 pls.
PECK, S. B. 1989. A survey of insects of the Florida Keys: post-Pleistocene land-bridge
islands: Introduction. Florida. Entomol. 72: 603-612.
WOOD, S. L. 1954. A revision of North American Cryphalini (Scolytidae: Coleoptera).
Univ. Kansas Sci. Bull. 36: 959-1089.
WOOD, S. L. 1982. The bark and ambrosia beetles of North and Central America (Col-
eoptera: Scolytidae), a taxonomic monograph. Great Basin Nat. Mem. 6: 1-1356.
WOOD, S. L. 1986. New synonymy and new species of American bark beetles (Coleopt-
era: Scolytidae), Part XI. Great Basin Nat. 46: 265-273.
WOOD, S. L., AND D. E. BRIGHT. 1992. A catalog of Scolytidae and Platypodidae
(Coleoptera), Part 2: Taxonomic index Vol. B. Great Basin Nat. Mem. 13: 1-1553.
FUNCTION OF GILLS AND MESONOTAL SHIELD
OF BAETISCA ROGERSI NYMPHS
(EPHEMEROPTERA: BAETISCIDAE)
MARY K. NOTESTINE
Department of Biology, University of Utah
Salt Lake City, Utah 84112, U.S.A.'
ABSTRACT
The nymphs of Baetiscidae Banks (Ephemeroptera) possess a unique enlarged
mesonotal shield which encloses the gills. The pattern of water circulation within this
mesonotal chamber is described for Baetisca rogersi Berner. Suggestions are made on
other functions of the shield.
Key Words: Mayflies, mesonotal chamber, respiration, morphology, nymphs,
Ephemeroptera, Baetisca, gills.
RESUME
Las ninfas de Baetiscidae Banks (Ephemeroptera) poseen un escudo alargado en el
mesonoto en el cual se encuentran las agallas. Se describe la forma de circulaci6n del
agua dentro de esta camera del mesonoto en Baetisca rogersi Berner. Se hacen sugerencias
acerca de otras funciones del escudo.
'Present address: Department of Zoology, University of New England, Armidale, NSW 2351, Australia.
,
'..-- ~ ~ ~ I .-. ----6.-.7. ,
.26-
1'-4
-Lrr
IN,
Florida Entomologist 76(3)
Mayfly nymphs of the families Baetiscidae and Prosopistomatidae are unusual in that
they possess an enlarged mesonotal shield covering the thorax and most of the abdomen
(Fig. 1). This shield forms a chamber (referred to here as the mesonotal chamber) which
entirely encloses the gills.
In 1950 Berner described the entry of water into and out of the mesonotal chamber
of Baetisca nymphs. Pescador & Peters (1974) reported briefly on the gill movements
and water currents produced in the nymphs of Baetisca rogersi Berner in conjunction
with a major paper on its life history and ecology. In the present study, observations
were made concerning the path of water through the mesonotal chamber and over the
gills of B. rogersi.
Fig. 1. Dorsal view of nymph of Baetisca rogersi. Arrows indicate the direction of
water flow through the mesonotal chamber when a cut (indicated by the dotted line) is
made to remove the posterior portion of the shield.
September, 1993
Notestine: Mesonotal Shield of Baetisca Nymphs
425
MATERIALS AND METHODS
Nymphs of B. rogersi were collected by Dr. G. F. Edmunds, Jr. at Rocky Comfort
Creek, Gadsden County, Florida on 30-III-1974 and returned alive to the University of
Utah. The nymphs were placed in aerated aquaria with a variety of substrate types and
allowed to acclimate for several days before observations were made.
Small observation aquaria were constructed by gluing microscope slides together
with silicon rubber adhesive. Fine nylon net was placed on the bottom of the aquaria
for a substrate; nymphs made minimal movement when the netting was available. All
observations were made using a dissecting microscope.
Suspensions of elemental silicon powder (325 pLm mesh and finer) were introduced
into the water to facilitate observations. Other powdered materials which were tried
included suspensions of lamp black, carmine, cellulose acetate and aluminium powder,
but silicon powder was considered to be superior as it remained in suspension and distinct
particles were easily visible.
Observations were first made with the mesonotal shield intact. The left posterior
quarter of the shield was then removed, permitting gill movement to be observed in
more detail.
RESULTS
The gills of B. rogersi are paired structures inserted dorsolaterally on abdominal
segments I-VI. All gills are membranous and tracheae are visible. The medial edges of
gills I and III-V are dissected to varying degrees; the edges of gill VI are entire. Gill
II is a large, platelike lamella with some sclerotization; the posterolateral area of this
gill is somewhat thickened and folded, forming a scoop-like structure. The body is
membranous in the area covered by the mesonotal shield and probably functions as a
respiratory surface in addition to the gills; elsewhere, the bodies of the nymphs are
highly sclerotized, reducing or preventing gas exchange.
At the start of a ventilation period, the nymph lowers the abdomen relative to the
shield, permitting water to enter the mesonotal chamber near the posterolateral edge.
Water exits along the median line between the sixth pair of gills which are small, delicate,
and appear to remain passively shut. The nymphs can prevent the entry of water into
the mesonotal chamber as the dorsolateral edges of the abdominal terga and the median
abdominal hump can be held against the shield.
Figure 1 illustrates the path of water flow through the mesonotal chamber when the
posterior corner of the shield is removed. The large platelike gill II appears to draw
water into the chamber. The water moves towards the anterior of the chamber then
flows medially and to the posterior to exit between the VIth pair of gills.
The large, filamentous gill on segment I overlies gill II and apparently has no role
in the active propulsion of water through the chamber; it moves in synchrony with gill
II. Gills III-V overlap and beat slightly out of synchrony, assisting in directing the
water through the mesonotal chamber. Occasionally there is a slight twitch of the gills
after the large gill beats, as if the gills are readjusting their position with respect to
each other. There is a median furrow between the gills on segments III-Vwhich is
covered by gill II; these gills are raised above the abdomen, forming a distinct space
or area through which water flows.
Removal of the posterior corner of the shield does not hamper gill movement. Water
flows into the gill area in approximately the same region as observed with the shield
intact and flows out the posterior median channel between gills VI. However, if a larger
portion of the shield is removed (anterior to the lateral spine), the flow of water over
the gills is seriously affected; the area between the gills and the abdomen collapses,
preventing adequate water flow.
Florida Entomologist 76(3)
September, 1993
In the region where water is drawn into the mesonotal chamber, there is a sparse
row of hairs on the edge of the mesonotal shield. If the shield is touched lightly with a
probe or the animal is disturbed in some manner (e.g., a suspension of fine particles
injected over the nymph), the abdomen elevates to fit tightly against the shield. This
presumably protects the gills within the chamber from sand or other particulate matter
that may either physically damage the gills or interfere with their respiratory function.
DISCUSSION
The beating of the gills in many mayfly nymphs produces a flow of water over and
around the body (Eastham 1939, Eriksen & Moeur 1990, Wingfield 1939). The large
mesonotal shield of Baetisca nymphs forms a chamber within which the gills lie; ventilat-
ory currents of water, produced by the beating of gill II, carry fresh oxygenated water
to the respiratory surfaces within the chamber. As water enters the chamber by the
beating of gill II, water is expelled through the median excurrent channel formed by
the gills on abdominal segment VI. My study provides further information on the move-
ment of the water within the chamber formed by the mesonotal chamber and is in
agreement with studies by Pescador & Peters (1974) and Berner (1950).
To function as gas exchange units, gills need to be kept clean of dirt, sand or other
material (Eastham 1939, Needham et al. 1935). The habitats of nymphs of Baetisca
vary, depending both on species and the maturity of the nymphs. Some nymphs may
rest on sand or pebbly riffles in protected areas; others partially bury themselves in silt
and sand (Edmunds et al. 1976). In any of these habitats, exposure to silt and other
substances which interfere with the respiratory function of the gills may be encountered.
The mesonotal chamber thus functions to protect the gills from both physical damage
and from becoming clogged with particulate matter.
Morgan & Grierson (1932), Wingfield (1939), Eriksen (1963) and Eriksen & Moeur
(1990) have shown that the general body surface of mayfly nymphs may be important
in respiration; however, its importance is greatly reduced when the body is highly
sclerotized as in nymphs of Baetisca. The highly dissected form of gills I and III-V and
the extensive tracheation increases the surface area available for respiratory exchange.
The hairs on the posterior edge of the mesonotal shield may have a sensory function
similar to the hairs found on the gill opercula of Caenis horaria nymphs (Eastham 1936);
Eastham determined that these hairs were able to detect potentially damaging sub-
stances, such as particulate matter in the water. The sparse distribution of these hairs
on the mesonotal shield of Baetisca nymphs would not allow them to sieve particles
from entering the chamber; however, when fine particles are introduced to the water
around the shield, the abdomen is raised, preventing their entry.
Nymphs of Baetisca crawl up to 1 m from the water to emerge as subimagos (Edmunds
& McCafferty 1988); the length of time for emergence ranges from 4 to 10 minutes in
the laboratory and 5 to 7 minutes in the field (Pescador & Peters 1974). The mesonotal
shield would assist in conserving moisture within the gill chamber during this period
and may indirectly facilitate successful emergence by preventing desiccation.
Nymphs of Baetisca are difficult to detect on sandy or rocky substrate due to their
coloration (dark and often mottled) and because the spines and other protuberances
found on the shield and body help to break up the nymphal outline. Edmunds (1977)
noted that B. lacustris McDunnough (= B. bajkovi Neave) nymphs in nature strongly
resemble the pebbles among which they live. Pescador & Peters (1974) also suggested
that the spines and other dorsal elevations may function to decrease current resistance
in the nymphs.
426
Notestine: Mesonotal Shield of Baetisca Nymphs
427
ACKNOWLEDGMENT
I wish to thank G. F. Edmunds, Jr. for providing live material for the present study.
Thanks also to W. L. Peters and M. L. Pescador for suggested changes; many helpful
comments were made by an anonymous reviewer of a much earlier draft of this paper.
Rebecca Francis prepared the figure. This work was supported by a National Science
Foundation grant to G. F. Edmunds, Jr., on the "Higher Classification of the
Ephemeroptera" (DEB 76 09970 A02).
REFERENCES CITED
BERNER, L. 1950. The mayflies of Florida, University of Florida Press, Gainesville,
267p.
EASTHAM, L. E. S. 1936. The sensillae and related structures on the gills of nymphs
of the genus Caenis (Ephemeroptera). Trans. R. Entomol. Soc. London. 85: 401-
414.
EASTHAM, L. E. S. 1939. Gill movements of nymphal Ephemera danica (Ephemeropt-
era) and the currents produced by them in water. J. Exp. Biol. 16: 18-33.
EDMUNDS, G. F., JR. 1977. Baetisca bajkovi in Wyoming (Ephemeroptera: Baetis-
cidae). Pan-Pacif. Entomol. 53: 222.
EDMUNDS, G. F., JR., S. L. JENSEN, AND L. BERNER. 1976. The mayflies of North
and Central America. Univ. Minnesota Press, Minneapolis, 330p.
EDMUNDS, G. F., JR., AND W. P. MCCAFFERTY. 1988. The mayfly subimago. Annu.
Rev. Entomol. 33: 509-29.
ERIKSEN, C. H. 1963. Respiratory regulation in Ephemera simulans Walker and
Hexagenia limbata (Serville) (Ephemeroptera). J. Exp. Biol. 40: 455-467.
ERIKSEN, C. H., AND J. E. MOEUR. 1990. Respiratory functions of motile tracheal
gills in Ephemeroptera nymphs, as exemplified by Siphlonurus occidentalis
Eaton, pp. 109-118 in I. C. Campbell, [ed.], Mayflies and Stoneflies, Kluwer
Academic Publ., Netherlands.
MORGAN, A. H., AND M. C. GRIERSON. 1932. The functions of the gills in burrowing
mayflies (Hexagenia recurvata). Physiol. Zool. 5: 230-245.
NEEDHAM, J. G., J. R. TRAVER, AND Y. Hsu. 1935. The biology of mayflies with a
systematic account of North American species. Comstock Publ. Co., Ithaca, N.Y.,
759p.
PESCADOR, M. L., AND W. L. PETERS. 1974. The life history and ecology of Baetisca
rogersi Berner (Ephemeroptera: Baetiscidae). Bull. Florida St. Mus., Biol. Sci.
17: 151-209.
WINGFIELD, C. A. 1939. The function of the gills of mayfly nymphs from different
habitats. J. Exp. Biol. 16: 363-373.
428 Florida Entomologist 76(3) September, 1993
MORPHOLOGY OF THE DIGESTIVE AND REPRODUCTIVE
SYSTEMS OF PEREGRINUS MAIDIS
(HOMOPTERA: DELPHACIDAE)
JAMES H. TSAI AND JOAN L. PERRIER
Fort Lauderdale Research and Education Center
University of Florida, IFAS
3205 College Avenue
Fort Lauderdale, FL 33314, U.S.A.
ABSTRACT
The corn delphacid, Peregrinus maidis (Ashmead) (Homoptera: Delphacidae) is the
only known vector of maize stripe tenuivirus and maize mosaic rhabdovirus in tropical
and subtropical areas. The morphology of its digestive and reproductive systems was
studied by light microscopy and illustrations were made to aid in dissections and injections
of pathogenic innoculum for vector studies. Two salivary glands, located one on each
side of the head, extend into the mesothorax. Each gland is divided into two types of
lobes which form the principle and accessory glands. The esophagus, a narrow muscular
tube, extends from the cibarial diaphragm to the abdomen and empties into the midgut.
Parallel to the esophagus, extending from the midgut into the head, is the anterior
diverticulum. This closed sac is often filled with air bubbles. The midgut, a tube of
uniform diameter, winds in a consistent pattern from the esophagus to the rectum. No
filter chamber was observed. The two pairs of Malpighian tubules originate at the
posterior end of the midgut with each pair being fused for the proximal two-thirds of
their length. The hindgut consists of a rectal sac and rectum. P. maidis females have
two large ovaries containing an average of 16 ovarioles. They open successively into the
lateral oviduct, the median oviduct, the common oviduct, and the vagina. The sper-
matheca and the bursa copulatrix open into the common oviduct. A spermathecal gland
is also present. The male has two lateral testes with three to four follicles each. A pair
of accessory glands fill the abdomen, often extending into the thorax.
Key Words: Internal morphology, anatomy, planthopper, maize, rhabdovirus, tenuivirus.
RESUME
El delphacido del maiz Peregrinus maidis (Ashmead) (Homoptera: Delphacidae) es
el anico vector conocido del tenuivirus de la hoja rayada del maiz y del rabdovirus del
mosaico del maiz en areas tropicales y subtropicales. Se ha estudiado la morfologia de
su sistema digestive y reproductive bajo microscopic y se han hecho ilustraciones para
ayudar en las disecciones e inyecci6n del pat6geno en los studios de vectores. Dos
glandulas salivares, localizadas a cada lado de la cabeza, se extienden hasta el mesotorax.
Cada glandula se divide en dos tipos de lobulos llamados las glandulas principles y
accesorias. El es6fago, un tubo estrecho musculoso, se extiende desde el diafragma hasta
el abdomen y se vacia en el estomago medio. El diverticulo anterior se encuentra paralelo
al es6fago, extendiendose desde el estomago medio hasta la cabeza. Este saco cerrado
a menudo se llena de burbujas de aire. El estomago medio, un tubo con diametro
uniform, mantiene una forma consistent desde el esofago hasta el recto. No se observe
camera de filtramiento. Los dos tubos de Malpighi se original en el final posterior del
estomago medio, y cada par esti ligado aproximadamente a los dos tercios de su parte
final. El estomago inferior, el saco rectal y el recto. Las hembras de P. maidis tienen
dos ovarios grandes los cuales contienen un promedio de 16 ovariolas. Estas ovariolas
se abren sucesivamente en el oviducto lateral, el oviducto medio, el oviducto comfn y
la vagina. La espermateca y la bolsa copulatrix se abren en el oviducto comdn. La
Tsai & Perrier: Planthopper Internal Morphology 429
glandula de la espermateca tambinn estA present. El macho tiene dos testiculos laterales,
y cada uno tiene de tres a cuatro foliculos. Un par de las glandulas accesorias llena el
abdomen, extendiendose a veces hasta el torax.
In tropical and subtropical areas, maize (Zea mays L.) can become infected with
destructive viruses including maize stripe tenuivirus (MStV) and maize mosaic rhab-
dovirus (MMV) (Tsai & Falk 1988). These two viruses are transmitted by the planthopper
Peregrinus maidis (Ashmead), their only known vector (Nault & Knoke 1981, Tsai &
Falk 1988). MMV and MStV were first reported by Kunkel (1921) and Storey (1936),
respectively. However, according to Brewbaker (1979), the presence of these viruses
has been evident for many centuries and they may have played a role in the disappearance
of the classic Mayan civilization. This point is disputed by Nault (1983) who argues that
P. maidis, MStV and MMV originated in Africa and were not introduced to the Americas
until post-Columbus times.
Because of the economic importance of MStV and MMV in tropical and subtropical
countries, both viruses and their vector have been the subject of many studies. These
studies have included the biology of P. maidis (Nault & Knoke 1981, Tsai & Wilson
1986), transmission of MMV and MStV (Ammar et al. 1987, Gingery et al. 1979, 1981,
Nault & Gordon 1988, Tsai 1975, Tsai & Zitter 1982, Tsai & Falk 1988), characterization
of the viruses (Falk & Tsai 1983, 1984, Gingery et al. 1981, Lastra & Carballo 1983,
Tsai & Falk 1988), and the discovery of the presence of MMV and MStV in various
organs and tissues of P. maidis by electron microscopy and serological technology
(Ammar 1985, 1987, Ammar & Nault 1985, Falk et al. 1988, Herold & Munz 1965, Falk
& Tsai 1984, 1985, Nault & Gordon 1988). These latter studies involved dissections of
the insects to assay for the presence of the virus in different organs. Because it is
difficult to perform these dissections with accuracy, a guide to the internal morphology
is needed, since information on internal structures of P. maidis is limited to reports by
Ammar (1985, 1986, 1987), who described some major organs of P. maidis on an ultra-
structural level, and Backus (1985), who studied the structure of auchenorrhynchan
mouth parts and the mechanisms of feeding behavior. Accordingly, we initiated this
detailed study of the internal morphology of P. maidis for the purpose of facilitating
the study of the fate MMV and MStV in P. maidis after its acquisition or injection.
MATERIALS AND METHODS
Peregrinus maidis was reared in the laboratory on Z. mays L. var. Saccharata
"Guardian" in a growth room at 24 C and 12 h light. Approximately 500 adults of both
sexes were dissected. Insects that had been placed in a freezer at 0 C for periods of
15 min to 24 h were dissected in distilled water on paraffin using fine dissecting needles
and forceps. Initially, the insects were dissected in a stain solution of one part safranin
red to 60 parts deionized water. The organs removed were left in the solution for a
period of 5-30 minutes, rinsed, and observed with a dissecting microscope and a light
microscope at magnifications from 10X to 400X. When stains were not used, the organs
were placed on a black background in order to observe the delicate structures. For
observation of other fine structures, such as the salivary glands and the spermathecal
gland, cold-anesthetized insects were kept at 7.5 C and dissected in Clarke's solution
(Sogawa 1965) using neutral red (Sogawa 1965) or methylene blue chloride to stain the
living tissue. For structural study of the salivary glands, a 1:1 solution of the above
stains was used.
Florida Entomologist 76(3)
RESULTS AND DISCUSSION
Digestive System
Salivary glands. The salivary glands of P. maidis, which are present on each side
of the thorax and head (Sg in Fig. 1A), consist of principal and accessory glands. The
principal gland contains six to eight acini, or follicles (P sg in Fig. 1B). Eight have been
observed in P. maidis by Ammar (1985, 1986) and in Delphacidae in general by Sogawa
(1965). Approximately 80% of the 500 insects dissected for this study contained seven
acini, which varied in size and shape. The variation in numbers and morphology of acini
could be due to the age of the insect or to physiological factors. The principal gland is
found mainly in the prothorax whereas the accessory gland is found in the head (A sg
in Fig. 1B). The ducts from the acini in the principal gland join to form the principal
duct (P sd in Fig. 1B). At this juncture the accessory duct (A sd in Fig. 1B) also connects
to the principal duct. The two principal ducts unite to form the common salivary duct
Sg
Oe
Ad
Mg
Mt
Rec
1A
Fig. 1A. Dorsal view of digestive system of adult female. S g, salivary gland; Oe
esophagus; A d, anterior diverticulum; Mg midgut; M t, Malpighian tubules; Rec, rectum.
Vertical bar = 1.0 mm.
430
September, 1993
Tsai & Perrier: Planthopper Internal Morphology
A sg -
Psd
Sd Psg
B
IB
Fig. lB. Detail of salivary glands. P sg, principal salivary gland; A sg, accessory
salivary gland; p sd, principal salivary duct; A sd, accessory salivary duct; S d, salivary
duct; A-H, acini types. Vertical bar = 0.5 mm.
