|
(ISSN 0015-4040)
FLORIDA ENTOMOLOGIST
(An International Journal for the Americas)
Volume 67, No. 2 June, 1984
TABLE OF CONTENTS
67th Annual Meeting of the Florida Entomological Society .----.- i
68th Annual Meeting-First Announcement ............ ---....... --- ii
BENSCHOTER, C. A., AND P. C. WITHERELL-Lethal Effects of Suboptimal
Temperatures on Immature Stages of Anastrepha suspense ....- 189
ALI, A., D. M. SAUERMAN, AND J. K. NAYAR-Pathogenicity of Indus-
trial Formulations of Bacillus thuringiensis serovar. israelensis
to Larvae of Some Culicine Mosquitoes in the Laboratory ............ 193
BOCZEK, J., AND R. DAVIS-New Species of Eriophyid Mites (Acari:
Eriophyidae) -.......--....-- ... .....-.....----.. ---------..--.........--... ...-....- --. 198
JONES, V. P., AND J. G. MORSE-A Synthesis of Temperature Dependent
Developmental Studies with the Citrus Red Mite, Panonychus
citri (McGregor) (Acari: Tetranychidae) --------.---__........... .---. 213
GAGNE, R. J., AND G. M. BEAVERS-Contarinia spp. (Diptera: Ceci-
domyiidae) from Shoots of Slash Pine (Pinus elliotti Engelm.)
with the Description of a New Species Injurious to Needles .... 221
LLOYD, J. E.-Evolution of a Firefly Flash Code .-....----..._.....-------------..... 228
LANDOLT, P. J.-Reproductive Maturation and Premating Period of the
Papaya Fruit Fly, Toxotrypana curvicauda (Diptera: Teph-
ritidae) .--.................----------------------........................ ........................ 240
LIN, J., AND J. D. HARPER-Isolation and Culture of Entomophthora
gammae, a Fungal Parasite of Noctuid Larvae .........................--- 245
ZOEBISCH, T. G., D. G. SCHUSTER, AND J. P. GILREATH-Liriomyza tri-
folii: Oviposition and Development in Foliage of Tomato and
Common W eed Hosts ........--- ............-....---..... .............. ............... .. 250
WITHERELL, P. C.-Methyl Bromide Fumigation as a Quarantine Treat-
ment for Latania Scale, Hemiberlesia lataniae (Homoptera:
Diaspiididae) --......-- .......- ----.. .....----. ....-........... -.................... 254
BROWER, J. H., AND L. D. CLINE--Response of Trichogramma pretiosum
and T. evanescens to Whitelight, Blacklight or No-Light Suction
Traps -----..............................................................-----------------------------........................ 262
ELVIN, M. K., AND P. E. SLODERBECK-A Key to Nymphs of Selected
Species of Nabidae (Hemiptera) in the Southeastern USA .......... 269
Continued on Back Cover
Published by The Florida Entomological Society
FLORIDA ENTOMOLOGICAL SOCIETY
OFFICERS FOR 1983-84
President .---------. ------...-.. -...... --... ................... ...-..........- .. C. W McCoy
President-Elect ----.................--..--..-..----- ----...-- .....--. M. L. Wright, Jr.
Vice-President .........----- --.----....----...... .--.. .....--...... J. A. Reinert
Secretary ...... -....-- .................-.......... .... ...... D. F. Williams
Treasurer --..--........... .... ...........---...............-........--. A. C. Knapp
J. R. Cassani
J. L. Knapp
D. C. Herzog
Other Members of the Executive Committee .... K. Lee
C. A. Morris
W. L. Peters
C. A. Musgrave Sutherland
PUBLICATIONS COMMITTEE
Editor ..............--------...-.-- .............. C. A. Musgrave Sutherland
Associate Editors .................. ..------- ------ .....-------. D. C. Herzog
O. Sosa, Jr.
M. D. Hubbard
J. R. McLaughlin
J. B. Heppner
H. V. Weems, Jr.
Business Manager -----........................ ---.. .......................... A. C. Knapp
FLORIDA ENTOMOLOGIST is issued quarterly-March, June, September,
and December. Subscription price to non-members is $20.00 per year in
advance, $5.00 per copy. Membership in the Florida Entomological Society,
including subscription to Florida Entomologist, is $15 per year for regular
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and subscriptions should be addressed to the Business Manager, P. O. Box
7326, Winter Haven, FL 33883-7326. Florida Entomologist is entered as
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Authors should consult "Instructions to Authors" on the inside cover of
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figures and tables, and 8 copies of the entire paper. Include an abstract and
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will be obtained where possible.
Manuscripts and other editorial matter should be sent to the Editor,
C. A. Musgrave Sutherland, 4849 Del Rey Blvd., Las Cruces, NM 88001.
This issue mailed June 30, 1984
THE 67th ANNUAL MEETING OF THE
FLORIDA ENTOMOLOGICAL SOCIETY
The Florida Entomological Society will hold its 67th Annual meeting on
24-27 July 1984 at the Holiday Inn, 6515 International Drive, Orlando FL
32809; telephone-1-(305)-351-3500. Room rates will be $58.00, for single,
double, triple, or quadruple.
Questions concerning the local arrangements should be directed to:
FREDERICK L. PETITT, Chairman
Local Arrangements Committee
Florida Entomological Society
Walt Disney World-Epcot Center-The Land
P.O. Box 40
Lake Buena Vista, Florida 32830 USA
Phone: 1-(305)-827-7256
To present a paper, the tear out sheet must be postmarked and sent no
later than 15 MAY 1984, to:
JAMES A. REINERT, Program Chairman
Ft. Lauderdale Research and Education Center
University of Florida
3205 S.W. College Avenue
Ft. Lauderdale, Florida 33314 USA
Eight minutes will be allotted for presentation of oral papers, with 2
minutes for discussion. In addition, there will be a separate session for
members who may elect to present a Project (or Poster) Exhibit.
The 3 oral student papers judged to be the best on content and delivery
will be awarded monetary prizes during the meeting. Student authors must
be Florida Entomological Society Members and must be registered for the
meeting. Awards will be $125.00, 75.00 and 50.00.
The 3 student display presentations judged to be the best on content and
preparation will also be awarded monetary prizes during the meeting.
Student authors must be Florida Entomological Society Members and must
be registered for the meeting. Awards will be $125.00, 75.00 and 50.00.
Registration Schedule' for Annual Meeting:
Preregistration Registration On Site
Full & Sustaining Members $35.00 $40.00
Student not in Student Contest 18.00 20.00
Student in Student Contest 13.00 15.00
Each Extra Banquet Ticket 10.00 10.00
'Each fee includes one banquet ticket.
68th ANNUAL MEETING-FLORIDA ENTOMOLOGICAL SOCIETY
First Announcement
In 1985, the 68th annual meeting of the Florida Entomological Society
will be held at the Ocho Rios Sheraton Hotel, Ocho Rios, Jamaica, W.I.
Meeting dates are from Monday, 5 August to Thursday 8 August 1985. The
Ocho Rios Sheraton is located on Mallards Beach on the north coast of
Jamaica and is a complete resort facility offering excellent meeting facilities
and day and night entertainment.
Emmer Travel, Inc. of Gainesville, FL has been designated the official
travel agency of these meetings. They will make all of your travel arrange-
ments including airline tickets and hotel reservations. The land/hotel pack-
age will be $145.00 per person (double occupancy) or $260.00 per person
(single occupancy). This price includes:
*4 days/3 nights hotel accommodations
*all Jamaican room taxes
*all service charges on the rooms
*porter service at the hotel
*welcome rum swizzle on arrival at the hotel
*transportation from/to the Montego Bay airport
Children under 17 stay FREE at the hotel when they stay in the room
with 2 adults. Those under 17 must pay $22.00 for round-trip transportation
from/to Montego Bay. Persons wishing to stay after the meetings will pay
$70.00 per room per night, including taxes and service charges. Children
under 17 staying with adults after the meetings are not charged.
A $50.00 per person deposit will secure your reservations. The balance
will be due by 15 June'1985. All costs are fully refundable if the reservation
is cancelled prior to 21 June 1985. Thereafter, a cancellation charge of $75.00
per person on the land/hotel package will be levied.
Information on airfare rates, airline schedules and meeting registration
fees will be forthcoming soon.
To make reservations, send check for $50.00 to Emmer Travel, Inc., 2801
SW Archer Road, Gainesville, FL 32608. Include your name, address, and
phone number. For further information, call Emmer Travel, Inc. toll free at
(800)-342-2223 (Florida residents) or (800)-874-8487 (nationwide) or
(904)-377-1222 (in Gainesville).
FIRST CALL FOR PAPERS
Submitted papers for the 68th annual meetings of the FES should be 8
minutes long. Time allowed will be 10 minutes: 8 minutes for presentation
and 2 minutes for discussion. Use the following tear sheet to submit a paper
title.
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SLIDE POLICY FOR ANNUAL MEETINGS
The following slide policy will govern slide presentations at the Annual
Meetings. Only Kodak Carousel projectors for 2 x 2 slides will be available.
However motion picture projectors will be available by special request to
the Local Arrangements Chairman prior to the date of the meeting.
Authors should keep slides simple, concise, and uncluttered with no more
than 7 lines of type on a rectange 2 units high by 3 units wide. All printed
information should be readable to an audience of 300 persons.
A previewing room will be designated for author's use. A projectionist
will be available in the previewing room at least one hour before each session.
Authors are expected to give the projectionist their slides in the previewing
room prior to each session. Slides will be returned to the authors after each
session in the meeting room.
Authors are expected to organize their slides in proper order in their
personal standard Kodak Carousel slide tray (no substitution, please). Only
a few slide trays will be available in the previewing room from the projec-
tionist for hardship cases. Slides in the tray should be in correct order start-
ing with slot #1 of the tray and positioned correctly (position of slides to go
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on the tape: 1. author's name, 2. session date, and 3. presentation time.
Benschoter & Witherell: Suboptimal Temperatures
LETHAL EFFECTS OF SUBOPTIMAL TEMPERATURES
ON IMMATURE STAGES OF ANASTREPHA SUSPENSE
C. A. BENSCHOTER AND P. C. WTTHERELL1
Subtropical Horticulture Research Unit
Agricultural Research Service, S & E, USDA
Miami, FL 33158 USA
ABSTRACT
Immature stages of Anastrepha suspense (Loew) (Diptera: Tephritidae)
were exposed for variable periods of time to temperatures ranging from 1.7
to 15.60C. Lethal effects varied inversely with temperature. Regression
equations were calculated and LT50 and LT5, values (lethal time for 50%
and 95% mortality) are presented. Data points for all stages showed high
linearity when percentage mortalities were converted to probits and plotted
against log-days (exposure time), providing correlation coefficients within
the range of 0.934-0.999. Susceptibility to cold decreased with the age of the
eggs at the temperatures and exposure periods tested. Less than 50% of
mature larvae were killed from exposure to 15.60C for 28 days, but 7.20C for
7 days produced 99.8% mortality. Exposure to 15.60C had essentially no
lethal effect on pupae and 12.80C for 28 days killed only 45.4% of them.
Two-day-old pupae were more sensitive than older groups exposed to 4.40C.
By comparison, mortality of 2-day-old pupae exposed to this temperature for
3 days was 99.8% while mortality of 10-day-old pupae exposed for 15 days
was 99.9%. The order of susceptibility (LTg,) of immature stages of A.
suspense exposed to 7.20C was larvae > eggs > pupae.
RESUME
Estadios inmaduros de Anastrepha suspense (Loew) (Diptera: Tephri-
tidae) fueron sometidos durante diferente peri6dos de tiempo a tempera-
turas de 1.7 a 15.60C. El efecto letal vari6 inversamente a la temperature.
Se calcul6 la ecuaci6n de regresi6n y los valores de TL5s y TL95 (tiempo
letal para mortalidades de 50 y 95%). Todos los estadios mostraron alta
linealidad cuando los percentages de mortalidad se pasaron a probits y se
representaron en grAfica coeficientes de correlaci6n de rango de 0.934 a 0.999.
La susceptibilidad al frio disminuy6 con la edad de los huevos para los
periods de tiempo y exposici6n probados. Menos de un 50% de larvas
maduras murieron al exponerlas a 15.6 C durante 28 dias, pero una ex-
posici6n a 7.20C durante 7 dias produjo una mortalidad de 99.8%. La ex-
posici6n de las pupas a 15.60C no tuvo efecto letal y a 12.8C durante 28
dias solo mat6 el 45.4%. Las pupas de dos dias de edad fueron mas sensibles
que el grupo de mayor edad expuestos a 4.40C. En comparaci6n la mortalidad
do pupas de dos dias de edad expuestas a esta temperature durante tres
dias fu6 de 99.8%, mientras que la mortalidad de pupas de 10 dias de edad
expuestas durante 15 dias fu6 de 99.9%. En orden de suceptibilidad al frio
(TL95) de estadios inmaduros de A. suspense expuestos a 7.20C fu6 en orden
descendiente: larva, huevo, pupa.
Data concerning the lethal effects of suboptimal temperatures on the
Caribbean fruit fly, Anastrepha suspense (Loew) are lacking. Prescott and
'Methods Development Station, USDA, APHIS, PPQ, 13601 Old Cutler Road, Miami, FL
33158 USA.
189
Florida Entomologist 67 (2)
Baranowski (1971) determined the optimal temperatures for development
of immature stages of this species over the range of 10-35C.
The USDA-APHIS-PPQ Treatment Manual (1983) lists a cold treatment
for fruit infested by Anastrepha species other than the Mexican fruit fly,
Anastrepha ludens (Loew). This all-inclusive group presumably includes the
Caribbean fruit fly even though there is no published information on this
species.
This paper investigates the efficacy of using low temperature to control
A. suspense and reports the results of exposing immature stages of this fly
to constant temperatures ranging from 1.70-15.60C.
MATERIALS AND METHODS
All insect stages used in these experiments were taken from the labora-
tory colony.
Eggs were collected from 1 to 2-wk-old laboratory stock flies. The num-
bers of eggs used in each test lot were estimated volumetrically with an
eyedropper, then placed in random batches on small squares of wet blotting
paper. Each blotter was placed in a petri dish which was enclosed in a plastic
bag to retain moisture. After cold exposure the blotter containing the eggs
was placed on a small sponge which elevated the eggs above water in the
bottom of a petri dish. The water was used to trap hatched larvae which
crawled off the blotter. Dilute (0.03%) sodium benzoate solution was used
as a mold inhibitor in the moist environment required for eggs. After
incubation at 25-270C and 85+% RH for 4 days, larvae and unhatched eggs
were counted with a dissecting microscope to determine the number of eggs
treated and percent hatch. Eggs (2, 8, and 24 h old) were held at 1.70C for
1-10 days, at 4.4C for 3-15 days, and at 7.2C for 6-18 days, 3 replicates per
treatment.
Mature larvae (8 days old) were washed from laboratory diet and placed
in lots of about 200 (ineasured volumetrically) into 29.6-ml (8 oz) waxed
paper cups containing moist vermiculite (6 ml H2O per 50 ml vermiculite).
Six small holes were punched ii the lids of the cups to allow air exchange.
Larvae were exposed to 7.2, 10.0, 12.8 and 15.60C for 7, 14, 21 and 28
days, 8 replicates per treatment (except 3 replicates at 7.20C). Larvae that
were able to pupate and emerge as adult flies were counted as survivors.
Pupa selected randomly from a single lot were measured volumetrically
into test aliquots of 175-200 and placed in wax paper cups described for
larvae. At 3, 6, and 10 days of age, they were exposed (3 replicates) to 7.2,
10, 12.8 and 15.60C for 7, 14, 21 and 28 days. In separate tests, pupae 2, 4, 6,
8 and 10 days old were exposed about 300 per test unit (5 replicates) to
4.40C for 3, 7, 11 and 15 days. Survival was based on the number of adult
flies that emerged following treatment.
Data were corrected for natural mortality in controls by Abbott's formula
(1925). Then, percent mortality values were transformed to probits and ex-
posure periods (days) to logarithms. The transformed data were used to
calculate time mortality regression equations and LT5s and LT95 values. The
linear regression equation took the form of Y = a + bx where Y = probit
mortality, A = y intercept, b = slope, and x = log days. Visual examination
of the plotted data (not presented) revealed that, in some instances, the
lowest data points did not align with higher points which otherwise showed
190
June, 1984
Benschoter & Witherell: Suboptimal Temperatures 191
good linearity. These lower points were not used in computing the regression
lines. This tendency of point deviation at the lower end of the mortality
line is clearly demonstrated by data of Baker (1939) regarding effects of
low temperature on fruit flies infesting fruits in Hawaii.
RESULTS AND DISCUSSION
When data points were plotted on graph paper, sensitivity to cold gen-
erally decreased with age of the eggs for all temperatures tested (Table 1).
At 1.70C, 8 days exposure produced 100% mortality of 2- and 8-h-old eggs,
and 10 days of exposure resulted in 99.87% kill of 24-h eggs. At 4.40C, 100%
kill of 2- and 8-h eggs resulted from exposures of 9 and 12 days, respec-
tively, while 15 days exposure produced 99.87% mortality of 24-h eggs.
Complete mortality was not attained in any of the 7.20C tests. Ten (10)
days of exposure destroyed 99.5% of the 2-h eggs and 99.2% of 8-h eggs,
while at 14 days it produced 98.6% mortality of 24-h eggs.
Results for larvae exposed to 7.2, 10, 12.8 and 15.60C for 7, 14, 21 and
28 days are presented in Table 2. Lethal effects varied inversely with tem-
perature. A temperature of 7.20C was so severe that 99.8% mortality re-
sulted from 7 days exposure. Consequently, not enough data points were
available to provide a regression equation for this temperature. At the other
extreme, the lethal effect of 15.60C was very slight, with less than 50%
mortality after 28 days exposure.
Response of pupae to cold exposure was similar to that for the other
stages, with pupal mortality increasing as temperature decreased. Results
are shown in Table 3. At 4.40C, 2-day-old pupae were the most sensitive to
TABLE 1. EFFECT OF LOW TEMPERATURE ON HATCHABILITY OF EGGS OF
Anastrepha suspense, 3 REPLICATES.
Regression
equation
Age of eggs No. eggs LT (days)1 (Y=a+bx)
(h) treated 50% 95% a b
1.70C"2
2 5561 1.6 3.4 4.07 4.82
8 5005 2.3 5.4 3.32 4.56
24 4686 2.2 5.0 3.42 4.62
4.4 C3
2 2976 1.3 4.7 4.69 2.94
8 2998 3.7 6.2 0.99 7.12
24 3748 5.4 9.1 -0.51 7.48
7.20C4
2 6272 2.3 6.1 3.65 3.84
8 6251 2.7 7.2 3.39 3.82
24 7677 8.3 10.7 -3.30 9.03
ILT = lethal time in days at indicated temperatures for 50% and 95% mortality.
28 exposure periods ranging from 1-10 days.
35 exposure periods ranging from 3-15 days.
45 exposure periods ranging from 2-14 days.
Florida Entomologist 67 (2)
June, 1984
TABLE 2. EFFECT OF SUBOPTIMAL TEMPERATURES ON SURVIVAL OF MATURE
(8-DAY-OLD) LARVAE OF Anastrepha suspense.
Regression
Treatment1 No. equation
temperatures larvae LT (days)2 (Y=a+bx)
(oC) treated 50% 95% a b
7.2 2671 <5.0 <7.0 3 -
10 4938 4.9 10.3 1.49 5.10
12.8 6309 10.5 31.0 1.44 3.49
15.6 6195 22.1 3.30 1.27
1Exposure periods were 7, 14, 21 and 28 days. 8 replicates, except 3 replicates at 7.2 C.
-LT = lethal time in days for 50% and 95% mortality.
3Insufficient data points for regression analysis.
TABLE 3. EFFECT OF SUBOPTIMAL TEMPERATURES ON
Anastrepha suspense.
SURVIVAL OF PUPAE OF
Regression
No. equation
Age of pupae pupae LT (days)' (Y=a+bx)
(days) treated 50% 95% a b
4.40 C
0.25 (hr)
7.6
2.8
3.6
5.7
7.20C3
11.2
4.7
7.5
18.0
12.9
17.7
40.6
31.9
46.0
10oC3
12.803
6.25 (hr)
21.0
6.9
7.2
9.8
18.8
10.4
13.3
33.3
20.8
30.0
156.6
85.5
196.4
7.28
1.71
3.07
1.97
-0.15
-2.71
1.82
-0.81
-2.71
-3.92
-3.94
0.47
-0.80
0.64
1.08
3.74
4.28
5.47
6.85
7.35
4.76
6.64
6.15
8.02
7.17
2.81
3.86
2.62
15.603
192
5879
6329
6132
6730
7336
2208
2022
2209
2270
2035
2270
2258
2054
2321
2222
2061
2327
ILT lethal time in days (except where shown in hours) at indicated temperatures for
50% and 95% mortality.
2Exposure periods were 3, 7, 11 and 15 days. 5 replicates.
3Exposure periods were 7, 14, 21 and 28 days. 3 replicates. No lethal effects at 15.60C.
Benschoter & Witherell: Suboptimal Temperatures 193
cold, their longevity being measured in hours rather than days. Comparing
results for pupae in the other age groups, 6-day-old pupae were uniformly
more susceptible to cold than younger or older individuals at all temperatures
tested. Mortality of pupae in the 12.80C tests was very moderate with less
than 50% kill of 6-day old pupae exposed for 28 days. Response of pupae
at 15.60C was negligible and was rated as "no effect".
Results of exposing immature stages of A. suspense to suboptimal tem-
peratures indicated that temperatures of 12.80C or higher would have little
practical value as a control measure against this insect. The order of
susceptibility (LT95) of immature stages of A. suspense exposed to 7.20C
was larvae > eggs > pupae.
The data points in all of the tests had high correlation coefficients (0.934-
0.999) indicating a high degree of linearity. Because of this, the regression
equations may be used to estimate exposure periods (at a given temperature)
for any desired level of mortality, or to predict mortalities at other (lower)
temperatures not actually tested.
REFERENCES CITED
ABBOTT, W. S. 1925. A method of computing the effectiveness of an insecti-
cide. J. Econ. Ent. 18: 265-7.
BAKER, A. C. 1939. The basis for treatment of products where fruit flies are
involved as a condition for entry into the United States. USDA Circ.
No. 551. 7 p.
PRESCOTT, J. A. III, AND R. M. BARANOWSKI. 1971. Effects of temperature on
the immature stages of Anastrepha suspense (Diptera: Tephritidae).
Florida Ent. 54: 297-303.
USDA-APHIS-PPQ Treatment Manual. 1983. Sec. VI, T107: 23-25.
PATHOGENICITY OF INDUSTRIAL FORMULATIONS OF
BACILLUS THURINGIENSIS SEROVAR. ISRAELENSIS
TO LARVAE OF SOME CULICINE MOSQUITOES1
IN THE LABORATORY
ARSHAD ALI
University of Florida, IFAS, Agricultural Research and Education Center,
P. O. Box 909, Sanford, FL 32771 USA
AND
DONALD M. SAUERMAN AND JAI K. NAYAR
Florida Medical Entomology Laboratory
200 9th Street, S.E.
Vero Beach, FL 32962 USA
ABSTRACT
In the laboratory, Teknar, a flowable concentrate formulation, and
Bactimos and Vectobac, 2 wettable powder formulations of Bacillus
thuringiensis serovar israelensis (Bti) were tested against laboratory main-
'Diptera: Culicidae.
Florida Entomologist 67 (2)
trained late 3rd and early 4th instars of Aedes taeniorhynchus (Wiedemann),
Anopheles albimanus Wiedemann, Culex nigripalpus Theobald, Cx. restuans
Theobald, Cx. salinarius Coquillett, Cx. quinquefasciatus Say, and Wyeomyia
vanduzeei Dyar and Knab.
Aedes taeniorhynchus was susceptible (LCgo = 0.114 to 0.772 ppm) to
the test formulations. Culex nigripalpus was generally the most susceptible
to each formulation, followed by Cx. salinarius, Cx. quinquefasciatus, and Cx.
restuans. The 3 formulations of Bti were relatively ineffective against An.
albimanus and Wy. vanduzeei. Considering the relative potencies of the test
formulations of Bti, Bactimos invariably was the most effective formulation
and Teknar@ the least against the species tested under laboratory conditions.
RESUME
En el laboratorio, Teknar, una formulaci6n fluida concentrada, y
Bactimos y Vectobac, 2 formulaciones humedecibles de polvo de Bacillus
thuringiensis serovar israelensis (Bti) fueron probadas contra tarde tercero
y temprano cuarto estadio mantenidos en el laboratorio de Aedes taeniorhyn-
chus (Wiedemann), Anopheles albimanus Wiedemann, Culex nigripalpus
Theobald, Cx. restuans Theobald, Cx. salinarius Coquillett, Cx. quinque-
fasciatus Say, and Wyeomia vanduzeei Dyar and Knab.
Aedes taeniorhynchus fu6 susceptible (LCgo = 0.114 a 0.772 ppm) a las
formulaciones probadas. Culex nigripalpus fu6 generalmente la mas sus-
ceptible a cada formulaci6n, seguida por Cx. salinarius, Cx. quinque-
fasciatus, y Cx. restuans. Las 3 formulaciones de Bti fueron relativamente
ineficientes contra An. albimanus y Wy. vanduzeei. Considerando la relative
potencia de las formulaciones de Bti probadas, Bactimos invariablemente
fu6 la formulaci6n mas efectiva, y Teknar@ la menos efectiva contra las
species probadas bajo condiciones de laboratorio.
A particularly potent isolate of the entomogenous bacterium, Bacillus
thuringiensis Berliner,'was discovered by Goldberg and Margalit (1977) in
soil of sewage lagoons in Israel. This isolate, corresponding to a new sero-
type H-14, was designated the variety israelensis by de Barjac (1978). In
the past 6 years, B. thuringiensis serovar. israelensis (Bti) has been tested
in the laboratory and field in different parts of the world against at least 70
mosquito species (Anonymous 1982) and has proven to be a highly effective
mosquito larvicide. Some commercial producers have developed a variety of
increasingly toxic and potent formulations of this biocide for use against
mosquitoes and some other aquatic pest and vector insects. At present, sev-
eral wettable powder (WP), flowable concentrate (FC), granular (G), and
slow or sustained release formulations of the microbial insecticide are avail-
able and more are being formulated for testing and eventual marketing.
