(A Revision of Bulletin 151)
UNIVERSITY OF FLORIDA
AGRICULTURAL EXPERIMENT STATION
Wilmon Newell, Director
FLORIDA TRUCK AND
GARDEN INSECTS
By J. R. WATSON
Fig. 1.-Bean leaf-roller: Adult; Natural Size.
Bulletins will be sent free upon application to the
Agricultural Experiment Station
GAINESVILLE
LIBRARY
FLORIDA EXPERIMENT STA I tio
OAINESVILLE, FLORIDA
Bulletin 232
June, 1931
BOARD OF CONTROL
P. K. YONGE, Chairman, Pensacola RAYMER F. MAGUIRE, Orlando
A. H. BLENDING, Bartow FRANK J. WIDEMAN, West Palm Beach
W. B. DAVIS, Perry J. T. DIAMOND, Secretary, Tallahassee
STATION EXECUTIVE STAFF
JOHN J. TIGERT, M.A., LL.D., President R. M. FULGHUM. B.S.A., Asst. Editor
WILMON NEWELL, D.Sc., Director IDA KEELING CRESAP, Librarian
H. HAROLD HUME, M.S., Asst. Dir., Re- RUBY NEWHALL, Secretary
search K. H. GRAHAM, Business Manager
S. T. FLEMING, A.B., Asst. Dir., Admin. RACHEL MeQUARRIE, Accountant
J. FRANCIS COOPER, M.S.A., Editor
MAIN STATION-DEPARTMENTS AND INVESTIGATORS
AGRONOMY
W. E. STOKES, M.S., Agronomist
W. A. LEUKEL, Ph.D., Associate
G. E. RITCHEY, M.S.A., Assistant*
FRED H. HULL, M.S., Assistant
J. D. WARNER, M.S., Assistant
.OHN P. CAMP, M.S.A., Assistant
ANIMAL HUSBANDRY
A. L. SHEALY, D.V.M., Veterinarian in
Charge
E. F. THOMAS, D.V.M., Asst. Veterinarian
R. B. BECKER, Ph.D., Associate in Dairy
Husbandry
W. M. NEAL, Ph.D.. Assistant in Animal
Nu'rition
C. R. DAWSON. B.S.A., Assistant Dairy
Investigations
CHEMISTRY
R. W. RUPRECHT, Ph.D., Chemist
R. M. BARNETTE, Ph.D., Associate
C. E. BELL, M.S., Assistant
J. M. COLEMAN, B.S., Assistant
H. W. WINSOR, B.S.A., Assistant
H. W. JONES, B.S., Assistant
COTTON INVESTIGATIONS
E. F. GROSSMAN, M.A., Assistant
P. W. CALHOUN, B.S., Assistant
ECONOMICS, AGRICULTURAL
C. V. NOBLE, Ph.D., Agricultural Economist
BRUCE McKINLEY, A.B., B.S.A., Associate
M. A. BROOKER, Ph.D., Assistant
ECONOMICS, HOME
OUIDA DAVIS ABBOTT, Ph.D., Head
L. W. GADDUM, Ph.D., Biochemist
C. F. AHMANN, Ph.D., Physiologist
ENTOMOLOGY
J. R. WATSON, A.M., Entomologist
A. N. TISSOT. M.S., Assistant
H. E.. BRATLEY, M.S.A., Assistant
I. W. ZIEGLER, B.S., Assistant
HORTICULTURE
A. F. CAMP, Ph.D., Horticulturist
HAROLD MOWRY, B.S.A., Associate
M. R. ENSIGN, M.S., Assistant
A. L. STAHL, Ph.D., Assistant
G. H. BLACKMON. M.S.A.. Pecan Culturist
C. B. VAN CLEEF, M.S.A., Greenhouse
Foreman
PLANT PATHOLOGY
W. B. TISDALE, Ph D., Plant Pathologist
G. F. WEBER, Ph.D., Associate
A. H. EDDINS, Ph.D., Assistant
K. W. LOUCKS. M.S., Assistant
ERDMAN WEST, M.S., Mycologist
BRANCH STATIONS AND FIELD WORKERS
L. O. GRATZ, Ph.D., Asso. Plant Pathologist in charge, Tobacco Exp. Sta. (Quincy)
R. R. KINCATD, M.S., Assistant Plant Patholoeist (Quircy)
W. A. CARVER, Ph.D., Assistant Cotton Investigations (Quincy)
RAYMOND M. CROWN, B.S.A., Field Asst., Cotton Investigations (Quincy)
JESSE PEEVES, Farm Superintendent, Tobacco Experiment Station (Quincy)
J. H. JEFFERIES, Superintendent, Citrus Experiment Station (Lake Alfred)
GEO. D. RUEHLE, Ph.D., Assistant Plant Pathologist (Lake Alfred)
W. A. KUNTZ, A.M., Assistant Plant Pathologist (Lake Alfred)
B. R. FUDGE, Ph.D., Assistant Chemist (Lake Al'red)
W. L. THOMPSON. B.S., Assistant Entomologist (Lake Alfred)
R. V. ALLISON, Ph.D., Soils Specialist in charge Everglales Experiment S'a. (Belle Glade)
R. W. KIDDER, B.S., Foreman, Everglades Experiment Station (Belle Glade)
R. N. LOBDELL, M.S., Assistant Entomologist (Belle Glade)
F. D. STEVENS. B.S., Su-arcane Agronomist (Belle Glade)
H. H. WEDGEWORTH, M.S., Associate Plant Patholovist (Belle Glade)
B. A. BOURNE, M.S., Associate Plant Physiolo-ist (Belle Glade)
J. R. NELLER, Ph.D., Associa'e Biochemist (Belle Glade)
A. DAANE, Ph.D.. Associate Agroromist (Belle Glade)
FRED YOUNT, Office Assistant (Belle Glade)