(S d in Fig. 1B) which extends into the head to the salivary syringe which in turn opens
into the salivary canal in the stylets (Ammar 1985, Backus 1985, Sogawa 1965). Because
numerous fat bodies fill the head and surround the salivary glands, it is sometimes
difficult to separate the smaller and more translucent acini from the fat bodies.
Foregut. Backus (1985) described the ciberial and pharyngeal regions of the mouth-
parts of several leafhoppers. The foregut begins at the bases of the mandibular and
maxillary stylets with the precibarium. Fluid passes from the stylets to the precibarium
then into the cibarium (or sucking pump) and then to the esophagus. However, the
structure of the cibarium and pharynx in planthoppers appears to be different from that
in leafhoppers (Ammar 1985). In P. maidis, the esophagus is a narrow tube that originates
posterior to the cibarium and extends to the anterior of the abdomen where it empties
into the midgut (Oe in Fig. 1). At this point, there appears to be a slight constriction
which may indicate the esophageal valve (Ammar 1985). Because of its muscular sheath
(Snodgrass 1935), the tissue of the esophagus appears stronger and more elastic than
that of the midgut.
Midgut. Parallel to the esophagus, extending from the midgut into the head, is a
closed tube or sac (A d in Fig. 1, 3). This structure, described by Ammar (1985) as the
anterior diverticulum, is often filled with air bubbles. Compared to the esophagus, the
tissue in this region is more fragile and resembles that of the midgut. Again there seems
to be a slight constriction between the anterior diverticulum and the midgut.
The midgut of P. maidis is a long tube of uniform diameter, which winds from left
to right toward the rectum (Mg in Fig. 1, 2). No sheath or membrane enclosing the
midgut has been observed, which would suggest there is no filter chamber (Ammar
1985). The pattern of winding of the midgut, similar to the patterns observed by Mishra
(1980) and Goodchild (1966), suggest the possibility of a different type of filtering device.
Figures 4 and 5 illustrate the central loop of the midgut pulled away to reveal the contact
of the anterior and posterior regions of the midgut.
Florida Entomologist 76(3)
September, 1993
Oe
SOAd
Oe
Ad
-Mg Mg
Mt
I Rec
2 3
Fig. 2. Ventral view of alimentary canal. Oe, esophagus; A d, anterior diverticulum;
Mg, midgut; M t, Malpighian tubules; Rec, rectum. Vertical bar = 1.0 mm.
Fig. 3. Foregut and midgut. Oe, esophagus; A d, anterior diverticulum; Mg, midgut.
Vertical bar = 1.0 mm.
Malpighian Tubules. At the posterior end of the midgut there is a slight swelling
from which the two pairs of Malpighian tubules arise (Mt in Fig. 1, 4). Each pair is
fused (Ammar 1985) for the proximal two-thirds of its length, at which point the distal
ends form a fork extending toward the anus.
Hindgut. Posterior to the origins of the Malpighian tubules, the midgut opens into
the hindgut (Hg in Fig. 4). At this junction, a pyloric value (Ammar 1985) is visible.
The hindgut consists of a rectal sac and a rectum (Rec in Fig. 4). These tissues are
translucent but elastic and strong.
432
Tsai & Perrier: Planthopper Internal Morphology 433
Reproductive System
Female. The ovaries of P. maidis consist of an average (N=250) of 16 ovarioles
(16+2). The ovariole is comprised of developing oocytes and eggs connected to the
lateral oviduct by a pedicel (Ovl, L od, Ped in Fig. 6). Each ovariole ends anteriorly
with a terminal filament which unites with those of the other ovarioles to form a suspen-
sory ligament (S Ig in Fig. 6) (Snodgrass 1935). These in turn appear to attach with the
ligaments of the other ovary to form a median ligament (M Ig in Fig. 6) which attaches
to a fat body (Ammar 1985) in the thorax.
The ovaries each form a calyx before connecting to the lateral oviducts (Cal, L od
in Fig. 6) which join to form a short median oviduct (Snodgrass 1935). This in turn opens
into a common oviduct (C od in Fig. 6). At this juncture a curved tubular spermatheca
(Ammar 1985) opens into the common oviduct (Spt, C od in Fig. 6). The contents of this
structure are often orange in color. At its distal end a long fragile tube extends to the
spermathecal gland (Ammar 1985) which seems to partially surround the neck of the
bursa copulatrix (Spt gl, B cp in Fig. 6). The bursa copulatrix is a globular, narrow-necked
structure that opens into the common oviduct at its junction with the vagina (Vag in
Fig. 6), which then connects with the ovipositor. In our study, we have not observed
the presence of oviduct glands (Asche 1985).
Male. Peregrinus maidis males have two lateral testes which are light red in color.
These are found ventrally in the posterior of the abdomen (Tes in Fig. 7). Sixty-five
percent of the 250 insects observed appeared to have three follicles per testes (Ammar
1985). Upon more careful dissection of 20 insects, a fourth follicle was observed on ten
of these. The absence of the fourth follicle could be due to their fragile nature. The
follicles join together and then open into a short, narrow vas deferens. This organ
enlarges to form the seminal vesicle (Sem v in Fig. 7) which opens into a common
ejaculatory duct (Ej d in Fig. 7).
Fg Fg Mg
Mg Hg
Mt Hg
Rec M t Hg
Rec
Mt
4 5
Fig. 4-5. Alimentary canal with midgut partially straightened: 4., dorsal view; 5.,
ventral view. Fg, foregut; Mg, midgut; Hg, hindgut; M t, Malpighian tubules; Rec,
rectum. Vertical bar = 1.0 mm.
Florida Entomologist 76(3)
M Ig
S Ig
SOv
Ped L od
Cal Spt
Spt gl M od
B cp C od
,/ ,Ovp
6
Fig. 6. Female reproductive system. Ventral view. Ov, ovary; Ovl, ovariole; S Ig,
suspensory ligament; M Ig, median ligament; Ped, pedicle; Cal, calyx; L od, lateral
oviduct; M od, median oviduct; C od, common oviduct; Spt, spermatheca; Spt gl, Sper-
matheca gland; B cp, bursa copulatrix; Vag, vagina; Ovp, ovipositor. Vertical bar = 1.0
mm.
The two lateral accessory glands also open into the ejaculatory duct (A gl, Ej d in
Fig. 7). They are basically tube-shaped (see Fig. 8 which illustrates the accessory gland
of an immature male). In mature males, these glands enlarge to fill the abdomen and
the posterior of the thorax. The membrane surrounding the milky substance of these
glands is delicate and easily ruptured, which presents difficulties when making dissections
and injections.
September, 1993
434
Tsai & Perrier: Planthopper Internal Morphology
Sem v
A gl
Vdf
Tes Ej d
7
Fig. 7. Male reproductive system. Dorsal view. Tes, testes; V df, vas deferens; Sem
v, seminal vesicle; A gl, accessory gland; Ej d, ejaculatory duct. Vertical bar = 1.0 mm.
Fig. 8. Young adult male accessory gland showing basic tubular structure. A gl,
accessory gland. Vertical bar = 1.0 mm.
ACKNOWLEDGMENTS
We wish to thank Drs. E. D. Ammar and E. A. Backus for suggestions and reviewing
the manuscript. This research was supported in part by grants from the Pioneer Hi-Bred
International, Inc. and The American Seed Research Foundation, Washington, D.C.
Florida Agricultural Experiment Stations Journal Series # R-01456.
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AMMAR, E. D. 1986. Ultrastructure of the salivary glands of the planthopper, Pereg-
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AMMAR, E. D. 1987. Ultrastructural studies on the planthopper Peregrinus maidis
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AMMAR, E. D., AND L. R. NAULT. 1985. Assembly and accumulation sites of maize
mosaic virus in its planthopper vector. Intervirology 24: 33-41.
AMMAR, E. D., R. E. GINGERY, AND L. R. NAULT. 1987. Interactions between maize
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Florida Entomologist 76(3)
ASCHE, M. 1985. Phylogenie de Delphacidae. Marburger. Entomol. Publ.
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TSAI, J. H., AND S. W. WILSON. 1986. Biology of Peregrinus maidis with descriptions
of immature stages (Homoptera: Delphacidae). Ann. Entomol. Soc. Amer. 79:
395-401.
TSAI, J. H., AND B. W. FALK. 1988. Tropical maize pathogens and their associated
insect vectors, pp. 177-201 in K. F. Harris [ed.], Advances in disease vector
research. Springer-Verlag, New York.
September, 1993
Labatte: Within-Plant Distribution of FAW
WITHIN-PLANT DISTRIBUTION OF FALL ARMYWORM
(LEPIDOPTERA: NOCTUIDAE) LARVAE ON CORN DURING
WHORL-STAGE INFESTATION
J. M. LABATTE
INRA Station de Zoologie
rte de St cyr
78000 Versailles, France
ABSTRACT
Field experiments on the within-plant distribution of larvae of the fall armyworm,
Spodoptera frugiperda (J. E. Smith) (Lepidoptera: Noctuidae), on the early-whorl to
late-whorl stage of corn, Zea mays L., revealed that most larvae were found in the
wrapped leaves of the whorl. Beta density function for describing larval distribution
showed that larval instar, infestation date and environmental conditions did not influence
this process. Larval distribution and its time course was accurately described with a
single Beta density function for all infestations. This function gave 64%, 25%, 8%, 2%
and 1% of larvae in the highest visible leaf and leaves just above, respectively. When
the tassel began development in the whorl (pre-tasseling corn stage), most larvae (80%)
were found in this location. After tasseling, larvae moved down to the lower leaves and
into the ear (75%).
Key Words: Spodoptera frugiperda, Zea mays, mathematical model.
RESUME
Los ensayos en campo, sobre la distribuci6n de las larvas de Spodopterafrugiperda
(J. E. Smith) (Lepidoptera: Noctuidae) durante las etapas de crecimiento vegetative del
mafz, Zea mays L. han demostrado que la mayoria de las larvas se encuentran en las
hojas del cogollo. La utilizaci6n de una funci6n de densidad Beta, para describir la
distribuci6n de las larvas, ha mostrado que el estado de las larvas, el perfodo de infestaci6n
y las condiciones del medio no influyen la distribuci6n de las larvas. La distribuci6n de
las larvas y su cin6tica fueron descritas apropiadamente por con una funci6n simple de
densidad Beta para cada infestaci6n. Esta funci6n ha dado 64%, 25%, 8%, 2% y 1% de
larvas en la hoja mAs alta y las hojas immediatamente inferiores. Cuando la pancfula
comienza su desarrollo, la majoria de las larvas (80%) fueron encontradas en ella. Despues
de floraci6n, las larvas bajaron hasta las hojas bajas y hasta la mazorca (75%).
The fall armyworm (FAW), Spodopterafrugiperda (J. E. Smith) (Lepidoptera: Noc-
tuidae), is a major pest of corn, Zea mays L., in the southeastern United States, Central
America and the Caribbean islands. Typically, damage to corn is caused by foliar feeding
of FAW larvae during the whorl stage (Buntin 1986). Yield losses may reach 50% (Cruz
& Turpin 1983). Chemical control has been used successfully to control FAW larvae in
corn fields (Pitre 1986) and is currently the main control practice. Nevertheless, insec-
ticidal control requires as many as 8 applications to be effective (Hruska & Gladstone
1988), and development of resistance to selected insecticides has been reported (Young
1979, Leeper 1984, Pitre 1986, Young 1986, Guillebeau & All 1991). Improvement of
FAW management requires: (1) a better knowledge of dynamic FAW biological processes
relative to feeding damage and their influence on the use and the impact of control
practices (Lewis & Nordlund 1984, Gardner et al. 1984), and (2) development of alterna-
tive, effective control practices based on host plant resistance and microbial control
(Gardner et al. 1984, Hamm & Wiseman 1986, Carpenter & Wiseman 1992).
438 Florida Entomologist 76(3) September, 1993
To achieve this goal, research should be directed towards a better understanding of
larval dynamics and the quantitative description of the natural relationships between
FAW larval biology, the corn crop, and environmental factors (Fig. 1). A description
of larval dynamics in relation to foliar damage is important because larvae are the main
target of control practices. Quantification of these processes under natural conditions
is necessary to describe the impact of host plant resistance and other interactions on
microbial control.
This paper deals with the study of FAW larval within-plant distribution in whorl-stage
corn. Larval within-plant distribution has an influence on two important processes: (1)
location of damage, and (2) impact of control practices whose efficiency depends on larval
distribution (contact probability) (Gardner et al. 1977). Several studies on larval distri-
bution have been reported. Luginbill (1928) observed positive phototropism, which may
account for the presence of young larvae on the topmost portions of the plants. Vickery
(1929) reported that young larvae feed in the shade or in protected situations, such as
between the young leaves of corn. Morrill & Greene (1973a) determined that most larvae
were present in plant whorls in pre-tassel field corn, and in husks and ears in post-tassel
corn. They explained these results by a negative geotropism and/or positive photo-
tropism, and a positive thigmotactism (Morrill & Greene 1973b). Despite this work,
changes in the distribution of FAW larvae over time and the effects of larval age and
environmental conditions on larval distribution within the corn plant, are still unknown.
In addition, previous studies have not resulted in a quantitative description of FAW
ENVIRONMENTAL --------
FACTORS
PATHOGEN .......................... ... temperature, rainfall,parasite,uv
PERSISTENCE
V V V /
DISEASE CONTACT
DEVELOPMENT PROBABILITY
I CORN PHENOLOGY
Impact of INFESTATION
control practices date,level
LARVAL LARVAL LARVAL
MORTALITY DEVELOPMENT DISTRIBUTION
antibiosis -----------_--- --------- Anon preference
CORN VARIETY
LARVAL antibiosis A A W W
DAMAGE----------------
rlarval dynamic CROP PHYSIOLOGY
. i ~ tolerance I
----) maize breeding t
:-------------------------r---- -
----> impact of control practices .
--'-> interactions with cropELD LOSSES
YIELD LOSSES
Damage threshold
Fig. 1. Diagram showing the different processes on which control practices, breed-
ing, yield losses and their relationships depend.
Labatte: Within-Plant Distribution of FAW
439
larval within-plant distribution. This paper presents a model which quantifies the propor-
tion of larvae on the different internodes and organs of the corn plant during the pre-tas-
seling period.
MATERIALS AND METHODS
All field studies were conducted at Petit-Bourg, Guadeloupe in corn fields of the
'Spectral' corn variety sown at the usual density of 50,000 plants per hectare with an
inter-row distance of 0.75 m. All corn field study sites were at least 0.1 ha in size.
Plants were artificially infested with FAW egg masses obtained from the laboratory
after two to five generations. FAW egg masses were initially collected from Guadeloupe
field corn and reared using Poitout's diet (Poitout & Bues 1974). FAW egg masses and
adults were identified by J. Etienne (Dept. Zoology, INRA Guadeloupe). Egg masses
were pinned to the undersides of the uppermost expanded leaves. Artificial infestation
made it possible to choose different infestation dates and to evaluate the effects of
different weather conditions. A total of eleven infestations were examined over a wide
range of plant maturity stages and environmental conditions (Table 1).
Determination of larval development and distribution required the dissection of plant
samples. Sampling began from a few hours to two days after egg hatch. At least five
corn plants were dissected daily until no larvae were found (due either to mortality or
pupation). The head capsule width and the position of each larva (organ and internode)
were recorded. The development stage and the number of visible and expanded leaves
of dissected plants were also recorded. Larval instar was determined based on capsule
width. Vertical distribution of larvae was compared using Smirnov's test (Sokal & Rohlf
1981).
RESULTS AND DISCUSSION
The vertical distribution of larval FAW over time within various vegetative parts
of the corn plant is presented in Fig. 2. Except for infestation 9, where larvae were
found in the ear and tassel, most larvae were found in the leaves of the whorl in the
early-whorl to late-whorl stages (Fig. 2, infestations 1 to 8). No larvae were found on
or in the stalk.
Early- to Late-Whorl Infestation
Typically, larvae fed in the wrapped-up leaves of the whorl; few larvae were found
in unprotected areas. Dissections carried out a few hours after egg hatch indicated that
TABLE 1. FAW INFESTATION CONDITIONS DURING DIFFERENT EXPERIMENTS.
No. of Daily Total
Plot Infestation Days After Mean Temp. Rainfall
Number Date Sowing Corn Stage (C) (mm)
1 1 Feb1992 15 Whorl-4 leaves 23.6 20.4
2 9 Oct 1991 18 Whorl-6 leaves 25.3 74.0
3 13 May 1992 20 Whorl-5 leaves 25.5 -
4 29Aug 1991 23 Whorl-7leaves 26.1 26.5
5 11 May 1992 29 Whorl-71eaves 25.5 -
6 24 Feb 1992 30 Whorl-7 leaves 23.6 101.5
7 7 Mar 1992 35 Whorl-8 leaves 23.7 17.8
8 25 Dec 1991 37 Whorl-10 leaves 23.4 144.6
9 14 Jan 1992 55 Perceptible tassel 23.4 61.0
Florida Entomologist 76(3)
September, 1993
INFESTATION 1 INFESTATION 2 INFESTATION 3
0- ....- ,r. ...- 0- ..... ,--- ---- 0-
0 10 20 0 10 20 0 10 20
days days days
INFESTATION 4 INFESTATION 5 INFESTATION 6
1 1 1 rW
0 .2 .2
0 -0 0------------ 0-
0 10 20 0 10 20 0 10 20
days days days
INFESTATION 7 INFESTATION 8 INFESTATION 9
0 0 I -. 0 1
0 10 20 0 10 20 0 10 20
days days days
Fig. 2. Time course of FAW larval distribution in nine stages of infestation in corn.
Solid line represents mean larval location, vertical line is the standard deviation. The
X-axis represents days after egg hatch. The Y-axis represents the normalized vertical
location of larvae, with 0 being the seventh leaf below the highest visible leaf and 1 the
highest visible leaf (see text).
newly-hatched larvae moved quickly into the topmost portions of the plant (Fig. 2,
infestations 2 and 4). More than 85% of larvae were found in the two highest visible
leaves within 12 h after egg hatch. A similar distribution was observed in infestations
1, 3, and 5 to 8 when dissections began the first or second day after egg hatch (Fig. 2).
Lack of foliar damage on the leaves below the whorl during the initial days after infes-
tation confirmed this observation.
The time course of larval distribution showed that larvae fed in the topmost part of
the plant from a few hours after egg hatch until the end of larval development (Fig. 2).
Thus, no important change in larval location was observed for different instars. This
observation was confirmed by Smirnov's test analysis (Table 2). The pattern of larval
location on the plant was similar with most of the infestations (Table 3), except in
infestations 1 and 7 where fewer larvae were found in the highest visible leaf, and
infestation 9 where larvae moved down when the tassel became visible.
Density functions were used to quantify larval vertical distribution on corn. Beta
density functions (Johnson & Kotz 1972) were chosen because they are defined on a
finite interval (0-1), their parameters are easily interpreted (the mean and standard
deviation of the distribution), and they have been adapted to describe the vertical
Labatte: Within-Plant Distribution of FAW
TABLE 2. ANALYSIS OF DIFFERENCES IN THE VERTICAL WITHIN-PLANT DISTRIBU-
TION OF DIFFERENT FAW INSTARS.
No. Instar
Instar Larvae' 2 3 4 5 6
1 521 NS3 S2 NS NS NS
2 730 S NS NS NS
3 596 NS NS NS
4 379 NS NS
5 283 NS
6 51
'Data for infestations 1 to 8 were combined.
'S = significantly different at 5% level (Smirnov's test).
'NS = not significantly different at 5% level (Smirnov's test).
distribution of insects (Labatte & Got 1993). Analytical expression of these density
functions (f(X)) is as follows:
f(X) = X(p-' (1-X)(q-)/B(p,q)
E = p/(p+q)
SD = [r ( P-__
S(p+q)2(p+q+l) J
where p,q are the function parameters; B(p,q) = G(p)G(q)/G(p+q) (G= Gamma function);
X is the vertical position; E is the mean larval location; and SD is its standard deviation.
Larval vertical distribution was defined on the interval 0-1, with eight possible
locations from 0, the seventh leaf below the highest visible leaf, to 1, the highest visible
leaf. No larvae were found below the first location.
The density function parameters, E and SD, were estimated by minimization of the
sums of squares of the residuals with the S programs (Chambers & Hastie 1992), a
programming environment for users of UNIX systems.
These functions were used to compare inter-instar and inter-plot larval distribution
(Fig. 3 and 4). Development of the distribution model required the assumption that the
model was valid under different environmental conditions. To test this, we generated
TABLE 3. ANALYSIS OF DIFFERENCES IN THE VERTICAL WITHIN-PLANT DISTRIBU-
TION OF FAW LARVAE AMONG DIFFERENT PLOTS (INFESTATION DATES).