Some of these formulations are currently registered for use against mos-
quitoes and simuliid black flies in the United States.
This paper reports laboratory evaluations of 3 industrial formulations of
Bti against 7 species of mosquitoes maintained in the laboratory.
MATERIALS AND METHODS
The formulations evaluated were 2 WPs, Bactimos (Biochem Products,
Montchanin, DE) and Vectobac (Abbott Laboratories, North Chicago, IL),
June, 1984
Ali et al.: Pathogenicity of Bt israelensis
195
and a FC, Teknar (Sandoz, Inc., San Diego, CA). The reported potencies
of Bactimos@ and Vectobac, respectively, were 3500 Aedes aegypti (AA)
IU/mg, and 2000 AA IU/mg, while Teknar contained 1500 AA IU/mg.
For laboratory assays, a mixture of late 3rd and early 4th instars of
Aedes taeniorhynchus (Wiedemann), Anopheles albimanus Weidemann,
Culex nigripalpus Theobald, Cx. restuans Theobald, Cx. salinarius Coquillett,
Cx. quinquefasciatus Say, and Wyeomyia vanduzeei Dyar and Knab were
used. These species were maintained at the Florida Medical Entomology
Laboratory at Vero Beach, Florida.
The procedures of bioassays were generally the same as described by
Mulla et al. (1982). Twenty larvae were placed in a 120-ml disposable cup
containing 100 ml of tap water (pH 6.8 0.2). Distilled water (pH 6.9
0.2) was used for Wy. vanduzeei because of the high larval mortality of this
species occurring in tap water (Nayar et al. 1979). The Bti formulations
were suspended in distilled water by using a commercial blender for 1 to 2
min to make a 1% stock suspension (wt/vol) of each formulation. The
suspension was maintained with a magnetic stirrer for making subsequent
serial dilutions and transfers for treatments. Each formulation was tested
on 3 or more different occasions. Four or 5 triplicate concentrations of a
formulation were applied each time and 3 cups were left untreated as con-
trols. Stock suspensions and their serial dilutions were freshly prepared on
each occasion. After a 24-h exposure period in a controlled temperature (27
10C) holding room, larval mortality was recorded. The corrected mortal-
ity of a species at different concentrations of a formulation was subjected to
log-probit regression analysis.
RESULTS AND DISCUSSION
Larvae of Ae. taeniorhynchus were susceptible (LCgo = 0.114 to 0.772
ppm) to the 3 test formulations of Bti (Table 1). The activity of these
formulations against Ae. taeniorhynchus did not correspond with their rela-
tive potencies. For example, Bactimos was 2.33X more potent than Teknar@
and 1.75X more potent than Vectobac, but showed 6.77X and 2.98X better
activity against Ae. taeniorhynchus than Teknar@ and Vectobac, respec-
tively. Similarly, Vectobac was 1.33X more potent than Teknar but
showed 2.27X better activity than Teknar against Ae. taeniorhynchus.
Among the species of Culex, Cx. nigripalpus was most susceptible to Bti,
followed by Cx. salinarius, Cx. quinquefasciatus, and Cx. restuans. The LCgo
values of Bactimos against these Culex species ranged from 0.117 to 0.552
ppm, while those of Vectobac and Teknar varied from 0.234 to 1.192 ppm
and 0.265 to 1.721 ppm, respectively.
All 3 formulations of Bti were relatively ineffective against An. albimanus
with LCg0 values ranging from 2.683 ppm (Bactimos) to 11.446 ppm (Vec-
tobac). Similarly, Wy. vanduzeei also remained relatively unaffected; the
LCgo value of Teknar@ against this species was 4.706 ppm.
There is no previous laboratory work on the activity of Bti against larvae
of Cx. nigripalpus, Cx. salinarius, and Wy. vanduzeei. However, the levels of
larvicidal activity of the 3 formulations of Bti against Ae. taeniorhynchus
and Cx. quinquefasciatus observed in this study are generally similar to the
activity of comparable Bti formulations tested against the same species in
earlier investigations (Ali et al. 1981, Mulla et al. 1982, Purcell 1981, Van
Florida Entomologist 67 (2)
June, 1984
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Ali et al.: Pathogenicity of Bt israelensis 197
Essen and Hembree 1980). The LCgo value of the 2 species for any com-
parable formulation was <1.0 ppm (Mulla et al. 1982).
It is obvious that An. albimanus and Wy. vanduzeei were relatively less
susceptible to Bti under laboratory conditions. While Wy. vanduzeei may
have inherent tolerance to Bti, the tolerance of Anopheles is probably due to
its surface feeding habit (Mulla et al. 1982, Nugud and White 1982). Float-
ing formulations of Bti might be more effective against Anopheles larvae.
From this study, it is evident that Bti offers a good potential for the con-
trol of Ae. taeniorhynchus, Cx. nigripalpus, Cx. quinquefasciatus, Cx.
salinarius, and Cx. restuans. Among the formulations tested under laboratory
conditions, Bactimos invariably was the most effective material against
these species and Teknar the least when their relative potencies are taken
into account.
Florida Agricultural Experiment Stations Journal Series No. 4777.
REFERENCES CITED
ALI, A., R. D. BAGGS, AND J. P. STEWART. 1981. Susceptibility of some
Florida chironomids and mosquitoes to various formulations of
Bacillus thuringiensis serovar. israelensis. J. Econ. Ent. 74: 672-7.
ANONYMOUS. 1982. Data sheet on the biological control agent Bacillus
thuringiensis serotype H-14 (de Barjac 1978). WHO/VBC/79.750,
Rev. 1, 46 p.
DE BARJAC, H. 1978. Une nouvelle vari6t6 de Bacillus thuringiensis tres
toxique pour les moustiques: B. thuringiensis var. israelensis serotype
14. C. R. Acad. Sci. (Paris) 286D: 797-800.
GOLDBERG, L. J., AND J. MARGALIT. 1977. A bacterial spore demonstrating
rapid larvicidal activity against Anopheles sergentii, Uranotaenia
unguiculata, Culex univitattus, Aedes aegypti, and Culex pipiens.
Mosq. News 37: 355-8.
MULLA, M. S., B. A. FEDERICI, AND H. A. DARWAZEH. 1982. Larvicidal
efficacy of Bacillus thuringiensis serotype H-14 against stagnant water
mosquitoes and its effects on nontarget organisms. Environ. Ent. 11:
788-95.
NAYAR, J. K., P. A. PIERCE, AND J. S. HAEGER. 1979. Autogeny in Wyomyia
vanduzeei in Florida. Entomologia exp. appl. 25: 311-6.
NUGUD, A., AND G. WHITE. 1982. Evaluation of Bacillus thuringiensis sero-
type H-14 formulations as larvicides for Anopheles arabiensis (species
B of the An. gambiae complex). Mosq. News 42: 36-40.
PURCELL, B. 1981. Effects of Bacillus thuringiensis var. israelensis on Aedes
taeniorhynchus and some nontarget organisms in the salt marsh. Mosq.
News 41: 476-84.
VAN ESSEN, F. W., AND S. C. HEMBREE. 1980. Laboratory bioassay of
Bacillus thuringiensis against all instars of Aedes aegypti and Aedes
taeniorhynchus larvae. Mosq. News 40: 424-31.
Florida Entomologist 67 (2)
NEW SPECIES OF ERIOPHYID MITES
(ACARI: ERIOPHYOIDEA)
JAN BOCZEK1 AND ROBERT DAVIS
Stored-Product Insects Research and Development Laboratory
Agricultural Research Service, USDA
Savannah, Georgia 31403 USA
ABSTRACT
Nine species of eriophyid mites are described, 3 from Poland: Aceria
malvacearum n.sp., Aculus malvae n.sp., and Epitrimerus tanaceti n.sp.; 5
from Brazil: Aculus pitangae n.sp., A. cauliflorus n.sp., A. catappae n.sp.,
A. solani n.sp., and Phyllocoptes caseariae n.sp.; and, 1 from Colombia:
Calacarus guerreroi n.sp.
RESUME
Son descritas nueve species de acaros eriofidos, tres de las cuales fueron
colectadas en Polonia: Aceria malvacearum n. sp.; Aculus malvae n. sp.;
Epitrimerus tanaceti n. sp.; cinco en Brasil: Aculus pitangae n. sp.; A.
cauliflorus n. sp.; A. catappae n. sp.; A. solani n. sp. y Phyllocoptes caseariae
n. sp.; y una en Colombia: Calacarus guerreroi n. sp.
The eriophyids (Eriophyoidea) are undoubtedly the most numerous of the
plant feeding mites although, at present, only 1859 species are known (Davis
et al., 1982).
Nine new species of eriophyid mites are described in this paper, 3 from
Poland: Aceria malvacearum n.sp., Aculus malvae n.sp., and Epitrimerus
tanaceti n.sp.; 5 from Brazil: Aculus pitrangae n.sp., A. cauliflorus n.sp.,
A. catappae n.sp., A. 'solani n.sp., and Phyllocoptes caseariae n.sp.; and, 1
from Colombia: Calacarus guerreroi n.sp.
Type materials are deposited at the Department of Applied Entomology,
Agricultural University of Warsaw, Warsaw, Poland.
Aceria malvacearum Boczek and Davis, NEW SPECIES
(Fig. 1)
FEMALE: 258 pm (range of 8 specimens 204-301 pm) long; 56 pm wide;
wormlike; yellowish. Rostrum 19 pm long; rostral seta 10 pm long; chelicerae
18 pm long. Dorsal shield 38 pm long, 40 pm wide, without lobe over rostrum,
with short median, 1 admedian line and 3 submedian lines on each side.
Dorsal tubercles on rear shield margin; 26 pm apart; with dorsal setae 44 pm
long, reclinate and diverging. Foreleg 66 pm long, tibia 8 pm long; claw
10 pm long; feather-claw 9 pm long, 8-9 rayed. Hindleg 50 pm long; hind
coxal setae 28 pm apart. First pair of coxae with longitudinal ornamenta-
tion. Thanosome with about 65 microtuberculate rings; microtubercles tri-
angular. Lateral setae 40 pm long, on sternite 13; 1st ventral setae 56 pm
long, on sternite 26; 2nd ventral setae 30 pm long; caudal setae 41 pm long;
1Present Address: Department of Applied Entomology, Agricultural University of Warsaw,
Nowoursynowska 166, Poland.
June, 1984
Boczek & Davis: New Eriophyids
199
Fig. 1. Aceria malvacearum n. sp.: AP-internal female genitalia; C-
claws; D-dorsal view; DA-anterior dorsal view; GF-external female
genitalia; and SA-anterior lateral view.
accessory setae 3 pm long. Female genital coverflap 20 pm long, 24 pm wide;
with about 14 longitudinal striae; genital setae 23 pm apart, 18 pm long.
MALE: Unknown.
NYMPH II: 165 pm long; shield 32 pm long; dorsal setae 20 pm long;
dorsal tubercles 20 pm apart, abdomen with 63 rings.
HOST: Malva sylvestris L. (Malvaceae).
RELATION TO HOST: Vagrant on undersurface of the leaves.
Florida Entomologist 67 (2)
TYPE MATERIAL. Holotype: female on slide, Poland, Warsaw-Lazienki,
22-VI-1982, D. Zalewska. Paratypes (7): females on slides, same data as
holotype.
This species is close to Aceria elacanthi Keifer and can be distinguished
by the shield pattern, size and location of the dorsal tubercles and the shape
of the featherclaw. The dorsal shield A. elacanthi is subtriangular, with a
broken median line and one pair of admedian lines; the dorsal tubercles are
large, situated slightly ahead of rear shield margin; the featherclaw is
4-rayed. In the new species dorsal shield is rhomboidal, with a complete
median line and 3 pairs of admedian lines; the dorsal tubercles are small,
and on rear shield margin; the featherclaw is 8-9 rayed.
Aculus malvae Boczek and Davis, NEW SPECIES
(Fig. 2)
FEMALE: 186 pm (range of 12 specimens 180-203 pm) long; 82 pm wide;
fusiform; yellowish-white. Rostrum 24 pm long; curved down; rostral seta
6 pm long. Shield 49 pm long; 75 pm wide, with broad anteriorly rounded
lobe over rostrum, with minute granules; shield pattern of only 2 admedian
lines curving laterad at both ends. Dorsal tubercles on rear margin of shield;
45 pm (32-51 pm) apart; dorsal setae 18 pm long, reclinate and diverging.
Foreleg 57 pm long, with granulated tibiae and tarsi; tibia 11 pm long, claw
6 pm long, knobbed featherclaw 5-rayed, 5 pm long. Hindleg 54 pm long, tibia
9 pm long. Both pairs of coxae ornamented. Hind coxal setae 26 pm apart.
Thanosome with about 40 dorsal rings, generally microtuberculate; and about
78 sternites with mictrotubercles. Tergal microtubercles elliptical, ventral
ones almost rounded. Lateral setae 32 pm long, on sternite 56. Telosome with
5 rings; setae 30 pm long; microtubercles elongated; caudal setae 47 pm long;
accessory setae 2 pm long. Female genital coverflap 12 pm long, 24 pm wide
with 12 longitudinal striae; genital setae 17 pm apart, 20 pm long.
MALE: 179 pm long; shield 48 pm long; genitalia 23 pm wide.
NYMPH II: 154 pm long, shield 43 pm long; dorsal setae 12 pm long,
30 pm apart; abdomen with 54 microtuberculate tergites.
HOST: Malva sylvestris L. (Malvaceae).
RELATION TO HOST: Vagrant on undersurface of the leaves.
TYPE MATERIAL. Holotype: Female on slide, Poland, Warsaw-Lazienki,
22-VI-1982, D. Zalewska. Paratypes (6) : females (5) and male (1) on slides,
same data as holotype.
This species is close to Aculus fockeui (Nalepa and Troussart) and can
be distinguished by the presence of shield spines, the shape of female
genitalia and the featherclaw. In A. fockeui the shield lobe has 2 distinct
spines; the female genitalia has 16-18 longitudinal striae; and the feather-
claw is 4-rayed. In the new species the shield lobe is without spines; the
female genitalia has 12 striae; and the featherclaw is 5-rayed.
Epitrimerus tanaceti Boczek and Davis, NEW SPECIES
(Fig. 3)
FEMALE: 172 pm (range of 11 specimens 172-203 pm) long; 63 pm wide;
straw-yellow; fusiform. Rostrum 17 pm long; chelicerae 20 pm long. Dorsal
shield 50 pm long; 56 pm wide. Shield smooth, only laterally with some
200
June, 1984
Boczek & Davis: New Eriophyids
GM
Fig. 2. Aculus malvae n. sp.: AP-internal female genitalia; C-claws;
DA-anterior dorsal view; GF-external female genitalia; GM-external
male genitalia; S-lateral view; and SA-anterior lateral view.
granulation. Dorsal tubercles on rear margin of shield; 20 pm apart, with
dorsal setae 8 pm long, pointed vertically and curved centrally. Foreleg 45 pm
long; tibia 7 pm long; claw 6 pm long, knobbed; featherclaw 4-rayed, 5 pm
long. Hindleg 40 pm long. Both pairs of coxae with linear troughs. Hind
coxal setae 23 pm apart. Thanosome with 36 (36-41) tergites and about
70 sternites. First 3 tergites covered with delicate elongated microtubercles,
201
Florida Entomologist 67 (2)
Fig. 3. Epitrimerus tanaceti n. sp.: AP-internal female genitalia; C-
claws; D-dorsal view; DA-anterior dorsal view; ES-lateral view of
tergite-sternite juncture; GF-external female genitalia; and SA-anterior
lateral view.
further tergites have such microtubercles only in central and lateral parts
forming dorsally 3 longitudinal bands. Lateral setae 20 pm long on sternite
14; 1st ventral setae 46 pm long, on sternite 31; 2nd ventral setae 14 pm
long, on sternite 49. Telosome with 5 microtuberculate rings and 22 pm long
setae. Caudal setae 22 pm long; accessory setae 3 pm long. Female genital
202
June, 1984
Boczek & Davis: New Eriophyids
203
coverflap 13 pm long, 24 pm wide, with 12 longitudinal striae; genital setae
14 pm apart, 25 pm long.
MALE: Unknown.
NYMPH II: 105 pm long; with microtuberculate rings.
HOST: Tanacetum vulgare L. (Compositae).
RELATION TO HOST: Vagrant on undersurface of the leaves.
TYPE MATERIAL. Holotype: Female on slide, Poland, Warsaw-Powsin
Park, 13-VIII-1982, D. Zalewska. Paratypes (3): Females on slides, same
data as holotype.
This species is close to Epitrimerus jaceae Liro and can be distinguished
by the shape and pattern of the dorsal shield and the tergites. In E. jaceae
the dorsal shield is longer than wide, with a few broken admedian lines; the
tergites are smooth. In the new species, the dorsal shield is as long as wide
with one short admedian line and some granulations laterally; the tergites
have microtubercles in central and lateral regions forming a central longi-
tudinal band.
Aculus pitangae Boczek and Davis, NEW SPECIES
(Fig. 4)
FEMALE: 185 pm (range of 23 specimens 166-191 pm) long; 60 pm wide;
beige; fusiform. Rostrum 18 pm long; rostral seta 6 pm long. Shield sub-
triangular, with lobe over rostrum, 42 pm (36-44 pm) long, 65 pm wide.
Shield pattern with 2 distinct admedians, submedians forming a ridge which
parallels shield margin, beginning and ending at the base of dorsal tubercles.
Dorsal tubercles on rear margin of shield: 41 pm apart, dorsal setae 12 Am
long, reclinate and slightly diverging. Foreleg 48 pm long; genu 5 pm long
with setae 22 pm long; tibia 7 pm long, with seta 2 pm long. Claw 6 pm long,
knobbed; featherclaw 4-rayed, 6 pm long. Hindleg 42 pm long, genu 4 pm
long, tibia 5 pm long. Coxae ornamented, with small lines; hind coxae with
dots; with setae 22 pm apart. Thanosome with 29 (26-34) tergites and 63
sternites. Tergites with 4 longitudinal bands of microtubercles reaching
telosome. Sternites with oval, minute microtubercles. Lateral setae 12 pm
long, on sternite 15; 1st ventral setae 44 pm long, on sternite 30; 2nd ventral
setae 11 pm long, on sternite 48. Telosome with 6 rings and 16 pm long setae.
Caudal setae 60 pm long; accessory setae absent. Genital coverflap 11 pm
(10-12 pm) long; 18 pm (16-19 pm) wide; with 12 longitudinal striae; genital
setae 12 pm apart, 12 pm long.
MALE: Unknown.
HOST: Eugenia uniflora L. (Myrtaceae).
RELATION TO HOST: Vagrants on undersurface of the leaves.
TYPE MATERIAL: Female on slide, Brazil, Piracicaba, Sao Paulo, 19-IX-
1980, J. Boczek. Paratypes (22): Females on slides, same data as holotype.
This species is close to Aculops eugeniae Keifer (1977) described from
the same host plant from Florida. However, it differs in the shield pattern,
in the tegrite microtubercles, and from the n. sp. in its relationship to the
host. In A. eugeniae the shield has a broken median and 4 curved admedian
lines; the tergites have microtubercles their entire length; and the mite
causes bead galls on the upper surface of leaves. The new species has a dorsal
shield with 2 pairs of admedian lines only; the tergites have microtubercles
Florida Entomologist 67 (2)
Fig. 4. Aculus pitangae n. sp.: AP-internal female genitalia; C-claws;
DA-anterior dorsal view; ES-lateral view of tergite-sternite juncture;
GF-external female genitalia; S-lateral view; and SA-anterior lateral
view.
204
June, 1984
IC)
Boczek & Davis: New Eriophyids
205
forming 3 longitudinal bands; and they are vagrants on undersurface of the
leaves not causing any apparent damage.
Aculus cauliflorus Boczek and Davis, NEW SPECIES
(Fig. 5)
FEMALE: 193 pm (range of 15 specimens 166-197 pm) long; 65 pm wide,
yellowish; fusiform. Chelicerae 16 pm long. Dorsal shield subtriangular with
rounded lobe over rostrum; with dorsal tubercles 32 pm apart, situated on
rear margin of shield. Dorsal setae 10 pm long, reclinate and diverging.
Dorsal shield with 2 indistinct broken submedian lines. Thanosome with 18
smooth tergites and about 70 microtuberculate sternites. Microtubercles oval.
DA
Fig. 5. Aculus cauliflorus n. sp.: AP-internal female genitalia; C-
claws; D-dorsal view; DA-anterior dorsal view; ES-lateral view of
tergite-sternite juncture; GF-external female genitalia; GM-external male
genitalia; and SA-anterior lateral view.
Florida Entomologist 67 (2)
Lateral setae 27 pm long on sternite 12; 1st ventral 56 pm long, on sternit-
30; 2nd ventral 8 pm long on sternite 49. Caudal setae 48 pm long; accessory
setae 4 pm long. Forelegs 50 pm long; genu 6 pm long with seta 19 pm long;
tibia 9 pm long with seta 4 pm long; claw 6 pm long, knobbed; featherclaw
4-rayed. Hindleg 45 pm long; genu 6 pm long with seta 6 pm long. Telosome
with 5 rings and 20 pm long setae. Female genital coverflap 16 pm (16-20 pm)
long, 22 pm (20-24 pm) wide, with 12 longitudinal striae; genital setae 16 pm
apart, 12 pm long. Coxae slightly granulated; hind coxal setae 23 pm apart.
MALE: 154 pm long; shield 40 pm long; dorsal setae 6 pm long; abdomen
with 23 tergites; genitalia 15 pm wide; genital setae 14 pm apart.
HOST: Acnistus cauliflorus Schott. (Solanaceae).
RELATION TO HOST: Vagrants on undersurface of the leaves.
TYPE MATERIAL. Holotype: Female on slide, Brazil, Piracicaba, Sao Paulo,
19-IX-1980, J. Boczek. Paratypes (14): Females (13) and male (1) on slides,
same data as holotype.
This species is close to Aculus schlechtendali (Nalepa) and can be dis-
tinguished by the shape and the pattern of dorsal shield, presence of micro-
tubercles on tergites and the shape of female genital coverflap. In A.
schlechtendali the dorsal shield is semicircular, with median and some
admedian lines; the tergites are smooth; and the female genital coverflap
has striae in one rank. In the new species the dorsal shield is subtriangular
with one pair of broken admedian lines; the tergites have microtubercles
laterally; and the female genital coverflap has striae in 2 separate ranks.
Aculus catappae Boczek and Davis, NEW SPECIES
(Fig. 6)
FEMALE: 166 pm (range of 15 specimens 151-196 pm) long; 62 pm wide,
amber; fusiform. Rostrum 20 pm long, with seta 7 pm long; chelicerae 16 pm
long. Shield 41 pm (32-42 pm) long, 48 pm wide. Dorsal shield with median
line fragmented and largely indistinct on posterior 1/3 of shield. Admedian
lines complete in most specimens and forming a circular pattern on posterior
1/3 of shield. First and 2nd submedian lines slightly fragmented but dis-
tinguishable from anterior margin to dorsal tubercles. Additional submedian
lines fragmented and presenting appearance of a hairy pattern on shield
margins. Dorsal tubercles 27 pm apart, on rear margin of shield; dorsal
setae 12 pm long, pointed reclinate and diverging. Foreleg 54 pm long; genu
6 pm long with seta 21 pm long; tibia 10 pm long with seta 5 pm long; claw
7 pm long, knobbed featherclaw 7-rayed. Hindleg 51 pm long. Thanosome
with 52 (39-54) tergites and about 80 sternites. Both tergites and sternites
microtuberculate; microtubercles elliptical. Lateral setae 22 pm long, on
sternite 13; 1st ventral setae 64 pm long, on sternite 27; 2nd ventral setae
16 pm long, on sternite 48. Telosome with 6 rings and 32 pm long setae.
Caudal setae 80 pm long; accessory setae 4 pm long. Female genital cover-
flap 13 pm (10-13 pm) long, 21 pm (16-24 pm) wide, with about 12 longi-
tudinal ribs; genital seta 15 pm apart, 20 pm long.
MALE: 151 pm long; shield 36 pm long.
HOST: Terminalia catappa L. (Combretaceae)
RELATION TO HOST: Vagrant on undersurface of the leaves.
TYPE MATERIAL. Holotype: Female on slide, Brazil, Piracicaba, Sao Paulo,
June, 1984
206
Roczek & Davis: New Eriophyids
Fig. 6. Aculus catappae n. sp.: AP-internal female genitalia; C-claws;
DA-anterior dorsal view; ES-lateral view of tergite-sternite juncture;
GF-external female genitalia; S-lateral view; and SA-anterior lateral
view.
19-IX-1980, J. Boczek. Paratypes (12): Females (10) and males (2) on
slides, same data as holotype.
This species resembles Acerimina terminaliae Keifer, and can be dis-
tinguished by the number of coxal setae, featherclaw rays and shape of
208 Florida Entomologist 67 (2) June, 1984
genital coverflap. In A. terminaliae there is only one pair of forecoxal setae;
the featherclaw is 6-rayed; and the female genital coverflap has diagonally
lateral lines basally and is somewhat lobed laterally. In the new species there
are 2 pairs of forecoxal setae; the featherclaw is 7-rayed; and the genital
coverflap has striae of even length, and no lateral lobes.
Aculus solani Boczek and Davis, NEW SPECIES
(Fig. 7)
FEMALE: 231 pm (range of 21 specimens 170-237 pm) long; 56 pm wide,
amber; spindleform. Chelicerae 15 pm long. Dorsal shield subtriangular, 42
pm (40-44 pm) long, with median line visible as 2 short fragments on pos-
terior 1/2 of shield. Medial, admedial, and submedial lines complete on
anterior 1/4 of shield. A ridge formed by portions of the submedial lines,
beginning and ending at the base of the dorsal tubercles, parallels the shield
margin. Dorsal tubercles 40 pm apart, on rear margin of shield; dorsal setae
14 pm long; reclinate and diverging. Forelegs 36 pm long; femur 10 pm long;
tibia 10 pm long with setae 7 pm long; claw 8 pm long, slightly knobbed;
featherclaw 6 pm long, 4 rayed. Hind legs 32 pm long. Forecoxae with 1st
setae 12 pm long; 2nd setae 32 pm long; hindcoxal setae 47 pm long.
Thanosome with 22 (22-24) smooth tergites and about 64 sternites. Sternites
with oval microtubercles. Lateral setae 20 pm long, on sternite 6; 1st lateral
setae 85 pm long, on sternite 26; 2nd lateral 22 pm long, on sternite 42.