M. R. BEDSOLE, M.S.A., Assistant Chemist (Bel'e Glade)
A. N. BROOKS, Ph.D., Associate Plant Pathologist (Plant City)
R. E. NOLEN, M.S.A., Field Assistant in Plant Pathology (Plant City)
A. S. RHOADS, Ph.D., Associate Plant Pathologist (Cocoa)
C. M. TUCKER, Ph D., Assoc;ate Plant Patholo-ist (Hastings)
H. S. WOLFE, Ph.D., Asso. Horticul'urist in charge, Sub-Trop. Exp. Sta. (Homestead)
L. R. TOY, B.S.A., Assistant Horticulturist (Hormestead)
STACY O. HAWKINS. M.A., Field Assistant in Plant Patholo"y (Homestead)
D. G. A. KELBERT, Field Assistant in Plant Pathology (Bradenton)
FRED W. WALKER, Assistant Entomologist (Monticello)
D. A. SANDEPS, D.V.M., Associate Veterinarian (West Palm Beach)
M. N. WALKER, Ph D., Assee'a'e Plant Pa'hologi=t (Leesburz)
W. B. SHIPPY, Ph.D., Assistant Plant Pathologist (Leesburg)
C. C. GOFF, M.S. Assisant Entomologist (Leesbur")
J. W. WILSON, Ph.D., Assistant Entomologist (Pierson)
*In cooperation with U. S. Department of Agriculture.
CONTENTS
IN TRODUCTION .... ....... ... ... ............ ---
ACKNOWLEDGMENTS ...........................
LIFE HISTORY OF INSECTS.. ...... .... ........ ---b...
INDIRECT METHODS OF COMBATING INSECTS ......
Cultural M ethods ............ ........ .... ....
Destroy W orm y Fruit ............................. ... ..
Trap Crops .............. .. .... ....... ... .- -
N natural E nem ies ................................- .....-- 8
DIRECT METHODS OF COMBATING INSECTS.......... ......-
Insecticides ..................... ............. ... 9.
Stomach Poisons .......... .. ... 10
Contact Insecticides ............ ......................... ... 12
Fum igation ....... .......................... ... ....-. ----- 16
H eat ................................. ........... 17
GENERAL GARDEN INSECTS AND'PESTS ......... 18
INSECTS INJURIOUS TO BEANS ......... ....... 26
INSECTS INJURIOUS TO LIMA BEANS ......... .. 31
INSECTS INJURIOUS TO BEETS ........ .... 32
INSECTS INJURIOUS TO CABBAGE .........
INSECTS INJURIOUS TO CANTALOUPES 47
INSECTS INJURIOUS TO CARROTS .............47
INSECTS INJURIOUS TO CELERY .............47
INSECTS INJURIOUS TO CORN ......... ......... 50
INSECTS INJURIOUS TO COWPEAS .........60
INSECTS INJURIOUS TO CUCUMBERS ................... 63
INSECTS INJURIOUS TO DASHEENS ................- .. 68
INSECTS INJURIOUS TO EGGPLANT ................ .. 68
INSECTS INJURIOUS TO LETTUCE ..................... 70
INSECTS INJURIOUS TO MUSKMELONS .................. .... 71
INSECTS INJURIOUS TO MUSTARD .................... 72
INSECTS INJURIOUS TO OKRA ...................... 72
INSECTS INJURIOUS TO ONIONS .. .................... 74
INSECTS INJURIOUS TO PARSLEY ................... 76
INSECTS INJURIOUS TO PEAS .................. 76
INSECTS INJURIOUS TO PEPPERS ..................... .... 79
INSECTS INJURIOUS TO POTATOES ..... ........................-- 80
INSECTS INJURIOUS TO RADISHES ......................... 83
INSECTS INJURIOUS TO ROSELLE .............................. 83
INSECTS INJURIOUS TO SQUASH ....................------ .. 84
INSECTS INJURIOUS TO STRAWBERRIES ................. ... 85
INSECTS INJURIOUS TO SUNFLOWERS ................ 92
INSECTS INJURIOUS TO SWEET POTATOES ............ 93
INSECTS INJURIOUS TO TOMATOES ................- ..- 96
INSECTS INJURIOUS TO TURNIPS ..... ........... -... -- -- 105
INSECTS INJURIOUS TO WATERMELONS ........................ -. --. 106
INDEX .............. .......... .. 109
FLORIDA TRUCK AND GARDEN
INSECTS
BY J. R. WATSON
Truckers and kitchen gardeners, for whom this bulletin has
been especially prepared, will find in it the description, with
illustration, the life-history, and a statement of the best meth-
ods for the control of the insects which commonly trouble them.