No. Plot
Plot Larvae 2 3 4 5 6 7 8 9
1 552 S' S S S S NS2 S S
2 618 S NS NS NS S NS S
3 122 NS NS NS S NS S
4 284 NS NS S NS S
5 146 NS S NS S
6 298 S NS S
7 408 S S
8 657 S
9 588
'S = significantly different at 5% level (Smirnov's test).
'NS = not significantly different at 5% level (Smirnov's test).
Florida Entomologist 76(3)
September, 1993
INSTAR 1 (E= 0.895 SD= 0.089)
1 1
0-*0
location
INSTAR 4 (E= 0.877 SD= 0.109)
1
0 i i i1i i i
0 1
location
INSTAR 2(E=0.89 SD= 0.093)
11
0 1
location
INSTAR 5 (E= 0.881 SD= 0.14)
1
O $
I ___ r~ 1
OH - - - -
location
INSTAR 3 (E= 0.864 SD=0.121)
1
0
0 1
location
INSTAR 6 (E= 0.885 SD=0.109)
1-
0 7
location
Fig. 3. Mean larval location for each instar with Beta density function fittings. The
X-axis represents the normalized vertical location, with 0 being the seventh leaf below
the highest visible leaf and 1 the highest visible leaf (see text). Histograms represent
the proportion of larvae in each of the eight locations. The dotted line represents the
fitting of the Beta density function estimated for each instar. Beta density function
parameters are given in each graph. The solid line represents the fitting of the Beta
density function estimated for all the instars (E = 0.89 + 0.003, SD = 0.102 + 0.037).
distribution estimates for different conditions. To evaluate the effects on the model of
different plots (stages of infestation) or instars, we carried out model estimations by
assigning identical values to the parameters. A comparison of the goodness-of-fit of the
model, when estimated plot-by-plot or instar by instar, by assigning identical parameters
for all the plots or instars, makes it possible to evaluate the accuracy of the model under
different conditions.
The density functions estimated for each observation (dotted lines of Figs. 3 and 4)
describe the larval vertical distribution well, with less than a 10% difference between
observed and fitted distributions. These fittings provided a graphical reference for the
goodness-of-fit. In order to evaluate the influence of larval instar or infestation date, a
single density function (solid line) was estimated by first assigning identical parameters
for all the instars (Fig. 3) and then for all the infestations (Fig. 4). The goodness-of-fit
of the single functions allowed a similar description of larval distribution compared to
observation-by-observation fittings. These results indicate that differences in larval
instar, corn stage or environmental conditions did not influence larval distribution in
early- to late-whorl of corn. The single function estimated for all the infestations was
used to describe larval distribution over time for infestations in early- to late-whorl
corn. Fig. 5 presents an illustration of the fittings obtained with this function for each
infestation. Larval distribution is accurately described with only small differences be-
tween observed and fitted distributions.
Pre-tasseling Infestation
Infestation 9 was carried out at the pre-tasseling stage of corn. The tassel was well
developed in the whorl at the beginning of the infestation and most larvae were attracted
to it (Fig. 6). The percentage of larvae in the tassel reached up to 80% before the tassel
emerged. This percentage progressively decreased until tasseling, when few larvae were
found in this location.
442
Labatte: Within-Plant Distribution of FAW
INF 1 (E=0.862 SD=0.116)
1-
0-1
location
443
INF 2 (E= 0.893 SD= 0.096) INF 3 (E= 0.902 SD= 0.053)
11 1-
] __ __ __ 0-_
location
location
INF 4 (E= 0.891 SD= 0.067)
1
0- a
location
INF 7 (E= 0.861 SD=0.11)
1-
0 i
location
INF 5 (E= 0.881 SD= 0.167)
1 i
0 -
location
INF 8 (E= 0.913 SD= 0.099)
1 i
01
location
INF 6 (E=0.895 SD=0.101)
1
0.J
0-
0 1
location
INF 9 (E= 0.642 SD=0.315)
1 -
location
Fig. 4. Mean larval location for each infestation stage with Beta density function
fittings. For legends see Fig. 3, except that the instar is replaced by time of infestation.
Parameters of the single Beta density function estimated for all the infestations are E =
0.88 0.002 and SD = 0.104 0.028.
When the tassel emerged, the larvae moved to the lower leaves and the ear (Figs.
2, 6). The percentage of larvae in the ear increased progressively after tasseling and
reached up to 75% at the end of the larval development, a few days after female flowering.
This time course is in agreement with the observations of Morrill & Greene (1973a).
CONCLUSIONS
This study demonstrated that the within-plant distribution of FAW larvae in the
leaves remained constant from the early- to late-whorl stages of corn development. The
fitting of a single density function for all the larval instars and all stages of corn devel-
opment permitted a good description of the FAW larval distribution with few discrepan-
cies. The average percentages of larvae in all infestations were 64%, 25%, 8%, 2%, and
1% on the highest visible leaf and on the successive leaves just below, respectively.
This distribution remained constant until the tassel became well developed in the whorl,
whereupon most larvae were found in this structure. After tasseling, most larvae moved
to lower leaves and to the ear.
This study demonstrated that, for early- to late-whorl stage corn, FAW larvae were
in unprotected areas for less than one day, immediately after egg hatch. They were
subsequently found in the wrapped-up leaves of the whorl and remained in this protected
area until the end of their development. This behavior could explain the variable results
444
Florida Entomologist 76(3)
day: 0 nb: 179
1-o
C
0- . . . .i i
0 1
location
day: 3 nb: 61
1-
- A
0 1
0 1
location
day: 9 nb: 14
1-
0 1
0 location
day: 9 nb: 14
1-i
1 n17_ .
location
day: 1 nb: 101
1
0
2
0- I I I I I .
0 1
location
day: 4 nb: 73
1-
0 1
location
day: 7 nb: 19
1 -
0
0 1
location
day: 10 nb: 7
1I
0 I
0 1
location
September, 1993
day: 2 nb: 87
1
0
0 1
location
day: 5 nb: 16
1-1
._2
0 1
0-
location
day: 8 nb: 21
1
0 1
location
day: 11 nb: 6
1-
C
1 0
0 1
location
day: 13 nb: 12
10 i
o_.111 11
location
Fig. 5. Description of the time course of larval within-plant distribution for infesta-
tion 2 using the Beta density function parameters. For legends see Fig. 3. Each graph
represents a daily observation. The numbers indicate the observation day after egg
hatch and the numbers of larvae found.
Labatte: Within-Plant Distribution of FAW
445
LEAVES
0
-i
m
0 0
0O 80
60 70
1- TASSEL
O0
0 \B \ 0
60 70
1- EAR
0
08
60 A \70
days after sowing
Fig. 6. Time course of the larval inter-organ distribution for infestation 9. The full
arrow indicates the day when 50% of plants were in tassel, the empty arrow the day
when 50% of female plants were in flower.
obtained with some microbial controls such as Bacillus thurigiensis (Gardner & Fuxa
1980), and the necessity to apply microbial insecticides with a high clearance sprayer
or in granular formulations to direct the treatment into the leaves of the whorl (Gardner
et al. 1984).
Quantitative studies on other biological control agents, including the en-
tomopathogenic hyphomycete, Paecilomyces fumosoroseus, and the nuclear polyhed-
rosis virus, SfNPV, are currently in progress in order to describe the persistence of
these microbial agents within the plant and their relationships with larval dynamic
processes (Maniania & Fargues 1985, Fargues et al. 1991, Biache et al. 1991). The
present study of FAW within plant distribution over time will enable a better understand-
ing of the probability of contact between the microbial agent and FAW larvae, and the
impact of the microbial agent on larval mortality. This will result in improved methods
446 Florida Entomologist 76(3) September, 1993
for evaluation of the effectiveness of microbial control, will help to explain variable
results, and will ultimately lead to improvements in microbial control strategies.
REFERENCES CITED
BIACHE, G., M. SEVERINI, AND A. KERMARREC. 1991. Production, essai d'activit6s
au laboratoire et en plein champ de Baculovirus contre les noctuelles Spodoptera
frugiperda et Heliothis spp. Caribbean Meetings on Biological control. Guadeloupe
5-7 Nov. 1990. INRA ed.
BUNTIN, G. D. 1986. A review of plant response to fall armyworm, Spodoptera
frugiperda (J. E. Smith), injury in selected field and forage crop. Florida Entomol.
69: 549-558.
CARPENTER, J. E., AND B. R. WISEMAN. 1992. Spodopterafrugiperda (Lepidoptera:
Noctuidae) development and damage potential as affected by inherited sterility
and host plant resistance. Environ. Entomol. 21: 57-60.
CHAMBERS, J. M., AND T. J. HASTIE. 1992. Statistical models in S. Wadsworth &
Brooks/Cole, Pacific Grove, California. 608 p.
CRUZ, I., AND F. T. TURPIN. 1983. Yield impact of larval infestations of the fall
armyworm (Lepidoptera: Noctuidae) to midwhorl growth stage corn. J. Econ.
Entomol. 76: 1052-1054.
FARGUES, J., M. ROUGIER, R. GOUJET, AND B. ITIER. 1991. Paecilomyces
fumosoroseus persistence: inactivation of conidia by simulated sunlight radiation.
2nd European meeting on "Microbial Control of Pest", Rome, IOBC/WPRS Bull.,
14 (1) 82.
GARDNER, W. A., R. M. SUTTON, AND R. NOBLET. 1977. Persistence of Beauveria
bassiana, Nomuraea rileyi, and Nosema necatrix on soybean foliage. Environ.
Entomol. 6: 616-618.
GARDNER, W. A., AND J. R. FUXA. 1980. Pathogens for the suppression of the fall
armyworm. Florida Entomol. 63: 439-447.
GARDNER, W. A., R. NOBLET, AND R. D. SCHWEHR. 1984. The potential of microbial
agents in managing populations of the fall armyworm (Lepidoptera: Noctuidae).
Florida Entomol. 67: 325-332.
GUILLEBEAU, L. P., AND J. N. ALL. 1991. Use of pyrethroids, methomyl, and chlor-
pyrifos to control fall armyworm (Lepidoptera: Noctuidae) in whorl stage field
corn, sweet corn and sorghum. Florida Entomol. 74: 261-270.
HAMM, J. J., AND B. R. WISEMAN. 1986. Plant resistance and nuclear polyhedrosis
virus for suppression of the fall armyworm (Lepidoptera: Noctuidae). Florida
Entomol. 69: 541-548.
HRUSKA, A. J., AND S. M. GLADSTONE. 1988. Effect of period and level of infestation
of the fall armyworm, Spodoptera frugiperda, on irrigated maize yield. Florida
Entomol. 71: 249-254.
LABATTE, J. M., AND B. GOT. 1993. Modelling the within-plant distribution of Euro-
pean corn borer (Lepidoptera: Noctuidae) larvae on corn for pre-tasseling infes-
tation. J. Econ. Entomol. 86: 747-760.
LEEPER, J. R. 1984. Monitoring fall armyworm for susceptibility/resistance to
methomyl. Florida Entomol. 67: 339-342.
LEWIS, W. J., AND D. A. NORDLUND. 1984. Semiochemicals influencing fall ar-
myworm parasitoid behavior: implications for behavioral manipulation. Florida
Entomol. 67: 343-349.
LUGINBILL, P. A. 1928.The fall armyworm. USDA Tech. Bull. 34. 92p.
MANIANIA, N. K., AND J. FARGUES. 1985. Susceptibility of the Fall Armyworm,
Spodoptera frugiperda to the fungal pathogens Paecilomyces fumosoroseus and
Nomuraea rileyi. Florida Entomol. 68: 178-183.
MORRILL, W. L., AND G. L. GREENE. 1973a. Distribution of Fall Armyworm larvae.
1. Regions of field corn plants infested by larvae. Environ. Entomol. 2: 195-198.
MORRILL, W. L., AND G. L. GREENE. 1973b. Distribution of Fall Armyworm larvae.
2. Influence of biology and behavior of larvae on selection of feeding sites. Environ.
Entomol. 2: 415-418.
Herndndez & Pgrez: Natural Host Plants of Anastrepha 447
PITRE, H. N. 1986. Chemical control of the fall armyworm (Lepidoptera: Noctuidae):
an update. Florida Entomol. 69: 570-578.
POITOUT, S., AND R. BUES. 1974. Elevage de chenilles de 28 especes de L4pidoptBres
Noctuidae et de 2 especes d'Actiidae sur milieu artificial simple. Particularites
de l'l6evage selon les especes. Ann. Zool. Ecol. Anim. 6: 431-441.
SOKAL, R. R., AND F. J. ROHLF. 1981. Biometry. Freeman, 2nd ed., 859p.
VICKERY, L. A. 1929. Studies on the fall armyworm in the Gulf Coast District of
Texas. USDA Tech. Bull. 138. 64p.
YOUNG, J. R. 1979. Fall armyworm: control with insecticides. Florida Entomol. 62:
230-233.
YOUNG, J. R. 1986. Fall armyworm (Lepidoptera: Noctuidae) control through chemiga-
tion: an update. Florida Entomol. 69: 594-598.
THE NATURAL HOST PLANTS OF
ANASTREPHA (DIPTERA: TEPHRITIDAE)
IN A TROPICAL RAIN FOREST OF MEXICO
VICENTE HERNANDEZ-ORTIZ' AND ROGELIO PIREZ-ALONSO2
'Instituto de Ecologia A. C. Apartado Postal 63
91000 Xalapa, Veracruz, M6xico
2Facultad de Ciencias, Universidad Nacional Aut6noma
de M6xico. Cd. Universitaria, Mexico D. F., Mexico
ABSTRACT
The relationships between Anastrepha species and their host plants are recorded
and analyzed from a study carried out in a natural tropical community of Mexico (Estaci6n
de Biologia Tropical Los Tuxtlas, Veracruz). We sampled fruits of 55 plant species of
the tropical rain forest and found the following associations: Tapirira mexicana Marchand
was infested with A. sp. and A. obliqua (Macquart); Spondias radlkoferi J. D. Smith
with A. obliqua; Tabernaemontana alba Mill. with A. cordata Aldrich; Quararibea
funebris (Llave) Vischer with A. crebra Stone; Inga sapindoides Willd. with A. distinct
Greene; Brosimum alicastrum Sw. and Pseudolmedia oxyphyllaria J. D. Smith with
A. bahiensis Costa Lima; Psidium guajava L. with A. striata Schiner and A.fraterculus
(Wiedemann); Citrus aurantium L. and C. maxima (Burm.) Merrill with A. ludens
(Loew); Chrysophyllum mexicanum Brandegee ex Standley, Pouteria sapota (Jacq.)
H. Moore & Steam and Pouteria sp. with A. serpentina (Wiedemann). Also, we found
the species A. hamata (Loew), A. leptozona Hendel and A. minute Stone, whose hosts
in the Los Tuxtlas region are still unknown.
We sampled infestation rates in 10 of the 13 host plants. Of the 3704 fruits examined,
23.1% were infested. We encountered 2290 larvae, of which 1600 pupated. Parasitoids
or adult flies emerged from 85% of these. Infestation percentages of the different fruit
species were highly variable, ranging from 1.5% for P. oxyphyllaria to 66.7% for Pouteria
sapota. The mean number of larvae per fruit usually was between 1.25 and 2.59, and
in only the largest and heaviest fruits (such as C. aurantium, P. sapota and P. sp.)
were there more than 9.0 larvae present. Some fruit characteristics affecting the degree
of infestation are discussed, and the possible existence of a diapause period in some
Anastrepha species is noted.
Key Words: Fruit flies, fruit infestation, behavior, food preference.
448 Florida Entomologist 76(3) September, 1993
RESUME
Se registran y analizan las relaciones existentes entire las species de Anastrepha y
sus plants hospederas, en un studio realizado en una comunidad tropical natural de
Mexico (Estaci6n de Biologia Tropical Las Tuxtlas, Veracruz). Se muestrearon 55 es-
pecies de frutos del bosque tropical perennifolio, encontrando las siguientes asociaciones:
Tapirira mexicana infestada porA. sp. y A. obliqua; Spondias radlkoferi porA. obliqua;
Tabernaemontana alba por A. cordata; Quararibeafunebris por A. crebra; Inga sapin-
doides por A. distinct; Brosimum alicastrum y Pseudolmedia oxyphyllaria por A.
bahiensis; Psidium guajava por A. striata y A. fraterculus; Citrus aurantium y C.
maxima por A. ludens; Chrysophyllum mexicanum, Pouteria sapota y Pouteria sp.
por A. serpentina. AdemAs se encontraron las species A. hamata, A. leptozona y A.
minute, sin detectar sus hospederos en la region.
Examinamos muestras de 10 de estas species para evaluar porcentajes de infestaci6n.
Se revisaron un total de 3704 frutos, los cuales tuvieron un promedio general de infes-
taci6n del 23.1%. Se recuperaron 2290 larvas, de las cuales se obtuvieron 1600 pupas
(con una recuperaci6n del 85% de adults y parasitoides). Los porcentajes de infestaci6n
resultaron muy variables (desde 1.5% para Pseudolmedia oxyphyllaria hasta un 66.7%
para Pouteria sapota); se determine que el promedio general de larvas por fruto oscil6
entire 1.25 y 2.59, y solo en el caso de frutos de mayor peso y tamafio (como Citrus
aurantium, Pouteria sapota y Pouteria sp.) se presentaron 9 larvas en promedio o mAs.
Se discuten algunas caracteristicas del fruto en relaci6n al grado de infestaci6n y se
especula acerca de la presencia de un perfodo de diapausa en algunas species del g6nero.
The fruit flies of the genus Anastrepha compose one of the largest and most econom-
ically important insect groups in the American tropics and subtropics due to their damage
to cultivated fruits. This group comprises about 180 valid species, but hosts are unknown
for more than one half of them (Norrbom & Kim 1988). Studies on fruit flies such as A.
ludens (Loew), A. suspense (Loew), A. obliqua (Macquart), and A. fraterculus
(Wiedemann) have been carried out mostly in cultivated environments where most of
the available host plants are not native. Few studies on the biology of the genus Anas-
trepha have been carried out in natural or seminatural environments where most wild
hosts are found (Malavasi et al. 1980, Aluja et al. 1987, Jir6n & Hedstrim 1988). For
this reason, the original host-fruit fly relationships are unknown for most species.
Currently in Mexico there are 30 species of Anastrepha (Hernandez-Ortiz 1990), but
we have no knowledge of the food plants for nearly 50% of these. In the study of their
natural host relationships, we cannot assume the validity of host plant records from
other countries, because in some species geographic populations appear to have local
host preferences. For example, A. ludens in Mexico mainly infests introduced hosts
such as Mangifera indica L. and Citrus species (Baker et al. 1944, Aluja et al. 1987)
and the native hosts Sargentia greggii Watson and Casimiroa edulis Llave & Lex.
(Plummer et al. 1941, Hernindez-Ortiz 1992); however in Costa Rica its only known
host is Casimiroa edulis (Jir6n et al. 1988). Similarly, A. fraterculus in Mexico has as
its preferred host Psidium guajava L., and it is not economically important (Baker
1945, HernAndez & P6rez 1991). In Brazil, however, A. fraterculus attacks a wide
variety of native and introduced hosts, such as Mangifera indica and Citrus species,
and it is one of most economically important species in that country (Malavasi et al. 1980).
The main objective of this study was to determine the natural host plants of Anas-
trepha in a natural community with a high diversity of native plant species with potentially
susceptible fruits.
Herndndez & Perez: Natural Host Plants of Anastrepha 449
MATERIALS AND METHODS
Description of Study Area
This study was conducted on the grounds of the "Estaci6n de Biologfa Tropical Los
Tuxtlas," administered by the Universidad Nacional Aut6noma de M6xico, in the state
of Veracruz, Mexico. This station is located at 95 04'-95 09' W longitude, and 18
34'-18 36' N latitude, with elevations 150-530 m above sea level (Lot-Helgueras 1976)
(Fig. 1). The Reserve comprises an area of 700 ha, of which approximately one hundred
are disturbed by agricultural and animal husbandry activities (Ibarra & Sinaca 1987).
The climate of the region is of the type Af(m) according to Garcia (1973) and Soto-Esparza
(1976), which is defined as warm-humid in the tropics. It is characterized by a mean
temperature of 180C in the coldest month and with more than 60 mm of precipitation
in the driest month. The maximum temperatures occur in May, and minimum temper-
atures occur from December to February. Maximum rainfall occurs in summer and
extends into early autumn (mainly due to the influence of tropical hurricanes).
The climate parameters for Los Tuxtlas Station were taken from the Station Coyame
(reg. num. 029) and from records of the Reserve. They have an annual precipitation of
Fig. 1. Localization map of the Reserve "Estaci6n de Biologfa Tropical Los Tuxtlas,"
in the state of Veracruz, and the surrounding areas (From Lot-Helgueras 1976).