Telosome with 5 microtuberculate rings and setae 30 pm long. Female genital
coverflap 18 pm long, 24 pm wide, with 16 furrows; genital setae 22 pm
apart, 13 pm long.
MALE: 200 pm long; shield 44 pm long, with dorsal setae 14 pm long, with
28 tergites. Male genitalia 16 pm wide.
HOST: Solanum nigrum L. (Solanaceae).
RELATION TO HOST: Vagrant on both surfaces of the leaves.
TYPE MATERIAL. Holotype: Female on slide, Brazil, Piracicaba, Sao Paulo,
18-IX-1980, J. Boczek. Paratypes (13): Females (11) and males (2) on
slides, same data as holotype.
This species is close to Aculus rhamnivagrans (Keifer), and can be dis-
tinguished by the shield shape and the internal female genitalia. In A.
rhamnivagrans the shield is subtriangular with a long and wide lobe over
rostrum; the spermathecae are circular. In the new species the shield is
semicircular with a very broad, short lobe over rostrum; the spermathecae
are oval.
Phyllocoptes caseariae Boczek and Davis, NEW SPECIES
(Fig. 8)
FEMALE: 190 pm (range of 16 specimens 180-220 pm) long; 67 pm wide;
72 pm thick; amber; spindleform. Rostrum 24 pm long, curved downward
obliquely. Chelicerae 17 pm long. Shield 45 pm (44-48 pm) long, with short
lobe over rostrum; shield oval, surface with two declivities along median
line at anterior of shield and near its midpoint. Admedial lines visible sur-
rounding both declivities. Submedial lines extending from anterior margin
to base of dorsal tubercles. Overall surface appearance is that of several
fractured irregular placed rectangles. Dorsal tubercles 30 (29-32 Am)
Boczek & Davis: New Eriophyids
Fig. 7. Aculus solani n. sp.: AP-internal female genitalia; C-claws;
DA-anterior dorsal view; ES-lateral view of tergite-sternite juncture;
GF-external female genitalia; GM-external male genitalia; S-lateral
view; and SA-anterior lateral view.
209
IC )
Florida Entomologist 67 (2)
June, 1984
LES
ahf
Fig. 8. Phyllocoptes caseariae n. sp.: AP-internal female genitalia; C-
claws; DA-anterior dorsal view; ES-lateral view of tergite-sternite junc-
ture; FG-external female genitalia; GM-external male genitalia; S-
lateral view; and SA-anterior lateral view.
apart, 6 pm long, 11 pm ahead of rear margin of shield, erect and convergent.
Foreleg 50 pm long; femur 9 pm long, genu 6 pm long with setae 32 pm long,
tibia 10 pm long with setae 5 pm long; featherclaw 5-rayed, 6 pm long, claw
knobbed. Hindlegs 41 pm long; tibia 8 pm long; tarsus 6 pm long. Thanosome
210
Boczek & Davis: New Eriophyids
211
with 35 (31-36) broader tergites and about 59 sternites. Lateral ends of
tergites with spiny microtubercles and sternites with rounded microtubercles.
Lateral setae 12 pm long on sternite 5; 1st ventral seta 44 pm long on
sternite 37. Telosome with 5 rings and 20 pm long setae. Caudal setae about
64 pm long, accessory setae absent. Female genital coverflap 18 pm (18-24
pm) wide, with 14-16 elongate furrows; setae 22 pm apart, 12 pm long.
MALE: 152 pm long; dorsal shield 40 pm long; dorsal setae 5 pm long,
24 pm apart; 8 pm from rear margin of shield; chelicerae 14 pm long; male
genitalia 18 pm wide, genital setae 7 pm long.
NYMPH II: 140 pm long; 56 pm thick; shield 30 pum long; dorsal setae
4 pm long; dorsal tubercles 9 pm apart, with 40 rings with spiny micro-
tubercles.
HOST: Casearia sylvestris Sw. (Flacourtiaceae).
RELATION TO HOST: Vagrants on undersurface of leaf.
TYPE MATERIAL. Holotype: Female on slide, Brazil, Piracicaba, Sao Paulo,
19-IX-1980, J. Boczek. Paratypes (14) : Females (13) and male (1) on slides,
same data as holotype.
This species is close to Phyllocoptes abaenus Keifer and can be distin-
guished by the shield shape, the shape of microtubercles of the tergites and
by the number of featherclaw rays. In P. abaenus the shield has a long broad
lobe; the sternites have oval microtubercules their entire length; and the
featherclaw is 4-rayed. In the new species the shield is almost semicircular;
the sternites have spiny microtubercles only laterally; and the featherclaw is
5-rayed. This is the first eriophyid mite described from the plant family
Flacourtiaceae.
Calacarus guerreroi Boczek and Davis, NEW SPECIES
(Fig. 9)
FEMALE: 196 pm (range of 30 specimens 166-196 pm) long; 76 pm wide;
straw yellow; fusiform. Rostrum 36 pm long; seta 20 pm long. Chelicerae
40 pm long. Dorsal shield 50 pm long; 72 pm wide. Shield pattern in form of
network of ridges and granulation laterally. Shield lobe over rostrum wide,
short, rounded anteriorly. Dorsal tubercles and setae absent. Foreleg 66 pm
long, genu 5 pm long with seta 36 pm long; tibia 15 pm long, with seta 2 pm
long. Claw 6 pm long, knobbed featherclaw 6 pm long, 4-rayed. Hindleg 58 pm
long; genu 4 pm long; tibia 12 pm long. Thanosome with 54 (49-64) tergites
and about 97 sternites. Tergites forming central ridge and two adcentral
ridges with wax points. Microtubercles present on all sternites and usually
on some proximal tergites laterally. Telosome of 8 rings and setae 21 pm
long; caudal setae 98 pm long; accessory setae absent. Telosomal micro-
tubercles elongated. Lateral setae 36 pm long, on sternite 19; 1st ventral
setae 40 pm long, on sternite 47; 2nd ventral setae 36 pm long, on sternite
80. Female genital coverflap 22 pm long, 28 pm wide; epigynium with about
12 longitudinal striae; genital setae 18 pm apart, 12 pm long.
MALE: 154 pm long; with dorsal shield 56 pm long; genitalia 18 pm wide.
HOST: Manihot esculenta Crantz (Euphorbiaceae) (Cassava, Tapioca).
RELATION TO HOST: On the uppersurface of leaf; they prefer the basal
leaves of the plant. Infested leaves curl upward, and gradually shrink.
TYPE MATERIAL. Holotype: Female on slide, Colombia, Cali, 2-VIII-1982,
Florida Entomologist 67 (2)
Fig. 9. Calacarus guerreroi n. sp.: SP-internal female genitalia; C-
claws; DA.-anterior dorsal view; FG-external female genitalia; GM-ex-
ternal male genitalia; S-lateral view; and SA-anterior lateral view.
J. M. Guerrero. Paratypes (20): Females (13) and males (2) on slides,
same data as holotype.
This species is close to Calacarus microrostrus Chakrabarti and Gosh and
can be distinguished by the shape of female genitalia and the number of
featherclaw rays. In C. microrostrus the genital overflap is smooth; the
212
June, 1984
Boczek & Davis: New Eriophyids
213
featherclaw is 7-rayed. In the new species the genital coverflap has 12 longi-
tudinal striae; the featherclaw is 4-rayed.
We are pleased to name this mite for Mr. Jose Maria Guerrero, Centro
International de Agricultura Tropical, Apartado Aereo 6713, Cali, Colombia.
This is the first species of eriophyid mite found on cassava (Bellotti &
Schoonhoven 1978), an economical subsistence crop plant grown in about 90
developing countries.
ACKNOWLEDGEMENT
We would like to acknowledge the assistance of Dr. C. H. W. Flechtman,
ESALQ Zoologia, Piracicaba SP, Brazil, in collecting the Brazilian mites;
and of Miss Danuta Zalewska, laboratory assistant, Department of Applied
Entomology, Agricultural University of Warsaw, Warsaw, Poland, for draw-
ing the mites.
REFERENCES CITED
BELLOTTI, A., AND A. VAN SCHOONHOVEN. 1978. Mite and insect pests of
cassava. Ann. Rev. Ent. 23: 39-67.
DAVIS, R., C. H. W. FLECHTMAN, J. BOCZEK, AND H. BARKER. 1982. Catalogue
of eriophyid mites (Acari: Eriophyoidea). Agric. Univ. Warsaw
Press, Warsaw, Poland. 254 p.
KEIFER, H. H. 1977. Eriophyid studies C-13. California Dept. of Agric., Jan.
20, 1977.24 p.
A SYNTHESIS OF TEMPERATURE DEPENDENT
DEVELOPMENTAL STUDIES WITH THE
CITRUS RED MITE, PANONYCHUS CITRI (McGREGOR)
(ACARI: TETRANYCHIDAE)
V. P. JONES AND J. G. MORSE
Dept. of Entomology
University of California
Riverside, CA 92521 USA
ABSTRACT
A literature review revealed 12 temperature-humidity studies performed
on the citrus red mite, Panonychus citri (McGregor) (Acari: Tetranychi-
dae). An analysis of these studies using a heat unit scale indicated that they
were in surprisingly close agreement especially in view of the different host
plants and experimental techniques utilized. Theoretical thresholds for de-
velopment, degree days necessary to complete development, and temperature
dependent mortality for the egg, immature and adult female stages are
presented. This synthesis implies that further research with the citrus red
mite is needed in the area of variable temperature developmental rates,
fecundity and mortality rates.
RESUME
Una revision de la bibliografia revel6 12 studios de temperatura-
Florida Entomologist 67 (2)
humedad sobre Panonychus citri (McGregor) (Acari: Tetranychidae). Un
andlisis de estos studios usando una unidad de calor de escala indic6 que
estaban en sorprendente acuerdo, especialmente en vista de las diferentes
plants hospederas y t6cnicas experimentales utilizadas. Limite te6rico de
desarrollo, grades diaries necesarios para completar el desarrollo, mortalidad
de los huevos dependiente de la temperature, y las etapas de los inmaduros
y las hembras adults son presentados. Esta sintesis implica que mis in-
vestigaci6n sobre P. citri es necesaria en el &rea de grades de desarrollos
por temperature variable, fecundidad, y grades de mortalidad.
The citrus red mite, Panonychus citri (McGregor), is one of the most
important pests of citrus worldwide (Jeppson et al. 1975). In California
alone, the citrus red mite was estimated to cause an economic crop loss of
approximately 15.9 million dollars in 1977 (Buxton 1977). Its importance
has led to a number of studies dealing with the relationship between tem-
perature and the rate of development (Table 1). However, none of these
studies have defined parameters, such as degree days or developmental
thresholds, which are necessary for temperature dependent modeling efforts.
In this review, we provide a summary and analysis of these studies and
define several modeling parameters from a selected subset of all work done.
MATERIALS AND METHODS
Data were initially grouped into 3 categories which corresponded to the
egg, immature, and adult life stages. The data were summarized (Table 2)
and experimental methods reviewed. Experiments were eliminated which
utilized sub-optimal host plants, such as papaya (Maity and Chakrabarti
1978), or involved temperature regimes which were not sufficiently defined
for this type of analysis (English and Turnipseed 1941). Data from studies
marked with an in Table 2 were not used in the analysis.
Since there was apparently no high temperature mediated decrease in
developmental rates, data for the egg and immature stages were graphed as
(developmental time)-' vs. (temperature). Linear regression was used to
obtain least squares estimates of the slope and x-intercept. Degree days for
development and theoretical developmental thresholds were determined as
(slope)-1 and (x-intercept), respectively (Arnold 1959).
If more than one humidity was tested per temperature, humidities which
produced the fastest development time were selected. Only data for the female
stage were considered.
RESULTS AND DISCUSSION
High mortality was found to occur in both the egg and immature stages
at a constant temperature of ca. 300C (23.7 and 20.6 degree days per day,
respectively) (Fig. 1A,B). Based primarily on the work of Keetch (1971),
Munger (1963), and observations in greenhouse experiments where tem-
peratures peaked in excess of 30C for short periods without population de-
crease (Jones 1983), we feel that a sharp increase in mortality occurs only
after 1-3 days constant exposure to temperatures over 300C.
The 5 studies used for the egg development regression were in very good
agreement (R2 of 0.91, Fig. 1C). The developmental threshold was found to
214
June, 1984
Jones & Morse: Developmental Studies on Citrus Red Mite 215
TABLE 1. TEMPERATURE STUDIES" WITH Panonychus citri.
Authors
Host
Comments
Prendergast (1938)
English and Turnipseed
(1941)
Fukuda and Shinkaji
(1954)
Shinkaji (1959)
Munger (1963)
Tanka and Inoue (1970)
Beavers and Hampton
(1971)
Keetch (1971)
Chakrabarti and Maity
(1978)
Maity and Chakrabarti
(1978)
Yusuda (1978)
Saito (1979)
Grapefruit
Citrus paradisi
Orange
Citrus sinensis
Tangerine
Citrus reticulata
Tangerine
Citrus reticulata
Lemon
Citrus limon
Data incomplete. Mortality
in all cases unacceptably
high.
No raw data given. Mean
temperature regressed
against developmental
thresholds with only sum-
mary equations presented.
Egg stage data only. 6 hu-
midities tested per tempera-
ture.
Post-embryonic stage data
only. 4 humidities tested per
temperature
Data on high temperature
mortality conflicts with
other authors.
Citrus sp.
Lemon
Citrus limon
Lemon
Citrus limon
Papaya
Carica papaya
Papaya
Carica papaya
Citrus sp.
Satsuma mandarin
Citrus unshiu
3 humidities tested per tem-
perature.
Unfavorable host plant. De-
velopmental times don't
differ significantly with
temperature changes.
Same data, as Chakrabarti
and Maity (1978)
"All studies except English and Turnipseed (1971) done at constant temperature.
be 6.30C with 116.9 degree days necessary for mean egg development. For
immature development, the developmental threshold was 9.40C with 96.0
degree days (R2=0.66, Fig. 1D) found to be the mean developmental period.
For the preovipositional period and adults stage, linear regressions were
run for both period duration vs temperature (R2=0.60, 0.64, respectively)
and (period)-1 vs temperatures (R2=0.45, 0.57). We chose to represent the
data in terms of stage duration vs temperature although other factors may
be important such as host plant differences or experimental conditions (note
especially linear relationship between adult stage duration and temperature
Florida Entomologist 67 (2)
June, 1984
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June, 1984
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Jones & Morse: Developmental Studies on Citrus Red Mite 219
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I 40
0
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A TEMPERATURE (OC)
.40- R2=0.91
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Fig. 1. Effects of temperature on various aspects of Panonychus citri
development, a) Effect on egg mortality. b) Effect on mortality of the im-
mature stages. c) Effect on developmental rate of eggs. d) Effect on develop-
mental rate of immatures. e)Effect on the duration of the pre-ovipositional
period of adult females. (A lemon, O tangerine, 0 unspecified Citrus sp.,
A satsuma mandrin).
when the data is separated by host plant and data source-Fig. 1E and Table
2). Regressions for preovipositional period and adult stage duration vs tem-
A A
perature were y= 4.76-0.11x and y= 44.38-1.17x, respectively.
Egg production showed no apparent relationship to female lifespan or
temperature. The average egg production for data below 300C was 38.0 eggs
per female (S.E.=5.14) from all studies (because of the sharp decline in
egg production at temperatures over 300C, data taken over this temperature
were eliminated from this part of the analysis).
The sex ratio was in the range of 65-84% female in all cases except for
the studies of Beavers and Hampton (1971) where the sex ratio was 52%
female and Tanka and Inoue (1970) where sex ratio was 53.6% female at
300C. The average sex ratio from all studies was 71% female.
Although it is difficult to interpolate from constant temperature labora-
tory studies to studies of population dynamics in the field, the correlation
of population increases and decreases observed by Jeppson et al. (1957) and
McMurtry (1969) can, at least partially, be explained by temperature medi-
ated changes in development and mortality. The purpose of this paper is not
to provide an indepth analysis of temperature mediated changes in citrus
red mite population dynamics, but rather to orient future research to areas
Florida Entomologist 67(2)
June, 1984
where data necessary for a modeling effort aimed at the citrus red mite is
inadequate.
Our analysis has shown that temperature dependent studies from around
the world are in surprisingly close agreement and that adequate data are
available on constant temperature developmental rates of the citrus red mite.
Based on these results, future research projects are needed in the following
areas: (1) comparison of constant temperature developmental rates with
variable temperature rates, (2) determination of accurate mortality data
under variable temperature regime, especially high temperature mortality,
and (3) influence of host plant nutrition on mite development.
ACKNOWLEDGMENTS
The authors would like to thank Mr. Arata Iseki for translating several
of the articles written in Japanese.
REFERENCES CITED
ARNOLD, C. Y. 1959. The determination and significance of the base tem-
perature in a linear heat unit system. American Soc. Hort. Sci. 74:
430-45.
BEAVERS, J. B., AND R. B. HAMPTON. 1971. Growth, development, and mating
behavior of the citrus red mite (Acarina: Tetranychidae). Ann. Ent.
Soc. America 64: 804-6.
BUXTON, G. M. 1977. Estimated damage and crop loss caused by insect and
mite pests. California Dept. of Food and Agric. 12 p.
CHAKRABARTI, S., AND S. P. MAITY. 1978. Effect of temperature and relative
humidity on the life cycle of Panonychus citri (McGregor) (Acarina:
Tetranychidae). Sci. and Culture 44: 233-4.
ENGLISH, L. L., AND G. F. TURNIPSEED. 1941. The influence of temperature
and season on the citrus red mite (Paratetranychus citri). J. Agr.
Res. 62: 65-77..
FUKUDA, J., AND N. SHINKAJI. 1954. Experimental studies on the influence
of temperature and relative humidity upon the development of citrus
red mite. (Metatetranychus citri McGregor). (1) On the influence of
temperature and relative humidity upon the development of the eggs.
Bull. Tokai-Kinki Agric. Exp. Sta. (Horticulture). 2: 160-71.
JEPPSON, L. R., C. A. FLESCHNER, M. J. JESSER, AND J. O. COMPLIN. 1957.
Influence of season and weather on citrus red mite populations on
lemons in southern California. J. Econ. Ent. 50: 293-300.
JEPPSON, L. R., H. H. KEIFER, AND E. W. BAKER. 1975. Mites injurious to
economic plants. Univ. of California Press, Berkeley. 614 p.
JONES, V. P. 1983. Pest resurgence of, and sampling plans for, the citrus
red mite, Panonychus citri (McGregor) (Acari: Tetranychidae).
Ph.D. Dissertation. Univ. of Calif., Riverside. 104 p.
KEETCH, D. P, 1971. Ecology of the citrus red mite, Panonychus citri
(McGregor), (Acarina: Tetranychidae) in South Africa. 2. The in-
fluence of temperature and relative humidity on the development and
life cycle. J. Ent. Soc. South Africa 34: 103-8.
MAITY, S. P., AND S. CHAKRABARTI. 1978. Biological studies on Panonychus
citri (Acari: Tetranychidae). Indian J. Acar. 2: 55-9.
McMURTRY, J. A. 1969. Biological control of citrus red mite in California.
Proc. 1st International Citrus Symposium 2: 855-62.
MUNGER, F. 1963. Factors affecting growth and multiplication of the citrus
red mite, Panonychus citri. Ann. Ent. Soc. America 56: 867-74.
220
Gagne & Beavers: Contarinia from Slash Pine Shoots 221
PRENDERGAST, D. 1938. Studies of the biology of the citrus red mite,
Paratetranychus citri (McG.). Ph.D. Dissertation, Univ. California,
Riverside. 65 p.
SAITO, Y. 1979. Comparative studies on life histories of three species of
spider mites (Acarina: Tetranychidae). App. Ent. Zool. 14: 83-94.
SHINKAJI, N. 1959. Experimental studies on the temperature and relative
humidity influencing the development of the citrus red mite (Panony-
chus [Metatranychus] citri) (McGregor). (2) On the influence of
temperature and relative humidity on the post-embryonic development,
adult life span, and egg-laying potency of the citrus red mite. Bull.
Hort. Div. Tokai-Kinki Agr. Exp. Sta. 5: 129-42.
TANKA, M., AND K. INOUE. 1970. Fundamental studies on the utilization of
natural enemies in citrus groves in Japan. II. The method of predic-
tion of outbreaks of the citrus red mite, Panonychus citri (McG.).
Bull. Hort. Res. Sta., Japan, Ser. D. 6: 1-40.
YUSUDA, M. 1978. Reproduction and factors influencing dispersal of the
citrus red mite, Panonychus citri (McGregor) (Acarina: Tetrany-
chidae) under laboratory conditions. Japanese J. Appl. Ent. Zool. 22:
12-7.
-L-- -- -L -- --^-- --^-- -^-- -
CONTARINIA SPP. (DIPTERA: CECIDOMYIIDAE)
FROM SHOOTS OF SLASH PINE (PINUS ELLIOTTII
ENGELM.) WITH THE DESCRIPTION OF A
NEW SPECIES INJURIOUS TO NEEDLES
RAYMOND J. GAGNE
Systematic Entomology Laboratory, IIBIII, Agricultural Research Service
USDA, c/o U.S. National Museum of Natural History
Washington, DC 20560
AND
GREGORY M. BEAVERS
3103 McCarty Hall
University of Florida
Gainesville, FL 32611
ABSTRACT
A new species, Contarinia acuta Gagn6 (Diptera: Cecidomyiidae), which
damages developing needles of slash pine, Pinus elliottii Engelm., in Florida,
is described. It is distinguished from other North American species of
Contarinia infesting pine, and diagnostic illustrations are provided for the
larvae of the new species and those of 3 other, unnamed species of Contarinia
associated with needles of slash pine.
RESUME
Una nueva especie, Contarinia acuta Gagn6 (Diptera: Cecidomyiidae),
que dafia las hojas en desarrollo del pino Pinus elliottii Engelm. en la Flor-
ida, es descrita. Es distinguida de otras species Norteamericanas de Con-
tarinia que infestan pinos, e ilustraciones diagn6sticas son proveidas para
larvas de la nueva especie y de otras 3 species sin nombrar de Contarinia
asociadas con las hojas del pino P. elliottii.
Florida Entomologist 67 (2)
During research into the cause of needle damage on slash pine, Pinus
elliottii Engelm., 4 distinct species of Contarinia were found associated with
new shoots. A characteristic needle damage is caused by Contarinia acuta
Gagne n. sp. described in this paper. Larvae of the other 3 species are less
common than C. acuta and their particular role on the needles is still un-
known. They were not reared to the adult stage, which is advisable before
they can be named, but they are briefly described with illustrations so that
they can be distinguished in future studies.
Characteristic brown lesions (ca. 4 mm long) are formed on needles as a
result of the feeding of C. acuta larvae. Feeding occurs inside the fascicle
sheath of basally elongating needles (Fig. 1). After needle elongation has
been completed, the needles become dry and brittle at the lesion site and
frequently break (Fig. 2). Mature larvae drop to the ground and pupate in
the surface litter. In northern Florida, larvae have been collected as early as
mid-February, with 6 generations having been recorded in 1 year and up to
4 between May and September (Beavers, in preparation).
Contarinia acuta Gagn6, NEW SPECIES
Fig. 3-12
ADULT. Head. Eyes large, about 5 facets long at vertex, the facets
circular, closely approximated except at midheight of eye where they lie
slightly farther apart. Occiput rounded, without peak. Frontoclypeal setae
8-10. Labella hemispherical in frontal view with 4-5 setae. Palpus 4-seg-
mented. Male antennal flagellomere 3 (Fig. 3) binodal, bicircumfilar, the
circumfilar loops not attaining the next distal node. Female antennal flagel-
lomeres 1-3 as in Fig. 4; circumfilar loops slightly bowed (Fig. 5).
Thorax. Mesoscutal row with sparse setae in mostly single row inter-
spersed with scales. Mesanepisternum bare. Mesepimeron with 5 setae. Wing
length male, 158-164 mm (162, avg. of 5), female, 173-200 mm (190 avg. of
5); RS slightly bowed dpically, joining C behind wing apex. C broken, the
wing margin indented at juncture with R5. Claws barely shorter than
empodia.
Male abdomen (Fig. 8). Tergites 1-7 rectangular with basal pair of
trichoid sensilla, a caudal, single row of sparse setae, 2-4 lateral setae, and
0 scales; tergite 8 weakly sclerotized caudally but with at least 1-2 caudal
setae laterally, 0 lateral setae, 2 basal trichoid sensilla. Sternites 2-6 rec-
tangular with pair of basal, closely approximated trichoid sensilla, a mostly
single, caudal row of setae, and mixed setae and setiform scales grouped
near midlength; sternite 7 as for preceding except caudal row mostly
double; sternite 8 with midlength and caudal groups of setae continuous on
caudal half of sclerite, and basal trichoid sensilla not as closely approximated
as on sternites 2-7. Genitalia (Fig. 9 (dorsal) -10 (ventral) : cerci short,
broadly rounded with 2 caudoventral setae; hypoproct not deeply divided,
the lobes broad, with 2 long setae. Aedeagus longer than hypoproct, very
narrow, attenuate, and pointed at apex; gonocoxal apodeme broad; gonopod
stout; gonostylus broadest near midlength, tapering to apex, setulose
throughout.
Female abdomen (Fig. 6). Tergites 1-7 and sternites 2-7 as in male but
setae more numerous except for fewer laterals on tergites. Tergite 7 about
.14 length distal section of ovipositor. Tergite 8 longer than 7 with pair of
June, 1984
222
Gagne & Beavers: Contarinia from Slash Pine Shoots 223
Ma
Fig. 1-2. 1) Larva of C. acuta feeding on adaxial surface of needle re-
moved from fascicle. 2) Characteristic damage of C. acuta.
Florida Entomologist 67 (2)
':15 ''.' ^ i,
3 4 5
/ \
Fig. 3-7. Contarinia acuta: 3, 3rd & antennal flagellomere; 4, 1st through
3rd 9 flagellomeres; 5, 3rd 9 flagellomere; 6, 9 postabdomen; 7, 9 cerci
(dorsolateral).