Although mites, nematodes, and moles, are not insects, they are
discussed in this bulletin as pests of truck and garden crops.
Only those insects are considered which attack crops during
the season they are commonly grown in Florida. The trucker
in this State escapes many insect attacks that trouble the more
northern truckers because he raises many of his crops in the
winter while insect life is somewhat dormant, this dormancy
being due mostly to the lower temperatures but in part to the
comparative dryness of the Florida winter. The early fall crops
suffer severely because insect life has been stimulated to rapid
development by the hot, moist summer. However, some insects
thrive better in dry weather and are most troublesome in the
spring.
Much of the information in this reference bulletin is pub-
lished for the first time, from records of recent experiments by
the writer; the remainder is compiled from publications made
by this Station, by other stations, and by the United States De-
partment of Agriculture.
The truck or garden crops are named in alphabetical order.
Under each crop named will be found the descriptions and con-
trol measures of the more important insects which attack it.
Insects which commonly attack more than one crop are listed
under each one, but are discussed under the name of the crop
on which they are most commonly found or on which they in-
flict the most serious damage. Cross references point to these
discussions.
Under the heading, "General Garden Insects and Pests," will
be found discussions of several enemies of the garden generally,
being no more severe on one crop than on another.
ACKNOWLEDGMENTS
In gathering the material for this bulletin, the writer has had
valuable help from his assistants, A. C. Mason, A. N. Tissot,
Florida Agricultural Experiment Station
H. E. Brat!ey, L. W. Ziegler, and H. L. Dozier who made the
photographs for the original illustrations. The data on aphids
were gathered chiefly by Mr. Mason, Mr. Tissot, and W. L.
Thompson, and much of that relating to beetles by Mr. Dozier.
who also worked out the life history of the okra caterpillar. Dr.
E. D. Ball has supplied valuable information on celery insects.
The photographs for the major portion of the illustrations were
supplied by the Bureau of Entomology, U. S. Department of
Agriculture. Two were furnished by the North Carolina Agri-
cultural Experiment Station, one by the Porto Rico Experiment
Station, and one figure by the South Carolina Agricultural Ex-
periment Station. Figs. 4 and 5 are from drawings by Dr. J. W.
Wilson.
LIFE HISTORY OF INSECTS
In order to apply remedial measures intelligently, it is neces-
sary to know something of the manner of development of an
insect; the different stages through which it passes, the time
spent in each stage, and its habits. These make up its "life
history."
All insects during their lifetime, pass through four more or
less well-marked and different stages: (1) The egg; (2) the
larva or active young; (3) the pupa or the transition stage; and
(4) the adult or perfect insect, technically called the imago, and
which usually possesses wings.
In the life history of some insects, such as butterflies and
moths, beetles, and flies, the larva, called a caterpillar, grub, or
maggot, respectively, does not in the least resemble the adult
insect; and the pupa is inclosed in a rigid case incapable of
motion except for a twisting and turning of the abdomen, but
the pupa of the fly can often crawl. Such insects are said to
have a complete metamorphosis. In the life history of others,
as true bugs, thrips, and grasshoppers, the larva, commonly
called a nymph, resembles the adult insect, but is usually smaller,
has no wings and the organs of reproduction are but partly de-
veloped. It may be active during the pupal stage and have little
swellings where the wings are to appear. Such insects are said
to have an incomplete metamorphosis.
Hairless caterpillars are often called "worms" although they
are very different from true worms as represented by earth-
worms ("fish-worms"), tape-worms, and nematodes.
Bulletin 232, Truck and Garden Insects
Some insects are most easily controlled during the egg stage,
others in the larval, pupal or adult stages. Close study of the
life history of an insect will generally disclose its vulnerable
points.
Insects may be divided into two classes, biting and sucking,
according to their method of taking food. The biting insects,
represented by caterpillars, grasshoppers, and beetles, have jaws
for chewing and they eat holes in plants or consume all of the
tissue. The sucking insects, represented by true bugs, moths,
butterflies, flies, and thrips, have mouth-parts which form a
piercing and sucking tube while the crop acts as a pump. These
insects use only the juices of the plants for food.
INDIRECT METHODS OF COMBATING INSECTS
Ravages of insects may be controlled by either direct or
indirect methods. Direct methods include the application of
insecticides or poison baits, hand-picking and collecting in pans,
traps, or special appliances. Indirect methods refer to cultural
methods; the use of trap crops, and the protection of the
enemies of insects. As an ounce of prevention is worth a
pound of cure, a few precautionary measures taken at the right
time may forestall outbreaks of insects which it would be more
expensive to fight by direct measures.