Florida Entomologist 76(3)
4560 mm with a mean temperature of 23.4C, a discrete dry period from March to May,
and a rainy season from June to November (Soto-Esparza 1976, Carabias-Lillo & Guevara
1985) (Fig. 2).
The flora of the Reserve has been studied by several authors, and was listed by
Ibarra & Sinaca (1987), who recorded 118 families comprising 818 species (including
Angiosperms, ferns and related groups). According to Rzedowski (1988) and Estrada
et al. (1985), the vegetation is typical of a tropical rain forest ("Bosque tropical peren-
nifolio") with three arboreal strata. The upper stratum of the Reserve contains species
taller than 20 m, such as Ceiba petandra (L.) Gaertner, Bernoulliaflammea Olivier in
Hook, Talauma mexicana (DC.) Don, Lonchocarpus cruentus Lundell, Nectandra am-
bigens (Blake) Allen, Poulsenia armata (Miq.) Standley, Dussia mexicana (Standley)
Harms, Dendropanax arboreus (L.) Decne. & Planchon, Pterocarpus rohrii Vahl, Om-
phalea oleifera Hemsl., Pithecellobium arboreum (L.) Urban and Ficus species. In the
second stratum (10-20 m) are species such as Brosimum alicastrum Sw., Pseudolmedia
oxyphyllaria J. D. Smith, Quararibea funebris (Llave) Vischer, Croton schiedeanus
Schldl., Guarea glabra Vahl and Stemmadenia donell-smithii (Rose ex J. D. Smith)
Woodson. The third stratum (5-10 m) contains species such as Astrocaryum mexicanum
Liebm. ex Mart., Chamaedorea tepejilote Liebm. in Mart. and Faramea occidentalis
(L.) A. Rich. The disturbed forest areas ("acahual") of the Reserve contain typical
elements such as Cecropia obtusifolia Bertol., Trema micrantha (L.) Blume, Ochroma
pyramidale (Cav. ex Lam.) Urban, Heliocarpus appendiculatus Turcz., and Inga
tI"
M A M
J J A
SON D
Fig. 2. Weather in the Reserve of "Los Tuxtlas"; pluvial precipitation (vertical bars)
from Station records and the mean temperature (line) recorded from meteorological
station Coyame (From Soto-Esparza 1976, Carabias-Lillo & Guevara 1985). Dry period
March-May; rainy season June-November; tropical storms period December-February.
700
600
500
E
E
c 400
0
o--
oCU
S300
o
200
100
0
30
25
20 .
15 I
E
101
5
0
J F
September, 1993
Herndndez & Pgrez: Natural Host Plants of Anastrepha 451
species. With respect to fruiting phenology, a study by Carabias-Lillo & Guevara (1985)
indicated that fruit production in this tropical rain forest increases during the rainy season,
although there are some fruits all year long. Immature fruits are abundant at the
beginning of the rainy season in shrubs and trees, but are reduced during the dry season.
Sampling
Between 1985 and 1990, adult specimens of several Anastrepha species were collected
using light traps near the station building, Carpo-traps (decaying bananas mixed with
beer and sugar) and, less frequently, Malaise traps. Also, we employed five McPhail
traps with pellets of torula yeast during 6 weeks in different times of the first year.
During the period 1988-1990, fruits of 55 plant species (Table 1) were sampled on
TABLE 1. PLANT SPECIES SAMPLED IN THE BIOLOGICAL STATION OF LOS TUXTLAS,
VERACRUZ, MEXICO.
Family
Species
Anacardiaceae
Annonaceae
Apocynaceae
Asclepiadaceae
Bignoniaceae
Bombacaceae
Boraginaceae
Caricaceae
Cucurbitaceae
Ebenaceae
Euphorbiaceae
Guttiferae
Hippocrateaceae
Chrysobalanaceae
Icacinaceae
Juglandaceae
Lauraceae
Leguminosae
Meliaceae
Monimiaceae
Moraceae
Spondias radlkoferiJ. D. Smith
Tapirira mexicana Marchand
Cymbopetalum baillonii R. E. Fries
Rolliniajimenezii Saff.
Stemmadenia donell-smithii (Rose exJ. D. Smith) Woodson
Tabernaemontana alba Mill.
Thevetia ahouai (L.)
Marsdenia macrophylla (Kunth in H.B.K.) Fourn.
Gonolobusfraternus Schlecht
Amphitecna tuxtlensis Gentry
Quararibeafunebris (Llave) Vischer
Cordia megalantha Blake
Carica appaya L.
Jacaratia dolichaula (J. D. Smith) Woodson
Sicydium sp.
Psiguria triphylla (Miq.)
Diospyros digynaJacq.
Omphalea oleifera Hemsl.
Rheedia edulis (Seemann) Triano & Planch6n
Salacia megistophylla Standley
Couepiapolyandra (Kunth Rose in H.B.K.)
Mappia longipes Lundell
Juglans olanchana Standley & L. O. Wms.
Licaria sp.
Persea sp.
Ingajinicuil Schldl.
Inga sapindoides Willd.
Pithecelobium arboreum (L.)
Guarea glabra Vahl.
Guareagrandiflora A. DC.
Siparuna andina (Tul.) A. DC.
Brosimum alicastrum Sw.
Ficus insipida Wild.
Ficus sp.
Poulsenia armata (Miq.) Standley
PseudolmediaoxyphyllariaJ. D. Smith
Trophis mexicana (Liebm.) Bureau in DC.
452 Florida Entomologist 76(3)
TABLE 1. (CONTINUED).
Family
September, 1993
Species
Musaceae
Myrtaceae
Passifloraceae
Rubiaceae
Rutaceae
Sapotaceae
Solanaceae
Staphyleaceae
Verbenaceae
Vitaceae
Heliconia latispatha Benth.
Eugenia acapulcensis Steud.
Pimenta dioica (L.) Merr.
*Psidium guajava L.
Passiflora sp.
*Coffea arabica L.
Genipa sp.
*Citrus aurantium L.
*Citrus maxima (Burm.) Merrill
Chrysophyllum mexicanum Brandegee ex Standley
Pouteria campechiana (Kunth in H.B.K.) Baehni
Pouteria sapota (Jacq.) H. Moore & Steam.
Pouteria n. sp.
Solanum sp.
Turpinia occidentalis (Sw.) G. Don
Aegiphila costaricensis Mold.
Lippia sp.
Cissus sp.
*These species are introduced to the region.
different occasions for detection of larval infestations. Most samples were randomly
collected in the undisturbed areas of the Reserve, but some were also collected in
neighboring forest patches. Fruit samples were carried to the station's laboratory for
dissection. If larval infestations were found, the samples were weighed, and the number
of fruits and larvae counted. All third-stage tephritid larvae were placed in small plastic
containers for pupation. Any emerging adults were identified, sexed and counted.
Voucher specimens are deposited in the collections of the Institute de Biologia of the
Universidad Nacional Aut6noma de Mexico (IBUNAM) and the Instituto de Ecologia
in Xalapa, Veracruz (IEXV). The plant samples were compared to herbarium samples
at the Reserve and identified by Refugio Cedillo T., Guillermo Ibarra M., Santiago
Sinaca (IBUNAM), and Gonzalo Castillo (IEXV); nomenclature employed for plant
species is based on the work of Ibarra & Sinaca (1987).
RESULTS
The genus Anastrepha is represented in the region by the following species: A.
bahiensis Costa Lima, A. cordata Aldrich, A. crebra Stone, A. distinct Greene, A.
fraterculus (Wiedemann), A. hamata (Loew), A. leptozona Hendel, A. ludens (Loew),
A. obliqua (Macquart), A. serpentina (Wiedemann), A. striata Schiner, A. sp. near
perdita Stone, and A. minute Stone. The two latter species are new records for Mexico,
and the first three species were collected during this study and recorded for the first
time for Mexico by HernAndez-Ortiz (1987, 1990).
Only 13 of the 55 plant species sampled were infested by Anastrepha species: Spondias
radlkoferi and Tapirira mexicana (Anacardiaceae); Tabernaemontana alba
(Apocynaceae); Quararibea funebris (Bombacaceae); Brosimum alicastrum and
Pseudolmedia oxyphyllaria (Moraceae); Psidium guajava (Myrtaceae); Inga sapin-
doides (Leguminosae); Citrus aurantium and C. maxima (Rutaceae); Chrysophyllum
mexicanum, Pouteria sapota and an undescribed species of Pouteria (Sapotaceae). The
Herndndez & Pgrez: Natural Host Plants of Anastrepha 453
relationships between species of Anastrepha and their host plants are presented in Table
2. All hosts except P. guajava and the Citrus spp. are native to this region. S. radlkoferi,
T. mexicana, B. alicastrum and P. oxyphyllaria are recorded as host plants for the
genus Anastrepha for the first time.
Sample sizes (Table 3) were highly variable because fruit abundance and fruiting
season were variable. Hosts such as Inga sapindoides had many pods, but we found
only two that were infested; the same was true for fruits of C. maxima and C.
mexicanum. Thus, these plants were not included in Table 3. Infestation of other plants
ranged from 1.5% (of a total of 407 sampled fruits for P. oxyphyllaria) to 66.7% (of a
total of 25 sampled fruits for P. sapota). This variation apparently is not an effect of
sample size, because most samples had a significant quantity of fruits (Table 3, Fig. 4).
From the 10 host plants in which infestation rates were highest, we collected a total
of 3704 fruits randomly sampled, of which 23.1% were infested. We obtained 1600 puparia
from 2290 larvae with an adult emergence of about 85%. The lowest infestation rates
were recorded for A. bahiensis in B. alicastrum (1.9%) and P. oxyphyllaria (1.5%).
Highest infestations occurred in P. sapota attacked by A. serpentina (66.7%) and in P.
guajava attacked by A. striata and A. fraterculus (53.9%). Mean number of larvae per
fruit varied from 1.25 to 34.0, but only a few individual fruits yielded more than 9 larvae.
Total parasitism on all samples was 13.6%.
DISCUSSION AND CONCLUSIONS
Fruit Flies Recorded
Of the Tephritidae recorded for the Reserve, Anastrepha is the best represented
group (with 13 species). The specimen of A. minute is a new record of this species for
Mexico; previously it was only known from Panama (Foote 1967).
We were unable to monitor adults using McPhail traps, because few specimens were
collected by this method. These results could be correlated with the vertical distribution
of the population density of Anastrepha, which increases with canopy height (Vargas
1968, Hedstrom & Gonzalez 1987). The mean canopy height in this forest is about 25-35
m where our trapping density was lowest. Another possible explanation might be that
TABLE 2. NATIVE AND INTRODUCED HOST PLANTS OF ANASTREPHA FRUIT FLIES
IN LOS TUXTLAS, VERACRUZ, MEXICO.
Host Plant Local Common Name Anastrepha spp.
Tapirira mexicana Nompi A. sp. and obliqua
Spondias radlkoferi Jobo obliqua
Tabernaemontanaalba Lecherilla cordata
Quararibeafunebris Canela crebra
Inga sapindoides Inga distinct
Brosimum alicastrum Ojoche bahiensis
Pseudolmedia oxyphyllaria Tomatillo bahiensis
*Psidiumguajava Guayaba fraterculus and striata
*Citrus aurantium Naranja amateca or
Naranjaagria ludens
*Citrus maxima Pomelo ludens
Chrysophyllum mexicanum Zapote niflo serpentina
Pouteria sapota Zapote mamey serpentina
Pouteria n. sp. Zapotillo serpentina
*These species are introduced to the region.
Florida Entomologist 76(3)
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Herndndez & Perez: Natural Host Plants of Anastrepha 455
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Weight Fruit 0 No. Larvae/kg
Fig. 4. Relationship between infestation rate (larvae/kg fruit) and mean weight of
fruit (g) by host plant, rad = S. radlkoferi; mex = T. mexicana; alb = T. alba; fun =
Q. funebris; ali = B. alicastrum; oxy = P. oxyphyllaria; gua = P. guajava; aur = C.
aurantium; sap = P. sapota; nsp = Pouteria n. sp.
the protein of the McPhail traps is less attractive than other food sources for adults in
this environment. In this paper we do not pretend to make an analysis of the relative
abundance of populations of the Anastrepha species, because the distributions of native
host plants inside the Reserve are not homogeneous as in the case of cultivated plants.
The phenology of larvae and adults (Table 4) shows that most species do not appear
in several months of the year. It is possible that their larvae are infesting other fruits
not sampled by us, as adults were trapped during several months when no larval infes-
tations were found. These results could be related to fruiting seasons of the hosts which
are discussed in the following section.
Relationships Between Anastrepha and Their Host Plants
Of all recorded species, only A. ludens, A. obliqua, A. striata and A. serpentina are
considered economically important species in other regions of Mexico. It is evident that
in the Reserve, however, they are restricted to hosts of a single family. For example,
A. ludens (the Mexican fruit fly) is found associated with Citrus trees growing in
neighboring settlements that are approximately 25-30 years old. Apparently A, ludens
has not established populations inside the Reserve, perhaps because its native host
plants Sargentia greggii and Casimiroa edulis (Plummer et al. 1941, HernAndez-Ortiz
458 Florida Entomologist 76(3) September, 1993
1992) are not present in the region. Conversely, we found A. obliqua associated only with
T. mexicana and S. radlkoferi (Anacardiaceae), both of which are native plants. This
suggests an original relationship with the family Anacardiaceae. We found A. striata
and A. serpentina only infesting species of Myrtaceae and Sapotaceae, respectively.
We reared A. bahiensis only from fruits of B. alicastrum and P. oxyphyllaria,
suggesting that it prefers the family Moraceae. This species was previously reared in
Brazil from fruits of Helicostylis poeppigiana (Stone 1942), a plant also belonging to
the Moraceae.
In two cases, the fruits of single hosts were infested at the same time by two species,
T. mexicana by A. sp. and A. obliqua; and P. guajavabyA. striata and A.fraterculus.
We found no larvae and/or adult individuals of several species during part of the
year. For example, A. cordata was not collected from January to June; A. leptozona
from May to November; A. fraterculus from November to April; and A. striata from
October to February. We suggest three possible explanations: 1) a diapause period in
some tropical Anastrepha species after two or more generations, mainly in those breeding
in a single host plant; 2) the adult flies could survive long periods of no fruit; or 3) the
adults migrate to other areas during non-fruiting periods.
Phenology of the Hosts
Precipitation is one of the most important factors that influences the fruiting phenol-
ogy of hosts, because it affects soil humidity necessary for fruit maturation. It may also
have an indirect influence by affecting life cycles of pollinators and seed-dispersal
(Carabias-Lillo & Guevara 1985). The fruiting phenology of the hosts in the study site
varied throughout three years due to variable rainfall conditions (Fig. 3). It also varied
notably among individuals of the same species. Fruits of Q. funebris infested by A.
crebra were present for one long fruiting period each year, but the start and end of the
period varied by one or two months. Its fruit fly infestation rate in some periods was
very low, because adults appeared after most fruits had been attacked by undetermined
species of Lepidoptera.
Tabernaemontana alba, a species infested by A. cordata, usually fruits for a long
period from July to December. During this time the plants present all phenologic stages
(flowers, fruits and seeds). Other species, such as T. mexicana, had a short fruiting
period of only two or three months of the year.
Analysis of Samples
Natural infestations showed some variation in the proportion of larvae per fruit. The
lightest and smallest fruits frequently had the lowest mean (1.25-2.59 larvae per fruit in
species such as T. mexicana, Q. funebris and T. alba), whereas the biggest and heaviest
fruits had means of 9.0-34.0 larvae per fruit (in C. aurantium and Pouteria species).
These results suggest either a positive correlation between clutch size and fruit size,
or that multiple ovipositions occur in big fruits. The latter possibility is supported by
observations that single large fruits frequently contain all larval stages. Fruit size is an
important factor affecting clutch size in some tropical species such as Ceratitis capitata
(Wiedemann) (McDonald & McInnis 1985) and A. ludens (Berrigan et al. 1988), and it
plays an important role in the process of host selection for some species of the Rhagoletis
pomonella group (Prokopy & Bush 1973).
We feel that our results are significant for the following reasons: a) This was the
first study of fruit flies in a natural tropical community during a long continuous period,
and the infestation rates thus represent a more realistic picture of natural populations
than samples taken from cultivated environments; b) McPhail traps were not useful for
I _^__
Herndndez & Perez: Natural Host Plants of Anastrepha 459
monitoring adult populations of fruit flies in undisturbed areas of the tropical rain forest;
c) We speculate that a diapause period could be present in some tropical species of
Anastrepha, mainly in those breeding in a single host; d) Host fruit size plays an important
role in determining the number of larvae per fruit, at least in some Anastrepha species;
e) The Mexican fruit fly (A. ludens) is adapted to disturbed environments of the tropical
rain forest but is not a native element of this community, because we found it infesting
only hosts introduced to the region.
ACKNOWLEDGMENTS
We are grateful to Refugio Cedillo T., Guillermo Ibarra M., Santiago Sinaca
(IBUNAM) and Gonzalo Castillo (IEXV) for determinations of all plant samples, and
authorities of the Biological Station of "Los Tuxtlas," UNAM, for use of all research
facilities in the Reserve. We especially thank Enrique Ramirez G. and Adolfo Ibarra
for collecting many adult specimens of Tephritidae from 1985 to 1988, and Jorge Valen-
zuela for his assistance during the last four collecting trips. We thank Allen L. Norrbom
(USDA), Robert A. Wharton (TAMU), and Martin Aluja (IEXV) for their comments
on an earlier version of this manuscript.
This paper is a contribution to project "Diagn6stico y Conservaci6n de la Biodiversidad
en M6xico," partially supported by the CONACYT-MEXICO (Ref. 0239-N9107).
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AND J. HENDRICHS. 1987. Natural host plant survey of the economically impor-
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329-338.
BAKER, A. C., W. E. STONE, C. C. PLUMMER, AND M. MCPHAIL. 1944. A review
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BAKER, E. W. 1945. Studies on the Mexican fruitfly known as Anastrephafraterculus.
Jour. Econ. Entomol. 38: 95-100.
BERRIGAN, D. A., J. R. CAREY, J. GUILLtN, AND H. CELEDONIO. 1988. Age and
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Exp. Appl. 47: 73-80.
CARABIAS-LILLO, AND S. GUEVARA S. 1985. Fenologia de una selva tropical himeda
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[eds.], Investigaciones sobre la Regeneraci6n de Selvas Altas en Veracruz, M6xico
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FOOTE, R. H. 1967. Family Tephritidae, in A catalogue of the Diptera of the Americas
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adaptarlo a las condiciones de la Repdblica Mexicana). Institute de Geograffa,
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HERNANDEZ-ORTIZ, V. 1987. Notas sobre el g6nero Anastrepha en Mexico (Diptera:
Tephritidae). Folia Entomol. Mexicana 73: 183-184.
HERNANDEZ-ORTIZ, V. 1990. Lista preliminary de species mexicanas del g6nero Anas-
trepha (Diptera: Tephritidae) con descripci6n de nuevas species, registros y
sinonimias. Folia Entomol. Mexicana 80: 227-244.
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HERNANDEZ-ORTIZ, V. 1992. El g6nero Anastrepha Schiner en Mexico (Diptera: Tep-
hritidae). Taxonomfa, distribuci6n y sus plants hubspedes. Inst. de Ecologia
Publ. 33, Xalapa, 162 pp.
HERNANDEZ-ORTIZ, V., AND R. PeREZ-ALONSO. 1991. Infestaci6n natural de
guayaba silvestre por dos species de Anastrepha (Diptera: Tephritidae), pp.
426-427 in Memorias XXVI Congr. Nac. Entomol., Veracruz, M6xico.
HEDSTROM, I., AND I. GONZALEZ. 1987. Vertical distribution of guava fruit flies,
Anastrepha striata Schiner (Diptera: Tephritidae), in Costa Rican lowland guava
orchards: implications for monitoring attempts. Tropical Pest Management 33:
287-289.
IBARRA, M. G., AND S. SINACA. 1987. Listados florfsticos de Mexico VII. Estaci6n
deBiologia Tropical Los Tuxtlas, Veracruz. Univ. Nac. Aut6n. M6xico, Inst.
Biologia, M6xico, 51 pp.
JIRON, L. F., AND I. HEDSTROM. 1988. Occurrence of fruit flies of the genera Anas-
trepha and Ceratitis (Diptera: Tephritidae) and their host plant availability in
Costa Rica. Florida Entomol. 71: 62-73.
JIR6N, L. F., J. SOTO-MANITIU, AND A. L. NORRBOM. 1988. A preliminary list of
the fruit flies of the genus Anastrepha (Diptera: Tephritidae) in Costa Rica.
Florida Entomol. 71: 130-137.