224
June, 1984
Gagne & Beavers: Contarinia from Slash Pine Shoots 225
00
',, 0 .o
1
00 900 o
'I,
9 10
Fig. 8-10. Contarinia acuta: 8, S abdominal segments 6-8; 9 8 terminalia
(dorsal) ; 10, same (ventral).
basal trichoid sensilla and short caudal setae. Cerci (Fig. 7) short, setulose
throughout.
LARVA (last instar). Length 2.3-2.7 mm (2.6 mm, avg. of 20). Body
smooth except for anteroventral spicule fields on abdominal segments.
Spatula (Fig. 11) clove-shaped, the anterior edge deeply incised, the lobes
rounded. Papillae with short setae. Spiracles of abdominal segment 8 at
posterior margin. Terminal papillae as in Fig. 12.
HOLOTYPE, $, from slash pine shoots, Gainesville, FL, 28-VII-1981, G. M.
Beavers, deposited in Florida State Collection of Arthropods, Gainesville.
Paratypes (all from Florida and shoots of slash pine unless otherwise noted
Florida Entomologist 67(2)
and deposited in Florida State Collection and U.S. National Museum of
Natural History; GMB = G. M. Beavers; JLF = J. L. Foltz; RCW = R. C.
Wilkinson) : 6 8, 1 9,3 pupal exuvia, Gainesville, 13-VIII to 2-XI-81, GMB;
3 9 from pitch canker diseased terminals, 30-VII-1974, Flagler Co., RCW;
3 9, emerged from soil under slash pine, Newberry, 17-VIII-1979, RCW &
JLF; 5 pupae, Alachua Co., 16-VII-1982, GMB; 9 larvae, Trenton, 30 to
31-VII-1979, RCW & JLF; 3 larvae, pitfall traps, Newberry, 5-IX-1979,
RCW & JLF; 2 larvae, Newberry, 30-VII-1979, RCW & JLF; 3 larvae,
Gainesville, 26-VII-1979, RCW & JLF; 6 larvae, Gainesville, 7-VII-1981,
GMB; 7 larvae, pitch canker diseased terminals, Flagler Co., 27-VIII-1975,
RCW; 10 larvae, Flagler Co., 30-VII-1974; and 12 larvae from slash pine
needles, Alachua Co., 28-VII-1981, GMB.
Contarinia acuta is so-named for its extremely fine-pointed aedeagus.
Adults will readily key to Contarinia in Gagn6 (1981), and it is the only
species in that genus with such an attenuate aedeagus. It is otherwise dis-
tinguished from all other North American Contarinia on pine by the almost
equally long claws and empodia (all other cecidomyiids associated with pine
characteristically have much longer empodia than claws), the wide male
hypoproct, and the completely setulose female cerci. Contarinia baeri (Prell)
is the only other Contarinia known on pine in eastern North America, but
that species has long empodia relative to the claws, differently-shaped male
and female terminalia (unpub.), and its larva has each of the corniform
terminal papillae at the end of a long caudal process (Skuhravy 1973).
The larva of C. acuta can be separated from those of the other 3 species
of Contarinia associated with it on slash pine needles with the help of Fig.
11-8. In other Contarinia such differences are diagnostic and will presum-
ably be so here also. Contarinia sp. A. (Fig. 13-4) is distinguished by a
field of short spines almost surrounding the terminal corniform papillae. In
addition, its spatula is least incised anteriorly of all 4 species. Contarinia sp.
B. (Fig. 15-6) is rather similar to C. acuta except that the spatula is not as
deeply incised, resulting in slightly differently shaped anterior lobes. Con-
tarinia sp. C. (Fig. 17-8) has almost connate terminal corniform papillae
and its spatula is the largest of the 4 species. Larvae of Thecodiplosis also
have somewhat approximated corniform terminal papillae also, but without
associated adults we cannot definitely say to which of the 2 genera species C
belongs. For the present the larvae of species C are assigned to Contarinia
sensu lato.
Specimens of the 3 unnamed species of Contarinia from slash pine are
recorded as follows:
Contarinia sp. A.: 2 larvae, slash pine needle, Newberry, FL, 5-X-1981,
GMB; 3 larvae, pitfall trap, Alachua Co., FL, 15-VII-1981, GMB; 1 larva,
slash pine needle, Alachua Co., FL, 1-IX-1982, GMB.
Contarinia sp. B.: 2 larvae, pitfall traps, Newberry, FL, 25-1-1980,
R.C.W. & J.L.F.; 2 larvae, slash pine needles, DeLand, FL, 7-X-1982, GMB.
Contarinia sp. C.: 2 larvae, pitfall traps, Newberry, FL, 25-1-1980,
R.C.W. & J.L.F.; 1 larva, slash pine needle, Alachua Co., FL, 17-IX-1982,
GMB; 4 larvae, Perry, FL, 2-III-1977, R.C.W.
We are grateful to Drs. John L. Foltz and Robert C. Wilkinson, Depart-
ment of Entomology and Nematology, University of Florida, for initiating
this study, providing research facilities, and submitting specimens for
identification.
June, 1984
226
Gagne & Beavers: Contarinia from Slash Pine Shoots
11
13
15
Fig. 11-18. Larval spatulae with associated papillae and terminal seg-
ments (dorsal) of Contarinia spp. on slash pine shoots: 11-12, Contarinia
acuta; 13-14, Contarinia sp. A; 15-16, Contarinia sp. B; 17-18, Contarinia
sp. C.
227
Florida Entomologist 67(2)
REFERENCES CITED
BEAVERS, G. M. In preparation. Bionomics of four species of Contarinia
(Diptera: Cecidomyiidae) on slash pine needles. Univ. Florida,
Gainesville, M.S. Thesis.
GAGNE, R. J. 1981. Cecidomyiidae. Pages 257-92 In McAlpine, J. F. et al.
Manual of Nearctic Diptera. Vol. 1. Research Branch Agriculture
Canada Monograph No. 27. vi & 674 p.
SKUHRAVY, V. 1973. "Needle blight" and "needle droop" on Pinus sylvestris
L. in Europe and P. resinosa Ait. in North America (Diptera:
Cecidomyiidae). Z. Angew. Ent. 72: 421-8.
-a e -- -a aaa-- a--
EVOLUTION OF A FIREFLY FLASH CODE
JAMES E. LLOYD
Department of Entomology and Nematology
University of Florida
Gainesville, FL 32611 USA
ABSTRACT
The flash code of Photinus ignitus (male flashes once, female delays
long and then flashes) appears to have evolved from a code like that of
Photinus macdermotti (male flashes twice, female delays briefly and flashes)
by the omission of the second flash of the male pattern and the "connection"
of the historic between-flash interval of the male pattern and the female
short delay, thus producing the female long delay. Signaling variations and
situations necessary for, and that might have led to, such a change in the
hypothetical ancestor occur in today's macdermotti.
RESUME
El c6digo de luces de Photinus ignius (macho: 1 luz; hembra: pausa
larga, luz) aparentamente ha evolucionado de un c6digo parecido a el de
Photinus macdermotti (macho: 2 luces; hembra: pausa corta, luz). Ha
omitido la segunda luz del patron del macho y ha unido el intervalo hist6rico
entire luces del patron del macho con la pausa corta de la hembra, asi pro-
duciendo la pausa larga de la hembra. Variaci6nes de sefiales y situaciones
que permitiria y podria producer tal cambio en el antecesor hipot6tico se
observa en macdermotti en poblaciones actuales.
Firefly flashing behavior does not fossilize, but through a comparison of
related living species we can see the sorts of changes that occur in evolution,
and often get some notion of how and why these changes came about. Such
a comparative approach may suggest specific observations and experiments
that should be made, and focus attention on overlooked but significant details
of the behavior of living species. I have made observations on and experi-
mented with the flashing behavior of several species in the Photinus con-
sanguineus group (Green 1956, Lloyd 1969) and on species with which they
have pertinent interactions. I can suggest a reasonable scheme for the
evolution of the code of Photinus ignitus from a precursor like the code of
June, 1984
228
Lloyd: Firefly Flash Code
229
Photinus macdermotti-ignitus males emit a single flash and their females
delay several seconds before flashing their answer; macdermotti males emit
2 flashes and their females delay about 1 sec after the second flash before
responding (Fig. la, b; Lloyd 1966, 1969).
There are at least 9 Nearctic species in the consanguineus group of
Photinus and probably more remain to be discovered (Lloyd 1969, p. 38; and
unpublished). The flash patterns of mate-seeking males of 6 of the species
usually or always, depending upon the species, are composed of 2-5 flashes,
and those of 2 species are single flashes (Fig. la-g). Another is diurnal and
has given up flash communication for pheromones (Lloyd 1973a, 1977). The
most reasonable and conservative assumption as to the signal of the most
recent common ancestor of the group is that its males had a multi-flash
pattern. This is because most of the known living species in the group, the
only available sample to draw inferences from, have such patterns, and there
is no compelling evidence to the contrary. The 1-flash patterns of ignitus
and aquilonius are thus derivative, as is the loss of adult luminosity in
indictus. The apparent closest relatives and virtual sibling species (see
Lloyd 1969) of ignitus, the (1-flash) firefly whose code evolution I seek to
explain, are: consanguineus, green, macdermotti, and an unnamed species,
"Barber's photinus." In the codes, of these species, male flash patterns are
composed of 2 flashes, and female flash answers are delayed about 1 s after
the second (P2) male flash. The intervals between the 2 flashes in the male
patterns vary among the 4 species (Fig. lb-e), and females will not answer
paired flashes of inappropriate timing (Lloyd 1966, 1969, unpublished; Buck
and Buck 1972).
If the P2 (second) flash of macdermotti's pattern is omitted the resulting
(male-female) code is nearly that of ignitus (cf. Fig. la and lb,h). But
why would the females of some ancestral "macdermotti" population, whose
males emitted 2-flash patterns, have become responsive to 1-flash patterns?
Would there not have been strong selection pressure in the contexts of re-
productive isolation and sexual selection to avoid answering incorrect or
inadequate patterns? If females accepted 1-flash patterns could they be ex-
pected to delay 1 s beyond where the missing P2 flash would have been?; or
might they delay 1 s after P1? Why should males of this ancestor have be-
gun to emit 1-flash rather than 2-flash patterns? Field observations and lab
experiments provide some tentative answers.
METHODS AND MATERIALS
Field observations were made at numerous, diverse localities in eastern
U.S., mostly in Florida. Field and lab flashing behavior was electronically
recorded as described by Lloyd (1973b). Lab experiments used females from
Gainesville, FL (Oct.-Nov. 1979), kept on a 16L:8D photoperiod with the
dark phase beginning at 2 PM local time, about 30 min before experiments
began. Females were held in individual shell vials (8 dram, airtight), corked,
with a 5-mm cube of fresh apple to maintain humidity and provide water
and possible nourishment. Artificial flash patterns were produced with an
incandescent bulb shining along a 3-cm long, 6.7-mm-diam., covered lucite
rod whose exposed end had been filed and rounded to produce even illumina-
tion. The flasher was aimed at subjects (in their vials) from distances of
30-50 cm, and moved a few centimeters from time to time when responses
Florida, Entomologist 67 (2)
a f
fI I
1I I I I I I i
0 1 2 3 0 0.5 1 1.5
b 9
ALl A_____
d'P1 'fP2
I I I I II I I I
0 1 2 3 0 1 2
c h
missing
P2
doP1 0P2 $ P1 9
I II I III I ,
0 1 2 0 1 2 3
d
d'p1 P2 'P1 P2
I I I I I I I
0 1 2 0 1 2 3
e j
P'p1 P2 d'P1 Iv dP2 ?v
I I I 1 2 3
0 1 2 0 1 2 3
June, 1984
230
Lloyd: Firefly Flash Code
231
waned. Simulations of the 2-flash macdermotti pattern were made uniform
( <1%) by a stable electronic timing generator (Alton Electronics) whose
flash interval was verified and monitored by the electronic recording system
with which many of the experiments were recorded. Some experiments were
timed with a split-timer, digital stopwatch (Siliconix ET110). The flash
interval between P1 and P2 was approximately that measured over the past
several years in free flying macdermotti males (Fig. 2). Flash duration was
ca. 0.1 s. Test females (n=13) were collected as adults by their responses to
penlight simulations of their males' pattern and probably included both
virgins and nonvirgins; eggs in dissected females numbered: 1, 4, 6, 16, 16,
47, 70, and 78, suggesting that some had already laid eggs. Wing (1982) has
found through field study of marked individuals that females may mate at
least 3 times, and will attract males and copulate on consecutive evenings.
Experimental protocol was as follows: individual females were presented
with series of 5 (designated A-E) flash patterns at 5-10 s intervals; 10 series
were presented in succession with 1 min of darkness interposed between
series. Patterns in each series were either properly-timed (for ambient temp.,
Fig. 2) macdermotti patterns, or experimental, single flashes. The position
of the 13, 1-flash (=X) presentations in the various series from 1-10 are as
follows: series 1, no X; 2, X at E; 3, no X; 4, X at E; 5, X at E; 6, X at D
and E; 7, X at E; 8, X at D and E; 9, X at C and E; 10, X at C, D, and E.
There were 410 series presented, and in addition, a few longer series of
patterns.
RESULTS
Responsiveness to Experiment Flashes. When presented single flashes at
the end of and within series of 2-flash patterns timed like those of males of
their species, macdermotti females often answered, and, as anticipated, al-
most always at a long delay (see below). There was a range of response
levels: one female answered only 6% (3/49) of the 1-flash patterns but
answered 98% (169/173) of the preliminary and interspersed 2-flash (mac-
dermotti) patterns. At the other extreme one female answered 71% of the
1-flash patterns (36/51; 2-flash patterns = 95% 139/146), and another
89% (34/38; 2-flash patterns = 100% 113/113). (Totals in the preceding
introductory summary include data from a few modified procedures not in-
cluded in the remainder of this report.) No overall increased or reduction in
Fig. 1. Flash codes of species in the Photinus consanguineus group (a-g),
and other flash interactions. Flash forms drawn from chart traces of elec-
tronic recordings and, along with time intervals, are adjusted to about 230 C.
Horizontal axis, time in sec; vertical axis, relative intensity. Variations in
height among flashes not significant. Codes of: (a) P. ignitus, (b) P. mac-
dermotti, (c) P. consanguineus, (d) P. green, (e) "Barber's Photinus," (f)
P. lineellus, indicating variation occurring in a male's pattern, (g) P.
aquilonius. (h) An ignitus-like code is produced when a macdermotti female
answers a single flash (compare with 'a'). (i) P. macdermotti female mis-
takenly answered after P1; note identical delays after P1 and P2. (j) False
injection (Iv) and false female response ( 9v) of Photuris versicolor female
aggressive mimic, a predator) ; note different delays to P1 and P2 (see text,
Lloyd 1981 and in prep).
Florida Entomologist 67 (2)
232
3.2
2.8
Cd
1.6
1.2
L 2.4
ca
2.0
C.
b 1.6
1.2
15 20 25 30
Temperature (CC)
Fig. 2. P1P2 line for determining mac-value across temperature range.
Line was determined from P1P2 intervals of flying, flashing males. Values
indicated at lower temperatures are questionable (see text). Divide observa-
tion by P1P2 interval indicated on y axis to determine mac-value.
response level from the beginning of the 50-pattern test to the end was ap-
parent: comparisons of response to early vs late experiments in the tests
disclosed no difference (56% response to 2E and 4E vs 9C and 10C). (There
was a slight increase (i=0.24 "mac-value," see text; ca. 0.04 s at 240C) in
delay when the first 12 responses to 2-flash patterns of 9 females were com-
pared with their last 12 responses on tests. Seven of 9 females showed an
increase, on 12 of the 14 tests.) From test to test individuals sometimes
changed response level dramatically (e.g. 91, n=7 tests, range 0-100%;
95, n=3 tests, range 0-77%; 94, n=7 tests, range 15-77%). Other females
showed greater constancy among their tests (e.g. 9 3, n=4 tests, range 46-
100%; 913, n=3 tests, range 77-100%; 9 2, n=2 tests, both 8%).
The arrangement of patterns within the various series provided answers
to specific questions: Would females answer single flashes if they had seen
4, 3, or 2 macdermotti patterns first? Yes, and the mean response levels (both
pooled and of means) were 50-59% (and to controls, 95-98%; and re-
sponses to the 3 presentations were not significantly different (Table 1, nos.
1-3).
Would females answer 1-flash patterns that were preceded by 1-flash
patterns-i.e. answer more than one experimental pattern in succession?
Yes (Table 1, nos. 4, 6, 8), but if they did not answer the first 1-flash pattern
Observation
= mac value
dcP1-P2 Interval
June, 1984
Lloyd: Firefly Flash Code
10 10 00 05 CIOCO COCO
r-0 cccc cdi R
' O 00 1 CO "t C11
T-4 1 11 M
(Mt- m5i CO LO 'IV m0
Cr-1 CCO C'0 CO0
dd 565do
-00- -
CO .-I CA
000 0-
r- 5q
00
00 t- o cc
0 0
233
C LC
NM cq
TI 00 mS
00l 00 "O-I t- C
- -- - ~-
000 C 00 t- m
T- 1-1 cl
0
SCcO 0CMl
T-I 00 L- I'l
---- .-
C9O r-I CO'
00 L- I-4]
Cl
00 00
0
00
t O-Cl 11T
-q L- -i
mcl C- 1
b OS Cl Cl
00 la V b- 0 00 c0o
Ld do do d
Xb Xu Xu XO
- 0
TCl 1-
T-l
0
Xu
-3 -' ,-
0+ 0+ 0+ ;-4 0+ P,
CM. CM+ C+ cd 0+ ,W0 5 M)bO +
?-rJ
N l CO c' 0
co La cc t-
0
CO)
-x *
oo
do
-40
0
-40
09~
00
^
Florida Entomologist 67 (2)
June, 1984
0 I 04
ri^
-^ B .S"
g3 ^ g
72
a )i
r r 0 "
0 0 0
0 0
'0
a '0 r
a) 0 1 a)#
00
a) a a)
2 t
C
cd v00
# a4
s SoD
V ~
I fri$
40 a)
,Y 40 'Ca)
1 a) -a
-fi8^ &i a
a) a)
g g-
g-.4 f3r)< u^ o
* "sS S r "
40g#4 *Is
*agasa)C)O -s
* a ga01 a) g
.0l .>G4
- 6gWEis s i
^^s1*a)
Qj tJ 'M
#4P'~ .i~
c/i 'Ey1 1 ^ ls
5-38~ 5 ,
gX ~~'O a)
a, ig-i ; gos
oa)#4~ a) 0
gs*i*gs "S-
s^^^g ^g
40 PIij404 C) 0
a7a)
re.H ^
La)_ f 4.4 "4
ti~n +^ nStor
Rda) a)O
Pi ba -4 4
234
X X
QC
a) 0
0+
00
O^dOF
CO Mc "
0
a
, 0
04OK C' -
e lc. )
Lloyd: Firefly Flash Code 235
they were not likely to answer another one following it (Table 1, nos. 5, 7, 9).
There was not a significant difference in response level among 3, compared,
antecedent conditions (involving 2 vs 3 macdermotti patterns and 1 vs 2 1-
flash patterns; Table 1, nos. 4, 6, 8). Would females answer more than three
1-flash patterns in succession? Yes; 5 of the 13 females answered 3 or more
consecutive 1-flash patterns. The limit of female responsiveness to patterns
in succession was "probed" beyond the measure incorporated in the protocol
(series 10, C-E) by sometimes continuing to present 1-flash patterns after
10E, at 5-10 s intervals. High values for continuous answering of these
(extra) single-flash patterns for different females were 15, 14, 6, 5, and 4.
The 2 high females with 15 and 14 responses, in other post 10E series an-
swered 13 and 10, respectively. One was given 146 patterns after the 50-
pattern procedure. Each of the 16 times she stopped responding to 1-flash
patterns, she immediately answered a 2-flash pattern and 1-5 subsequent
1-flash patterns.
Response levels of females on individual tests and in total, during their
experimental careers and including as well as excluding zero test scores, were
examined for correlations with: days since capture, days till death, number
of eggs present at death (- at capture), and number of tests given. Only
"days until death" showed any significant correlation, and this was im-
proved by excluding zero-score tests and 2 very high scores that occurred one
day before death in 2 individuals (r = 0.63; Fig. 3). Female response to
1-flash patterns gradually dropped between 12 and 4 days before death (y =
0.28 + .06x), and then appears to drop sharply. If there actually is a sharp
break in the response curve at ca. 3 days it would explain and incorporate
several low and zero scores.
Timing of Female Responses. Female macdermotti flashed answers to
approximately 1800 1-flash and 2-flash stimulus patterns during this study.
In all but 26 their answers followed the P2 position, and roughly by 1 s
whether the P2 flash was present or not; thus, when timed from P1 the delay
ranged around 3 s (-19C, Fig. lh). Delays varied predictably with tem-
perature, as do other firefly flash parameters, including the delay of ignitus
females. In order to combine and compare measurements (of delays, etc.)
made at different temperatures, delays were divided by the male P1P2 in-
terval measured at various temperatures in free flying males over the past
several years (Fig. 2). The resulting number is referred to as a mac-value
(=mv; Lloyd 1981).
A total of 789 delays from 11 females were measured. The mean female
delay to 1-flash patterns (n=120) was about 3% longer than that to 2-
flash patterns (n=669; 1.33 vs 1.29 my), and this bias direction occurred in
8 of the 11 females. This difference is not significant if the responses of all
females (n=ll) are compared (t=1.50, DF=20). However, if the responses
of only the 8 are compared, the difference (1.37 vs 1.30 my; 5% longer) is
significant between 0.01 and 0.001 (t=3.76, DF=14). The mean female
delays to 2-flash patterns that were presented immediately before 1-flash
patterns were like those given to all other 2-flash patterns (before: x=1.29,
S=0.044; all: i=1.29, S=0.039; t=0.0, DF=20). The delays elicited by 2-
flash patterns immediately following 1-flash (experimental) patterns were
like those after all other 2-flash patterns (after: x=1.30, S=0.046; all:
x=1.29, S=0.039; t=0.553, DF=20).
Florida Entomologist 67 (2)
1.00 r o
*0 *
0
* *
** *
y =.28 +.06x
r =.63
. *
*. S
4
Days
6
Until Death
Fig. 3. Change in female response level as she ages, i.e. as a function of
"days until death." Note that about 4 days before death response level prob-
ably drops precipitously. Five 0 values and 2 very high values on day 1
(circles) were excluded from calculations to determine line.
There was more variation among the means of female responses to 1-
flash patterns (S=0.075) than 'among those to 2-flash stimuli (S=0.039;
F=3.73, DF=20, p<0.05). When two 1-flash patterns were answered in
succession (presentations 6D,E; 8D,E; 10C,D), the delay following the
second in the series was not significantly longer (79 9, 25 responses; S=
7.3%; t=1.70, DF=48).
Although extensive information was obtained on variations in female
delays-from stimulus to stimulus, among different tests on individual fe-
males, and among females,-it is largely uninterpretable at the moment.
(But experiments and field observations over the past several years have
suggested that it is possible that females convey information to males by
variations in their timing from pattern to pattern.) Durations of female
response flashes emitted after 1-flash patterns were like those following
2-flash patterns (69 9, 34 vs 62 flashes measured; i 0.14 s, 20-230 C;
t=0.316, DF=10).
Delay lengths of female responses during their experimental careers
showed no significant correlations with days since capture, days until death,
or number of eggs present at death.
Of the 26 flashes that females emitted after the P1 flash, 15 were meas-
ured. They were timed like flashes emitted after P2 flashes (differences not
236
June, 1984
Lloyd: Firefly Flash Code 237
significant, t=0.16, DF=23). Particular attention was given to this timing
because signal mimicking predators and competing males of this species in-
ject "extra" flashes between P1 and P2 of an approaching male (Lloyd
1979, 1981). It was conceivable that female macdermotti flashes occurring
after P1 could have some connection with the injected flashes of males and
predators. This does not seem to be the case (Fig. 1, cf i with j).
DISCUSSION
The experiments demonstrate that female macdermotti will answer 1-
flash patterns after they have seen 2-flash patterns characteristic of their
species, and that some females, or females sometimes, will answer several
in succession.
These experiments also demonstrate that female macdermotti answer
single flashes at long delays, thus producing a flash interaction similar to
that of ignitus (Fig. la,h), the species whose flash code is of evolutionary
interest here. Since vegetation can sometimes obscure one flash of a male
2-flash pattern, it seems reasonable that females would sometimes answer
incomplete patterns, thus helping the approach of a male they have already
identified as a member of their species.
But why should females rarely (26/I1800) treat a single stimulus flash
as P1 and not P2? I believe part of the answer is that firefly females have
a timing mechanism that measures flash pattern intervals (repetition cycles).
This could explain why competing males of Photinus pyralis that hover and
flash together near a responsive female do not flash immediately after a
female response, but instead wait a few seconds and then flash, thus, in near
synchrony (Maurer 1968, Lloyd 1979). Such a timer could also have some
role in a more complex coding used to detect the predaceous mimicries of
Photuris females (Lloyd 1983).
The time-measuring mechanisms of macdermotti females of primary im-
portance here are those that measure the interval of the 2 flashes in the
males' 2-flash pattern and the delay after P2. To recognize males of her
species, a macdermotti female measures the P1-P2 interval. If this interval
is appropriate, and P2 is seen during the critical "window," a timer counts
down to trigger the response flash at the appropriate time. P. macdermotti
females that answer a 1-flash pattern at the long delay have, in one simple
model, coupled the 2 timers. Additional experiments should permit more to be
said about the factors that influence "decision making" at the junction of
these timers.
Why would males of ignitus' ancestor have begun to emit 1-flash rather
than 2-flash patterns? (Note that their females were already responsive to
1-flash patterns after initial contact and identification.) At first they would
have emitted both 1-flash and 2-flash patterns, depending upon circum-
stances. There are 3 situations in which 1-flash patterns would have been
adaptive: (1) The typical species pattern was altered to avoid attracting
other males that would have competed for the female. At first this could
have been an advantage, but eventually, in evolutionary time, it would have
been countered by competitor recognition of the "secret code" approach, and
females should have encouraged the counter (sons would get "genes" for
the alternative mate-finding tactic).