CULTURAL METHODS
Frequently a slight change in the method of growing a crop
will forestall a serious outbreak of some insect. These modi-
fications of farm practice may be beneficial to the soil aside from
giving protection against insects. For instance, in many cases,
as soon as a crop is harvested the land should be plowed for the
next crop, turning under the refuse in which insects may propa-
gate. This will conserve the moisture, add humus to the soil,
and stop the breeding of insect pests by burying many of them.
Many insects spend the quiescent or pupal stage in the ground.
If the land is plowed and harrowed, most of these insects will
either be crushed outright, be left on the surface where birds
or other enemies can pick them up, have their pupal cells broken,
causing the insect to die from exposure to the elements, or they
will be buried so deeply that emergence is impossible.
A cover crop should be grown on truck land during the
summer; a crop being chosen which will not harbor the same
pests that infested the crop which has gone before, and, espe-
Florida Agricultural Experiment Station
cially, different from those of the crop which is to follow. If
the land is permitted to grow grass and weeds during the sum-
mer it gets thoroughly stocked with cutworms, white grubs, and
a great variety of other undesirable inhabitants.
Rotation of crops is as important from the standpoint of
insect control as from that of the maintenance of soil fertility.
If crop after crop of the same thing is planted, there is likely
to be such a serious accumulation in the soil of insect pests of
that crop as to make its culture unprofitable. Furthermore,
closely related plants should not follow each other in the rota-
tion, as their insect enemies are similar.
DESTROY WORMY FRUIT
Wormy fruit should be disposed of, usually by being picked
with the marketable fruit and sorted out at the packing house.
Too often it is left in the field. However, if the picking season
is brief and the insect is of a species that is not likely to crawl
out, the fruit may be left in the field to be destroyed with the
remainder of the refuse at the end of the season.
TRAP CROPS
The best way to get rid of an insect on a valuable crop may
be to furnish it with something it likes better; some cheap, easily
grown crop which it prefers to the more valuable one. Such a
crop is called a trap crop. The trap crop should be destroyed
as soon as heavily infested and before the insect has had time
to start a new generation. If allowed to stand too long, it may
increase rather than decrease the number of noxious insects on
the more valuable crop.
NATURAL ENEMIES
Every insect has its own specific enemies. Some animals
prey on insects in general and others on certain families of in-
sects. Such animals are often of great value in preventing
insect outbreaks and it is very important that they be protected
by the trucker. Many enemies of insects are other insects.
With the exception of wasps, these are not generally persecut-
ed by man. With higher animals it is different. Insects make
up a large percentage of the food of toads, lizards, and the
smaller varieties of snakes. These animals should be protected.
Skunks, too, feed largely on insects and should be protected,
even at the cost of making chicken houses proof against them.
Bulletin 232, Truck and Garden Insects
Most birds are valuable allies of man in the fight against
insects and weeds; and as such merit more rigid protection than
is now afforded them. To destroy them indiscriminately for the
small morsel of meat they afford or for mere sport is unwise.
They are worth more as destroyers of insects. An increase in
the number of insectivorous birds would decrease the loss from
insect depredations.
DIRECT METHODS OF COMBATING INSECTS
Among the direct methods of controlling insects, the primi-
tive one of collecting them by hand may be found the most satis-
factory in some cases. This is especially true in dealing with
the larger insects, which are readily seen or located by the
conspicuous damage done.
One of the best accessories for hand-collecting is a pan con-
taining a little water covered with a film of kerosene, or the
kerosene alone may be used. The insects are knocked into this
pan, and are finally killed by the kerosene, even though they may
crawl out of the pan.
INSECTICIDES
With reference to the use of insecticides, insects may be
divided, as stated previously, into two classes; those that have
biting mouth-parts and chew their food and those that have
sucking mouth-parts and get their nourishment by sucking the
juices of their food plants. The class of insects to be dealt
with may be determined readily by examining either the mouth-
parts of the insects or the nature of the damage to the plant.
If the insect has jaws or the plant has pieces chewed out of it,
the insect belongs to the biting class. If the mouth-parts are
in the nature of a lance or sucking tube, or the plant curls,
wilts, or turns yellow or is dwarfed, without any external in-
jury other than a small puncture, the insect belongs to the suck-
ing class. It is necessary, however, to examine the roots, as
well as the parts of the plant above ground, as injury to the
roots will cause the plants to wither and turn yellow, even in
the absence of destructive insects.
Biting insects can be poisoned by covering the plant with
a stomach poison, some substance which, when eaten with the
plant tissue, will poison them. Sucking insects must be killed
by a contact insecticide, some substance that kills the insect by
being drawn into its spiracles. Insects do not possess lungs
Florida Agricultural Experiment Station
and do not breathe through their mouths as do the higher ani-
mals, but through openings in their sides called spiracles.
Insecticides should be applied when insects first appear in
dangerous numbers, not withheld until considerable damage has
been done.
Insecticides may be applied in the form of either a liquid
spray or a dust. Some can be used in only one form.
Where the grower has a choice of either dusting or spray-
ing the form which he should use will depend much upon his
equipment, distance to water, weather conditions at the time,
supply and cost of labor, etc.