LOT-HELGUERAS, A. 1976. La estaci6n de Biologia Tropical Los Tuxtlas: pasado, pre-
sente y future, pp. 31-69 in A. G6mez-Pompa, C. VAzquez-YAnez, S. del Amo
and A. Butanda [eds.], Investigaciones sobre la regeneraci6n de selvas altas en
Veracruz, M6xico. Ed. C.E.C.S.A., M6xico.
MALAVASI, A., J. S. MORGANTE, AND R. A. ZUCCHI. 1980. Biologia de moscas-das-
frutas (Diptera, Tephritidae). I: lista de hospedeiros e ocorrencia. Rev. Brasileira
Biol. 40: 9-16.
MCDONALD, P. T., AND D. O. MCINNIS. 1985. Ceratitis capitata: Effect of host fruit
size on the number of eggs per clutch. Entomol. Exp. Appl. 37: 207-211.
NORRBOM, A. L., AND K. C. KIM. 1988. A list of the reported host plants of the
species of Anastrepha (Diptera: Tephritidae). U. S. Dept. Agr., APHIS-PPQ,
APHIS 81-52, 114 pp.
PLUMMER, C. C., M. MCPHAIL, ANDJ. W. MONK. 1941. The yellow chapote, a native
host of the Mexican fruitfly. U. S. Dept. Agr. Tech. Bull. 775: 1-12.
PROKOPY, R. J., AND G. L. BUSH. 1973. Ovipositional responses to different sizes of
artificial fruit by flies ofRhagoletis pomonella species group. Ann. Entomol. Soc.
America 66: 927-929.
RZEDOWSKI, J. 1988. Vegetaci6n de M6xico. Editorial LIMUSA, M6xico (Cuarta
reimpresi6n), 432 pp.
SOTO-ESPARZA, M. 1988. Algunos aspects climAticos de la region de Los Tuxtlas,
Veracruz, pp. 70-111 in A. G6mez Pompa, C. VAzquez-YAnez, S. del Amo and
A. Butanda [eds.], Investigaciones sobre la Regeneraci6n de Selvas Altas en
Veracruz, M6xico. Ed. C.E.C.S.A., Mexico.
STONE, A. 1942. The fruitflies of the genus Anastrepha. U. S. Dept. Agr. Misc. Publ.
439: 1-112.
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combat de las moscas de la fruta en el estado de Veracruz. Rev. Fit6filo 59: 15-21.
Hallman & Knight: Noctuid on Diospyros spp.
HYPOCALA ANDREMONA (LEPIDOPTERA: NOCTUIDAE)
DEVELOPMENT ON EIGHT SPECIES OF
DIOSPYROS (EBENACEAE)
GUY J. HALLMAN AND ROBERT J. KNIGHT, JR.
United States Department of Agriculture, Agricultural Research Service
13601 Old Cutler Road
Miami, FL 33158
ABSTRACT
Damage by Hypocala andremona (Cramer) (Lepidoptera: Noctuidae) larvae to Dios-
pyros spp. (Ebenaceae) was observed on the U. S. Department of Agriculture, Subtrop-
ical Horticulture Research Station in Miami, Florida. The larvae caused severe damage
to black sapote, D. digyna Jacq., and Japanese persimmon, D. kaki L. Damage was
also observed on D. sonorae Standl. and D. texana Scheele. Percentage survival of H.
andremona larvae ranged from 0% for D. montana Roxb. and D. mespiliformis Hochst.
ex A. DC. to 64% for tender foliage of D. digyna. The larval stage lasted 19 d on tender
foliage of D. digyna and 28-32 d for other Diospyros spp. No parasites emerged from
H. andremona collected in the field. These results indicate that D. digyna was the most
favorable of the hosts of H. andremona studied; however, tender foliage was necessary
for early instars to complete development. Also, the importation of parasites of H.
andremona might help reduce the equilibrium density of the pest.
Key Words: Larval damage, black sapote, parasites.
RESUME
El dafio causado por larvas de Hypocala andremona (Cramer) (Lepidoptera: Noc-
tuidae) a Diosporos spp. (Ebenaceae) fu6 observado en la Estaci6n de Investigaci6n de
Horticultura Subtropical del Departamento de Agricultura de los los Estados Unidos,
en Miami, Florida. Las larvas causaron dafos severos al sapote negro, D. digyna Jacq.
y D. kaki L. Tambi6n se observ6 dafo en D. sonorae Standl. y D. texana Scheele. El
porcentaje de sobrevivencia de larvas de H. andremona fu6 de un minimo del 0% para
D. montana Roxb. y D. mespiliformis Hochst. ex A. DC. a un maximo del 64% en el
follaje tierno de D. digyna. El estado larval dur6 19 dias comiendo follaje tierno de D.
digyna y 28-32 dias para otras species de Diospyros. No se encontr6 ningdn parasito
en larvas de H. andremona recogidas en el campo. Estos resultados indican que D.
digyna fu6 el mejor de los hospederos de H. andremona; sin embargo, se necesit6 follaje
tierno para cumplir el desarrollo de los primeros instares. La importaci6n de parasites
de H. andremona podria ayudar a reducir la densidad de equilibrio de la plaga.
Species of Hypocala (Lepidoptera: Noctuidae) feed on foliage of Diospyros spp.
(Ebenaceae), although Beeson (1941), cited by Thakur et al. (1984), gives Erioglossum
rubiginosum (Roxb.) Blume (Sapindaceae) as a host of H. rostrata F. in India. H.
rostrata has been referred to as the persimmon leafroller or tendu defoliator and was
recorded on foliage of Diospyros kaki L. (Japanese persimmon), D. lotus L. (date plum),
D. ehretioides Wall., and D. melanoxylon Roxb. in India (Beeson 1941, Thakur et al.
1984, Kumar et al. 1989). H. subsatura Guen6e fed on foliage ofD. kaki in India (Pruthi
& Batra 1960).
In March, 1990, H. andremona (Cramer) (syn. hill Litner) was found heavily defoliat-
ing black sapote, D. digyna Jacq., at the U. S. Department of Agriculture Subtropical
Florida Entomologist 76(3)
Horticulture Research Station (SHRS), Miami, Florida. Defoliation averaged approxi-
mately 20%, with some trees suffering 50%. A review of the literature retrieved little
information on H. andremona. This insect is common in the neotropics, and adult speci-
mens have been found as far north as Maine and Ontario (Forbes 1954, Holland 1968).
The objectives of this research were to obtain information on field biology of H. an-
dremona, observe damage to black sapote, compare different species of Diospyros as
hosts of H. andremona and survey for parasites.
MATERIALS AND METHODS
Observations were made on H. andremona attacking Diospyros spp. trees at the
SHRS. The following species of Diospyros are in the clonal germplasm collection at the
SHRS: D. digyna, D. kaki, D. mespiliformis Hochst. ex A. DC. (monkey guava), D.
montana Roxb., D. pallens (Thunb.) F. White, D. sonorae Standl., and D. texana
Scheele (black persimmon). D. digyna, D. sonorae, and D. texana are native to Mexico,
and the others are Old World tropical and subtropical species. A tree of D. virginiana
L. (common persimmon), native to the southeastern United States, located 3 km south-
west of the station (on Old Cutler Road near SW 160 Street) was also observed.
H. andremona larvae were collected from black sapote and reared at 24 1C and
70-90% RH on branches of excised black sapote foliage of different ages placed in water.
Observations were made for parasitism of these larvae. Emerging pupae were placed
in cages (0.2 m3) with the floors, tops, and frames made of PlexiglasT (3 mm thick).
Three sides consisted of aluminum screen (1 mm spacing between the threads), and the
front was a sliding Plexiglas door with a sleeved access port (0.1 m diam). Water for
the adults was provided from two plastic vials (20 ml) with the bottoms and part of the
sides cut out. A cylindrical sponge (25 mm diam, 35 mm long) was placed in the vial
and kept saturated with water. The vials were suspended in holes (29 mm diam) in the
back corners at the top of the cages. Several sucrose cubes (13 mm) were placed inside
the cages for adult nourishment.
Adults mated inside the cages, and eggs were laid mostly on the screen, with a few
laid on pieces of paper or black sapote foliage placed inside the cages. Ten to 25 neonate
larvae were collected from the cages with a fine-tipped paint brush and placed on foliage
of eight accessions of Diospyros (Table 1) located inside cages made from Petri dishes
(0.145 m diam). Both tender and mature foliage of D. digyna were used because tender
foliage of this tree is available year-round. A hole (3.1 cm diam) for inserting larvae
was cut into the top of the Petri dish and plugged with a rubber stopper (#7). A slit (6
x 20 mm) was cut down the side of the bottom half of the Petri dish to allow the end
of the stem to be inserted in water. Cylinders of dental cotton (7 mm diam, 35 mm long)
were used to plug the hole around the stem to keep larvae from escaping. The larvae
were kept at 24 1C, 70-90% RH, and foliage was replaced every 1-3 d as needed.
When larvae were 1-1.5 cm in length they were transferred to the Plexiglas cages
described above. Data on mortality and length of larvae were noted when the foliage
was changed. Cages were checked for pupae daily. The experiment was replicated four
times. The following data were analyzed as completely randomized models using the
ANOVA procedure (SAS Insitute 1989): percentage survival of larvae, number of days
to pupation, duration of the pupal stage, pupal weight, and percentage survival of pupae.
Means were compared using the Ryan-Einot-Gabriel-Welsch multiple F test.
RESULTS AND DISCUSSION
All 54 trees of D. digyna (PI-133380) on the station showed considerable defoliation
(15-50%) by H. andremona during the spring of 1990. Eggs were laid individually on
462
September, 1993
Hallman & Knight: Noctuid on Diospyros spp.
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newly forming (pale green) leaves and vegetative and flower buds; early instars fed on
these structures. Early instars also fed at the tips of leaves with their bodies parallel
to the leaf mid-vein. From there, they worked their way up the leaf removing large
sections of it. Early-instar larvae bored inside flowering buds causing them to abort.
Very few black sapote fruits set in 1990. When larvae were approximately 1/3 to 1/2
grown, they began to feed on mature (dark green) foliage, as well as newly forming
foliage. Early instars were not observed to feed on mature foliage in the field. Large
larvae bored into mature black sapote fruits as well as feeding on foliage. They were
always observed to enter the fruit at the edge of the calyx but would not penetrate
very far under the epidermis without boring far from the entrance. Sometimes the entire
larva entered the fruit, but would not remove > 5 ml of pulp. Occasionally, the fruit
would rot at this site; at other times the wound would become sealed and the fruit
continued to ripen normally. In any case, even if the wound healed, black sapote fruits
damaged by H. andremona were culled in local packing houses.
The continual destruction of newly emerging foliage caused a "witches broom" effect
as new branches developed below the destroyed vegetative shoots. There was consider-
able deformation and death of branches. Although various Lepidoptera and Coleoptera
larvae bore into damaged D. kaki in Florida (Miller & Crocker 1991), we did not observe
a borer problem in D. digyna damaged by H. andremona.
The lone female tree of D. kaki, PI-82033, was heavily damaged by H. andremona.
All of the flower buds had been eaten and defoliation was approximately 60%.
All three D. mespiliformis trees (PI-61810, PI-78256: two trees), all six D. montana
trees (two trees each of PI-119828, PI-124229, and M-10380), all three of D. pallens
bushes (M-23197), and both trees of Diospyros sp. (PI-52510) showed no damage by H.
andremona, nor were larvae found on the foliage.
Two of three D. sonorae trees (PI-76090) showed possible minor damage by H.
andremona, but no insects were found on the trees. One large male D. texana bush
(M-1408) had approximately 10% defoliation and some larvae of H. andremona. The D.
virginiana off-station had no damage from H. andremona.
Percentage survival of H. andremona larvae on Diospyros spp. ranged from 0% for
D. montana, D. mespiliformis, and mature D. digyna foliage to 64% for new, succulent
D. digyna foliage (Table 1). Survival was also high on D. kaki and D. virginiana, two
economic species in the southeastern United States. Larvae that died feeding on D.
digyna and D. kaki did so within the first 11-13 d, after which almost all of the surviving
larvae reached the pupal stage. Larvae that died feeding on D. virginiana did so within
the first 13-18 d. For larvae reared on D. texana, 40-60% mortality occurred within the
first 3-5 d, after which the mortality rate was low but constant until pupation. Although
larval survival for H. andremona fed D. pallens and D. sonorae was 3%, mortality was
higher on D. pallens initially and more gradual on D. sonorae. First instars placed on
mature foliage of D. digyna fed very little, did not grow, and died within 6 d. Mortality
of larvae placed on D. montana reached 50% in 4-7 d; some larvae survived 14-19 d,
although they never reached > 10 mm in length. First instars fed D. mespiliformis died
within 6-14 d and did not grow longer than 7 mm. Infectious diseases and cannibalism
were not noted to cause any mortality.
Duration of the larval period was shortest for larvae reared on new foliage of D.
digyna (Table 1). There were no significant differences in duration of the pupal stage,
pupal weight, or pupal survival (Table 1).
H. andremona developed best on tender foliage of D. digyna. Percentage survival
of larvae and pupal weight were highest, and duration of larval and pupal stages was
shortest on tender foliage of D. digyna, indicating that it was the most favorable host.
This might be partly due to conditioning of the pest on D. digyna, because the insects
used in these studies were collected from this host. Larvae were not often found on
other species of Diospyros in the field.
White: Movement of Sugarcane Borer Larvae
465
Of 306 H. andremona larvae of different sizes collected on D. digyna trees from
March, 1990, to June, 1991, and reared in the laboratory, none were observed to be
parasitized. It is rare for noctuids to lack larval parasites. A search for parasites of H.
andremona in the neotropics might be beneficial in reducing the amount of damage this
insect causes to Diospyros in Florida.
END NOTE
Mention of a proprietary product does not constitute an endorsement by the USDA.
J. Heppner, Department of Plant Industries, Florida Department of Agriculture &
Consumer Services, identified H. andremona. Wilhelmina Wasik and Elena Schnell
provided technical assistance.
REFERENCES CITED
BEESON, C. F. C. 1941. The ecology and control of the forest insects of India and the
neighboring countries, Part I. Government of India, New Delhi.
FORBES, W. T. M. 1954. Lepidoptera of New York and neighboring states: Noctuidae
part III. Cornell Univ. Agric. Exper. Sta. Memoir 329, Ithaca, New York.
HOLLAND, W. J. 1968. The moth book. Dover, New York.
KUMAR, S., L. PRASAD, AND H. R. KHAN. 1989. Bionomics and control of tendu
defoliator Hypocala rostrata L. (Lepidoptera: Noctuidae). Indian Forester 115:
258-263.
MILLER, E. P., AND T. E. CROCKER. 1991. Oriental persimmons in Florida. SS-FRC-
003, Florida Cooperative Extension Service, Gainesville.
PRUTHI, H. S., AND H. N. BATRA. 1960. Important fruit pests of north-west India.
The Indian Council of Agric. Research, New Delhi.
SAS INSTITUTE INC. 1989. SAS/STAT user's guide, version 6, fourth edition, volume
1. Cary, North Carolina.
THAKUR, J. R., P. R GUPTA, AND G. S. DOGRA. 1984. Some observations on the life
history of the persimmon leaf roller, Hypocala rostrata F. (Lepidoptera: Noc-
tuidae), pp. 385-387 in T. R. Chadha [ed], Advances in research on temperate
fruits. Parmar Univ. of Hort. & Forestry, Solan, India.
MOVEMENT AND ESTABLISHMENT OF SUGARCANE BORER
(LEPIDOPTERA: PYRALIDAE) LARVAE ON RESISTANT
AND SUSCEPTIBLE SUGARCANE
WILLIAM H. WHITE
Sugarcane Research Unit, Agricultural Research Service,
U.S. Department of Agriculture,
P.O. Box 470, Houma, LA 70361-0470
ABSTRACT
The movement and establishment of sugarcane borer, Diatraea saccharalis (F.),
larvae was studied on resistant and susceptible sugarcane. A field study was conducted
over three years on the cultivars 'CP 74-383' (susceptible), 'CP 65-357' (intermediate),
and 'CP 70-321' (resistant). Stalks of each cultivar were artificially infested with neonate
466 Florida Entomologist 76(3) September, 1993
sugarcane borer larvae and sampled at 10, 20, and 30 days after infestation. Larval
movement, entrance holes, and plant growth were mapped and recorded for each cultivar
and sample date. Larval recovery at 30 days after infestation was low and varied among
cultivars totalling 10.2% on CP 74-383, 7.0% on CP 65-357, and 3.5% on CP 70-321.
Larvae entered stalks of CP 74-383 earlier than those of CP 65-357 and CP 70-321; at
10 days after infestation, 48% of the larvae on CP 74-383 had entered the stalk, but
only 19% on CP 65-357 and CP 70-321. Larvae generally moved up the stalk before
entering, indicating that young internodes were preferred to older internodes for entry
sites. Larvae feeding on CP 74-383 were also more likely to damage multiple internodes.
This study suggests that a major component of sugarcane's resistance to sugarcane
borer is reducing the frequency of the establishment of young larvae in the stalk.
Key Words: Diatraea saccharalis, plant resistance, behavior, sugarcane, Saccharum spp.
RESUME
Se estudi6 el movimiento y establecimiento de larvas del barrenador de la cafla de
azucar, en cafias resistentes y susceptibles. Se condujo un studio de campo por tres
afios en los cultivares 'CP 74-383' (suscepible), 'CP 65-357' (intermedio) y 'CP 70-321'
(resistente). Se infestaron artificialmente tallos de cada cultivar con larvas neonatas de
barrenadores de cafia de azucar, muestreAndose a los 10, 20 y 30 dias despues de
infestados (DDI). Se hizo un mapa del movimiento de las larvas, huecos de entrada, y
del crecimiento de las plants y se registry esta informaci6n y la fecha de cada cultivar.
La recuperaci6n de las larvas a los 30 DDI fue baja y vari6 entire los cultivares con
promedios de 10.2% en CP 74-383, 7.0% en CP 65-357, y 3.5% en CP 70-321. Se encontr6
que larvas entran a los tallos de CP 74-383 mas pronto que aquellos de CP 65-357 y de
CP 70-321; a los 10 DDI, el 48% de las larvas en CP 74-383 habian entrado al tallo, pero
solo el 19% en CP 65-357 y en CP 70-321. Las larvas generalmente se movieron hacia
arriba en el tallo antes de entrar, lo que indica que los entrenudos nuevos son preferidos
a los viejos. Las larvas que se alimentaban de CP 74-383 dafiaban mas entrenudos. Este
studio sugiere que un component important en la resistencia hacia el barrenador de
la cafia de azucar es el reducir la incidencia de larvas j6venes en los tallos.
The sugarcane borer, Diatraea saccharalis (F.), is the major insect pest of sugarcane
(Saccharum spp.) in Louisiana (Long 1969). Plant resistance plays an important role in
managing damaging infestations of sugarcane borer and will assume a greater role in
the future. Although the mechanisms of sugarcane borer resistance are not completely
understood, some resistance mechanisms have been identified.
Kyle & Hensley (1970) conducted studies comparing the establishment and damage
of the sugarcane borer on two sugarcane cultivars. Their studies suggested that the
resistance of 'NCo 310' (compared to the susceptibility of 'CP 44-101') to sugarcane borer
was due primarily to higher mortality of larvae, especially of young larvae prior to
tunneling into the internodes. They found no experimental evidence that ovipositional
preference was responsible for low populations in NCo 310. In a later study, Coburn &
Hensley (1972) reported that the resistance in NCo 310 was due to the occurrence of a
tight leaf-sheath that inhibited establishment of larvae. Rind hardness of the target
internode has also been implicated as a resistance factor (Martin et al. 1975, Martin &
Cochran 1975). White & Hensley (1987) reported that plant tolerance may also be a
mechanism of resistance because some sugarcane cultivars are able to minimize sugarcane
weight and sugar loss following infestation by sugarcane borer.
Although there have been several studies on the general behavior of sugarcane borer
on sugarcane, no study has been done to examine the establishment of sugarcane borer
on sugarcane cultivars with different levels of resistance. Information from such a study
White: Movement of Sugarcane Borer Larvae 467
would be helpful in further understanding mechanisms of resistance. The objective of
this study was to determine patterns of movement and establishment of sugarcane borer
on resistant and susceptible sugarcane.
MATERIALS AND METHODS
Studies were conducted at the Sugarcane Research Unit, Houma, LA. Three sugar-
cane cultivars with different levels of resistance to the sugarcane borer were evaluated
in this study over a three year crop cycle. These cultivars, on the basis of previous
studies (Pollet et al. 1986), were classified as follows: 'CP 70-321', resistant; 'CP 65-357',
intermediate; and 'CP 74-383', susceptible. Cultivars were planted October 22, 1986 in
a randomized complete block design with nine replications. Individual plots were single
rows, 15 m long with an inter-row spacing of 1.8 m. A 1.2 m alley was maintained
between blocks. The experiment was buffered at both ends and border rows were planted
against both sides to eliminate edge effects. The cultivars were subjected to standard
Louisiana cultural practices; insecticides were neither needed nor applied to the plots
because of minimal native infestations of sugarcane borer.