(2) Males might omit P2 upon close approach to a responding light to
238 Florida Entomologist 67 (2) June, 1984
cause a signal-mimicking predator to reveal her identity. The omission of
P2 would probably cause Photuris females to stop answering or to answer
incorrectly either because: their neural mechanisms for answering after the
P2 flash were not like those of macdermotti females, whose machinery meas-
ures intervals between P1 and P2, and Photuris could not time from P1; or
because they "computed" the single flash as that of another species they
preyed upon and answered in its code. Experiments with Photuris versicolor
females (Florida), predators of macdermotti, indicate that they answer 1-
flash patterns with a short (<1 sec) delay, not a long one (Lloyd 1981, un-
published).
(3) Photuris females attack flashing males in the air, using the flashes to
aim their attacks, and they sometimes switch to this predatory tactic from
signal mimicry, when approaching males hesitate (Lloyd and Wing 1983).
A 2-flash ignitus ancestor might have omitted P2 on close approach to a fe-
male, or even during searching, because it provided a target for predators
that approach P1, during the P1P2 interval, and struck at P2. Several
factors could have been responsible for finally fixing the 1-flash pattern in
ignitus, but after viewing aerial attack behavior by various Photuris species
and noting its efficiency and frequency of occurrence at certain times, and
the effects it seems to have on macdermotti behavior (Wing 1982, Lloyd and
Wing 1983), I believe it could well have been the critical factor in fixing
ignitus' 1-flash pattern. Complete acceptance of 1-flash patterns by females
would follow the change in males if the risks to males were very great.
EPILOGUE
The high level of response to 1-flash patterns found in some females was
not anticipated. On numerous occasions over the past several years females
in the field and lab had been presented with single flashes and none had
flashed in response. Therefore, the experimental protocol used in this study
was not designed to determine whether females would answer 1-flash pat-
terns without prior 2-flash stimulation. This was tested on females taken
from the same locality as those used above, in the spring (n=5) and fall
(n=3) of 1983. They were presented 15 single flashes in 3 groups of 5 (in
the protocol described above), then an increasing number of normal (2-
flash) patterns was interspersed in subsequent groups of the tests. Response
level to normal patterns was 0.78, lower than in previous testing in which
normal patterns were more numerous (cf. 0.93-1.0, Table 1). Only 5 of 661
single flashes were answered at a time delay that indicated females judged
them to be Pl's. These responses occurred after normal patterns had been
presented and not when females had seen only single flashes. Thus, some
priming by the normal (species-typical) male pattern is necessary to elicit
long-delayed responses to single flashes. Of more interest is the fact that 3
females answered a total of 50 1-flash patterns at a time delay that indicated
that they judged them to be P2's. This is being studied.
ACKNOWLEDGMENTS
I thank John Alcock, John Sivinski, Tom Walker, Steve Wing, and an
anonymous referee for commenting on the manuscript; Ngo Dong for dis-
secting the fireflies; Ray Littel for statistical consultation; Laura Reep for
Lloyd: Firefly Flash Code
239
drawing the figures; Jack Schuster for composing the Resumen; and Barbara
Hollien for typing the manuscript. This study was supported by my Depart-
ment and N.S.F. Grant DEB-7921744. Florida Agricultural Experiment Sta-
tion Journal Series No. 4527.
REFERENCES CITED
BUCK, J. B., AND E. BUCK. 1972. Photic signaling in the firefly Photinus
green. Biol. Bull. 142: 195-205.
GREEN, J. W. 1956. Revision of the Nearctic species of Photinus (Lampy-
ridae: Coleoptera). Proc. California Acad. Sci. 28: 561-613.
LLOYD, J. E. 1966. Studies on the flash communication of Photinus fireflies.
Univ. Michigan Mus. Zool. Misc. Coll. 130: 1-95.
1969. Flashes, behavior and additional species of Nearctic Photinus
fireflies (Coleoptera: Lampyridae). Coleop. Bull. 23: 29-40.
S1973a. Chemical communication in fireflies. Environ. Ent. 1: 265-6.
1973b. Fireflies of Melanesia; bioluminescense, mating behavior, and
synchronous flashing. Environ. Ent. 2: 991-1008.
1977. Bioluminsecence and communication. Pages 164-83 in T. A.
Sebeok, ed. How animals communicate. Indiana Univ. Press, Blooming-
ton.
1979. Sexual selection in luminescent beetles. Pages 393-42 in M. and
A. Blum, eds. Sexual selection and reproductive competition in in-
sects. Academic Press, New York.
1981. Firefly mate-rivals mimic their predators and vice versa.
Nature 290: 498-500.
.1983. Bioluminescence and communication in insects. Annu. Rev.
Ent. 28: 131-60.
AND S. R. WING. 1983. Nocturnal aerial predation of fireflies by
light-seeking fireflies. Science 222: 634-5.
MAURER, U. M. 1968. Some parameters of photic signaling important to
sexual species recognition in the firefly Photinus pyralis. M.S. Thesis,
SUNY, Stony Brook, New York.
WING, S. R. 1982. The reproductive ecologies of three species of fireflies.
M.S. Thesis, Univ. of Florida, Gainesville.
Florida Entomologist 67(2)
REPRODUCTIVE MATURATION AND PREMATING
PERIOD OF THE PAPAYA FRUIT FLY,
TOXOTRYPANA CURVICAUDA
(DIPTERA: TEPHRITIDAE)
PETER J. LANDOLT1
Subtropical Horticulture Research Unit, USDA, ARS
13601 Old Cutler Road
Miami, FL 33158 USA
ABSTRACT
Female papaya fruit flies, Toxotrypana curvicauda Gerstaecker, obtained
from field-infested papayas, Carica papaya L., required 5 to 6 days to de-
velop mature ovaries comparable in size to those of ovipositing field-collected
females. Younger females, with ovaries less than 0.25 cm long, were absent
from papaya groves, suggesting that female papaya fruit flies do not search
out host plants until mature. In mating tests females mated when 5 days old
or older, while males mated at any age (one to 6 days after emergence) al-
though mating rates were less with one-day-old males.
RESUME
Hembras de la mosca de la papaya, Toxotrypana curvicauda Gerstaecker,
obtenidas de papayas, Carica papay L., infestadas en el campo necesitaron
5 6 6 dias para desarrollar ovarios maduros parecidos en tamafio a aquellos
de las hembras adults ponedoras de huevos coleccionadas en el campo. No
se encontraron en el campo hembras mas j6venes, con ovarios de menos de
de 0.25 cm, de longitud, sugiriendo 6sto que la hembra de la mosca de la
papaya no busca plant hospedera hasta su madurez. En pruebas de acopla-
miento las hembras se acoplaron al alcanzar 5 dias de edad o mas, mientras
que los machos se acoplaron a cualquier edad (de uno a 6 dias despu6s de
merger) aunque los niveles de acoplamiento fueron menores en machos de
un dia de edad.
Tephritid fruit flies generally are reproductively immature upon emer-
gence as adults and require a maturation period before mating and oviposi-
tion occur. Laboratory-reared Anastrepha suspense (Loew) begin mating at
10 days of age (Mazomenos et al. 1977), coinciding with maximum develop-
ment of male pheromone glands (Nation 1974) and attraction of females
to males (Nation 1972). Similar premating periods are 3 to 4 days in
Ceratitis capitata (Wiedemann) (Mourikis 1965), 12 to 14 days in Dacus
tryoni (Froggatt) (Fletcher 1969), and 7 to 8 days in Rhagoletis pomonella
(Walsh) (Prokopy et al. 1972). Many tephritids require a proteinaceous
food source (usually honeydew) during this period for development to sexual
maturity (Bateman 1972).
It was reported by Landolt and Hendrichs (1983) that female papaya
fruit flies, Toxotrypana curvicauda Gerstaecker, observed in field cages mated
and oviposited only when 6 days old or older, suggesting an obligatory pre-
'Insect Attractants Behavior & Basic Biology Research Laboratory, USDA, ARS, P.O. Box
14565, Gainesville, FL 82604 USA.
June, 1984
240
Landolt: Toxotrypana curvicauda 241
mating period. This paper describes the growth of the ovaries of female
papaya fruit flies after emergence and the mating propensity of males and
females of different ages. The primary purpose was to determine if such an
obligatory pre-mating period exists in the papaya fruit fly and how long it
lasts.
MATERIALS AND METHODS
Flies used in laboratory tests were obtained from infested papaya fruits,
Carica papaya L., collected in a commercial grove in Dade Co., Florida from
February through July 1982. Mature larvae from these fruit pupated in
moist soil placed 7 cm deep in 8 oz wax-cartons. These cartons of soil with
pupae were kept at 26-280C and 60-80% RH until adult emergence. Emerged
flies were sorted by sex daily (at 8-9 AM EST) and placed in (24 cm)3
screen cages with sugar cubes and a wet sponge.
Fifteen female papaya fruit flies of each age from 1 to 8 days old (1 day
= 6 to 30 h old) were dissected to measure ovarian development. Dissections
were made under 80% ethanol using a Bausch and Lomb binocular micro-
scope. All measurements were made at 10x with the aid of an ocular microm-
eter.
Flies tested for mating propensity were placed in 8 oz wax-coated cartons
with screen on both top and bottom, with 1 pair of flies per carton. Tests
were initiated at 1:30-2:00 PM EST and pairs were observed for mating
every 0.5 h thereafter until 4:00 PM. Mating observed in field cages was
highest at this time of day (Landolt and Hendrichs 1983). All combinations
of ages, from 1 to 6 days old, were tested for mating propensity with 40
pairs (4 groups of 10 pairs) per age combination. Groups of flies in which
mating occurred were not used in subsequent mating tests.
To obtain an estimate of the normal maximum size of papaya fruit fly
ovaries, 72 adult females were netted in a papaya grove during March 1982.
These were dissected and the ovaries measured to determine the normal range
of ovary size in a field population. Females collected while ovipositing
(n=32) were considered mature and were evaluated separately to determine
the size of ovaries in reproductively mature females.
RESULTS
Emerging female papaya fruit flies had undeveloped ovaries without
mature eggs. The average length and width of ovaries of 1-day-old flies were
1.25 and 0.44 mm respectively (Fig. 1), while the maximum egg length
average 0.23 mm (Fig. 2). In most flies at this age the abdomen was filled
with fat body as clusters of fat body cells. The length and width of ovaries
and length of eggs increased nearly linearly for 6 days after emergence,
decreasing thereafter. The average length and width of ovaries peaked at
3.14 and 0.75 mm respectively and the maximum length of eggs was 1.3 mm
in females 6 days old. The fat body of 3 to 4-day-old flies was restricted to
the posterior area of the abdomen but had disappeared in 6 to 7-day-old
females in which the ovaries had reached maximum size.
Ovipositing female papaya fruit flies collected in the commercial papaya
grove had ovaries with an average length of 3.1 mm (SE = 0.3) and width
of 0.9 mm (SE = 0.1), comparable to that of 5 to 6-day-old flies in the labo-
Florida Entomologist 67(2)
LENGTH
I i
WIDTH
451j
NO. DAYS POST-EMERGENCE
Fig. 1. Average length and width of ovaries of female papaya fruit flies
at 1 to 8 days post-emergence. Each average calculated from measurements
of ovaries of 15 flies.
ratory and significantly larger than that of 1 to 4-day-old females (Student's
t-test, p 2 0.05) (Table 1). Assuming that ovipositing females were repro-
ductively mature, then females in the laboratory reached maturity in 5 to 6
days. Ovaries of the field-collected females that were not ovipositing when
collected averaged 3.2 mm (SE = 0.3) in length and 0.9 mm (SE = 0.2) in
width and were nearly identical to those of ovipositing females. Of the 72
females collected in the field, none had ovaries as small as 1 to 3-day-old
females in the laboratory. This suggests that female papaya fruit flies do not
search out host plants until reproductively mature.
Mating rates for papaya fruit flies of various ages are presented in
Table 1. Males of all ages tested (1 to 6 days old) mated, although rates
were somewhat lower with males 1 day old. Generally, females did not mate
unless 5 days old or older, although a few matings were noted at 3 and 4
days (Table 1). Mating rates of females at 5 days were significantly higher
than at 4 days, with all ages of males (Student's t-test, p : 0.05).
DISCUSSION
The data on ovary and egg development (Fig. 1 and 2) and mating
propensity (Table 1) all indicate a pre-mating period in the female papaya
fruit fly. Attainment of maximum size of eggs and ovaries was coincident
with that of maximum mating propensity at 6 days post-emergence, and with
1 2 3
242
June, 1984
f
f I
Landolt: Toxotrypana curvicauda
1.4-
1.2-
1.0.
.I*
.46
I .2'
1 2 3 4 5 6 7 8
DAYS AFTER EMERGENCE
Fig. 2. Average maximum length of eggs in ovaries of female papaya
fruit flies at 1 to 8 days post-emergence. Each average calculated from
measurement of the largest eggs in each of 15 flies.
the age at which females mated in field-cage observations (Landolt and
Hendrichs 1983).
Unlike other tephritids studied (Bateman 1972), papaya fruit fly re-
productive development did not require feeding on protein rich foods. All
flies in these studies were given only sugar and water. Also, no difference
was detected between maximum ovary length of females held 5 days without
TABLE 1.
PERCENTAGE OF PAIRS OF PAPAYA FRUIT FLIES OF INDICATED AGES
THAT MATED, 2:00 TO 4:00 PM, APRIL TO JULY 1982, MIAMI, FL.
EACH PERCENTAGE CALCULATED FROM 40 PAIRS.
Age of Age of Females
males 1 day 2 days 3 days 4 days 5 days 6 days
1 day 0 0 0 5.4 30 50
2 days 0 0 0 7.5 85 80
3 days 0 0 0 7.5 45 85
4 days 0 0 7 14 73 87
5 days 0 0 0 16 65 87.5
6 days 0 0 2.5 15 60 71
243
Florida Entomologist 67 (2)
a protein source (2.8 0.6 mm, n=25) or with yeast hydrolysate paste (2.84
0.4 mm, n=25). Apparently, enough reserves are stored during the larval
stages to permit reproductive development without such feeding. This may
be related to young larvae feeding on the more nutritious seed embryos
within the fruit (Mason 1922) rather than on fruit pulp as do other
frugiverous tephritid larvae.
No premating period was evident in male papaya fruit flies. Toxotrypana
curvicauda apparently is the first tephritid species for which such a sharp
difference in reproductive maturation between the sexes has been demon-
strated. Maximum male mating propensity was reached by the second day
after emergence, coinciding with the age at which my personal observations
indicate that males begin puffing (indicative of pheromone release).
ACKNOWLEDGMENTS
Technical assistance was provided by L. Lichtenstein and B. Brown.
R. Nelson kindly allowed use of his papaya grove. Spanish translation of the
abstract was provided by Alicia Arner and Maria Nieto.
REFERENCES CITED
BATEMAN, M. A. 1972. The ecology of fruit flies. Ann. Rev. Ent. 17: 493-518.
FLETCHER, B. S. 1969. The structure and function of the sex pheromone
glands of the male Queensland fruit fly, Dacus tryoni. J. Insect
Physiol. 15: 1309-22.
LANDOLT, P. J., AND J. HENDRICHS. 1983. Behavior of the papaya fruit fly,
Toxotrypana curvicauda Gerstaecker (Diptera: Tephritidae). Annals
Ent. Soc. America 76: 413-7.
MASON, S. C. 1922. Biology of the papaya fruit fly, Toxotrypana curvicauda,
in Florida. USDA Bull. 1081: 1-9.
MAZOMENOS, B., J. L. NATION, W. J. COLEMAN, K. C. DENNIS, AND
R. ESPONDA. 1977. Reproduction in Caribbean fruit flies: Compari-
son between a laboratory strain and a wild strain. Florida Ent. 60:
139-44.
MOURIKIS, P. A. 1965. Data concerning the development of the immature
stages of the Mediterranean fruit fly, Ceratitis capitata (Wiedemann)
(Diptera: Tephritidae) in different host fruits and on artificial media
under laboratory conditions. Ann. Inst. Phytopathol., Benaki, 7 (N.S.) :
59-105.
NATION, J. L. 1972. Courtship behavior and evidence for a sex attractant in
the male Caribbean fruit fly, Anastrepha suspense. Ann. Ent. Soc.
America 1364-7.
1974. The structure and development of two sex specific glands in
male Caribbean fruit flies. Ann. Ent. Soc. America 67: 731-4.
PROKOPY, R. J., E. W. BENNETT, AND G. L. BUSH. 1972. Mating behavior in
Rhagoletis pomonella. II. Temporal organization. Canadian Ent. 104:
97-104.
244
June, 1984
Lin & Harper: Entomophthora gammae Culture
245
ISOLATION AND CULTURE OF
ENTOMOPHTHORA GAMMAE,
A FUNGAL PARASITE OF NOCTUID LARVAE
JING-SHYAN LIN AND JAMES D. HARPER
Department of Zoology-Entomology
Alabama Agricultural Experiment Station
Auburn University, AL 36849 USA
ABSTRACT
Entomophthora gammae (Weiser) was isolated by allowing conidia from
infected soybean looper, Pseudoplusia includes (Walker), larvae to shower
onto egg yolk agar. Fungal and bacterial contaminants were always present,
but at 200C, E. gammae grew fast enough to allow the subculture of hyphal
bodies to clean medium. Once isolated, the fungus was cultured on Czapek
solution agar, potato dextrose agar, Sabouraud dextrose agar, and
Sabouraud maltose agar, all containing 0.2% yeast extract, and on Grace's
insect tissue culture medium. It did not grow on Wolf's medium, potato
agar or potato dextrose agar without yeast extract. The fungus grew most
rapidly in culture when maintained at 25C and 100% RH. Conidia on glass
slides held at 250C germinated only at 100% RH. A gradual increase in
conidium size occurred over a 10-month period of continuous culture. At-
tempts to infect larvae with the cultured fungus were unsuccessful.
RESUME
Entomophthora gammae (Weiser) fu6 aislado permitiendo que las
conidias provenientes de las larvas del medidor de la soya, Pseudoplusia
includes (Walker) se dispersaran sobre agar de la yema de huevo de
gallina. Hongos y bacteria contaminants estuvieron siempre presents,
pero a 200C, E. gammae creci6 lo suficientemente rApido para permitir la
subculture de cuerpos hifales para clarificar el medio. Una vez aislado, el
hongo fue cultivado en una soluci6n de agar Czapek, papa dextrosa agar,
Sabouraud dextrosa agar y Sabouraud maltosa agar, todos los medios con-
tenian 0.2% de extract de levadura y sobre el medio Grace para cultivo de
tejidos de insects. No hubieron crecimientos sobre el medio Wolf, papa agar
o papa dextrosa agar cuando no se agreg6 extract de levadura. El creci-
miento miximo y la germinaci6n de las esporas ocurri6 a los 25'C y con un
100% de humedad relative. Un incremento gradual del tamafo de las
conidias ocurri6 durante los 10 meses de cultivos continues. Intentos para
infestar larvas con el hongo cultivado no tuvieron 6xito.
Several species of the noctuid subfamily Plusiinae are susceptible to
infection by Entomophthora (Tarichium) gammae (Weiser). Harper and
Garner (1973) reported this pathogen from soybean looper, Pseudoplusia
includes (Walker), and cabbage looper, Trichoplusia ni (Hiibner), and
Weiser (1965) reported it from Plusia gamma (L.) in Europe. It is a wide-
spread pathogen of P. includes in the southeastern United States where
this pest attacks soybean (Harper et al. 1983). Several studies on this
pathogen have defined environmental conditions which are related to its
ability to induce and maintain epizootics (Newman and Carner 1974,
1975a,b). This report presents results of work on the isolation and culture
Florida Entomologist 67 (2)
of E. gammae, on defining conditions for in vitro growth of the fungus, and
on laboratory infectivity studies.
METHODS AND MATERIALS
ISOLATION
Fourth- and fifth-instar P. includes larvae were collected on soybeans
in fields near Tallassee, Alabama. At the time of collection, an epizootic of
E. gammae was in progress. Larvae were placed in individual 30-ml cups
containing meridic diet (Shorey and Hale 1965) and returned to the lab-
oratory. Larvae infected with E. gammae typically died in late afternoon
and rapidly turned an abnormal pale yellow color. Dead larvae were taped
to the inside of the lids of 20 x 100 mm petri dishes containing either egg
yolk agar (EYA), potato agar, potato dextrose agar (PDA), Sabouraud
maltose agar, Sabouraud dextrose agar, or Wolf's medium (Wolf 1951).
Plates of each medium were held at 20 and 25C. By the following morning,
conidiophores and conidia had been produced, the latter having showered
onto the medium surface below.
Once Entomophthora could be identified microscopically on the plates,
it was transferred to fresh medium using a sterile inoculating needle. By
transferring at this stage, contaminants, which were always numerous,
were left behind. Several passages were sometimes necessary to completely
eliminate all contaminants.
CULTURE
Once isolated, small quantities of hyphae were transferred with sterile
inoculating loops to the centers of plates containing various media or into
tubes of liquid media and maintained at 20 or 250C. Transfers were made
every 14 days to maintain actively growing cultures. Cultures were also
held at 100C and transferred every 2 months without loss of viability.
GROWTH AND GERMINATION
Plates of EYA and PDA plus 0.2% yeast extract were inoculated with
E. gammae as described above and incubated in temperature cabinets main-
tained at 5 + 1 degree intervals from 5 to 350C. Colony size was determined
daily for 13 days by placing each dish over a cool light source and recording
the average of two diameter measurements taken at right angles to each
other.
Seven petri dishes containing pure sporulating cultures of E. gammae
were inverted over seven EYA plates and allowed to shower for 3-4 hours.
Inoculated plates were covered and maintained at the temperatures used in
the growth rate studies. Plates were examined daily under a microscope to
determine the percent germination of 100 conidia.
Humidity chambers were established using glass desiccator jars con-
taining saturated salt solutions to provide the following humidity levels
(Solomon 1951): <1% (CaC12 without water), 30% (CaCl2 6H20), 50%
[CO(NO,)2 4H,0], 70% (NH4Cl + KNO3), 90% (ZnSO4 7HO), 100%
(distilled water). Humidity in each chamber was checked with a humidity
246
June, 1984
Lin & Harper: Entomophthora gammae Culture 247
gauge (Bacharach Industrial Instrument Co.), allowing sufficient time after
closure for the humidity level to stabilize.
Sporulating cultures of E. gammae were inverted over glass slides for
3-4 h, and the slides were introduced into the chambers. All chambers were
held at room temperature (ca. 250C) under fluorescent lighting. Slides were
removed from the chambers at ca. 5-h intervals for 1 day and again at 57 h.
Percent germination was determined at each interval from the first 100
conidia encountered while scanning the central area of the slide.
INFECTIVITY STUDIES
Field collected cadavers exhibiting symptoms of E. gammae infection
were suspended over individual healthy, laboratory-reared P. includes
larvae held inside petri dishes. Seven larvae were successfully exposed in
this manner. Ten larvae were exposed to conidia showering from each of 3
separate, inverted culture plates which had been maintained in the labora-
tory through 17 transfers over a 1-year period. After 4-6 hours exposure, all
larvae were transferred to individual 1-ounce cups containing diet and were
held at either 90 or 100% RH until they pupated or died.
RESULTS
ISOLATION
Although several media supported growth of E. gammae, EYA held at
200C was the only medium-temperature combination from which a pure
culture could be initiated. The inoculation technique introduced many bac-
terial and fungal contaminants which at 250C overgrew the plates before
E. gammae colonies could become established. These contaminants grew
more slowly at 200C on EYA, and E. gammae colonies were able to develop
vegetatively and could be transferred to clean plates before being over-
grown. After the transfer of hyphal bodies, the mycelium grew vegetatively
for 2-3 days; then hyphal bodies produced conidia which were ejected.
Those landing on fresh medium germinated, produced germ tubes which
elongated, thickened and grew vegetatively, repeating the above cycle. This
process continued as a series of expanding concentric rings of growth until
the petri dish limited further growth.
CULTURE
Hyphal bodies transferred to media other than EYA exhibited varying
growth responses. Potato agar, Wolf's medium, and PDA did not support
growth. A very weak growth was obtained in Czapek solution containing
0.2% yeast extract. PDA + 0.2% yeast extract supported good growth,
while Sabouraud dextrose agar and Sabouraud maltose agar, both contain-
ing 0.2% yeast extract, supported even greater growth. Greatest growth
occurred on EYA containing 0.2% yeast extract and on Grace's insect tissue
culture medium. On EYA held at 25C, E. gammae, following the growth
cycle described above, covered a 10 cm plate within 1 week. On Grace's
medium, the inoculum floated to the surface and grew as a white, compact
mass.
Florida Entomologist 67(2)
GROWTH AND GERMINATION
Growth on EYA was so rapid and diffuse that growth rates were difficult
to determine. PDA + yeast extract supported slower growth with more
clearly defined colony borders; growth on this medium at 5 to 350C is pre-
sented in Table 1. Growth was clearly inhibited at the two temperature ex-
tremes. Most rapid growth occurred at 250C, followed in order by 20 and
30'C. Growth was negligible at 10 and 150C. Conidial germination and
hyphal development occurred equally well at 20, 25, and 300C, but no
germination or growth was observed at 5, 10 or 350C (Table 2).
In humidity chambers, 20% of conidia on glass slides germinated after
6 hours at 100% RH and one conidium germinated after 12 hours at 90%;
no germination occurred through 57 hours at any of the other RH levels
tested.
Distinct morphological changes occurred in E. gammae cultured con-
tinuously on EYA for 10 months. Naturally occurring conidia and those
produced by initial isolations were the typical shape and size (18.80 2.20
x 8.80 + 1.60 zm) reported for the fungus (Harper and Garner 1973).
After 10 months in culture, conidia were more oval, larger in size (28.77
TABLE 1. GROWTH OF Entomophthora gammae AT DIFFERENT TEMPERA-
TURES ON POTATO DEXTROSE AGAR CONTAINING YEAST EXTRACT.
Tempera-
ture (oC) Colony diameter (mm), at day after inoculation (n = 3 plates)1
1 2 3 4 5 6 7 8 9 10 11 12 13
10 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.5 0.8 0.8 1.2
15 0.3 0.3 0.3 0.3 0.3 0.3 0.6 1.2 1.4 1.9 2.9 3.1 4.6
20 0.3 0.3 1.1 2.8 4.2 5.8 7.3 9.8 12.8 19.8 23.8 28.8 33.8
25 0.3 1.1 2.1 5.6 7.1 10.6 13.6 19.6 24.6 31.6 36.6 38.6 43.6
30 0.3 0.3 0.4 2.1 3.1 4.9 6.6 8.6 11.6 14.6 16.6 20.6 23.6
'No growth occurred at 5 or 350C. All plates were inoculated with a 0.3 mm diameter
mass of hyphae.