STOMACH POISONS
Arsenicals.-The stomach poisons in most common use are
compounds of arsenic. The three commonly used are paris green,
lead arsenate, and calcium arsenate. Lead arsenate comes in
the form of either a powder or a paste and can be applied as
either a dust or a liquid.
Paris Green.- The oldest of the arsenicals, paris green, is
not used as extensively as formerly on truck crops, chiefly be-
cause of its tendency to burn tender foliage. One can diminish
this danger by adding to the solution hydrated lime or the milk
obtained from slaking quick lime. A good formula is:
Paris green ....................................... 1 pound
Lim e ........ .................................... 2 pounds
W ater ....................-...... ........ ....... 50 gallons
The lime should be first slaked in a little warm water, then
strained to remove all particles that might clog a spray nozzle.
and the milk added to the 50 gallons of water.
Lead Arsenate.-The arsenical now most used on truck crops
is lead arsenate. It is not as likely to burn as paris green.
One pound of the powder or 2 of the paste to 50 gallons of water,
makes a liquid about as strong as it is ordinarily necessary to
use. On very tender plants, such as beans, it is well to add 2
pounds of lime as in the paris green mixture. The powdered
form of lead arsenate is cheaper than the paste and but little
more troublesome to make up.
Calcium Arsenate.-This arsenical, commonly used on cotton
to combat the boll weevil, can be used on the more hardy
truck crops. It is, however, more liable to burn tender foliage
than lead arsenate. It is cheaper than lead arsenate. It is also
Bulletin 232, Truck and Garden Insects
lighter and consequently goes through a dusting machine more
easily.
MIXING LIQUID SPRAYS
In making up any of these substances in sprays, the proper
amount should be mixed first in a few gallons of water until all
lumps have disappeared and then be added to the bulk of the
water. It is better to put some substance into the solution that
will act as a spreader so that the spray will wet the surface of
the plants more evenly, and also stick better. In spraying glossy
plants like cabbage, this is imperative.
The principal spreaders are the following:
Milk of Lime (See under Paris Green)
Calcium Caseinate.- This material, which is obtained from
milk, from which the cream has been removed, is sold under
several trade names.
Flour Paste.-A good spreader can be made by boiling 2
pounds of flour or corn meal in 2 gallons of water. This will
suffice for 50 gallons of spray.
Glue makes an excellent spreader when the odor is not objec-
tionable. For 100 gallons of spray a pound of glue is boiled in
sufficient water to dissolve it.
FLUOSILICATES AND FLUORIDES
Other stomach poisons which are coming into use are the fluo-
silicates and fluorides. These differ from the arsenicals and
usually are applied in the dust form. There are several commer-
cial brands of these materials on the market. They have the
advantage that in amounts used on plants, they are not poison-
ous to man nor higher animals and therefore can be used on
truck crops up to the time of harvesting. Objections might be
taken to the appearance of the dusted material; as the dusts
are light colored they would be conspicuous on some truck crops.
Of the fluosilicates, sodium and calcium are the most used. To
prevent burning they must be carefully mixed with lime. In
practically all of the commercial brands on the market fluosili-
cates have been mixed with lime and are fairly safe if direc-
tions are carefully followed. But care must be taken in dusting
such tender plants as lettuce.
CONTACT INSECTICIDES
Nicotine.-This is one of the most common of the contact
insecticides used against small and delicate insects. It is also
Florida Agricultural Experiment Station
one of the safest, for in excessive dosages only is there any
danger of scorching the plants.
Nicotine is sold in several forms. That most commonly used
is a concentrated nicotine sulphate, usually containing 40 per-
cent. There are several commercial brands of this on the mar-
ket. They may be used either as liquid sprays or, mixed with
hydrated lime, in the form of dusts.
When used as a liquid they should be mixed with a spreader.
Calcium caseinate mentioned under arsenicals will be satisfac-
tory.
Soap is the spreader most commonly used. Fish oil soap
("whale oil") is the form most used but any cheap alkaline laun-
dry soap will do, or powdered soap but not washing powders
composed mostly of soda. If the water is soft from one to three
pounds per 50 gallons of water is sufficient but if the water is
hard more will be necessary.
Better spreaders than the ordinary soaps are the oleates. The
sodium and potassium oleates are those that are most used.
Many do not dissolve well in cold water, but in some commercial
brands now on the market this difficulty has been overcome.
There has been recently placed on the market certain oil de-
rivatives which are excellent spreaders. By the use of some of
these spreaders the amount of nicotine can be greatly reduced,
often to as low a dilution as 1 part in 3,000, at a material saving
in cost to the grower.
Nicotine sulphate-lime dusts are effective if they can be ap-
plied when the atmosphere is relatively quiet. A strong wind
carries away the fumes before they have time to kill. For most
small insects, such as aphids, a 3% dust is effective, if it stays
about the plant for a full minute and the day is warm and sunny.
This can be purchased from most dealers in insecticides or it
may be made by the growers, at a considerable saving in cost,
by thoroughly mixing 71/ pounds of 40% nicotine sulphate with
921/ pounds of hydrated lime. Full directions for mixing and an
illustration of a cheap home mixer will be found in Bulletin 183
of the Florida Agricultural Experiment Station.