During the 1987 growing season, 30 randomly selected stalks showing no insect
damage were marked in each plot. Ten stalks were assigned to each of three groups;
one group to be sampled 10 days after infestation (DAI), one 20 DAI, and one 30 DAI.
After assignment of groups, gelatin capsules (Eli-Lilly, Indianapolis, IN 46285), each
containing 5 neonate sugarcane borer larvae, were placed (one per stalk) behind the
leaf sheath of the youngest leaf of selected stalks with a visible dewlap (defined as the
outer surface of the junction to the leaf blade and leaf sheath) (van Dillewijn 1952). A
total of 450 larvae were applied per sampling date (DAI) treatment. Capsule lids were
removed to allow the escape of the larvae onto the leaf sheath. A system was developed
to designate leaves and internodes by age in order to track the movement of the larvae.
The youngest leaf with exposed dewlap, the node supporting this leaf, and the internode
below this node were all designated K+1 (Benda 1969). The next older leaf, its supporting
node and the internode below that node were designated K+2, and so forth. At 10-day
intervals, stalks were harvested and transported from the plots for inspection. Each
stalk was systematically searched for larvae, pupae and injury. This procedure was as
follows: 1) leaf blades with sheaths intact were removed from stalks and examined, 2)
unexpanded leaves of the whorl were removed and carefully unrolled, 3) stalks were
examined for entry holes, and 4) stalks containing entry holes were split and searched
for larvae or pupae. Although small larvae (10 days old) are difficult to locate, careful
and systematic search maximized the possibility of their detection. Using the present
K+1 internode as a reference point, larval location, larval instar and plant damage were
recorded. In this study, damage or injury was recorded when a sugarcane borer entry
hole was observed in an internode, and the larva had turned upwards or downwards
within the stalk. Shallow feeding holes (false-starts) by larvae were not counted as
damage.
The study was repeated in 1988 and 1989, but with modifications. Thirty stalks in
each plot were randomly selected; the K+ 1 leaf sheath was identified and marked and
one neonate sugarcane borer larva was placed behind that sheath using a camel-hair,
artist brush. This gave a total of 270 larvae per cultivar per year. Stalks were removed
from the plots only at 30 DAI and inspected as described above.
Recovery of larvae and pupae was low in all three years and in many plots larvae
or pupae were not recovered. By combining larval and pupal counts from 1988 and 1989,
we eliminated all but a few missing plots. Proc GLM [SAS Institute 1988] was used for
analysis of variance on larval and pupal counts. Proc ANOVA was used for analysis of
injury data because these data contained no missing values.
468 Florida Entomologist 76(3) September, 1993
RESULTS
In all three years, numbers of larvae and pupae recovered after 30 days were low
and variable among cultivars. In 1987, only 38 of the total of 450 (8.4%) larvae released
were recovered at 30 DAI from CP 74-383, 22 (4.9%) from CP 65-357, and 20 (4.4%)
from CP 70-321 (data not shown). In 1988 and 1989, the total number of larvae and
pupae recovered from the total of 540 ranged from a low of 19 (3.5%) for CP 70-321 to
a high of 55 (10.2%) for CP 74-383 (Table 1). During each year, more larvae were
recovered from the susceptible cultivar (CP 74-383) than either the intermediate (CP
65-357) or the resistant (CP 70-321).
In 1987, cultivars varied in the time required for larvae to become established. At
10 DAI, 31 of the 65 (48%) larvae recovered on the susceptible cultivar CP 74-383 had
bored into the stalk, while only 10 of the 54 (19%) larvae recovered on CP 65-357 and
7 of 36 (19%) from CP 70-321 were found within the stalk. At 30 DAI, 38 of the 38
(100%) larvae and pupae recovered from CP 74-383 were within the stalk, while 22 of
the 27 (81%) larvae and pupae recovered from CP 65-357 and 20 of 23 (87%) on CP
70-321 were within the stalk.
Distribution of sugarcane borer larvae on the stalk varied among instars. Larvae 10
days old were more widely distributed along the stalk and were found on older internodes,
compared with 20- and 30-day-old larvae or larvae and pupae. Ten-day-old larvae were
found on the K+0 through the K+9 internodes, but the majority of larvae were found
on the K+3 and K+4 internodes (Fig. 1). As larvae on all cultivars began to penetrate
into the stalk 20 DAI, the distribution of internodes that harbored larvae (inside and
outside) decreased (Fig. 2). Also, larvae began to move up the stalk to establish them-
selves in the younger internodes; most larvae at 20 DAI were found on the K + 1 and
K+2 internodes. At 30 DAI, when the majority of the larvae and pupae were found
within the stalk, 60% of those larvae were found on the K + 0, K +1, and K + 2 internodes
(Fig. 3). These data suggest that sugarcane borer larvae are less selective at the leaf-feed-
ing stage (instars 1-3), but require younger internodes for acceptable entry sites as they
begin to establish themselves within the stalk (instars 4 & 5). Ring et al. (1991) found
similar behavior by the Mexican rice borer, Eureoma loftini (Dyar). Larvae of this
insect migrate from oviposition sites at the base of the stalk to green leaf sheaths at
the top, ultimately to penetrate and complete development within the stalk. Larvae
were found to prefer 10-day-old internodes as penetration sites.
The pattern of establishment of larvae on the susceptible cultivar, CP 74-383 and
intermediate cultivar, CP 65-357 was somewhat more consistent from year to year,
compared with establishment on the resistant cultivar CP 70-321. The majority of the
TABLE 1. PERCENTAGE OF INFESTED STALKS INJURED AND PERCENTAGE OF
STALKS WITH MULTIPLE ENTRANCE HOLES, 30 DAYS AFTER INFESTA-
TION (DAI) WITH SUGARCANE BORER LARVAE., 2, 8
Total No. Larvae Mean Stalks
and Pupae Mean No. Larvae/ Mean % of with Multiple
Cultivars Recovered4 Pupae Recovered Injured Stalks Entrance Holes
CP 74-383 55 (10.2%) 6.1 a 35% a 20% a
CP 65-357 38 (7.0%) 4.2 b 20% b 12% b
CP 70-321 19 (3.5%) 2.1 b 20% b 7% b
'Combined 1988 and 1989 data. Injury is defined as an internode penetrated by a larva. The larva need not be present.
'A total of 540 stalks were infested.
'Numbers within column followed by the same letter are not significantly different (P = 0.05; Fisher's protected
LSD).
'Numbers in parentheses represent percentage of total larvae released which were recovered.
White: Movement of Sugarcane Borer Larvae
--CP74-383
+ CP65-357
*- CP70-321
25
"O
> 20
0
0
(U,
cr
015
1-
4 10
a)
-0
: 5
z
2 3 4 5 6
Leaf and Internode Number
7 8 9
Fig. 1. Distribution of sugarcane borer larvae on shoots of three sugarcane cultivars
10 days after infestation (1987).
larvae established on the K + 0 and K + 2 internodes on CP 74-383 and CP 65-357 (Fig.
4 & 5), while larvae became established in internodes K-1 through K+3 on CP 70-321
(Fig. 6). The more variable distribution of larval entry sites on CP 70-321 (Fig. 6) may
be a result of the increased difficulty of penetration into the internodes of this cultivar.
- CP74-383
+ CP65-357
*- CP70-321
+'
-1 0 1 2 3 4
Leaf and Internode Number
5 6
Fig. 2. Distribution of sugarcane borer larvae on shoots of three sugarcane cultivars
20 days after infestation (1987).
469
Neonates"\
Florida Entomologist 76(3)
September, 1993
CP74-383
+ CP65-357
CP70-321
Neonates
Placed
\YX
* +-
-2 -1 0 1 2 3 4 5 6 7
Leaf and Internode Number
Fig. 3. Distribution of sugarcane borer larvae on shoots of three sugarcane cultivars
30 days after infestation (1987).
--1987
+ 1988
-- 1989
-3 -2 -1 0 1 2 3 4 5 6 7
Leaf and Internode Number
Fig. 4. Distribution of sugarcane borer larvae and pupae on shoots of the cultivar
CP 74-383 thirty (30) days after infestation (1987, 1988, and 1989).
470
White: Movement of Sugarcane Borer Larvae
Martin et al. (1975) found a significant negative correlation (r = -.97) between the rind
hardness of the first internode accessible to attack and mean percentage of internodes
subsequently penetrated by sugarcane borer larvae. Although internode hardness was
not measured in this study, the data suggest that differences in internode hardness may
exist among the three cultivars. Also, tight leaf sheaths have also been shown to inhibit
establishment of larvae (Coburn & Hensley 1972). The cultivar CP 70-321 has tight leaf
sheaths while CP 74-383 leaf sheaths are not considered to be tight (CP 65-357 is
intermediate in leaf sheath tightness).
DISCUSSION
These data support earlier research indicating that a major component of resistance
to sugarcane borer is the prevention of establishment of young larvae within the stalk,
particularly the K+0 through K+2 internodes. Although success of establishment by
larvae varied significantly among cultivars (Table 1), successful stalk penetration, even
in the susceptible cultivar, was only 35%. It was also found that larvae are capable of
damaging multiple internodes. The percentage of stalks with multiple entrance holes
after infestation by a larva was significantly greater for the susceptible cultivar than
for the intermediate and resistant cultivars (Table 1). Although it is not known why
this pattern developed, nutritional differences among cultivars may be responsible for
varying levels of feeding injury.
It is possible that the multiple entrance holes on a stalk may have resulted from
multiple larvae rather than a single larva. Larvae appeared to move among neighboring
shoots of a stool (a group of stalks resulting from an individual vegetative bud), but as
mentioned previously, native infestations were light and infested stalks were at least
0.5 m apart minimizing the possibility of a native larva migrating to an artificially-infested
shoot.
-O
0
a) + 1987
a) ; +1988
on
0 -
2
CP 65-357 thirty (30) days after infestation (1987, 1988, and 1989).
*/ \ \
-3 -2 -1 0 1 2 3 4 5 6 7
Leaf and Internode Number
Fig. 5. Distribution of sugarcane borer larvae and pupae on shoots of the cultivar
CP 65-357 thirty (30) days after infestation (1987, 1988, and 1989).
472 Florida Entomologist 76(3) September, 1993
-0 14
()
(D
0 12 +
S) --1987
10 +1988
CL 1989
a. 8
6
(u
-j
4- 4-
0
2 -
E
z o. -^ ^----4--- ----*-- -^--*--
-3 -2 -1 0 1 2 3 4 5 6 7
Leaf and Internode Number
Fig. 6. Distribution of sugarcane borer larvae and pupae on shoots of the cultivar
CP 70-321 thirty (30) days after infestation (1987, 1988, and 1989).
Sugarcane borer larvae generally moved up the stalk before entering a new internode.
This finding suggests that mature internodes are protected from larval feeding. Ring
et al. (1991) found that threshold levels for Mexican rice borer could be increased 70 d
after formation of the first 10 internodes, indicating that mature internodes no longer
needed protection from larvae.
Although the fate of unrecovered larvae is unknown, traits that delay penetration
of larvae into the stalk undoubtedly increase larval mortality. The general pattern of
infestation was similar among the cultivars studied. However, the success of larvae on
CP 74-383 appeared to be related to the ability of larvae to enter the protection of the
stalk sooner than larvae on CP 65-357 or CP 70-321. Larvae remaining outside the stalk
are exposed to predators, insecticides and adverse weather for a longer period of time.
Thresholds based on an average percentage of bored internodes may not reveal traits
important in the micro-management of individual cultivars. With the availability of
resistant sugarcane cultivars, research should be done to develop thresholds for individ-
ual cultivars based on their modes of resistance.
ENDNOTE
Mention of a trademark or proprietary product does not constitute a guarantee or
warranty of the product by the U.S. Department of Agriculture and does not imply its
approval to the exclusion of the other products that may also be suitable.
Technical assistance was provided by D. A. Boudreaux, USDA, ARS, Sugarcane
Research Unit, Houma, LA.
REFERENCES CITED
BENDA, G. T. A. 1969. Numbering sugarcane leaves and shoots. Sugarcane
Pathologists Newsletter 3: 16-18.
COBURN, G. E., AND S. D. HENSLEY. 1972. Differential survival of Diatraea sac-
Escher & Lounibos: Insect Associates of Water Lettuce 473
charalis larvae on 2 varieties of sugarcane. Proc. Int. Soc. Sugar Cane Technol.
14: 440-444.
KYLE, MELVIN L., AND S. D. HENSLEY. 1970. Sugarcane borer host resistance
studies. Proc. Louisiana Academy of Science 23: 55-67.
LONG, W. H. 1969. Insecticidal control of moth borers in sugarcane, pp. 149-161 in
Pest of sugar cane. J. R. William, J. R. Metcalfe, R. W. Mungomery and R.
Mathes [eds.] Elsevier Scientific Publishing Company, Amsterdam/Oxford/New
York.
MARTIN, F. A., AND B. J. COCHRAN. 1975. Sugar cane internode rind hardness. Sugar
y Azucar 70: 26-30.
MARTIN, F. A., C. A. RICHARD, AND S. D. HENSLEY. 1975. Host resistance to
Diatraea saccharalis (F.): Relationship of sugarcane internode hardness to larval
damage. Environ. Entomol. 4: 687-688.
POLLET, D. K., T. E. REAGAN, AND W. H. WHITE. 1986. Pest management of sugar-
cane insects. LA Coop. Ext. Pub. 10 pp.
RING, D. R., H. W. BROWNING, K. J. R. JOHNSON, J. W. SMITH, JR., AND C. E.
GATES. 1991. Age-specific susceptibility of sugarcane internodes to attack by
the Mexican Rice Borer (Lepidoptera: Pyralidae). J. Econ. Entomol. 84: 1001-
1009.
SAS INSTITUTE. 1988. SAS User's Guide: Statistics. SAS Institute, Cary, NC.
VAN DILLEWIJN, C. 1952. Botany of sugarcane. The Chronica Botanica Company,
Waltham, Mass.
WHITE, W. H., AND S. D. HENSLEY. 1987. Techniques to quantify the effect of Dia-
traea saccharalis (Lepidoptera: Pyralidae) on sugarcane quality. Field Crops
Res. 15: 341-348.
INSECT ASSOCIATES OF PISTIA STRATIOTES
(ARALES: ARACEAE) IN SOUTHEASTERN FLORIDA
R. L. ESCHER AND L. P. LOUNIBOS
University of Florida,
Florida Medical Entomology Laboratory,
200 9th St. SE, Vero Beach, FL 32962
ABSTRACT
Emergence traps and plant quadrat samples were used to survey insects associated
with monocultures of Pistia stratiotes (L.) in an abandoned aquaculture pond and a
roadside drainage ditch in St. Lucie County, Florida, USA. From 12-14 months of
biweekly or monthly sampling, 47,251 specimens representing 13 orders, 90 families,
and more than 300 species were identified. Of the 20,221 individuals from emergence
traps, 96.5% were Diptera, of which 87.1% belonged to the Chironomidae. Plant quadrats
yielded 27,030 specimens of which 55.0% were aquatic Diptera, 22.3% Odonata, 13.3%
Hemiptera, and 8.7% Coleoptera. Mosquito larvae of the genus Mansonia accounted
for 86.9% of the aquatic Diptera.
Mean numbers of individuals from both trapping techniques were highest in the fall
and lowest in the winter and spring. The more protected aquaculture pond had consis-
tently more species of aquatic insects, but the emergence traps in the drainage ditch
caught more species of aerial insects. These results are interpreted on the basis of
Florida Entomologist 76(3)
September, 1993
differences in plant cover at the two sites. The two trapping techniques are regarded
as complementary for surveying the insects of P. stratiotes, although the fauna from
quadrat samples are more likely to be associated directly with the plant.
Surveys of the insect faunas of water lettuce in Ghana, Argentina, and in Florida
show many similarities in the relative abundances of representatives of the same orders
and families, suggesting comparable community structures. Many of the abundant Dip-
tera (Ceratopogonidae, Chironomidae, Culicidae) and Odonata (Coenagrionidae, Libel-
lulidae) associated with water lettuce in southeastern Florida and the Chaco of Argentina
belong to the same genera and are probable ecological homologs.
Key Words: Aquatic insects, water lettuce, mosquitoes, Diptera, Chironomidae, Man-
sonia, community structure.
RESUME
Se utilizaron trampas de salida y muestras de cuadrados de plants para examiner
los insects asociados con monocultivos de Pistia stratiotes (L.) (lechuga de agua) en
una charca de acuacultura abandonada y en una zanja de desagie, las dos ubicadAs en
St. Lucie County, Florida, EU. Durante 12 a 14 meses de muestreo se colectaron 47,251
esp6cimenes de 13 6rdenes, 90 families y mas de 300 species. De los 20,221 individuos
colectados en las trampas de salida, 96.5% fueron Diptera, de las cuales 87.1% per-
tenecieron a los Chironomidae. Los cuadrados de las plants produjeron 27,030 es-
pecimenes de las cuales 55.0% fueron Diptera acuatica, 22.3% Odonata, 13.3% Hemiptera,
y 8.7% Coleoptera. Las larvas de los mosquitos del genero Mansonia constituyeron el
86.9% de la Diptera acuatica.
Los ntmeros promedios de individuos de los dos m6todos de capture, fueron mas
altos en el otofio y mas bajos en el invierno y la primavera. La charca de acuacultura,
el habitat mas protogido, produjo mas species de insects acuAticos, pero la zanja de
desagie produjo mas species de insects voladores, capturados en las trampas de salida.
Estos resultados se interpretan a base de diferencias en la cobertura de plants en los
dos sitios. Los dos metodos de capture se consideran complementarios para examiner
los insects de P. stratiotes, aunque es probable que la fauna de las muestras de cuadrados
este asociada mas directamente con las plants.
ExAmenes de la fauna entomol6gica de la lechuga de agua en Ghana, Argentina y
Florida son similares en la abundancia relative de representantes de las mismas 6rdenes
y families, lo cual sugiere estructuras comparable de sus comunidades. Muchos de los
Dipteros abundantes (Ceratopogonidae, Chironomidae, Culicidae) y Odonata (Coen-
agrionidae, Libellulidae) asociados con lechuga de agua en el sureste de Florida y en el
Chaco de Argentina son miembros de los mismos generos y probablemente hom6logos
ecol6gicos.
The survey reported here is part of a study on the population regulation of Mansonia
spp. mosquitoes whose larvae and pupae attach to the roots of the floating macrophyte,
Pistia stratiotes (L.) (water lettuce). The purpose of a comprehensive survey was the
identification of fauna which might affect the abundance of Mansonia dyari Belkin,
Heinemann and Page and Mansonia titillans Walker, two mosquito pests known to
inhabit P. stratiotes in south Florida (Lounibos & Escher 1985). Initial findings included
the discovery of odonate larvae and cyprinodontiform fish as predators of Mansonia
immatures at one of our study sites (Lounibos et al. 1990, 1992).
Water lettuce is regarded as a nuisance in much of Florida because its rapid growth
clogs waterways (Tarver et al. 1978). In an effort to identify herbivores that might
reduce P. stratiotes levels, Dray et al. (1988) surveyed the fauna of water lettuce habitats
throughout Florida. In surveys covering one year, these authors collected a maximum
of four occasions at any one site, limiting the chances of observing seasonal changes in
Escher & Lounibos: Insect Associates of Water Lettuce 475
numbers and species of invertebrates. By contrast, in the present study, we tracked
insect densities for more than one year at two sites where P. stratiotes populations were
simultaneously monitored (DeWald & Lounibos 1990).
Previous faunal surveys of water lettuce have considered only those invertebrates
obtainable directly from the plant (e.g. Petr 1968, Poi de Neiff & Neiff 1983, Dray et
al. 1988). This method may overlook fauna which drop off the plant during its removal
from the habitat or others, such as boring insects, which fail to emerge from internal
plant tissues. In part to make our survey more comprehensive, we added emergence
traps, successfully used for monitoring the mosquito fauna of Florida macrophytes
(Lounibos & Escher 1983, 1985, Slaff et al. 1984), to our sampling protocol for water
lettuce insects. This method greatly increased the numbers and taxa of identified insects.
On the other hand, many of the insects captured in emergence traps may only incidentally
be associated with P. stratiotes, occurring, for example, in the substrate beneath the
plants contained by the emergence pyramids.
MATERIALS AND METHODS
Two relatively pure cultures of P. stratiotes in northern St. Lucie County (2730'N,
8030'W) were selected for study. Small floating macrophytes such as Lemna minor
(duckweed) or Salvinia spp. (water fern) were minor components of the aquatic plant
biomass. The Chinese Farm (CF) site was an abandoned aquaculture pond (17 x 10 m)
whose bottom was lined with black plastic. The Highway 614W (HY) site was a section
of roadside drainage ditch (30 x 9 m) with a sandy bottom. Water depths ranged from
0.5 to 1.0 m at both sites. Seasonal changes in density and growth characteristics of
water lettuce at the two sites have been described (DeWald & Lounibos 1990) as well
as information on the temporal and spatial distribution of selected insect fauna of the
host plant (Lounibos & Escher 1985, Lounibos & DeWald 1989, Lounibos et al. 1990,
Chan & Linley 1990, 1991).