TABLE 2. CONIDIAL GERMINATION AND GROWTH OF Entomophthora gammae
ON EGG YOLK AGAR AT DIFFERENT TEMPERATURES FOLLOWING
INOCULATIONS
Temperature (C) % Germination' Growth2
24 h 48 h 72 h 96 h
10 0 0 0 0
15 0 0 0 0
20 30 80 + ++
25 70 90 + ++ ++ +
30 60 95 ++ ++
35 0 0 0 0
'Based on examination of 100 conidia at each temperature.
2O No growth, + = poor growth, + + = Good growth, + 4 4 = Very good growth.
June, 1984
Lin & Harper: Entomophthora gammae Culture 249
4.34 x 19.85 4.65 pm), and contained larger and more numerous oil
globules. In culture, conidiophores were difficult to find. Conidia were
normally formed and ejected from the tips of the stocky hyphal bodies. The
membrane or gelatinous layer which surrounds the naturally occurring
conidium is often quite thick in relation to conidium size (Harper and
Garner 1973). After continuous culture, this layer became very thin.
Repeated attempts to infect P. includes larvae with conidia from cul-
tures of E. gammae were unsuccessful, and only one of 7 larvae became in-
fected after exposure to freshly sporulating, field collected larvae. The in-
fected larva died after 7 days, became mumonified, retained its shape, and
became glossy black in color. On dissection, the cadaver was found to be
filled with typical E. gammae resting spores as described by Harper and
Garner (1973).
DISCUSSION
There is considerable information on optimal conditions for growth and
development of many species in the Entomophthoraceae. Members of the
Entomophthoraceae vary considerably in their nutritive requirements.
Coagulated egg yolk or media containing egg yolk has proven satisfactory
for culturing many species (see review by King and Humber, 1981). EYA
was clearly the optimal solid growth medium for E. gammae in this study.
Once isolated, the fungus grew on a number of standard mycological media
if supplemented with yeast extract. While resting spores are commonly
produced by E. gammae under field conditions (Harper and Garner 1973,
Newman and Garner 1975b), they were never produced on any medium
under any of the conditions utilized in this study.
Temperature requirements for growth of the Entomophthoraceae vary
considerably (Gustafsson 1965, Hall and Bell, 1960, 1961). In this study,
the optimal temperature for growth of E. gammae in vitro was 250C or
slightly lower. Spore germination on medium also appeared to be optimal in
the same temperature range, which agrees with an earlier report by New-
man and Garner (1975a), who found that sporulation by E. gammae on
cadavers was maximal at 21 and 26.7'C.
The procedures used to determine optimal humidity conditions for spore
germination served only as an indication of this requirement, as the re-
sponse was very low. However, it is clear that germination occurred only at
or near conditions of 100% humidity, which is also in agreement with re-
sults of Newman and Garner (1975a). They found no germination of
conidia of this species at 90% RH, only 1% at 95% RH, and 95% at 100%
RH.
Lack of infectivity by the cultured fungus may have resulted from the
environmental conditions or techniques employed, or from a loss of infec-
tiousness following repeated subculturing. The low level of infectivity using
fresh cadavers as the inoculum source suggests that the inoculation tech-
nique was inadequate. However, the gradual change in spore morphology
with continued culture indicates that a selection process was occurring,
possibly for an organism that was better adapted for saprophytic growth
at the expense of pathogenicity. This phenomenon would reinforce findings
with other pathogens which have shown the importance of maintaining
minimal passage stock cultures to insure maintenance of desirable char-
Florida Entomologist 67 (2)
June, 1984
acteristics in cultures used for experimental or production purposes.
Alabama Agricultural Station Journal No. 15-83449.
REFERENCES CITED
GUSTAFSSON, M. 1965. On species of the genus Entomophthora Fres. in
Sweden II. Cultivation and physiology. Lantbr. Hogsk. Annlr. 31:
405-57.
HALL, I. M., AND J. V. BELL. 1960. The effect of temperature on some
entomophthoraceous fungi. J. Insect Pathol. 2: 247-53.
.1961. Further studies on the effect of temperature on the growth
of some entomophthoraceous fungi. J. Insect Pathol. 3: 289-96.
HARPER, J. D., AND G. R. CARNER. 1973. Incidence of Entomophthora sp. and
other natural control agents in populations of Pseudoplusia includes
and Trichoplusia ni. J. Invertebr. Pathol. 22: 80-5.
HARPER, J. D., M. SHEPARD, AND R. M. MCPHERSON. 1983. Geographical and
seasonal occurrence of parasites, predators and entomopathogens.
Pages 7-19 In "Natural Enemies of Arthropod Pests in Soybeans".
H. R. Petri, ed. Southern Coop. Ser. Bull. 285. 90 p.
KING, D. S., AND R. A. HUMBER. 1981. Identification of the Entomoph-
thorales. Pages 107-127 In "Microbial Control of Pest and Plant
Diseases 1970-1980". H. D. Burges, ed. Academic Press, London.
NEWMAN, G. G., AND G. R. GARNER. 1974. Diel periodicity of Entomophthora
gammae in the soybean looper. Environ. Ent. 3: 888-90.
1975a. Environmental factors affecting conidial sporulation and
germination of Entomophthora gammae. Environ. Ent. 4: 615-8.
1975b. Factors affecting the spore form of Entomophthora gammae.
J. Invertebr. Pathol. 26: 29-34.
SHOREY, H. H., AND R. L. HALE. 1965. Mass-rearing of the larvae of nine
noctuid species on a simple artificial medium. J. Econ. Ent. 58: 522-4.
SOLOMON, M. E. 1951. Control of humidity with potassium hydroxide, sul-
furic acid, or other solutions. Bull. Ent. Res. 42: 543-53.
WEISER, J. 1965. Notes on two new species of the genus Tarichium Cohn
(Entomophthoraceae). Ceska Myko. 19: 201-4.
WOLF, F. T. 1951. The cultivation of two species of Entomophthora on
synthetic media. Bull. Torrey Bot. Club 78: 211-20.
LIRIOMYZA TRIFOLII:
OVIPOSITION AND DEVELOPMENT IN FOLIAGE
OF TOMATO AND COMMON WEED HOSTS
T. G. ZOEBISCH, D. J. SCHUSTER AND J. P. GILREATH
Agricultural Research & Education Center
5007-60th Street East
Bradenton, FL 34203 USA
ABSTRACT
Oviposition and development of Liriomyza trifolii (Burgess) were
studied in the laboratory in foliage of tomato, Lycopersicon esculentum
Mill. cv. 'Walter,' a common nightshade, Solanum nodiflorum Jacq., com-
mon beggar-tick, Bidens alba (L.) DC., and downy groundcherry, Physalis
pubescens L. Liriomyza trifolii oviposited successfully in foliage of all plant
250
Zoebisch et al.: Liriomyza trifolii
251
species. However, females exposed simultaneously to all plant species de-
posited more eggs per cm2 of tomato foliage than per cm2 of foliage of the
other plant species. Differences among plant species in percent egg hatch,
percent pupation or pupal weight of L. trifolii were not significant. Larvae
pupated most rapidly from foliage of nightshade.
RESUME
Se estudi6 en el laboratorio la oviposici6n y el desarrollo de Liriomyza
trifolii (Burgess) en follaje de tomate, Lycopersicon esculentum Mill.
variedad 'Walter,' Solanum nodiflorum Jacq., Bidens alba (L.) y Physalis
pubescens L. Liriomyza trifolii oviposit6 con buen 6xito en el follaje de todas
las species antes mencionadas. Sin embargo, las hembras expuestas simul-
tAneamente a todas las species de plants depositaron mas huevecillos por
cm2 en el follaje de tomate que en las demds species de plants. No se
encontraron diferencias significativas entire las species de plants con
respect a la eclosi6n, porciento de pupaci6n y peso pupal de L. trifolii. Las
larvas que provenian del follaje de Solanum nodiflorum puparon mis
rApidamente.
Liriomyza spp. leafminers are considered important pests of tomato
although evidence indicates they are secondary in nature (Oatman and
Kennedy 1976, Johnson et al. 1980). Nevertheless, in Florida, if populations
are not controlled, up to 70% by weight of the 5th harvest may be lost
(Schuster, unpublished data).
An understanding of the role of alternative host plants in the popula-
tion dynamics of the pest is important for the management of any pest.
Alternative host plants may serve as sources of epidemic numbers of pests
or as sources of low levels of pests which may initiate and maintain infesta-
tions in crop plants.
The most abundant leafminer attacking tomato on the west coast of
Florida at the present time is L. trifolii (Burgess) (Schuster, unpublished
data). The role of alternative host plants in the population dynamics of
this pest is not known. The host range of L. trifolii has been summarized
by Stegmaier (1966), Spencer (1973), and Spencer and Stegmaier (1973).
However, no records are available regarding the relative suitability of weed
hosts for L. trifolii.
As a first step in elucidating the role of weeds in L. trifolii population
dynamics, we compared oviposition, egg hatch and larval development of
L. trifolii in foliage of tomato, eggplant and selected weeds. Nightshade,
downy groundcherry and common beggar-tick were selected for evaluation
because 80-95% of the Liriomyza larvae observed on weeds on the perim-
eters of commercial tomato fields on the west coast of Florida during the
spring of 1982 occurred on these plants (Schuster, unpublished data). Pig-
weed was included as a less favorable host (as determined by field observa-
tions).
MATERIALS AND METHODS
Experiments were conducted in a room at ca. 270C and 12 h photoperiod.
Liriomyza trifolii adults for all experiments were obtained from a colony
that had been maintained for at least 3 generations on Phaseolus limensig
252 Florida Entomologist 67 (2) June, 1984
var. limenanus L. H. Bailey cv. 'Henderson' bush bean by techniques similar
to those of Ketzler and Price (1982). Four to 6 week old seedlings of tomato
(Lycopersicon esculentum Mill., cv. 'Walter'), a common nightshade
(Solanum nodiflorum Jacq.), downy groundcherry (Physalis pubescens L.),
common beggar-tick (Bidens alba (L.) DC), pigweed (Amaranthus viridis
L.) and eggplant (S. melongena L. cv. 'Florida Market') in 10-cm-diam.
pots were used to evaluate the ovipositional response of flies. The first 4
species were used in the experiments to evaluate development. Plants of sim-
ilar age were used in each replication.
Percentage data were transformed by arcsine V%/100 prior to statistical
analysis but are presented in the original scale. Two-way analyses of vari-
ance were performed on all data and, if significant F values (P = 0.05) for
plant species effects were detected, Duncan's new multiple range test was
used to compare means.
To study ovipositional preference, 1 seedling of each of the 6 plant
species was randomly assigned to a position in a circle within a 61 x 61 x 61
cm cage covered with nylon organdy in a greenhouse. About 100 L. trifolii
adults were released into the cage for 24-48 h after which the numbers of
eggs deposited were counted with the aid of a dissecting microscope. Leaf
area for each plant was measured to the nearest 0.1 cm2 with a LI-COR
Model LI-3000 area meter (Lambda Instruments Corp., Lincoln NB). The
adults were fed honey 24 h prior to testing and during the test were pro-
vided with a 9-cm diam. filter paper dipped in honey. The experiment was
replicated 9 times.
To evaluate the impact of plant host on oviposition (in the absence of
alternative plant choices) and development of immature stages, clip cages
were constructed (Beegle et al. 1981) so that 4.5 cm2 of leaf surface could
be enclosed. One male and 2 female L. trifolii were confined 24 h on the
upper surface of the leaflet with a clip cage supported so that the plane of
the leaflet was horizontal. One clip cage was used on each of 2 leaflets of
about the same age from the middle of each plant. The adults were fed
with honey at least 24 h prior to testing to enhance oviposition. Two drops
of honey were also placed on the inside of each cage. Eggs were counted on
each leaflet and were marked as they hatched. To prevent overcrowding, the
first 3 to 5 larvae per leaflet were allowed to survive while all others were
killed with a dissecting needle. In order to obtain puparia, the leaflets were
covered with polyethylene bags with small ventilation punctures. Puparia
were weighed to the nearest 0.01 mg with a semi-microbalance. Twelve
plants were used per plant species for the oviposition, egg hatch and pupal
weight measurements and 6 were used to determine the time to pupation.
RESULTS AND DISCUSSION
When L. trifolii females were permitted a choice among the plant spe-
cies, significantly more eggs were deposited in foliage of tomato, nightshade
and eggplant than in foliage of the other plant species (Table 1). No eggs
were deposited in foliage of pigweed. Because the leaf sizes varied among
the plant species, egg counts were converted to a per cm2 basis. On an area
basis, significantly more eggs were observed in tomato foliage than in
foliage of the other plant species. More eggs were deposited per cm2 of
nightshade foliage than per cm2 of downy groundcherry or pigweed foliage.
Zoebisch et al.: Liriomyza trifolii
TABLE 1.
253
OVIPOSITION OF Liriomyza trifolii ON SELECTED HOST PLANTS
WHEN ADULTS WERE EXPOSED SIMULTANEOUSLY TO ALL PLANT
SPECIES (CHOICE) AND WHEN ADULTS WERE CONFINED ON FOLIAGE
OF SINGLE PLANT SPECIES (NO CHOICE).
Choice No choice
Plant Eggs/plant Eggs/cm2 Eggs/cm2
Tomato 120.2 a1 1.4 a 5.0 a
Nightshade 119.9 a 0.8 b 6.3 a
Eggplant 94.7 a 0.5 be 5.5 a
Downy groundcherry 45.7 b 0.1 cd 4.9 a
Common beggar-tick 31.6 bc 0.5 be 4.3 a
Pigweed 0.0 c 0.0 d 0.1 b
1Means within a column not followed by the same letter are significantly different at the P =
0.05 level, Duncan's new multiple range test.
When L. trifolii females were confined on foliage of individual leaflets of
the plant species and thus, were not given a choice of oviposition site, sim-
ilar numbers of eggs were deposited in foliage of all plant species except
pigweed (Table 1).
Larvae from foliage of nightshade pupated in significantly less time than
larvae from foliage of the other plant species (Table 2). The percent egg
hatch, percent pupation or pupal weights of L. trifolii were not significantly
affected by the plant species evaluated.
Nightshade, downy groundcherry and common beggar-tick were demon-
strated to be acceptable hosts of L. trifolii in the laboratory. All 3 species
may support populations of L. trifolii and serve as sources of infestation for
tomato in the field. Of the 3, nightshade may serve as a source of greater
numbers of L. trifolii since, when females were given a choice, more eggs
were deposited on a per plant basis in nightshade foliage than in downy
groundcherry or common beggar-tick foliage. In addition, less time was re-
quired for larvae to complete development in nightshade foliage. Manage-
ment of these weeds, particularly nightshade, might aid in the management
of L. trifolii on tomato. However, the role of these weeds as sources of para-
sites of Liriomyza must first be elucidated. It must also be confirmed that
TABLE 2. DEVELOPMENT OF Liriomyza trifolii IN FOLIAGE OF SELECTED HOST
PLANTS.
% egg Days to % Pupal
Plant hatch pupation pupation wt. (mg)
Downy groundcherry 96.7 N.S.1 4.8 a2 74.6 N.S. 0.48 N.S.
Tomato 95.7 4.8 a 83.3 0.45
Nightshade 91.9 4.1 b 88.2 0.48
Common beggar-tick 91.1 5.0 a 89.1 0.45
1N.S. indicates no significant differences among means at the P = 0.05 level, F tests in
two-way analyses of variance.
'Means within a column followed by the same letter are not significantly different at the
P = 0.05 level, Duncan's new multiple range test.
254 Florida Entomologist 67 (2) June, 1984
L. trifolii reared from foliage of the weed species are not host-conditioned
and will oviposit and develop on tomato.
ACKNOWLEDGMENT
We wish to thank Dr. David Hall for identification of the weed species
utilized in these experiments.
Florida Agricultural Experiment Stations Journal Series No. 4675.
REFERENCES CITED
BEEGLE, C. C., H. T. DULMAGE, D. A. WOLFENBARGER, AND E. MARTINEZ.
1981. Persistance of Bacillus thuringiensis Berliner insecticidal ac-
tivity on cotton foliage. Environ. Ent. 10: 400-1.
JOHNSON, M. W., E. R. OATMAN, AND J. A. WYMAN. 1980. Effects of in-
secticides on populations of the vegetable leafminer and associated
parasites on summer pole tomatoes. J. Econ. Ent. 73: 61-6.
KETZLER, L. D., AND J. F. PRICE. 1982. Methods for growers to evaluate
effects of their cultural practices on Liriomyza trifolii leafminers in
a simple laboratory. Proc. Florida State Hort. Soc. 95: 162-4.
OATMAN, E. R., AND G. G. KENNEDY. 1976. Methomyl induced outbreak of
Liriomyza sativae on tomato. J. Econ. Ent. 69: 667-8.
SPENCER, K. A. 1973. Agromyzidae (Diptera) of Economic Importance.
W. Junk B.V., The Hague. 418 p.
SPENCER, K. A., AND C. E. STEGMAIER, JR. 1973. Arthoropods of Florida
and Neighboring Lands, Vol. 7. Agromyzidae of Florida with a sup-
plement on species from the Caribbean. Florida Dept. Agric. Con-
sumer Serv., Div. Plant Industry, Bureau Ent. Contribution No. 171.
205 p.
STEGMAIER, C. E., JR. 1966. Host plants and parasites of Liriomyza trifolii
in Florida (Diptera: Agromyzidae). Florida Ent. 49: 75-80.
METHYL BROMIDE FUMIGATION AS A
QUARANTINE TREATMENT FOR LATANIA SCALE,
HEMIBERLESIA LATANIAE
(HOMOPTERA: DIASPIDIDAE)
PETER C. WITHERELL
Miami Methods Development Station USDA, APHIS, PPQ
Miami, FL 33158 USA
ABSTRACT
Fumigation tests using methyl bromide at normal atmospheric pressure
showed that 16 g/m3 for 21/ h at 22.80C or above, or 32 g/m3 for 21/ h at
18.3 to 22.20C was sufficient as a quarantine treatment against latania scale,
Hemiberlesia lataniae on nursery stock. For use on avocado fruits, recom-
mendations are for 24 g/m3 for 21/ h at 22.80C or above, and 32 g/m3 for
3 h at 18.3 to 22.20C. Microscopic examination of fumigated and control
scales showed that certain body movements, particularly pharyngeal pulsa-
tion, is a much more reliable indicator of scale viability than the mere
presence of body fluids. Following fumigation, body fluids required up to
31 days to dehydrate completely, under humid conditions.
Witherell: Fumigation for Latania Scale
RESUME
Pruebas de fumigaci6n con bromura de metilo a una presion atmosferica
normal demostraron que 16 g/m3 por 21/ horas a 22.80C o mas, o 32 g/m3
por 22 horas de 18.3 a 22.20C fu6 suficiente como un tratamiento de
cuarantena contra la escama latania, Hemiberlesia lataniae en viveros
de plants. Para usar en frutas de aguacate, las recomendaciones son 24
g/m3 por 21 horas a 22.80C o mas, y 32 g/m3 por 3 horas de 18.3 a 22.2'C.
ExAmenes microsc6picos de escamas fumigadas y el control demonstraron
que movimientos del cuerpo, especialmente pulso faringeo, es un indicador
mejor de la viabilidad de la escama que la mera presencia de los fluidos
corporales. La perdida total de fl6idos corporales tom6 hasta 31 dias post-
tratamiento en condiciones hdmedas despuds de fumigarse.
Latania scale, Hemiberlesia lataniae (Signoret) is widespread through-
out tropical and subtropical areas, and is also found in greenhouses in
temperate climates (Dekle 1976, Hamon 1979, Nakahara 1982). The species
is polyphagous, and is known to infest more than 300 plant species in Flor-
ida (Dekle 1976). It is a serious pest of palms and other ornamentals,
particularly ponytail palm or elephant-foot tree (Beaucarnea recurvata
Lem.), Australian pine (Casuarina equisetifolia), loquat (Eriobotrya
japonica), and rose (Rosa spp.). Leaves, stems, and fruits may all be
damaged as a result of the insects sucking plant juices.
H. lataniae was best described by Ferris (1938). The armor is usually
round (female) or oval (male), but may be irregular in shape when sev-
eral scales overlap or crowd together. The armor is strongly convex and 1.5
to 2 mm in diameter when mature. Exuviae are large, pale brown, centrally
located to sub-centrally, and are surrounded by a dirty white area. When
the armor is carefully removed with a pin, the soft, lemon-yellow, flattened,
sac-like body is revealed. The body is attached to the host by thread-like
stylets that arise near the middle of the body, and extend as long or longer
than the body. Legs are absent, in all secondary stages except 1st instar
nymphs (crawlers).
H. lataniae is quarantined in some foreign countries. This often presents
a barrier to the free flow of international commerce. During the recent out-
breaks of Mediterranean fruit fly (Ceratitis capitata (Wied.)) in Cali-
fornia, avocado fruits originating from outside regulated areas of that state
were shipped to Japan and elsewhere. Shipments received a combined treat-
ment of methyl bromide (MB) plus refrigeration as a precaution (i.e., MB
@ 32 g/m3 for 21 h at 21.10C or above, followed by 7 days of storage at
7.20C or below).'
Subsequently, inspectors of the Japanese Ministry of Agriculture, Fish-
eries and Forestry (MAFF), reported live latania scales in 3 out of 5 sea
containers of California avocados, which had received the USDA's pre-
cautionary treatment against Mediterranean fruit fly. The Japanese au-
thorities re-treated these fruits with hydrogen cyanide (HCN). The Cali-
fornia avocado industry then requested a fumigation schedule be developed
which would allow acceptance of certified fruit. A predeparture treatment
1Equivalent to 32 oz./1000 ft.3. This is Treatment Schedule T 102(a) (1) of the USDA
Plant Protection and Quarantine Programs Treatment Manual (Anon. 1981).
255
Florida Entomologist 67 (2)
would eliminate the necessity and cost of an additional treatment upon ar-
rival in Japan, and would give the avocados a longer shelf-life.
To determine scale viability Japanese inspectors puncture or crush the
scale, and if body fluids are present, the scale is considered to be alive.
(This is the so-called "squash test".) Determining scale mortality on com-
modities receiving quarantine fumigation treatment presents a special prob-
lem. Several factors are involved, including time elapse between treatment
and inspection and temperature and RH during in-transit storage. More-
over, the waxy scale covering may prevent large female scales from desic-
cating, so that when the last scales have dehydrated, the commodity has
exceeded its marketable shelf-life.
A more time-consuming but more accurate method of assessing scale
viability is the so-called "pump test", an unpublished technique developed
at the University of California, Riverside. Naked specimens are examined
microscopically for vital signs, viz., slight body movements, particularly the
pumping activity of the pharynx. The experiment reported here was de-
signed to clarify the question of treatment efficacy by microscopically ex-
amining fumigated scales.
METHODS AND MATERIALS
Attempts to obtain scale-infested avocado fruits from packing houses in
Florida and California were unsuccessful. Moreover, since avocados are not
a favored host of this insect (D. Fiskaali, California Dept. of Food & Agric.,
pers. comm.), securing sufficient numbers of infested fruits presented a
formidable problem. Therefore, a more favored host was obtained, viz.,
ponytail palm or elephant-foot tree, Beaucarnea recurvata Lem. (Liliaceae).
In addition, unpublished results of MB fumigations of latania scale, by the
California Dept. of Food & Agriculture in 1936 through 1948, were ob-
tained and analysed.
Twenty moderate-to-heavily infested potted ponytail palms (ca. 46 cm
tall) were purchased locally, and scales were microscopically examined to
confirm that some scales were alive. Plants were stored over night at the
fumigation temperatures, in the room equipped with fumigation chambers.
The following morning, plants were divided into treatment groups (1 or 2
plants each). There were approximately equal numbers of scale insects in
each treatment group. Fumigation trials were conducted, using the follow-
ing test schedules (MB at normal atmospheric pressure) :
(A) 16 g/m3 for 21/2 h; 22.8-23.9 and 18.30C temperatures
(B) 32 g/m3 for 2%1 h; 22.8-23.9 and 18.30C temperatures
(C) 48 g/m3 for 2%1 h; 22.8-23.9 and 18.30C temperatures
(D) 32 g/m3 for 4 h; 24.4-25 and 200C temperatures2
(E) Combination of MB fumigation plus cold treatment: 32 g/m3 for 21
h; 24.4-25 and 200C temperatures, followed by 7 days in storage at
4.4-7.2 C3
(F) Controls (no treatment)
2This is Treatment Schedule T 105 (a) (1) of the USDA Plant Protection and Quarantine
Programs Treatment Manual (Anon. 1981), except that temperature during treatment must'
be 21.10C or above. (Recommended for avocados.)
3This is Treatment Schedule T 102 (a) (1) of the USDA Plant Protection and Quarantine
Programs Treatment Manual (Anon. 1981), except that the temperature during treatment
must be 21.10C or above; during storage, 7.200 or below. (Recommended for avocados.)
June, 1984
Witherell: Fumigation for Latania Scale
257
MB gas concentrations within the fumigation chambers were monitored
during the course of the treatments by using a Gow-Mac gas analyser.4
Following treatment, plants were isolated from each other and placed in
a greenhouse, except for plants receiving Treatment E. The latter were
placed in a walk-in cold room (4.4-7.20C, lights on). RH in the two loca-
tions ranged from 75 to 90%. Plants were watered (roots only) twice
weekly, immediately following examination of scales.
A representative sample of 100 scales per treatment was microscopically
examined twice a week post-treatment over a 31-day period to document the
rate of desiccation and mortality. All stages were examined, except eggs.
During inspection, one or more leaves were removed from the plant, and
examined under a binoccular, dissecting microscope (15X), using a 30 W
spotlight. Plants receiving Treatment E (fumigation plus refrigeration)
were exposed to room temperature before they were inspected. High magni-
fication (45 or 90X) was used to give a more detailed view. The scale cover
(armor) was teased off with a pin to reveal the yellow, sac-like body be-
neath. The large body of mature females often had a cluster of yellow eggs
and/or crawlers immediately adjacent to it. If alive, the female would con-
tract, expand, undulate, or twist when gently prodded with a blunt object.
If no movement was detected, the insect was teased from the substrate, and
turned upsidedown. The triangular-shaped base of the mouthparts was ex-
amined for pulsating or pumping action in the pharynx of live specimens.