There is now on the market an extract consisting of free nico-
tine dissolved in water-50% nicotine. The price per unit of
nicotine is the same as that in nicotine sulphate.
By the use of free nicotine one can make a considerably cheap-
er dust because this nicotine is so quickly available. A 2% dust
has been found effective, that is, instead of 71/ pounds of nico-
Bulletin 232, Truck and Garden Insects
tine sulphate in 921/2 pounds of hydrated lime, 4 pounds of 50%
free nicotine is added to 96 pounds of lime.
Some types of dusters are constructed so that these materials
can be mixed in the hopper. These types of dusting machines
have the great advantage that they avoid a considerable loss
in nicotine when the dusts are transferred from the mixing ma-
chine to the hopper of the duster. By the use of this self-mix-
ing duster the amount of nicotine can be considerably reduced.
Finely ground tobacco stems and refuse have some value as a
contact insecticide, especially on plants like strawberries and
melon vines which lie close to the ground, but their chief value
is that of a repellant. They stick better if applied when the
plants are wet with dew or rain. 25% of finely ground tobacco
dust can be mixed with the nicotine sulphate-lime dust without
appreciably reducing its efficiency. This reduces the cost of the
dust.
Extracts of Derris.-Derris is a poisonous plant of the East
Indies where it is grown mostly as a green manure crop in young
rubber plantations. It has long been used in Europe and Asia
as an insecticide but only recently has it been used in the United
States, where extract from it is being sold in the form of an
oily liquid. Derris is similar to nicotine in its action but some-
what slower. It is used for small insects and at about the same
concentration as 40 percent nicotine sulphate. Like nicotine sul-
phate it can be mixed with soap, oil emulsions, calcium caseinate,
or bordeaux, or lead arsenate, but in the form in which it is
used in this country, unlike nicotine sulphate, it does not need
a spreader. When mixed with any of the above mentioned in-
secticides to make a combination spray, care must be taken to
mix the other ingredients first and then add the derris extract
diluted with several gallons of water to the diluted mixture. If
added in considerable amount to a concentrate it may be precipi-
tated out. It cannot be used to make a dust. It is somewhat
cheaper than nicotine sulphate.
Derris does not kill as promptly as does nicotine. It will be
24 hours or more after application before all aphids which have
received a fatal dose will have died, whereas in the case of nico-
tine compounds death takes place in a few minutes.
Derris will give a good kill at somewhat lower temperatures
than will nicotine.
Kerosene Emulsion.-For large insects, as well as small ones,
Florida Agricultural Experiment Station
kerosene emulsion is an old remedy, but unless made and applied
carefully it is likely to scorch tender foliage. The stock solu-
tion is:
H ard soap.. ...... ........... ........................ 1/2 pound
Hot water (soft) .......................... ... .. ... 1 gallon
Kerosene (coal oil) .........-.. ..... .............. gallons
Shave the half pound of laundry soap into the gallon of
soft water, stirring it until the soap is dissolved. When all is
in solution, remove the liquid to a safe distance from the fire
and add the kerosene. Emulsify the solution quickly with a
bucket pump by turning the nozzle back into the bucket and
forcing the solution through the pump several times until a
smooth creamy emulsion is formed. If this is done properly no
free oil will collect on the surface when the solution cools.
For spraying dormant trees and shrubs use 1 part of the
solution to from 5 to 7 parts of water. On ordinary growing
plants dilute with 10 to 15 parts of water, depending on the
insect to be killed. The weakest solution given will kill plant
lice.
Soap.-Any strong, alkaline laundry soap is a good insecti-
cide. Fish-oil soap is the form most commonly used. The high-
er priced, more neutral toilet soaps are not as good because the
free alkali of the cheaper soaps is needed to kill the insects.
Certain commercial brands of soap made from pine oil or
pine tars are especially good insecticides as well as excellent
spreaders. One pound of soap to 8 gallons of soft water will kill
most small, soft-bodied insects. If more soap is added, the kill-
ing power of the solution is increased but little, and if more
than 8 pounds to 50 gallons of soft water is used the killing
power is actually decreased. More than two or three pounds to
50 gallons of water is liable to burn tender plants. If the water
is hard more soap will be needed as some of it is used in soften-
ing the water.
Pyrethrum or Persian Insect Powder.-Pyrethrum is much
used against household insects. It is also frequently used in the
field and has been extensively used in Florida in the control of
the celery leaf-tyer.
Extracts of pyrethrum dissolved in various carriers, mostly
4il derivatives, are now on the market. They are somewhat
more expensive than the compounds of nicotine and therefore
are hardly to be recommended against insects which can be
killed with nicotine compounds. But they will kill many insects
Btdletin 232, Truck and Garden insects
which are killed with difficulty, if at all, by nicotine compounds,
such as the bean leaf hopper. They are valuable insecticides to
be used against insects which are not readily killed by nicotine
compounds, particularly during the cooler weather of winter.
Calcium Cyanide is one of the most deadly contact insecticides.