Emergent insects were collected for one week periods twice per month from June
1986 through May 1987 with two pyramidal traps which floated atop one square meter
of P. stratiotes (Slaff et al. 1984). The 24 x 24 cm capture plates, exposed with Tack
Trap only on alternate weeks, were brought to the laboratory in a case designed to
keep them separate and free of contamination. Before fresh plates were installed, traps
were cleaned of spiders and aerial predators, especially adult Odonata. At six- to eight-
week intervals, traps were changed to new locations in the pond or ditch to allow for
possible local depletion of insect fauna.
A 30 x 30 x 70 cm stainless steel sampling tool with serrated teeth was used monthly
from January 1986 through March 1987 to cut five 900 cm2 quadrats from the water
lettuce at each site. Quadrat locations were chosen from random numbers that corres-
ponded to locations on a 2 x 5 m grid outlined by PVC pipe at both sites (DeWald &
Lounibos 1990). After the sampling tool had penetrated the mat, an internal trap door
was closed to allow withdrawal of the underlying water column with the cut plants. No
quadrats were cut during February 1986 because of a die-back of P. stratiotes (DeWald
& Lounibos 1990). Each sample was returned in a 20-liter bucket to the laboratory
where plants were shaken vigorously to dislodge insects that were then sorted alive in
clean water in white enamel trays by eye under a bright light.
Specimens were preserved in 70% ethanol or point-mounted, and representatives
sent to specialists (See Acknowledgments) who made all taxonomic determinations except
for selected families such as the Culicidae which were identified by the authors. Voucher
specimens returned from specialists were used to identify the remaining collections.
Where specific determinations were not possible, the indeterminate taxa are recorded
in tables as "sp.", or, if believed to represent more than one species, "spp." Seasonal
Florida Entomologist 76(3)
abundances of total insect numbers and species are presented as means ( SE) of quadrat
or emergence trap samples for a given date. Only seasonal patterns of the most abundant
species are presented, but the data for other taxa are available upon request to the
authors.
RESULTS
Emergence Traps
A total of 20,221 specimens representing 12 orders (Fig. 1) was collected from
emergence traps at the two sites. Diptera accounted for 96.5% of all specimens identified
(Table 1), approximately two orders of magnitude more than the numbers of the next
most abundant orders, Hymenoptera and Homoptera (Fig. 1). Differences between sites
in orders of insects represented were not marked, although Ephemeroptera were recov-
ered only at HY and the few Lepidoptera and Strepsiptera were found only at CF.
Diversity at the family level was greatest among the Diptera, represented by 22
families, followed by the Coleoptera with 18-19 families (Table 2), and Hymenoptera
with 13 families (Table 3). Twenty-seven individuals of Psocoptera came from eight
families (Table 5).
Chironomidae accounted for 87.1% of all Diptera in emergence traps and, of these,
three taxa, Stempellina sp. nov., Larsia decolorata (Malloch) and Monopelopia boliekae
Beck & Beck dominated numerically at both sites (Table 1). More species of
Ceratopogonidae were recognized than for any other insect family (cf. Tables 1-5).
I CF
CHY
COL COLL DIP EPH HEM HOM HYM LEP 000 PSO STR THY
Fig. 1. Total numbers, by order, of insects captured in two emergence traps exposed
for one week at fortnightly intervals at Chinese Farm (CF) and Highway 614W (HY),
St. Lucie County, Florida from June 1986 through May 1987. Abbreviations: COL =
Coleoptera, COLL = Collembola, DIP = Diptera, EPH = Ephemeroptera, HEM =
Hemiptera, HOM = Homoptera, HYM = Hymenoptera, LEP = Lepidoptera, ODO =
Odonata, PSO = Psocoptera, STR = Strepsiptera, THY = Thysanoptera.
476
September, 1993
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486 Florida Entomologist 76(3) September, 1993
Mean numbers of insects per sampling date showed prominent seasonal variations;
the largest numbers of individuals were collected in October and November at both
sites, followed by sharp declines in December that persisted through the winter and
spring (Fig. 2). The seasonal patterns for total insect numbers paralleled the phenology
of the numerically dominant chironomids Stempellina sp. nov., L. decolorata and M.
boliekae, which each peaked in abundance during October at CF and were rare at both
sites in the winter and spring (Fig. 3). Differences between CF and HY in average
numbers of insects per trap in August and October are attributable to the greater
numbers of the common chironomids at CF during those periods (Fig. 3).
The average number of insect species per trap sample showed a different seasonal
pattern than that for numbers of individuals, and differences between the two sites
were pronounced during the winter months (Fig. 4). At both sites the mean number of
species per trap remained between 15 and 28 from June through October 1986, then
declined in November to ten in December. Subsequently, the mean number of species
increased during winter at HY but not at CF, species numbers at the latter site not
recovering until April. The hibernal differences in mean number of species at the two
sites were attributable mainly to a greater variety of Chironomidae at HY (Table 6).
Plant Quadrats
A total of 27,030 insects representing seven orders was identified from plant samples
(Fig. 5). Diptera accounted for 55.0% of all identifications, followed by Odonata (22.3%),
Hemiptera (13.3%) and Coleoptera (8.7%) (Tables 7-10). Numbers of individuals in these
commoner orders were greater at CF, the abundance of Diptera being more than an
order of magnitude higher at CF than HY (Fig. 5). Ephemeroptera and Lepidoptera
immatures were recovered at both sites, albeit more commonly at HY (Table 11).
1400
0L
< 1200 -
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0 1000 HY
z
J 800
2ih
i1J 600 -
a-I
Z 400
<
20 0
JUN JUL AUG SEP OCT NOV DEC JAN FEB MAR APR MAY
1986 MONTHS 1987
Fig. 2. Seasonal changes in mean numbers of insects per emergence trap at Chinese
Farm (CF) and Highway 614W (HY). Error bars represent 1 SE of the mean.
Escher & Lounibos: Insect Associates of Water Lettuce
1000 r
800
Stempellina sp. nov.
600
400
200
Monopelopia boliekae
J A
1986
Larsia decolorata
SO N D
MONTHS
1987
Fig. 3. Seasonal changes in mean numbers per emergence trap of the three most
abundant chironomid species: Stempellina sp. nov., Monopelopia boliekae, and Larsia
decolorata at Chinese Farm (CF) and Highway 614W (HY). Error bars represent 1
SE of the mean; upper bars omitted from high CF values to compress figure.
Numbers of families represented were low compared to those identified from
emergence traps (cf. Tables 1-5, 7-11), the highest number of families recognized being
seven from the Diptera and Hemiptera.
Larvae of Culicidae accounted for 88.2% of all Diptera and, of these, 98.4% belonged
to the genus Mansonia (Table 7). Although Mansonia spp. were the most abundant
487
o CF
* HY
Florida Entomologist 76(3)
September, 1993
40
0 CF
0 HY
CL
230-
w '
w /
20 ik r i
S 1 I
JUN JUL AUG SEP OCT NOV DEC JAN FEB MAR APR MAY
1986 MONTHS 1987
Fig. 4. Seasonal changes in mean numbers of insect species per emergence trap at
Chinese Farm (CF) and Highway 614W (HY). Error bars represent 1 SE of the mean.
dipterans at both sites, specimens of this genus were more than an order of magnitude
more abundant at CF. More species of Culicidae were recognized than for any other
family of Diptera, but equally as many species were recorded in the coleopterous families
Dytiscidae and Hydrophilidae (Table 8).
The mean number of insects per quadrat varied seasonally at CF but much less so
at HY (Fig. 6). Differences between sites were attributable to the overall greater insect
abundance at CF and the seasonal pattern of Mansonia spp., whose larvae were com-
monest in the autumn and winter (Fig. 7). The commonest coleopteran, Suphisellus
insularis (Sharp), was most abundant at HY in the winter of 1986 and at CF in the
summer of the same year (Fig. 8).
The mean number of species per quadrat sample remained between 13-17 at CF
throughout the study period but fluctuated between 4-16 at HY (Fig. 9). Numbers of
species were lowest at HY during the winter of both 1986 and 1987.
DISCUSSION
Trapping Techniques
As with any faunal survey, trapping methods bias collections in favor of certain
taxonomic groups. For example, agitation of plants from our quadrat samples probably
freed aquatic insects for capture, but would rarely have released herbivores feeding
inside water lettuce, a guild better sampled by the plant submersal method of Dray et
al. (1988). Similarly, our emergence traps favored the capture of lightweight, phototropic,
volant insects. Large aerial insects, such as odonate adults, were commonly encountered
488
Escher & Lounibos: Insect Associates of Water Lettuce 489
U 00
m
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Florida Entomologist 76(3)
September, 1993
10 CF
iMHY
10
Lr 2
10' 10
m
z
10
COL DIP EPH HEM LEP NEU ODO
Fig. 5. Total numbers, by order, of insects recovered from five quadrats of water
lettuce collected monthly at Chinese Farm (CF) and Highway 614W (HY) from February
1986 through March 1987. Abbreviations as in Fig. 1 and NEU = Neuroptera.
flying within the emergence pyramids, but rarely caught (Table 5), suggesting that
either they did not fly to the apices of traps or were too strong to be held by the adhesive
on plates. These free-flying odonates, as well as spiders and hylid frogs, consumed an
unknown portion of the emergent insect fauna, in spite of routine cleaning of traps
before and after placement of the sticky plates. This suspected high predation of flying
adults in traps precludes the use of the combined quadrat-emergence trap data to calcu-
late "emergence success" of certain groups, such as mosquitoes, whose larvae and adults
were collected by the separate methods.
Specious Richness
Diptera accounted for the majority of individuals and species from both emergence
traps and quadrats. The particularly high number of species from certain families, such
as the Ceratopogonidae, may be due in part to the taxonomic expertise available for
discriminating such groups compared to other, poorly known, families. Emergence traps
yielded a much larger number of identified taxa than quadrat samples, even though the
490
Escher & Lounibos: Insect Associates of Water Lettuce
TABLE 7. NUMBERS OF DIPTERA LARVAE COLLECTED IN QUADRAT SAMPLES OF
WATER LETTUCE AT TWO SITES IN ST. LUCIE COUNTY, FLORIDA, JANU-
ARY 1986-MARCH 1987.
CF HY
CERATOPOGONIDAE
Bezzia sp. 41 9
Dasyhelea sp. 22 9
CHAOBORIDAE
Chaoborus sp. 156 0
Corethrella sp. 5 0
CHIRONOMIDAE
Gen. spp. indet. (Chironominae) 185 87
Gen. spp. indet. (Orthocladinae) 122 44
Gen. spp. indet. (Tanypodinae) 165 55
CULICIDAE
Anopheles sp. 36 11
Anopheles crucians Wiedemann 15 0
Coquillettidia perturbans (Walker) 4 0
Culex erratucus (Dyar & Knab) 33 0
Culex nigripalpus Theobald 17 0
Culex salinarius Coquillett 7 0
Mansonia spp. 11855 1041
Uranotaenia lowii Theobald 3 6
Uranotaenia sapphirina (Osten Sacken) 8 7
Gen. sp. indet. 50 12
STRATIOMYIDAE
Hedriodiscus trivittatus (Say) 767 81
SYRPHIDAE
Gen. sp. indet. 3 3
TABANIDAE
Gen. sp. indet. 4 3
TOTAL DIPTERA: families 7; individuals 14,866.
TABLE 8. NUMBERS OF COLEOPTERA LARVAE AND ADULTS COLLECTED IN QUAD-
RAT SAMPLES OF WATER LETTUCE AT TWO SITES IN ST. LUCIE COUNTY,
FLORIDA, JANUARY 1986-MARCH 1987. QUESTION MARK DENOTES PRO-
VISIONAL IDENTIFICATION.
CF HY
CARABIDAE
Gen. spp. indet. (larvae) 33 45
DYTISCIDAE
Celina solossoni Mutchler 5 30
Copelatus caelatipennis princeps Young 1 11
Desmopachria grana complex? LeConte 1 0
Hydaticus bimarginatus (Say) 1 0
Hydroporus lynceus complex Sharp 0 5
Hydrovastus pustulatus compressus Sharp 9 36
Laccophilus proximus proximus Say 2 0
Liodessus affinis (Say) 0 1
Gen. spp. indet. (larvae) 17 8
Florida Entomologist 76(3)
September, 1993
TABLE 8. (CONTINUED).
CF HY
HALIPLIDAE
Peltodytesfloridensis Matheson 0 2
Peltodytes sexmaculatus Roberts 2 1
Gen. spp. indet. (larvae) 3 3
HELODIDAE
Gen. spp. indet. (larvae) 64 2
HYDROPHILIDAE
Enochrus blatchleyi (Fall) 1 0
Enochrus pygmaeus pygmaeus (Fabricius) 1 3
Neohydrophillus castus (Say) 1 0
Paracymus nanus? (Fall) 6 3
Paracymus sp. 2 1 0
Paracymus sp. 3 4 0
Tropisternis blatchley D'Orchymont 1 2
Tropisternis lateralis nimbatus (Say) 1 0
Gen. spp. indet. (larvae) 37 43
NOTERIDAE
Hydrocanthus oblongus Sharp 346 47
Hydrocanthus regius Young 6 75
Suphis inflatus LeConte 0 4
Suphis punticollis Crotch 0 1
Suphisellus insularis (Sharp) 430 452
Gen. spp. indet. (larvae) 579 194
TOTAL COLEOPTERA: families 6; individuals 2340.
TABLE 9. NUMBERS OF HEMIPTERA COLLECTED IN QUADRAT SAMPLES OF WATER
LETTUCE AT TWO SITES IN ST. LUCIE COUNTY, FLORIDA, JANUARY
1986-MARCH 1987. QUESTION MARK DENOTES PROVISIONAL IDENTIFICA-
TION.
CF HY
BELOSTOMATIDAE
Belostoma lutarium (Stal) 17 10
CORIXIDAE
Gen. sp. indet. 3 0
HEBRIDAE
Hebrus sp. 8 4
MESOVELIIDAE
Gen. sp. indet. 4 0
NAUCORIDAE
Pelocoris carolinensis? Torre-Bueno 85 165
NEPIDAE
Ranatra australis Hungerford 1 0
PLEIDAE
Plea sp. 3146 152
TOTAL HEMIPTERA: families 7; individuals 3,595.
Escher & Lounibos: Insect Associates of Water Lettuce 493
TABLE 10. NUMBERS OF ODONATA COLLECTED IN QUADRAT SAMPLES OF WATER
LETTUCE AT TWO SITES IN ST. LUCIE COUNTY, FLORIDA, JANUARY
1986-MARCH 1987.
CF HY
ANISOPTERA
Gen. spp. indet.
AESCHNIDAE
Coryphaeschna adnexa (Hagen)
LIBELLULIDAE
Erythemis simplicicollis (Say)
Pachydiplax longipennis (Burmeister)
Miathyria marcella (Selys)
ZYGOPTERA
Gen. spp. indet.
COENAGRIONIDAE
Ischnuraposita Hagen
Ischnura ramburii (Selys)
Ischnura sp.
Telebasis byersi Westfall
178
87
16
2522
TOTAL ODONATA: families ?; individuals 6,032.
TABLE 11. NUMBERS OF EPHEMEROPTERA, LEPIDOPTERA AND NEUROPTERA
COLLECTED IN QUADRAT SAMPLES OF WATER LETTUCE AT TWO SITES
IN ST. LUCIE COUNTY, FLORIDA, JANUARY 1986-MARCH 1987. QUES-
TION MARK DENOTES PROVISIONAL IDENTIFICATION.
CF HY
EPHEMEROPTERA
BAETIDAE
Gen. sp. indet. 5 115
TOTAL EPHEMEROPTERA: families 1; individuals 120
LEPIDOPTERA
ACROLOPHIDAE (larva)
Acrolophus sp. 0 1
PYRALIDAE (larva)
Samea multiplicalis (Guen6e) 20 39
Parapoynx? sp. 16 0
TOTAL LEPIDOPTERA: families 2; individuals 76
NEUROPTERA
SIALIDAE
Gen. sp. indet. 0 1
TOTAL NEUROPTERA: families 1; individuals 1
total numbers of individuals captured by the two methods were similar. Although this
difference in species richness between the methods is real, its magnitude is accentuated
by the large numbers in quadrat samples of immature forms that could not be identified
to species.
Florida Entomologist 76(3)
0 CF
* HY
1200
1000
800
600
J F M A M J J A S O N D J F M
1986
MONTHS
1987
Fig. 6. Seasonal changes in mean numbers of insects per quadrat sample of water
lettuce at Chinese Farm (CF) and Highway 614W (HY). Error bars represent 1 SE
of the mean.
Seasonality
Certain of the insect fauna associated with water lettuce would be expected to follow
changes in growth characteristics of the host plant. At our study sites, maximum biomass
of P. stratiotes was observed in the autumn (DeWald & Lounibos 1990). Flowering
occurred synchronously at both CF and HY in November and December. Hibernal
declines in plant density and biomass were dependent on site and winter low tempera-
tures. Spring regrowth was characterized by the asexual propagation of numerous small
plants with small leaves.
The maximum abundance of insects collected in both emergence traps and quadrats
(Figs. 2, 6) coincided with the autumnal peak biomass of P. stratiotes (DeWald & Lounibos
1990). The emergence maxima were attributable to Chironomidae (Fig. 3), of unknown
relationships to water lettuce, and the quadrat maxima were due primarily to Mansonia
larvae (Fig. 7), which occupy the prolific root systems of P. stratiotes. The higher
numbers of Mansonia immatures at CF were probably related to the more luxuriant
P. stratiotes growth at that site (DeWald & Lounibos 1990).
By contrast, the seasonal changes in numbers of species per emergence trap (Fig.
4) are not similarly related to changes in water lettuce cover. In fact at HY, high
numbers of species in January and February were associated with sparse cover by P.
stratiotes during that period (DeWald & Lounibos 1990). Because the majority of these
i
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e---~--~-~Y{
F \\ 2'''-c
200
September, 1993
f
Escher & Lounibos: Insect Associates of Water Lettuce
495
0 CF
* HY
Mansonia sp.
JF M A M J J A S O N D J F M
MONTHS
1987
Fig. 7. Seasonal changes in mean numbers of larvae of Mansonia spp. mosquitoes
per quadrat sample of water lettuce at Chinese Farm (CF) and Highway 614W (HY).
Error bars represent 1 SE of the mean.
O CF
50 r HY
Suphisellus
insularis
t--
d \
JP
J F M A M J
1986
J A S O N D J F M
MONTHS
1987
Fig. 8. Seasonal changes in mean numbers of Suphisellus insularis beetles per
quadrat sample of water lettuce at Chinese Farm (CF) and Highway 614W (HY). Error
bars represent 1 SE of the mean.
1000
800
600
400
200
0
1986
40
30
20
I I .
Florida Entomologist 76(3)
September, 1993
0 CF
* HY
15 -
I l i l l l l l i l l
AM J J ASO
MONTHS
N D J FM
1987
Fig. 9. Seasonal changes in mean numbers of insect species per quadrat sample of
water lettuce at Chinese Farm (CF) and Highway 614W (HY). Error bars represent -
1 SE of the mean.
species were chironomids (Table 6), we suggest that the hibernal opening of the water
lettuce mat at HY allowed recruitment of drifting or emerging insects that were not
ordinarily associated with P. stratiotes.
Other Water Lettuce Surveys
In their survey of 61 Florida water bodies harboring water lettuce, Dray et al. (1988)
tallied approximately 47,000 invertebrates, a total coincidentally similar to ours from
two sites. However, over two-thirds of their specimens were amphipods, and only 109
taxa were recognized, with many immature forms identifiable only to the family level.
Nevertheless, many similarities are apparent from comparisons of the geographically
broad survey of Dray et al. (1988) and our localized, intensive study in St. Lucie County.
In both, Diptera accounted for the largest number of individual insects, and Chironomidae
and Ceratopogonidae were well represented. Odonata were common in both surveys,
but Dray et al. (1988) reported relatively few Anisoptera, and their commonest dam-
selflies, Enallagama sp. and Nehalennia sp., were not recognized at our study sites
(Tables 5 & 10, Lounibos et al. 1990). A large number (18-19) of beetle families was
noted by both studies; most species were rare, but Noteridae were numerically dominant
in both surveys. Leafhoppers, aphids and pyralid larvae occurred in both surveys, but
were apparently commoner in the pan-Florida study. Caddisfly larvae, found abundantly
on water lettuce in north Florida (Dray et al. 1988), did not occur on P. stratiotes at
our sites.