Often, also the threadlike stylet tube moved.
Scales examined were classified into 3 categories:
(D) Dead (dry, with no body juices)
(L) Live (showing pulsation or other body movements)
(M) Moribund (body juices still intact, at least partially, but body show-
ing no movement when prodded)
The latter category also included scales in various stages of decomposition,
as well as those which were parasitized.
RESULTS AND DISCUSSION
Early unpublished work by the California Dept. of Food & Agriculture
on MB fumigation for quarantine control of latania scale is summarized in
Table 1. All treatments were reported as 100% effective. Steinweden (1948),
however, reported poor control with MB at 32 g/m3 at 15.50C against this
scale on avocados (2-h fumigation).
In tests conducted in Miami, FL, the ponytail plants tolerated the treat-
ments well, except for Treatment D at 24.4-250C, which resulted in ex-
cessive browning of the outer whorls of leaves ("tip burn"). Latania scales
showed a definite preference for the upper leaf surface of ponytail palm,
and congregated in the leaf axils, where the tissue is succulent.
Thoroughness of treatment, as indicated by periodic monitoring of gas
concentration during the course of fumigation, can be expressed in terms of
a "CT product" (mean concentration of MB gas (g/m3) X time in hours).
The CT products of Treatments A through F were calculated as follows:
tests at 22.8-250C, 38.1, 71.9, 105, 113.2, 81.9, and 0, respectively, and tests
at 18.3-200C, 35, 73.8, 106.9, 126.7, 83.1, and 0, respectively.
4Manufactured by Gow-Mac Instrument Co., Bridgewater, NJ (Model No. 20-350).
258 Florida Entomologist 67 (2) June, 1984
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Witherell: Fumigation for Latania Scale 259
The efficacy of Treatments A through F is shown in Table 2. At the
dosages used, MB fumigation was 100% effective at 22.8-250C. Good results
even at the low dosage of 16 g/m3 for 2/ h (Treatment A) confirms the
validity of earlier data from California (Table 1). At cooler temperatures
(18.3-200C), fumigation was still effective, except in Treatment A (16 g/m3
for 2/2 h), where 4-25% (k = 13.1%) survival occurred. Similar scale
survival was recorded in the controls (Treatment F), i.e., 1-26% (i =
12.4% survival).
Body decomposition and moisture loss occurred over an extended period
of time under the humid conditions prevalent in Florida, and at the high
RH at which fresh fruits and vegetables are best stored. At 31 days post-
treatment a few insects retained some body moisture. Among the controls
examination revealed 32 to 99% (j = 73.5%) of the scales were dead (D);
1 to 62% (k = 22.4%) were alive (L); and 0 to 12% (i = 3.5%) were
moribund (M). For all practical purposes scales classified as "moribund"
were dead. There was no "delayed-action mortality," when lack of move-
ment rather than lack of moisture was used as the criterion of death. A
few fumigated scales recorded as "moribund" contained a wasp larva, which
appeared to be dead.
As the scales decomposed and lost moisture, their bodies changed from
a bright lemon-yellow color, bloated and flexible, to an amber, moist, to
straw colored and dehydrated. Immature scales, especially, desiccated
quickly, became dry, brittle, and dark brown in color. Fully mature female
scales dehydrated more slowly than others. Occasionally the armor of dead
scales sloughed off prior to inspection. Also, some of the dead scales ex-
amined contained an opening made by thrips or emerging wasps. In con-
trols, live thrips were occasionally found within hollowed-out scales.
Whether these thrips were predators or merely scavengers is unknown.
Color and consistency provide good evidence of mortality, but should not
be the only consideration when examining freshly fumigated scales. The
progression of color changes was somewhat slower among scales which had
received Treatment E. This is probably a result of the preservative effect
of refrigeration. Inasmuch as these scales retained their lemon-yellow color
longer, warming them and checking for slight movement was deemed
especially important for this group. No movement, however, was ever ob-
served.
CONCLUSIONS AND RECOMMENDATIONS
The results of this study lead to the following conclusions and recom-
mendations:
1.) The "squash test" for determining viability of armored scales in the
field is not an adequate test for fumigated specimens. An accurate assess-
ment of treatment efficacy can be made only by microscopic examination to
detect slight body movements and pharyngeal pulsations.
(2) During fumigation, the dosage, length of exposure, and temperature
of the commodity are factors critical to the success of treatment. Higher
dosages of a fumigant are required at lower temperatures, in order to effect
a complete kill, because of reduced metabolism in the insects (Monro 1969,
Anon. 1981). Data from California (D. Fiskaali, unpubl, Steinweden 1948)
illustrated that MB at a dosage of 32 g/m3 for 2 h was completely effective
Florida Entomologist 67 (2)
June, 1984
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Witherell: Fumigation for Latania Scale 261
at 21.10C, but killed only 28.3% of the latania scales at 15.60C. Based on
the results of the present study, the following are the minimum schedules
that can be recommended as effective against latania scale on ornamentals
(MB at normal atmospheric pressure) :
16 g/m3 for 2 h; 22.80C or above.
32 g/m3 for 2 h; 18.3 to 22.20C.
Air circulation should be provided so that temperatures throughout the
chamber load are relatively uniform, and never below 18.30C.
(3) If the scale-infested commodity being fumigated is avocado, one
should bear in mind that these fruits, like many others, tend to absorb MB
gas (P. C. Witherell, unpub. data). Gas loss is even greater if the fruits
are packed in corrugated fiberboard cartons or under tarpaulin. Accordingly,
fumigation schedules of slightly higher dosage or longer exposure time than
aforementioned would be advisable. The following schedules, therefore, are
recommended for use against latania scales on avocado (MB at normal
atmospheric pressure) :
24 g/m3 for 2 h; 22.80 C or above.
32 g/m3 for 3 h; 18.3 to 22.20C.
Fruit load in the chamber or under tarpaulin should be 70% or less, cal-
culated by the height of the chamber or enclosure. Treatments D and E, at
21.10C or above-both of which are prescribed for use on avocados against
eggs and larvae of fruit flies (Anon. 1981)-are also 100% effective against
latania scale. These schedules, however, may cause some phytotoxic damage
to the fruit. Tolerance of avocado to fumigation depends, to some extent,
on the variety of fruit. Varieties exhibit a wide range of tolerance to MB
(Witherell et al. 1982). Normal fruit rots, particularly anthracnose, de-
velop faster after MB fumigation, since the ripening process is accelerated
by 2 to 4 days. Vigorous brushing of fruits to remove scales is also possible,
but probably impractical for large shipments.
ACKNOWLEDGMENTS
I wish to thank Mr. Kenneth D. Havel (USDA, APHIS, PPQ, Hoboken,
NJ), Miss Alicia Arner (USDA, ARS, Miami, FL), and Mr. Don A. Fiskaali
(California Dept. of Food & Agric.) for their help with this manuscript. I
also thank Mr. David Lowe (formerly with Florida DACS, DPI) for pro-
viding a source of infested material.
POST SCRIPT: In a recent meeting between USDA and Japanese MAFF
officials in Tokyo, the data in this paper were presented. Agreement was
reached that Japanese inspectors will use microscopic examination to de-
termine scale insect mortality in fumigated commodities.
REFERENCES CITED
ANONYMOUS. 1981. Plant Protection and Quarantine Programs Treatment
Manual (as revised). Sect. VI, Series T-100, pp. 1-29. USDA, APHIS,
PPQ, Hyattsville, MD.
DEKLE, G. W. 1976. Page 71 In: Florida Armored Scale Insects. Vol. 3
of: Arthropods of Florida and Neighboring Land Areas. Florida
DACS, DPI, Gainesville, FL.
Florida Entomologist 67 (2)
FERRIS, F. G. 1938. Atlas of Acale Insects of North America. Vol. 2, Ser.
Nos. 137-268. California: Stanford Univ. Press.
HAMON, A. B. 1979. Latania scale, Hemiberlesia lataniae (Signoret)
(Homoptera: Coccoidea: Diaspididae. Ent. Circ. No. 208. Florida
DACS, DPI, Gainesville, FL, 2 p.
MONRO, H. A. U. 1969. Manual of Fumigation for Insect Control. FAO
Agric. Stud., No. 79. Rome: FAO, UN, 381 p.
NAKAHARA, S. 1982. Checklist of the Armored Scales (Homoptera:
Diaspididae) of the Conterminous United States. USDA, APHIS,
PPQ, Beltsville, MD, 110 p. (p. 42).
STEINWEDEN, J. L. 1948. Commodity treatments. Pages 236-41 In: 29th
Annu. Rep., period ending Dec. 31, 1948. California Dep. Agric. Bull.
37.
WITHERELL, P. C., D. H. SPALDING, AND C. A. BENSCHOTER. 1982. Tolerance
of Florida avocado cultivars to methyl bromide fumigation treatments
effective against fruit flies. Proc. Florida State Hort. Soc. 95: 227-9.
RESPONSE OF TRICHOGRAMMA PRETIOSUM AND
T. EVANESCENSI TO WHITELIGHT, BLACKLIGHT
OR NO-LIGHT SUCTION TRAPS
J. H. BROWER AND L. D. CLINE
Stored-Product Insects Research and Development Laboratory
Agricultural Research Service, USDA
Savannah, GA 31403 USA
ABSTRACT
The response of Trichogramma pretiosum Riley and T. evanescens
Westwood to blacklight, whitelight, or no-light suction traps in empty 44.7
m3 rooms showed that significantly more (P<0.01) of both species re-
sponded to blacklight than to whitelight or no-light traps. About 40% and
60% of the T. evanescens and T. pretiosum, respectively, were caught in the
blacklight trap. No significant difference (P>0.05) was found in the re-
sponse of T. pretiosum to whitelight and no-light traps, while significantly
more (P<0.05) T. evanescens were caught in the whitelight trap than in the
no-light trap. Females, especially those of T. evanescens, appeared to be
more responsive than males as more females than males of both species
were usually caught. The implications of these findings should be considered
in planning releases of Trichogramma for control of storage moths in
warehouses.
RESUME
El comportamiento de Trichograma pretiosum Riley and T. evanescens
Westwood hacia trampas de succi6n de luz negra, luz blanca, o trampas sin
luz en cuartos vacios de 44.7 m3, indic6 que significativamente (P < 0.01)
ambas species respondieron m6s a las trampas de luces negras que a las
trampas de luces blancas o a las de sin luces. Alrededor de 40% y 60% de
T. evanescens y T. pretiosum respectivamente fueron atrapadas en la
trampa de luz negra. No se encontr6 ninguna diferencia significativa (P >
'Hymenoptera, Trichogrammatidae
June, 1984
262
Brower & Cline: Light Trapping Trichogramma 263
0.05) en el comportamiento de T. pretiosum hacia trampas con luz blanca o
sin luz, mientras que significativamente mas (P < 0.05) T. evanescens
fueron atrapadas en trampas de luz blanca que en trampas sin luces.
Hembras, especialmente aquellas de T. evanescens, parecen responder mis
que los machos, mientras que mas hembras que machos de ambas species
fueron usualmente atrapadas. Las implicaciones de este descubrimiento
debe de considerarse cuando se planee soltar Trichograma para controlar
polillas en almacenes.
Traditionally pests of stored-food commodities have been controlled by
chemical means, but recently the potential of biological control methods has
received more attention. Some studies have suggested that various species
of parasitic Hymenoptera might be useful as control agents for stored-
product Lepidoptera (Corbet and Rotheram 1965, Reinert and King 1971,
Takahashi 1973, Press et al. 1977), and it is well known that eggs of
stored-product moths can serve as laboratory hosts for the rearing of
Trichogramma (Alden and Farlinger 1931, Morrison and King 1977). In
fact, eggs of the Angoumois grain moth, Sitotroga cerealella (Olivier)2, are
usually used to produce the large numbers of Trichogramma needed for
releases to control field crop pests (Morrison et al. 1976). Thus, Brower
(1983) suggested that large numbers of Trichogramma might be released
periodically into warehouses to reduce or eliminate populations of stored-
product moth pests. However, the effectiveness of parasites in indoor situa-
tions has not been studied extensively and many questions need to be
answered regarding warehouse releases.
Many parasites and predators seem to be lured to and can often be col-
lected at warehouse windows and around lights (Ghani and Sweetman
1955), and Trichogramma spp. are known to be positively phototactic
(Morrison et al. 1976, Martin 1969). To determine the strength of this at-
tractancy to light we tested the response of 2 species of Trichogramma to
whitelight, blacklight, and no-light suction traps.
MATERIAL AND METHODS
EXPOSURE ROOMS
Tests were conducted in two adjacent rooms that were each ca. 44.7 m3.
Several modifications had to be made to the rooms to make them tight
enough to confine the small test insects: (1) clear plexiglass shields were
built around the light fixtures and electrical outlets, (2) 295 p-mesh Nitex@
screens were placed over the heating and return air ducts, (3) special doors
were constructed that could be closed tightly, (4) an anteroom connecting
the rooms was built to reduce the chances of any accidental introduction of
unwanted insects, and (5) all cracks and crevices were caulked and re-
caulked as needed between replicates.
The test conditions of the rooms were kept as constant as was practical.
The minimum temperature was 27%j C; the maximum temperature was
not controlled, but it never exceeded 311 40C. The fluorescent ceiling lights
automatically turned on at 0700 h and off at 1900 h which coincided with the
2Lepidoptera, Gelechiidae
Florida Entomologist 67 (2)
light-dark cycle at which the Trichogramma were reared. The relative
humidity in the rooms fluctuated between 40-60%.
LIGHT TRAPS
The New Jersey mosquito light traps8 used in these tests were identical
except for their light sources. The whitelight (WL) trap had a 25-watt
clear incandescent bulb; the blacklight (BL) trap had a 32-watt, ca. 0.3 m
circline fluorescent blacklight lamp (GE FC12T10-BL Rapid Start). The
standard wire screen funnel was lined with 295 p-mesh Nitex@ screen and
the collection jars contained a small amount of deobase to retain and kill
the trapped insects. Both traps were modified so the light source could be
turned off with the fan left running, thus creating a no-light, suction trap.
One light trap was suspended from the ceiling of each room in the
corner furthest from the door, so that the center of the light source was ca.
0.5 m away from the walls and the ceiling and ca. 2.1 m from the floor. The
traps ran continuously during the tests and the collection jars were changed
daily.
TEST INSECTS
Two species of Trichogramma were used in this test, T. pretiosum Riley
and T. evanescens Westwood. T. pretiosum cultures were obtained from the
Cotton Insects Research Laboratory, College Station, TX; and they origi-
nated from a field collection in Arkansas. T. evanescens cultures were ob-
tained from the Southern Grain Insects Research Laboratory, Tifton, GA;
and they had originated in Poland. Both species were reared for many
generations at the Savannah Laboratory on the eggs of the almond moth,
Cadra cautella (Walker)4, in a controlled environment at 27+2140C and
60-5% RH with a 12L:12D light cycle. Large numbers of almond moth
eggs were collected by placing 0- to 2-day-old adults in inverted 3.8-liter jars
with screen bottoms. Eggs were removed after 24 h, sifted to remove debris,
and placed in open plastic petri dishes for exposure to adult Trichogramma.
The 0- to 24-h-old almond moth eggs were exposed by placing the open petri
dish in a closed 3.8-liter jar along with an open petri dish containing large
numbers of parasitized almond moth eggs that contained Trichogramma 0-
to 24-h before emergence. The almond moth eggs were exposed to Tri-
chogramma adults for 8 h and then removed from the exposure chambers.
One day before adult Trichogramma emergence, parasitized almond
moth eggs were counted into groups of 200, and each group was glued to a
labeled 9 cm filter paper disk and placed in a petri dish. Dishes containing
each species were then placed in the center of either the WL or BL room,
or were reserved as controls. The parasitized eggs were placed in the rooms
at ca. 1400 h. Emergence of control insects held at the aforementioned con-
trolled conditions usually started by 0800 h the following morning.
Trap catches were removed each morning for 6 days and the specimens
were separated by species, sexed, counted, and recorded. The 2 species were
3Manufactured by Hausherr's Machine Work, R. D. 1, Old Freehold Road, Toms River,
NJ 08753.
'Lepidoptera, Pyralidae.
264
June, 1984
Brower & Cline: Light Trapping Trichogramma
265
tested simultaneously and 4 replicates were run for each light trap both with
and without the trap lights on.
After 6 days, the petri dishes were removed from the light-trap room
and from the control cabinet, and the eggs were examined microscopically to
determine percentage of Trichogramma emergence. Control adults were
counted and random samples of 50 adults from each replication were sexed
to determine sex ratio for each of the 2 species. Significance of the data was
determined by comparing sample means with Student's t-test of paired
observations.
RESULTS
Parasitized control eggs averaged 97.4% emergence and a male:female
ratio of 1:1.31 for T. pretiosum and 97.9% emergence and a sex ratio of
1:1.02 for T. evanescens. Over 99% of the eggs that had emergence holes
produced only a single Trichogramma adult. The average percentage of
emergence in the WL and BL rooms, respectively, was 97.7 and 97.4 for
T. pretiosum and 98.1 and 97.9 for T. evanescens. The sex ratios or num-
ber of emerged adults could not be determined in the experimental rooms.
BL traps were significantly more attractive (P<0.01) to both species of
Trichogramma than WL traps, which were only about one-third as effective
in catching either species (Table 1). However, significantly more (P<0.05)
T. pretiosum than T. evanescens were caught in both WL and BL traps.
Also, significantly more females than males of T. pretiosum were caught by
both BL (P<0.01) and WL (P<0.05) traps. BL traps caught significantly
more (P<0.05) T. evanescens females than males, but there was no signifi-
cant difference between catches of males and females in WL traps.
When the traps were operated with their lights off but the suction fans
on, there were no significant differences (P>0.05) between the 2 types of
traps for either species (Table 1). However, there was a consistent trend
for the WL type of trap to catch more insects than the BL type of trap.
This non-significant difference may have been caused by the greater restric-
TABLE 1. TOTAL NUMERICAL RESPONSE OF MALES AND FEMALES OF Tri-
chogramma pretiosum AND T. evanescens TO WHITELIGHT, BLACK-
LIGHT OR NO-LIGHT SUCTION TRAPS OVER A 6 DAY TRAPPING PERIOD.
(MEAN OF 4 REPS) a
Response by sex
Trap type Species response T. T.
and light T. T. pretiosum evanescens
sources pretiosum evanescens $ 9 S 9
Lighted WL 41.8 25.5 16.0* 25.8 7.5 ns 18.0
** ** ** ** ** **
Lighted BL 123.8 81.1 42.0 ** 81.8 29.3 51.8
No-light WL 36.8 ** 13.8 19.0 ns 17.8 2.3 11.5
ns ns ns ns ns ns
No-light BL 25.1 ** 9.3 10.8 ns 14.3 2.0 7.3
aSignificance between pairs of values in rows or in columns is indicated by: ns = none,
* = P<0.05, ** =P<0.01 as determined by Student's t-test.
Florida Entomologist 67(2)
June, 1984
tion of airflow by the large, circular BL bulb. This pattern of greater catch
by the WL type trap was opposite from the pattern found when the trap
lights were on. Significantly more (P<0.01) T. pretiosum than T. evanescens
were caught in both traps. Males and females of T. pretiosum were caught
with equal frequency in the no-light traps, but significantly more (P<0.05)
females than males of T. evanescens were caught in both no-light traps.
The temporal pattern of Trichograma catch was probably influenced by
emergence pattern, flight propensity, trap type, and species. For T.
pretiosum most catch occurred on the 2nd day (Table 2) in lighted traps
with very little catch on the 3rd and 4th days and none on the 5th or 6th
days. The catch was somewhat delayed in the no-light traps and fewer
insects were trapped. T. evanescens responded most strongly to the WL
trap on the 1st day and catch decreased thereafter (Table 2). Response to
the BL trap and to no-light traps was very similar in this species with the
greatest catch occurring on the 2nd day.
DISCUSSION
General observations of Trichogramma spp. usually show a movement
toward or aggregation near light sources (Martin 1969, Morrison et al.
1976). However, to our knowledge no controlled studies of this phenomenon
have been published until now. This study showed that T. pretiosum and
T. evanescens moved several meters to a BL source, but that an incandescent
WL source was only minimally attractive. More than 41% and 63% of the
emerged T. evanescens and T. pretiosum adults, respectively, were caught
by the BL traps, but less than 22% of either species was caught by the WL
traps. This observation supports the supposition of Costas (1941) that WL
only increases the activity and dispersion of Trichogramma, but not ori-
ented movement. Previous observations of positive phototactic behavior of
Trichogramma may have resulted from increased movement or attraction
to the UV portion of most WL sources. Females of T. pretiosum were
caught significantly more often than males by both BL and WL traps, but
the interpretation of this finding must be tempered by the fact that the sex
ratio of this species was skewed in favor of females. Equal numbers of
females and males of T. pretiosum were caught in the no-light traps. Fe-
males of T. evanescens were caught significantly more often than males in
TABLE 2. PERCENTAGES OF Trichogramma pretiosum AND T. evanescens
ADULTS CAUGHT IN WHITE LIGHT, BLACK LIGHT AND NO-LIGHT
SUCTION TRAPS DURING 5 DAYS OF OPERATION.
T. pretiosum T. evanescens
Lighted Lighted Combined Lighted Lighted Combined
Day WL BL no light WL BL no light
1 28.7 22.2
2 62.3 67.7
3 8.4 8.5
4 0.6 1.6
5 0 0
16.2 51.0 34.3 38.3
48.6 23.2 55.5 51.4
32.0 9.8 8.3 8.7
3.2 1.0 1.9 1.6
0 0 0 0
266
Brower & Cline: Light Trapping Trichogramma 267
the no-light traps. Females are apparently more active fliers than males of
this species since the sex ratio was near unity in the controls. Females of
other species of parasitic wasps have also been shown to be very attracted
to BL sources (Hagstrum and Sharp 1975, Cline et al. 1983).
A comparison of the response of T. pretiosum with that of T. evanescens
showed some species specific differences. A significant difference (P<0.05),
was found between the number of T. evanescens caught by the WL trap
with the light on and the number caught with the light off. In contrast,
there was no significant difference (P>0.05) between the numbers of T.
pretiosum caught by the WL trap with the light on or off. Of course, be-
cause of the strong response to BL, both species were caught significantly
more often by the BL trap than by the no-light trap.
The release of large numbers of insectary-reared Trichogramma into
commodity storage for control of moth populations has been proposed
(Brower 1983). Recently, 2 species of Trichogramma have been found
naturally parasitizing almond moth eggs in peanut storage in Georgia
(Brower, in press). In order to maximize the chances of success, the find-
ings reported here indicate that BL traps should not be used concurrently
with Trichogramma releases. If monitoring of moth populations is es-
sential then pheromone traps or perhaps WL traps could be used. It might
also be desirable to eliminate or reduce UV sources such as open windows,
doors, skylights, etc. to reduce Trichogramma loss to the outside. However,
the warehouse should probably not be kept in total darkness because Tri-
chogramma may not find or parasitize their hosts in total darkness (Costas
1941, Orphanides and Gonzalez 1970, Ashley et al. 1973). If light traps are
to be used to sample for the presence of or to monitor populations of Tri-
chogramma, then BL traps should be selected rather than WL traps be-
cause of the greater response to BL.
ACKNOWLEDGEMENTS
The authors are grateful for the help of R. K. Morrison, Cotton Insects
Research Laboratory, USDA, ARS, P. O. Box DG, College Station, TX
77841, who kindly supplied cultures of T. pretiosum and to D. A. Nordlund,
Southern Grain Insect Research Laboratory, USDA, ARS, Georgia Coastal
Plains Experiment Station, Tifton, GA 31793, who supplied the cultures of
T. evanescens.
Mention of a commercial or proprietary product does not constitute an
endorsement by the USDA. Revised for publication 15 February 1984.
REFERENCES CITED
ALDEN, C. H., AND D. F. FARLINGER. 1931. The artificial rearing and
colonization of Trichogramma minutum. J. Econ. Ent. 24: 480-83.
ASHLEY, T. R., D. GONZALEZ, AND T. F. LEIGH. 1973. Reduction in effective-
ness of laboratory-reared Trichogramma. Environ. Ent. 2: 1069-73.
BROWER, J. H. 1983. Utilization of stored-product Lepidoptera eggs as hosts
by Trichogramma pretiosum Riley (Hymenoptera: Trichogram-
matidae). J. Kansas Ent. Soc. 56: 50-4.
BROWER, J. H. 1984. The natural occurrence of the egg parasite, Tri-
chogramma, on almond moth eggs in peanut storage in Georgia. J.
Georgia Ent. Soc. (In Press).
268 Florida Entomologist 67 (2) June, 1984
CLINE, L. D., B. R. FLAHERTY, AND J. W. PRESS. 1983. Response of selected
parasitoids and predators of stored-product insects to whitelight or
blacklight traps. J. Econ. Ent. 76: 298-301.
CORBET, S. A., AND S. ROTHERAM. 1965. The life history of the ichneumonid
Nemeritis (Devorgilla) canescens (Gravenhorst) as a parasite of the
Mediterranean flour moth, Ephestia (Anagasta) kuehniella Zeller,
under laboratory conditions. Proc. R. Ent., Soc. London 40: 67-72.
COSTAS, L. A. 1941. The effect of varying conditions on oviposition by Tri-
chogramma on eggs of Angoumois grain moths. J. Econ. Ent. 34:
57-8.
GHANI, M. A., AND H. L. SWEETMAN. 1955. Ecological studies on the
granary weevil parasite, Aplastomorpha calandrae (Howard).
Biologia 1: 118-39.
HAGSTRUM, D. W., AND J. E. SHARP. 1975. Population studies on Cadra
cautella in a citrus pulp warehouse with particular reference to
diapause. J. Econ. Ent. 68: 11-4.
MARTIN, F. J. 1969. Searching success of predators in artificial leaf litter.
American Midland Natur. 81: 218-27.
MORRISON, R. K., AND E. G. KING. 1977. Mass production of natural
enemies. Pages 183-217. In: Ridgway, R. L., and S. B. Vinson (eds.).
Biological control by augmentation of natural enemies. Plenum Press,
New York. 480 p.
R. E. STINNER, AND R. L. RIDGWAY. 1976. Mass production of Tri-
chogramma pretiosum on eggs of the Angoumois grain moth. South-
western Ent. 1: 74-80.