It is more commonly used as a fumigant. (See under Fumiga-
tion.)
Bordeaux.-Bordeaux mixture, the common fungicide, is used
to repel such insects as flea-beetles. But its chief interest with
regard to insect control, lies in the fact that it can be combined
with most arsenicals. This makes a spray that will kill both
fungi and biting insects. Nicotine compounds also can be mixed
with bordeaux to kill sucking insects. In mixing these insecti-
cides with bordeaux, let the bordeaux solution take the place of
the water called for in the formula.
The following directions for preparing bordeaux mixture are
given by Dr. G. F. Weber of the Department of Plant Pathology
of this Station. (For fuller directions see Press Bull. 400.)
"Stock Solution A, Bluestone: Dissolve at the rate of 1 pound of blue-
stone to 1 gallon of water; put 50 pounds of bluestone into a clean bag and
suspend it in the top of a 50-gallon barrel of water. It will dissolve over
night. Never use a metal container for this purpose. Always stir the stock
solution before taking any out.
"Stock Solution B, Lime: Slake 50 pounds of rock lime and dilute it in
50 gallons of water. Be careful not to drown or burn the lime while slaking.
Always stir the stock solutions before taking any out. Do not stir the
two stock solutions with the same stick.
"Hydrated lime may be used in place of rock lime. If hydrated lime
is used it is necessary to use 1/2 again as much as rock lime. Thus 75
pounds rather than 50 pounds should be used in 50 gallons of water.
"In making Bordeaux mixture observe the following direc-
tions: Dilute the required amount of bluestone solution to half
the amount of spray to be made. Dilute the required amount
of lime in a separate container to half the amount of spray to
be made. Then pour the contents of the two containers at the
same time into a third container or spray tank, stirring the
combined mixture as the two are poured together. Be sure to
place a fine strainer either over the faucets on the barrels or on
top of the spray tank so that all of the liquid will be well
strained; this will prevent nozzle trouble in the field.
"If it is impractical to use the above method of mixing the
bordeaux, the following method may be used: Pour the diluted
lime solution into the spray tank, set the agitator going and add
slowly the diluted bluestone solution.
Florida Agricultural Experiment Station
"Different Amounts of 4-4-50 Bordeaux Mixture: In making 50 gallons
of the mixture, use 4 gallons of stock A, diluted to 25 gallons, and 4 gal-
lons of stock B, diluted to 25 gallons. Run both of these into the sprayer
at the same time with the agitator going. For larger amounts, use the
same proportions. For instance, to make 100 gallons of spray, use 8 gal-
lons of stock A, diluted to 50 gallons, and 8 gallons of stock B, diluted to
50 gallons. Mix as above."
The lead arsenate or nicotine compounds should be added to
the diluted bordeaux after it is completely made up.
FUMIGATION
The trucker or gardener will ordinarily use this method of
killing insects only in the soil, in greenhouses, coldframes and
bins where seeds or other plant products are stored.
The common fumigants are:
Carbon Bisulphide.-See weevils, under corn, page 58.
Paradichlorobenzene.-See weevils, under corn, page 58.
Hydrocyanic-Acid Gas.-This gas is cheaper than carbon bi-
sulphide for fumigating large rooms and buildings and has the
added advantage of being noninflammable. It is extremely
poisonous and great care must be exercised not to inhale it. It
is made in two ways:
THE POT METHOD
Compute the cubic contents of the room; then close it tightly
and stuff all cracks with rags, or paste paper over them.
Get a large earthenware jar and pour into it 2 fluid ounces of
water for each 100 cubic feet of space. Into this water pour 11/2
fluid ounces of commercial sulphuric acid for each 100 cubic feet
of space. Be sure to pour the acid into the water and not the
water into the acid; otherwise you will probably break the jar
by the heat generated and may be severely burned by the sput-
tering acid. Into this diluted acid drop 1 ounce of sodium
cyanide for each 75 cubic feet of space. The jar should be so
large that it is not more than one-third full before the cyanide
is added, otherwise it is likely to boil over. After dropping
the cyanide in, leave the room promptly, shutting the door and
locking it. The gas will begin to form at once. Cyanide is
one of the most powerful poisons and should be handled with
extreme care. It is well for the operator to wear rubber gloves
if the skin has been injured on any part of his hand and the
hands should be thoroughly washed before being permitted to
touch the lips.
The foregoing dose is twice that of the "horticultural dose"
Bulletin 232, Truck and Garden Insects
and is about as strong as can be used in a tight room or box
without endangering the germinating power of the seed. The
horticultural dose is that used on nursery stock and is intended
to kill insects without injuring the plants.
Potassium cyanide may be used if sodium cyanide is not to
be had, but it is more expensive and one must use 25 percent
more of it to get the same amount of gas.
CALCIUM CYANIDE METHOD
A newer and much more simple method of generating hy-
drocyanic acid gas is by the use of calcium cyanide. This ma-
terial gives off the gas immediately upon exposure to moist
atmosphere or soil from which it absorbs water. The material
is simply dusted over the surface to be fumigated. It is par-
ticularly to be recommended for soil fumigation (see under
nematodes) and for greenhouses. In very dry buildings water
will need to be supplied, at least with some forms.