On Volta Lake in Ghana, Petr (1968) tracked changes in abundance and density of
P. stratiotes and its associated invertebrates. As in Florida, both dipterous larvae and
20 r
J FM
1986
I
Escher & Lounibos: Insect Associates of Water Lettuce 497
odonate nymphs accounted for the greatest numbers and biomass. Culicid larvae were
more common than ceratopogonids or chironomids, the latter preferring Ceratophyllum
at the same site. Anisoptera were more abundant than Zygoptera at Volta Lake. Else-
where in Africa, Balfour Browne (quoted in Rzoska 1974) recorded the remarkable
number of 44 species of Dytiscidae, Hydraenidae, and Hydrophilidae from 62 plants of
P. stratiotes collected in the White Nile.
Notable similarities exist between the results of our survey and the aquatic fauna
associated with water lettuce in Argentina. At three sites in the Chaco, Diptera were
dominated by the ceratopogonids Bezzia sp. and Dasyhelea sp., the chironomids
Monopelopia sp., Larsia sp., and Tanytarsus sp., and the culicid Mansonia sp. (Poi de
Neiff & Neiff 1983). The commonest odonates on Argentinian water lettuce were the
coenagrionid Telebasis willinkii and the libellulid Miathyria marcella. Apparently many
of these insects of the same genus and/or species occupy homologous niches on P.
stratiotes in Florida and the Argentinian Chaco. The hemipteran, lepidopteran, and
coleopteran water lettuce faunas of the two regions also exhibited many parallels.
Life Histories
Very little is known about the specificity of the fauna associated with water lettuce,
a topic impacting both the origins of this cosmotropical macrophyte as well as its potential
for biological control (Dray et al. 1988). In the following consideration of selected families,
we address a few instances of possible insect-host plant specializations.
Culicidae. Of all identified fauna, mosquitoes of the genus Mansonia accounted for
the largest number of individuals (Table 7). Although these immatures were not identified
to species, more than 80% of adults of this genus were M. dyari (Table 1), confirming
earlier surveys that reported the dominance of this species on water lettuce elsewhere
in St. Lucie County (Lounibos & Escher 1985). Based on analyses of the oviposition
behavior of this species, as well as its rarity on other macrophytes in south Florida
(Slaff & Haefner 1985), Lounibos & DeWald (1989) suggested that M. dyari may be a
specialist for P. stratiotes. Other South American Mansonia closely related to M. dyari
show similar oviposition specializations for water lettuce (L. P. L., unpublished data),
and the absence of comparable, mosquito-host plant specificity in the Old World tropics
is evidence for the origin of P. stratiotes in tropical America.
Ceratopogonidae. Our investigations of the insect fauna associated with water lettuce
at CF led to the description of three new species of Ceratopogonidae (Chan & Linley
1988, 1989a, Wirth & Linley 1990) and observations on their biology (Chan & Linley
1989b, 1990, 1991). Although all three species were caught in our emergence traps, only
Dasyhelea chani Wirth & Linley was abundant (Table 1). The other two, Atrichopogon
wirthi Chan & Linley and Forcipomyia dolichopodida Chan & Linley are associated on
water lettuce with cavities used by pyralid and dolichopodid larvae (Chan & Linley
1989a, b) whose habits may indicate some host specificity. Bezzia glabra (Coquillett),
the next most common ceratopogonid in emergence traps, is predatory and suspected
of consuming the detritovore D. chani (Chan & Linley 1991). Many of the other
ceratopogonids, such as Culicoides, listed in Table 1 probably passed their larval stages
in the substrate beneath the floating plants, and just happened to emerge in our traps
(W. Wirth, 1304 NW 94th St., Gainesville, FL, personal communication).
Chironomidae. Although some Chironomidae are known as miners, surface leaf feed-
ers, or net spinners on aquatic macrophytes (e.g. Berg 1950, Van der Velde & Hiddink
1987), there is little described about the life histories of the common species in our
emergence traps. Perhaps surprisingly, the most abundant taxon, accounting for over
8,000 identifications, is an undescribed species belonging to the genus Stempellina,
members of which are commonly associated with spring seeps or runs (J. Sublette,
Florida Entomologist 76(3)
University of Southern Colorado, Pueblo, CO., personal communication). However, it
should not be discounted that Stempellina sp. nov., M. boliekae and L. decolorata may
favor associations with floating aquatic macrophytes. Poi de Neiff & Neiff (1983) reported
collecting Monopelopia sp. and Larsia sp. larvae directly from P. stratiotes plants in
Argentina, and our emergence maxima for the three abundant species occurred in the
autumn when water lettuce was densest (Fig. 3, DeWald & Lounibos 1990).
Cecidomyiidae. Larvae of this family feed in decaying organic matter (e.g. Anarete
sp.) or, alternatively, may be herbivores or predators (R. Gagne, Systematic Entomology
Laboratory, USDA, Beltsville, MD., personal communication). The absence of represen-
tatives of this family in quadrat samples (Table 7) is evidence that larvae of this group
are not aquatic.
Coleoptera. Adults and larvae of the family Noteridae accounted for 91.2% of all
beetles in quadrat samples (Table 8). The most abundant of these, S. insularis (formerly
S. floridanus), has been known for its association with water hyacinth in southern
Florida (Young 1954).
Odonata. Elsewhere we have described food items, seasonality of occurrence and
growth measurements of the commonest odonates associated with water lettuce at CF
(Lounibos et al. 1990). Of these, Telebasis byersi Westfall, Miathyria marcella (Selys)
and Erythemis simplicicollis (Say) are commonly associated with aquatic plants (Westfall
1957, Paulson 1966, Dunkle 1989) but have no known specificity for P. stratiotes.
Hymenoptera. With the exception of the Formicidae, all identified members of this
order (Table 3) are parasitic on various insects that occur on water lettuce, including
lepidopteran eggs (Telenomus, Trichogramma), lepidopteran larvae (Agathis, Glyp-
tapanteles), stratiomyiid larvae (Chalcis), Diptera (Aphanogmus, Platygaster), aphids
(Lysiphlebus), Cicadellidae (Oligosita), Homoptera (Anagrus, Alaptus, Erythemelus),
and Coleoptera (Anaphes) (personal communications ofE. Grissell, P. Marsh, M. Schauff
and D. Vincent, Systematic Entomology Laboratory, USDA, Beltsville, MD).
Lepidoptera. The semi-aquatic larval stages of the pyralid moths Samea multiplicalis
and Synclita obliteralis are known to damage water lettuce plants, but neither is host-
specific (DeLoach et al. 1979, Habeck et al. 1986).
ACKNOWLEDGMENTS
For help with collections we are grateful to L. DeWald, L. Fox, V. Larson and N.
Nishimura. Data management was facilitated by N. Nishimura. Earlier drafts of the
manuscript were improved by the comments of F. A. Dray, Jr., J. R. Linley, J. R.
Rey, J. E. Sublette, and W. W. Wirth.
The study would not have been possible without the identifications provided by the
following specialists, to whom we are indebted: J. K. Barnes (Phoridae), G. W. Byers
(Tipulidae), H. A. Denmark (Thysanoptera, Aphididae), J. H. Epler (Chironomidae),
D. C. Ferguson (Pyralidae), J. H. Frank (Staphylinidae), R. J. Gagne (Scatopsidae,
Cecidomyiidae, Sciaridae), E. E. Grissell (Chalcididae), W. L. Grogan
(Ceratopogonidae), D. H. Habeck (Pyralidae), A. B. Hamon (Coccoidea, Alyrodidae),
J. B. Heppner (larval Lepidoptera and Coleoptera; larval Stratiomyidae), M. Lacey-
Theisen (Diptera), A. S. Menke (Dryinidae), P. M. Marsh (Platygastridae, Scelionidae,
Brachonidae, Ceraphronidae), S. A. Marshall (Sphaeroceridae), W. N. Mathis
(Milichiidae, Ephydridae), F. W. Mead (Hemiptera, Homoptera), E. L. Mockford
(Psocoptera), M. L. Pescador (Ephemeroptera), R. V. Peterson (Psychodidae), C. W.
Sabrosky (Chloropidae, Stenomicridae), M. E. Schauff (Mymaridae, Encyrtidae,
Aphelinidae, Eulophidae), R. J. Snider (Collembola), G. J. Steck (Dolichopodidae,
Drosophilidae), L. A. Stange (Hymenoptera), J. E. Sublette (Chironomidae), M. C.
Thomas (Ptilidae, Scolytidae, Lampyridae, Mordellidae, Phalacridae, Lathridiidae,
498
September, 1993
Escher & Lounibos: Insect Associates of Water Lettuce 499
Helodidae, Coceinelidae, Chrysomelidae, Carabidae, Corylophidae, Curculionidae), C.
R. Thompson (Formicidae), F. C. Thompson (Syrphidae, Dolichopodidae), D. L. Vincent
(Trichogrammatidae), M. J. Westfall (Odonata), W. W. Wirth (Chaoboridae,
Ceratopogonidae), N. E. Woodley (Stratiomyidae, Tachinidae), R. E. Woodruff (Hydro-
philidae), and F. N. Young (Hydraenidae, Dytiscidae, Limnichidae, Hydrophilidae,
Noteridae, Haliplidae).
Research was supported by U.S. Army contract DAMD 17-85-C-5182. This is Univer-
sity of Florida IFAS Journal Series No. R-02925.
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Monogr. 20: 85-99.
CHAN, K. L., AND J. R. LINLEY. 1988. Description ofAtrichopogon wirthi new species
(Diptera: Ceratopogonidae) from leaves of the water lettuce (Pistia stratiotes) in
Florida. Florida Entomol. 71: 186-201.
CHAN, K. L., AND J. R. LINLEY. 1989a. A new Florida species of Forcipomyia (Eup-
rojoannisia) (Diptera: Ceratopogonidae) from leaves of the water lettuce, Pistia
stratiotes. Florida Entomol. 72: 252-262.
CHAN, K. L., AND J. R. LINLEY. 1989b. Laboratory studies on the immature stages
ofAtrichopogon wirthi (Diptera: Ceratopogonidae). Florida Entomol. 72: 85-88.
CHAN, K. L., AND J. R. LINLEY. 1990. Distribution of immature Atrichopogon wirthi
on leaves of the water lettuce, Pistia stratiotes. Environ. Entomol. 19: 286-292.
CHAN, K. L., AND J. R. LINLEY. 1991. Distribution of immature Dasyhelea chani
(Diptera: Ceratopogonidae) on leaves of Pistia stratiotes. Ann. Entomol. Soc.
Amer. 84: 61-66.
DELOACH, C. J., D. J. DELOACH, AND H. A. CORDO. 1979. Observations on the
biology of Samea multiplicalis on waterlettuce in Argentina. J. Aquatic Plant
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DEWALD, L. B., AND L. P. LOUNIBOS. 1990. Seasonal growth of Pistia stratiotes L.
in south Florida. Aquatic Botany 36: 263-275.
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CENTER. 1988. A study of the fauna associated with Pistia stratiotes L. (water
lettuce) in Florida. Tech. Rpt. A-88-6, U.S. Army Eng. Waterways Exp. Sta.,
Vicksburg, Miss.
DUNKLE, S. W. 1989. The Dragonflies of the Florida Peninsula, Bermuda, and the
Bahamas. Scientific Publishers, Gainesville, Florida.
HABECK, D. H., K. HAAG, AND G. BUCKINGHAM. 1986. Native insect enemies of
aquatic macrophytes-moths. Aquatics 8: 17-19, 22.
LOUNIBOS, L. P., AND L. B. DEWALD. 1989. Oviposition site selection by Mansonia
mosquitoes on water lettuce. Ecol. Entomol. 14: 413-422.
LOUNIBOS, L. P., AND R. L. ESCHER. 1983. Seasonality and sampling of Coquillettidia
perturbans in south Florida. Environ. Entomol. 12: 1087-1093.
LOUNIBOS, L. P., AND R. L. ESCHER. 1985. Mosquitoes associated with water lettuce
(Pistia stratiotes) in southeastern Florida. Florida Entomol. 68: 169-178.
LOUNIBOS, L. P., R. L. ESCHER, L. B. DEWALD, N. NISHIMURA, AND V. L. LAR-
SON. 1990. Odonata associated with water lettuce (Pistia stratiotes L.) in south
Florida. Odonatologica 19: 359-366.
LOUNIBOS, L. P., N. NISHIMURA, AND L. B. DEWALD. 1992. Predation of Mansonia
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mesofauna asociada a Pistia stratiotes L. (Araceae) en algunos ambientes acuaticas
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41: 95-102.
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the central Florida, USA phosphate region. J. Med. Entomol. 22: 624-629.
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and Wetland Plants of Florida. Florida Dept. of Nat. Res., Tallahassee, Florida,
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WESTFALL, M. J. 1957. A new species of Telebasis from Florida (Odonata-Zygoptera).
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WIRTH, W. W., AND J. R. LINLEY. 1990. Description ofDasyhelea chani new species
(Diptera: Ceratopogonidae) from leaves of the water lettuce (Pistia stratiotes) in
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YOUNG, F. N. 1954. The Water Beetles of Florida. Univ. of Florida Press, Gainesville.
CRYPTOTERMES CHASEI, A NEW DRYWOOD
TERMITE (ISOPTERA: KALOTERMITIDAE)
FROM THE DOMINICAN REPUBLIC
RUDOLF H. SCHEFFRAHN
Ft. Lauderdale Research and Education Center
University of Florida, Institute of Food & Agric. Sciences
3205 College Avenue, Ft. Lauderdale, FL 33314
ABSTRACT
The soldier and imago of Cryptotermes chasei n. sp. from La Altagracia Province,
Dominican Republic, are described for the first time. This is the ninth species of Cryp-
totermes reported from the West Indies.
Key Words: Species description, soldier, imago, Hispaniola.
RESUME
Se described por vez primera, el soldado y el imago de Cryptotermes chasei sp. n.
de la Provincia de Altagracia, Repfiblica Dominicana. Esta es la novena especie de
Cryptotermes registrada de las Indias Occidentales.
Scheffrahn: New Dominican Cryptotermes
The cosmopolitan genus Cryptotermes Banks is the third largest of 22 living genera
in the family Kalotermitidae (Krishna 1961, Tsai & Chen 1963). Only Neotermes
Holmgren and Glyptotermes Froggatt have more species. Since Snyder's (1949) early
species assignments and Krishna's generic revision (1961), the contemporary taxonomic
understanding of Cryptotermes has been advanced by Gay & Watson (1982) for Australian
species and by Bacchus (1987) for the remaining species worldwide. The latter two
studies resulted in the description of 13 new Cryptotermes species, raising the living
total to 47 species. Two fossil species of Cryptotermes, described from winged images,
are presently known (Pierce 1958, Krishna & Bacchus 1992).
A new species of Cryptotermes was collected during an ongoing survey of termites
of the Dominican Republic. The soldier and imago castes of Cryptotermes chasei n. sp.
are described herein.
MATERIALS AND METHODS
Two samples of C. chasei n. sp. from separate colonies were collected on 11-VI-1992
at Bavaro (18041'N, 6826'W; 2 soldiers, 14 winged images including 2 general images,
pseudergates, and brachypterous nymphs) and Juanillo (18"29'N, 6825'W; 7 soldiers,
1 winged general imago, 1 queen, pseudergates, and nymphs), La Altagracia Province,
Dominican Republic. Both locations were within 1 km of the coast near the extreme
eastern tip of the island of Hispaniola. Colonies, exposed with a hatchet, were dwelling
inside standing native wood. The termites were collected by aspirator and field-preserved
in 85% ethanol.
Line drawings of specimens were prepared at 20-100X magnification with the aid of
a camera lucida attached to a light microscope. Measurements, adapted partly from
Roonwal (1970), were made with an ocular micrometer. Distances between genal and
frontal horns and width of frontal flange were measured because they were especially
useful in describing soldiers of C. chasei. Terms used to describe the soldier head
morphology follow those defined by Gay & Watson (1982). Scanning electron micrographs
were made with a Hitachi S-4000 field emission microscope (10kV) of a single C. chasei
soldier dehydrated in absolute ethanol and 1,1,1,3,3,3-hexamethyldisilazane (Nation
1983) prior to sputter coating with gold.
The holotype soldier from Juanillo and morphotype winged imago from the Bavaro
site are deposited in the collection of the National Museum of Natural History,
Washington, D.C. Paratype soldiers and alates are deposited in the Florida State Col-
lection of Arthropods, Fla. Dept. Agric. Cons. Serv., Division of Plant Industries,
Gainesville, Florida, and in the author's collection at the University of Florida Research
and Education Center in Ft. Lauderdale, Florida.
Cryptotermes chasei, new species
SOLDIER (Figs. 1-6; Table 1). Frontal flange, frons (see below), and horns ferrugin-
ous with black borders. Color grading to light ferruginous near eye spot and mostly
yellowish in posterior half. Mandibles ferruginous at base, blackening distally. Head
slightly longer than wide, posterior and lateral margins quadrate in dorsal aspect with
lateral margins narrowing anteriorly near posterior margin of eye spots. Head with few
scattered long hairs. Elliptical eye spots conspicuously hyaline and bulging above lateral
plane of head. Frontal flange weakly elevated above but not overhanging frons; divided
medially, where widest, by shallow depression; flange more elevated and narrowing
toward apex above antennal fossae. Frontal flange and frons narrower than head width
below; maximum width of frontal flange less than distance between genal horns and
genae anterior to eyes allowing for unobstructed dorsal view of lateral margins of both
Florida Entomologist 76(3)
September, 1993
genae from horns to eyes. Distance between frontal horns less than distance between
genal horns. Frontal horns blunt, most prominent when viewed laterally; arising from
lateral base of frontal flange. Genal horns more pointed than frontal horns, especially
when viewed lateroventrally. Frons and frontal flange sloping about 45; dominant pat-
tern of rugosity on frons consists of weak longitudinal sculpturing. Upper and lower
planes of frons divided into thirds by pigmentation as follows: upper plane with a median
darkened triangulate patch and lighter ovoid or horseshoe-shaped patches to each side,
lower plane abstractly mirroring these markings. Anteclypeus, if visible, bilobed along
labral suture; labrum broad, trilobed. Mandibles long, broad, smooth, and projecting
almost squarely from head; roundly humped laterally in basal 1/3-1/4. Dentition poorly
developed, teeth very short and rising gradually from mandibles. Postmentum with
lateral margins nearly parallel in middle, narrowing toward posterior, posterior 2/3
concolorous with head, anterior 1/3 unpigmented. Pronotum ferruginous brown, anterior
edge darker. Anterior margin of pronotum entire or only microscopically serrate, incision
shallow and square; all margins with scattered long and short hairs. Antennae 11-14
segmented; third, second, and first, in order, progressively longest; 4th and 5th shortest.
Comparisons. Cryptotermes chasei soldiers differ from other Cryptotermes spp.,
except perhaps C. secundus (Hill) from Australia, in that the distance between the
lateral margins of the frontal flange is clearly less than that between the lateral margins
of the genal horns. Soldiers of C. chasei most closely resemble those of C. dudleyi
Banks, a species described from Panama (Banks 1918) and globally distributed as a pest
of structural wood in the tropics (Bacchus 1987) including Panama (Snyder 1922). In C.
502
Scheffrahn: New Dominican Cryptotermes
Figs. 1-2. Scanning electron micrographs of Cryptotermes chase n. sp. soldier. Dor-
sal (1) and oblique (2) view of head.
dudleyi, the frontal flange is more pronounced, sloping nearly vertically, and has a
sharply incised median furrow not seen in C. chase. The frontal flange of C. dudleyi
is about equal or greater in width than the distance between the genae at any position
anterior to the eyespots, while in C. chase, the width of the frontal flange is always
less than the distance between the anterior genae or lateral margins of the genal horns.
The frontal horns of C. chase project from and are continuous with the lateral bases
of the frontal flange, whereas, the frontal horns of C. dudleyi project inside and independ-
ent of the flange. In C. chase, the mandibles are longer, wider, and have much smaller
and more obtusely angled teeth, and eyespots are larger and more distinctly hyaline
than in C. dudleyi soldiers. Finally, the pronota of C. dudleyi, especially in specimens
from Panama, are more deeply incised and serrate than C. chase.
IMAGO (Figs. 7-10; Table 2). Head and antennae yellowish; pronotum yellowish,
darkening to light yellow-brown near margins; mesonotum and metanotum pale yel-
lowish, first 2 abdominal tergites concolorous with metanotum, middle 5-6 tergites
medium brown, remaining apical tergites yellowish with brown posterior margins. Ven-
tral surface of body yellowish-white except for brown lateral margins of sternites; tibiae
and tarsi yellowish. Head with sparse short hairs; cranial sutures indistinct. Eyes sub-
triangular, large; elliptical ocellus with indistinct hyaline border touching eye. Forewing
scale medium brown except for a hyaline stripe posterior to origin of cubitus. When
503
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