ORPHANIDES, F. M., AND D. GONZALEZ. 1970. Importance of light in the biol-
ogy of Trichogramma pretiosum. Ann. Ent. Soc. America 63: 1734-40.
PRESS, J. W., B. R. FLAHERTY, AND R. T. ARBOGAST. 1977. Interactions
among Nemeritis canescens (Hymenoptera: Ichneumonidae), Bracon
hebetor (Hymenoptera: Braconidae), and Ephestia cautella (Lepi-
doptera: Pyralidae). J. Kansas Ent. Soc. 50: 259-62.
REINERT, J. A., AND E. W. KING. 1971. Action of Bracon hebetor Say as a
parasite of Plodia interpunctella at controlled densities. Ann. Ent.
Soc. America 64:' 1335-40.
TAKAHASHI, F. 1973. An experimental study on the suppression and regula-
tion of the population of Cadra cautella (Walker) (Lepidoptera;
Pyralidae) by the action of a parasitic wasp, Nemeritis canescens
Gravenhorst (Hymenoptera; Ichneumonidae). Mem. Coll. Agric.,
Kyoto Univ. 104: 1-12.
_
Elvin & Sloderbeck: Key to Nabid Nymphs 269
A KEY TO NYMPHS OF SELECTED SPECIES
OF NABIDAE (HEMIPTERA) IN
THE SOUTHEASTERN USA
M. K. ELVIN1 AND P. E. SLODERBECK2
Department of Entomology and Nematology
University of Florida
Gainesville, FL 32611 USA
ABSTRACT
A key is presented for distinguishing nymphs of the 4 most commonly
recorded species of nabids (Hemiptera: Nabidae) found in row crops in the
southeastern United States: Nabis roseipennis Reuter, Nabis americoferus
Carayon, Tropiconabis capsiformis (Germar), and Hoplistoscelis deceptivus
(Harris). Characters used to separate the species include body shape and
patterns of pigmentation on the head, antennae, thorax, and legs.
RESUME
Una clave es presentada para distinguir las ninfas de las 4 species
registradas mas comunes de nAbidos (Hemiptera: Nabidae) encontrada en
cultivos de surcos en el sur-este de los Estados Unidos: Nabis roseipennis
Reuter, Nabis americoferus Carayon, Tropiconabis capsiformis (Germar),
and Hoplistoscelis deceptivus (Harris). Los caracteres usados para separar
las species incluyen la configuraci6n del cuerpo y la forma de la pigmen-
taci6n en la cabeza, antena, t6rax, y las patas.
Nabids (Hemiptera: Nabidae) belonging to the tribe Nabini are some
of the most common predators found in row crops in the southeastern
United States (Dinkins et al. 1970, Shepard et al. 1974, Deitz et al. 1976,
and Pitre et al. 1978). The 4 most commonly recorded species are Nabis
roseipennis Reuter, N. americoferus Carayon, Tropiconabis capsiformis
(Germar), and Hoplistoscelis deceptivus (Harris) (Dinkins et al. 1970,
Neal 1974, Deitz et al. 1976, and Pitre et al. 1978). The adults of these 4
species of nabids may be identified by using keys found in a monograph on
North American nabids (Harris 1928) or one of several keys to selected
species (Benedict and Cothran 1975, Deitz et al. 1976, Hormchan et al.
1976, and Irwin and Shepard 1980). Unfortunately, there are no keys
available for distinguishing to species the nymphs of these common preda-
tors. To amend this situation, we present a key to the nymphs of the 4 most
common species of nabids in row crops in the southeastern United States.
FAMILY: NABIDAE
Immature nabids have a long, slender, 4 segmented labium arising from
the anterior part of the head. The labium is not located in a rostral groove
in the gular region. They also have long, slender antennae, apical tarsal
1Present address: Dept. of Entomology, University of Arkansas, Fayetteville, AR 72701
USA.
-Southwest Area Extension Office, Kansas State University, Garden City, KS 67846 USA.
270 Florida Entomologist 67 (2) June, 1984
claws, and usually 3-4 pair of scent glands present on the abdomen (De-
Coursey 1971).
SEPARATION OF NYMPHAL INSTARS
The same general characteristics may be used to distinguish to species
individuals in each nymphal instar. However, for some nymphal instars,
there are unique characteristics that are used to separate the 4 species.
Such characteristics are noted in the key where appropriate.
The nymphal instar of a particular immature nabid can be determined
by assessing the amount of wing pad development. Individuals in the 1st
nymphal instar show no wing pad development (Fig. la, 2a, 3a, and 4a).
By the 2nd nymphal instar, the fore wing pads appear as slightly rounded,
lateral extensions of the dorsum of the mesothorax (Fig. 2b, 3b, and 4b).
Nymphs in the 3rd instar have obvious wing pads on the dorsum of both the
meso- and metathorax (Fig. 2c, 3c, and 4c). Individuals in the 4th nymphal
instar have hind wing pads that cover at least the dorsum of the first ab-
dominal segment and extend over the dorsum of the second abdominal seg-
ment (Fig. 2d, 3d, and 4d). By the 5th instar, the hindwing pads extend
over 1/3-1/2 of the dorsum of the abdomen (Fig. 2e, 3e, and 4e). Some
immatures of H. deceptivus show little or no wing pad development; how-
ever, they can be distinguished from immatures of the other 3 species by
their distinctive body shape (Fig. 1).
The following key is intended as a field key. Most of the characters used
for separating the species can be seen with the use of a hand lens; however,
some characters may require finer optics. Be aware that this key may not
account for the polymorphism that occurs within species, and that the
drawings are not to scale.
KEY
1. Body pear shaped with posterior part of abdomen 1-1/2-3
times as wide as head and thoracic regions. Body color usually
dark brown to black. Fig 1. - .- Hoplistoscelis deceptivus
1'. Body elongate oval. Posterior part of abdomen usually never
a b 6 c
Fig. 1. Hoplistoscelis deceptivus: lst-4th nymphal instars, a-d.
Elvin & Sloderbeck: Key to Nabid Nymphs
IA I 0 \
Fig. 2. Nabis roseipennis: lst-5th nymphal instars, a-e.
a b c d e
Fig. 3. Tropiconabis capsiforimis: lst-5th nymphal instars, a-e. The
dotted lines represent color patterns of stored specimens.
more than 1-1/2 times as wide as head and thoracic regions.
Body color variable, but usually light brown to orange in early
instars and light brown to gray in later instars. --..-....- 2
2(1'). Distal end of hind femur with a dark pigmented band. 1st and
2nd antennal segments with pigmented bands. In 4th and 5th
instars, pigmented bands may be faint or lacking on the 1st
antennal segment. Fig. 2. ...... __ ----------- -- Nabis roseipennis
2'. Distal end of hind femur and 1st and 2nd antennal segments
without pigmented bands. .... ...............----------------.. .. .. ..-- ...--- 3
3(2'). Freshly killed specimens, all instars: Vertex of head (top of
head between eyes) with distinct markings that either run
transversely between the eyes or are V-shaped. In the 1st in-
star, vertex of head is darkened. Stored specimens: In the 1st
instar, frontal sutures prominent between the eyes, frons with-
out pigmented, longitudinal lines (Fig. 3a). For the 2nd and
3rd instars, prothorax with considerable markings, and the
272 Florida Entomologist 67 (2) June, 1984
A---- A *-
a b d
Fig. 4. Nabis americoferus: 1st-5th nymphal instars, a-e.
abdomen is narrow and sides parallel (Fig. 3b-3c). In the 4th
and 5th instars, base of spines on front femur not darkened
(Fig. 3d-3e). ___..---------.....-....---------- Tropiconabis capsif ormis
3'. Freshly killed specimens, all instars: Vertex of head without
markings or markings do not run transversely between eyes
(Fig. 4a-4e). Stored specimens: In the 1st instar, frontal su-
tures not prominent, but frons with 2 dark longitudinal lines
which may extend onto the tylus (Fig. 4a). In the 2nd and
3rd instars, prothorax with few markings, and abdomen is
somewhat elongate oval (Fig. 4b-4c). For the 4th and 5th in-
stars, base of spines on front femur darkened (Fig. 4d-4e).
------Nabis americoferus
ACKNOWLEDGMENTS
We acknowledge Drs. K. Yeargan, D. Habeck, and R. Sailer for
critically reviewing an earlier draft of this manuscript. We also acknowl-
edge Ms. K. Braman for providing specimens and reviewing an earlier
draft of this manuscript, and Dr. R. Hemenway, for providing specimens.
We also thank Mr. S. Gross for the drawings used in the figures.
Florida Agriculture Experiment Station Journal No. 4825.
REFERENCES CITED
BENEDICT, J. H., AND W. R. COTHRAN. 1975. Identification of the damsel
bugs, Nabis alternatus Parshley and N. americoferus Carayon
(Heteroptera: Nabidae). Pan-Pacific Ent. 51: 170-1.
DECOURSEY, R. M. 1971. Keys to the families and subfamilies of the nymphs
of North American Hemiptera-Heteroptera. Proc. Ent. Soc. Wash-
ington 73: 413-28.
DEITZ, L. L., J. W. VAN DUYN, J. R. BRADLEY, JR., R. L. RABB, W. M.
BROOKS, AND R. E. STINNER. 1976. A guide to the identification and
biology of soybean arthropods in North Carolina. North Carolina
Agric. Expt. Stn. Tech. Bull. 238: 1-264.
DINKINS, R. L., J. R. BRAZZEL, AND C. A. WILSON. 1970. Species and rela-
Elvin & Sloderbeck: Key to Nabid Nymphs 273
tive abundance of Chrysopa, Geocoris, and Nabis in Mississippi cotton
fields. J. Econ. Ent. 63: 660-661.
HARRIS, H. M. 1928. A monographic study of the Hemipterous family
Nabidae as it occurs in North America. Ent. Amer. 9: 1-97.
HORMCHAN, P., L. W. HEPNER, AND M. F. SCHUSTER. 1976. Predacious
damsel bugs: Identification and distribution of the subfamily Nabinae
in Mississippi. Mississippi Agric. For. Expt. Stn. Tech. Bull. 76: 1-4.
IRWIN, M. E., AND M. SHEPARD. 1980. Sampling predaceous Hemiptera on
soybeans. Pages 503-531 In M. Kogan, and D. C. Herzog, eds.
Sampling methods in soybean entomology. Springer-Verlag, New
York. 587 p.
NEAL, T. M. 1974. Predaceous arthropods in Florida soybean agroeco-
system. M.S. Thesis. University of Florida, Gainesville, Florida. 194 p.
PITRE, H. N., T. L. HILLHOUSE, M. C. DONAHUE, AND H. C. KINARD. 1978.
Beneficial arthropods on soybeans and cotton in different ecosystems
in Mississippi. Mississippi Agric. For. Expt. Stn. Tech. Bull. 90: 1-9.
SHEPARD, M., G. R. GARNER, AND S. G. TURNIPSEED. 1974. Seasonal abun-
dance of predaceous arthropods in soybeans. Environ. Ent. 3: 985-8.
DAMAGE OF SUNFLOWER BY THE SOUTHERN
ARMYWORM (LEPIDOPTERA: NOCTUIDAE)
EVERETT R. MITCHELL
Insect Attractants, Behavior, and Basic Biology Research Laboratory,
Agricultural Research Service, USDA, Gainesville, FL 32604 USA
ABSTRACT
Spodoptera eridania (Cramer) occurred in economic infestations in ca.
50% of the 567 ha of sunflower planted in Alachua County, Florida in the
fall of 1982. Outbreaks occurred in sunflower having dense stands of pig-
weed (Amaranthus sp.), a primary host. After consuming pigweed, the
southern armyworm larvae moved en masse to the sunflower. Differences in
seed yields from sunflower heads harvested from plants with 0, 50, and
100% defoliation caused by larval feeding were highly significant. Seed
yields from plants showing 50 and 100% defoliation were reduced 45 and
98%, respectively, compared to plants showing little or no defoliation. The
impact of native parasites on S. eridania populations in sunflower was
negligible. Parasites recovered included Opion sp., Chelonus insularis
Cresson, Meteorus autographae Muesebeck, and tachinids.
RESUME
Infestaciones de Spodoptera eridania (Cramer) causando dafios eco-
n6micos, ocurri6 en aproximadamente et 50% de las 567 ha de girasoles
sembrados en el Condado de Alachue de la Florida en el otofio de 1982.
Brotes de infestaci6n ocurri6 en girasoles teniendo un denso establecimiento
de Amaranthus sp., que es un hospedero principal. Despu6s de comerse las
plants de Amaranthus sp., las larvas de S. eridania se movieron en masa
hacia el girasol. Diferencias en el rendimiento de semillas de girasoles
cosechadas de plants con un 0, 50, y 100% de defoliaci6n causado por las
larvas, fueron altamente significativas. Los rendimientos de semillas de
plants con un 50 y 100% de defoliaci6n fueron reducidos un 45 y 98%
respectivamente cuando se compararon con plants con poca o sin defoliaci6n.
Florida Entomologist 67 (2)
El impact de parasitos natives en poblaciones de S. eridania fu6 neglegible.
Los parisitos encontrados incluyeron Opium sp., Chelonus insularis Cresson,
Meteorus autographae Muesebeck, y tachinedos.
Increasing production costs, high land prices, and low commodity prices
are causing farmers to seek more effective means of using machinery and
land resources in the production of crops such as corn, soybean, and
sorghum. Double cropping is gaining favor as one way of spreading fixed
costs over a longer growing season. Double cropping also provides op-
portunities for more efficient utilization of fertilizer where a second crop
uses the residue from the first crop. Production of more than one crop on
the same land each year also reduces the financial risks for growers who
may experience losses in one crop because of inclement weather conditions,
insects, or other natural disasters.
Growers in north-central Florida are experimenting with sunflower,
Helianthus annuus L., as an alternate crop in double cropping systems.
Sunflower is resistant to frost, and yields are high when planted the first
half of February in the Gainesville, Florida area. When sunflower is planted
in early February in northern Florida, the crop escapes severe losses by
diseases and insects. Sunflower planted in August also shows promise as a
late-season crop in north-central Florida because late plantings usually are
not seriously damaged by mildew or rust, although the crop may have
heavy infestations of the corn earworm, Heliothis zea (Boddie), and the
sunflower moth, Homoeosoma electellum (Hulst) (Bailey et al. 1978).
This paper reports outbreaks of the southern armyworm, S. eridania
(Cramer), in sunflower in Alachua County, Florida, in October 1982. This
is the first documented report of this species as a pest of commercial sun-
flower. The impact of plant defoliation by southern armyworm larvae on
sunflower yields also was evaluated.
MATEIIALS AND METHODS
Approximately 567 ha of sunflower was grown in Alachua County in
1982, 50% of which were infested with southern armyworm larvae. Two
fields infested with southern armyworm were selected as study sites. Each
field was ca. 16 ha and was adjacent to cultivated sunflower on at least one
side. Study fields were separated by ca. 5 km, and were planted to sunflower
(cv. 'Dalgren 164') between 25 August (field A) and 28 August (field B).
Initial observations were made on 20 October when plants were ca. 1.75
m in height and in full bloom (i.e., ray petals fully exposed). The plants
were already infested with larvae when first examined. Approximately 450
larvae were collected from each field, classified as small (-0.8 cm), medium
(0.9-3.4 cm), or large (>3.5 cm), and placed individually in a 30 ml size
plastic cup containing sufficient diet (Leppla et al. 1979) for complete
larval development. Cups were checked several times a week, and the fate
of each larva recorded-larva died before pupation, pupa died, moth
emerged, or parasite emerged.
Degrees of plant defoliation by southern armyworm larvae on sunflower
head size (1 head/plant on 'Dalgren 164') was determined by measuring the
width of 10 consecutive mature heads at 10 randomly selected sites in dif-
274
June, 1984
Mitchell: Southern Armyworm on Sunflower
275
ferent areas of the field. Estimates of defoliation were made within 7 days
after most (>98%) of the larvae had matured and dropped from the plants
to the soil to pupate. Three defoliation levels were estimated: 0-5%-little
or no feeding damage on any leaves; 50%-nearly all leaves showing signs
of heavy feeding with many large holes and some leaves almost totally
consumed; 100%-all green leaf tissue consumed with only major leaf veins
and the stalk remaining (Fig. 1). Groups of 10 consecutive plants that most
nearly fit the leaf damage criteria for each of the 3 categories were selected
and marked for evaluation of head size and yield when the plants matured.
A total of 100 heads (10 replicates of 10 heads each) were measured for
each of the 3 defoliation levels. The effect of plant defoliation on seed yield
was determined by harvesting 10 consecutive mature heads from the same
areas from which the head measurements were taken. Heads were air dried,
hand threshed, and weighed. The data were analyzed using Student's t-test.
RESULTS AND DISCUSSION
Most of the larvae collected from fields A and B on 20 October were
medium-sized. Only a few were classified as small or large (ca. 10% for
each class). Examination of other infested fields in Alachua County revealed
a similar larval age, indicating that infestations apparently resulted from
a general flight of adults that occurred simultaneously over the entire area.
The southern armyworm is a polyphagous species that attacks a wide
variety of weeds and cultivated crops (tomatoes, potatoes, celery, sweet
potato, and various flowering ornamentals) (Kimball 1965). Pigweed,
Amaranthus sp. (Amaranthaceae), is a favored host of the southern army-
worm (Tingle et al. 1978). The severe armyworm infestations observed in
study fields A and B, as well as elsewhere in the area, were directly asso-
ciated with pigweed infestations of cultivated fields.
In those areas of the fields where armyworm densities were greatest,
Fig. 1. Defoliation levels used for assessing impact of southern army-
worm feeding on sunflower (left to right) : 0-5% damage, 50% damage, and
100% damage.
Florida Entomologist 67 (2)
larvae had consumed all but the stems of pigweed before moving to the
surrounding sunflower. Ten to 25 medium and large larvae/sunflower were
common throughout the infested areas when first observed. Virtually all
sunflower in field A, and an estimated 70% in field B, had a high level of
defoliation (50-100%).
After larvae consumed the sunflower foliage, they moved to the head.
Most head feeding was confined to the soft tissue on the backside and
periphery, but larvae chewing through the backside into the head was rare.
Heads were generally not totally destroyed by feeding larvae except when
the initial attack occurred during the late budding stage.
Sunflower defoliation had a significant effect on head size and on weight
of the seed produced (Table 1). Severe defoliation affected seed weight
much more than head size. Reduction in yield at the 50% defoliation level
reflected a reduced capacity on the part of the sunflower plant to furnish
the nutrients required to fill its seed, as was evident by the large number of
fully formed but "light" seed. Plants classified as 100% defoliated produced
only small heads with few or no seed.
The impact of native parasites on southern armyworm densities in sun-
flower was negligible, as is often the case with insect pests occurring in out-
breaks. Of the 996 larvae collected and held in the laboratory, 426 produced
adults (ca. an equal number of males and females), 159 produced parasites,
and 411 died from unknown causes. Parasites recovered included Ophion
sp. (16), Chelonus insularis Cresson (6), Meteorus autographae Muesebeck
(75), and tachinids (62). Forty-seven larvae yielded 1 fly each; 2 or more
flies were recovered from 15 larvae. Counting only live larvae that produced
adults or parasites, ca. 27% of the larvae were parasitized.
In conclusion, the southern armyworm can be a serious pest of sunflower
in fields where pigweed is allowed to grow in the crop. Egg masses or newly
hatched larvae were never found on sunflower in any field in this study,
which indicated that, the southern armyworm probably did not oviposit
directly on the sunflower. Therefore, the most obvious control measure for
TABLE 1. EFFECTS OF DEFOLIATION BY SOUTHERN ARMYWORM LARVAE ON
HEAD SIZE AND YIELD OF SUNFLOWER (CV. 'DALGREN 164').
ALACHUA COUNTY, FLORIDA. OCTOBER-NOVEMBER, 1982.
Defoliation i Head diam. R Seed wt/head
level (%) (mm S.E.)1 (g S.E.)1
Field A
0-5
50 149.5 3.2 a 31.8 2.0 a
100 117.5 3.7 b 8.1 1.1 b
Field B
0-5 131.7 3.5 a 74.6 4.1 a
50 123.5 4.0 a 40.7 3.6 b
100 84.1 3.1 b 1.2 0.3 c
'Means followed by different letters in the same column differ significantly at the 1%
level, Student's t-test.
276
June, 1984
Mitchell: Southern Armyworm on Sunflower
277
this sunflower pest involves early destruction of pigweed in and around
fields.
ACKNOWLEDGMENT
I thank Bill Copeland and Ron Hines for their assistance in locating
infested fields, collecting and rearing larvae, cleaning and weighing sun-
flower seed, and summarizing data. Revised manuscript received for publica-
tion 27 January 1984.
REFERENCES CITED
BAILEY, B. A., E. B. WHITTY, AND V. E. GREEN, JR. 1978. Agronomy facts:
Sunflower production in Florida. Florida Coop. Ext. Serv. Publ. No.
74, University of Florida, Gainesville. 4 p.
KIMBALL, C. P. 1965. Lepidoptera of Florida. Div. of Plant Industry,
Florida Dept. of Agric., Gainesville, FL. 363 p.
LEPPLA, N. C., P. V. VAIL, AND J. R. RYE. 1979. Mass rearing and handling
techniques for the cabbage looper. Pages 57-75 In Proc. Radioisotopes
and Radiation in Ent., Training course, FAO/IAEA.
TINGLE, F. C., T. R. ASHLEY, AND E. R. MITCHELL. 1978. Parasites of
Spodoptera exigua, S. eridania [Lep.: Noctuidae] and Herpetogramma
bipunctalis [Lep.: Pyralidae] collected from Amaranthus hybridus in
field corn. Entomophaga 23: 343-7.
POPULATION FLUCTUATIONS OF THE SCHAUS
SWALLOWTAIL (LEPIDOPTERA: PAPILIONIDAE)
ON THE ISLANDS OF BISCAYNE BAY, FLORIDA,
WITH COMMENTS ON THE BAHAMAN SWALLOWTAIL
WILLIAM F. LOFTUS AND JAMES A. KUSHLAN
National Park Service, South Florida Research Center
P.O. Box 279, Homestead, FL 33030 USA
ABSTRACT
Censuses of the Schaus swallowtail butterfly (Heraclides (= Papilio)
aristodemus ponceanus (Schaus)), a federally listed threatened species,
were conducted from 1979 to 1982 on islands in Biscayne Bay, southern
Florida. The population size was small during 1979 and 1980, but adults
were widely distributed in suitable habitat. Emergence season was similar
in both years, from late April to late June. Numbers of the Schaus swallow-
tail were lower in 1981, and the emergence period seemed to be retarded,
probably due to the very dry winter and spring. Following the wet winter
of 1981-1982, the largest numbers of adult Schaus swallowtails since 1972
were recorded. It appears that the severity of the winter dry season may
determine the population size of this species in southern Florida.
In combination with results of previous censuses, these data provide a
continuous eleven-year record of Schaus swallowtail population fluctuations
on the Biscayne Bay islands. Human disturbances, especially habitat de-
struction, have reduced the numbers and range of the Schaus swallowtail, so
the butterflies on these islands presently form the nucleus of its population
Florida Entomologist 67 (2)
in the United States. The Bahaman swallowtail (Heraclides (= Papilio)
andraemon bonhotei (Sharpe)) was not observed during the censuses, and
we conclude that it is not presently established on the islands we studied.
RESUME
Desde 1979 al 1982, en las islas de Biscayne Bay en el sur de la Florida
se hizo un censo de la mariposa, Heraclides (=Papilio) aristodemus
ponceanus, la cual el gobierno federal la ha declarado como una especie
amenazada de extinci6n. El ntmoro de la poblaci6n durante 1979 y 1980
fu6 minimo, pero los adults estaban bien distribuidos en habitaci6n ade-
cuada. La estaci6n de emersi6n fu6 muy similar durante los dos afios, desde
finales de Abril al final de Junio. Los niimeros de la mariposa Schaus fueron
mas bajos en 1981 y el period de emersi6n parece haber sido atrasado,
posiblemente debido al invierno y la primavera seca. Luego del invierno
hfmedo de 1981-1982, se registry el mayor numero de la mariposa Schaus
desde el 1972. Asi que parece que la severidad de la estaci6n seca del invierno
puede determinar el tamafio de la poblaci6n de esta especie en nuestra Area
de studio.
Junto a otros censos estos datos proven un record continue de once
afios de las fluctuaci6nes en la poblaci6n de la mariposa Schaus en los cayos
de la Bahia de Biscayne. Los disturbios humans, especialmente la destruc-
ci6n del ambiente han reducido los numeros y el Area geogrffica de la
mariposa Schaus y por lo tanto las mariposas en estas islas forman el
nfcleo de la poblaci6n de este especie en los Estado Unidos. La mariposa
Heraclides (=Papilio) andraemon bonhotei no se observ6 durante los censos,
y dudamos que est6 establecida alli.
The Schaus swallowtail (Heraclides (= Papilio) aristodemus ponceanus
(Schaus)) was first described at the turn of this century from the Miami
area of Dade County in southern Florida (Schaus 1911). It was eliminated
from that site as the city developed but was rediscovered further south on
the Florida Keys, Monroe County. The species received much attention fol-
lowing the 1935 hurricane because of a report of its extirpation on the keys
by the storm (Grimshawe 1940). Henderson (1945a, b) later documented
the continued existence of the Schaus swallowtail in the Florida Keys. By
this time, the butterfly had become a glamour species in great demand by
collectors, and, during the next two decades, both Klots (1951) and Kimball
(1965) noted that over-collection of this rare species was possible. In 1972,
Covell and Rawson (1973) and Brown (1973a, b) independently surveyed
the upper Florida Keys, including the Elliott Key group in Biscayne Bay,
Dade County, to the north of the main-line Florida Keys. They found that
the Schaus swallowtail was well-established on these northern islands where
Brown (1973a) reported seeing 100 adults in a day. From 1973 to 1976,
Covell (1977) continued to observe this species on the islands of Biscayne
Bay but found that it had decreased in numbers from the levels of 1972. He
speculated that the decrease may have been the result of winter drought
conditions that inhibited new growth of the larval food plants during those
years. Limited surveys were also conducted during 1977 and 1978, with few
adults being observed on the keys (J. Tilmant, pers. comm.).
The Bahaman swallowtail (Heraclides (= Papilio) andraemon bonhotei
(Sharpe)) has been recorded from southeastern Florida and the Florida
June, 1984
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