The material is put out in several forms such as a fine dust,
in the form of granules, in the form of flakes, etc. In using
the material follow the directions given for the particular form
being used. The flakes or granules are usually preferable for
soil fumigation as they are more easily handled. For dusting
in the air, the dusts are necessary.
Tobacco.-Tobacco is used as a fumigant in greenhouses and
other closed places. Sheets of "tobacco paper" manufactured
especially for the purpose, or tobacco stems and refuse may be
used. The material is set on fire and the fumes of nicotine given
off in the burning kills all tender insects in the space. Tobacco
stems are moistened so that they will smoulder and smoke but
produce no flame.
Naphthalene. Naphthalene, the active ingredient of moth
balls, is fairly good as a repellant to keep insects out of stored
grains and seeds but it does not kill them.
HEAT
A temperature of from 120 to 130 degrees Fahrenheit, if
maintained for a half hour, is fatal to practically all insect life.
If a bag of seed can be placed in an oven, with a dish of water
to supply moisture, and kept at a temperature of 120 to 130
degrees F. for from 20 to 30 minutes, insects in it will be killed
and the germinating power of the seeds will remain unimpaired.
Florida Agricultural Experiment Station
GENERAL GARDEN INSECTS AND PESTS
There are a number of insects that attack practically all gar-
den crops and could not well be included under only one of them.
They are treated here.
GRASSHOPPERS
These insects are particularly annoying on early fall crops.
At that time native vegetation is becoming dry and unattractive
and the grasshoppers, many of which are then in the late
nymphal or the adult stages and consume more vegetation than
the very young, flock to the farmers' crops.
There are many genera and species of grasshoppers. One
of the most common and troublesome is the red-legged grass-
hopper. This is one of the smaller kinds but makes up in
numbers what it lacks in size. On flatwoods and muck lands
the lubberly locust is often troublesome. This is the largest
grasshopper in Florida. The young are black with reddish
markings. There are two color-forms of the adults. Some are
of a striking yellow color and others are almost as black as the
larvae. These grasshoppers have very short wings and are in-
capable of flight.
Grasshoppers lay their eggs in the ground in waste places
at a depth of 1 or 2 inches. Cultivation will destroy the eggs
when they are laid in cultivated land; consequently it is in
small fields surrounded by waste land that grasshoppers are
most troublesome. As the amount of land under cultivation in
a neighborhood increases, these insects become less of a pest.
Control.-Birds, including domestic fowls, especially turkeys,
are very fond of grasshoppers. The general farmer should keep
a flock of turkeys, for their insecticidal value if for no other
reason. They would, of course, be out of place on a truck farm
or town lot. The lubberly locust is, however, distasteful to all
birds and will not be eaten by them.
The cheapest and most effective method of dealing with
grasshoppers is by means of poisoned baits, of which the so-
called Kansas formula is the best. It has proven very sat-
isfactory wherever tried. It is
Bran ......... .............................. 25 pounds
Paris green or white arsenic (oxide)........ 1 pound
W ater ................. ....................... 2/2 gallons
Lemons, oranges, or cantaloupes................ 3 or 4
Syrup ............. .. ........ ........... 2 quarts
Bulletin 232, Truck and Garden Insects
The paris green and bran should be thoroughly mixed (dry).
Lead arsenate should not be used. It does not work as well.
The lemons should be thoroughly grated or chopped very fine,
rind, pulp and juice, and added to the water. Moisten the bran
with the water until the whole is damp, not sloppy, so that when
sown broadcast over the land it will fall in small flakes. Last
of all add the syrup and thoroughly knead it into the bran. This
should be sown in the early morning, about sunrise or before.
Grasshoppers do not eat at night, and consequently have a
good appetite in the early morning, and the bait should be on
hand for their breakfast.
If sown in small flakes over the field there will be no likeli-
hood of chickens or other domestic animals picking it up, nor
will wild birds be endangered. Ordinarily there will be no danger
to chickens or other fowls eating the dead grasshoppers as
the fowls will not get enough arsenic in this way to harm them.
MOLE-CRICKETS
These are flat, like other crickets. Their front legs are
greatly enlarged and fitted for burrowing
deep in the ground during the daytime,
coming out at night to feed. They are
very destructive to vegetation, particularly
in gardens and seedbeds. They make,
just beneath the surface of the ground,
runways resembling those of moles but
very much smaller.
There are at least three native species
of mole-crickets that are somewhat de-
structive in truck patches, especially in
low ground where there is considerable
vegetable mold. In addition, the West
Indian mole-cricket or changea" (Fig. 3)
is becoming very troublesome in some sec-
tions of the State.
Control.- Sulphur placed in the seed
drill is said to act as a deterrent. Mole
crickets may be kept out of seedbeds by
a gauze floor. At the time the seedbed is
(Fig. 2). They live
A ,
; \1
Fig. 2.-Native mole-cricket.
Natural size. (Original.)
made, dig out the earth to the depth of a foot or so and place in
the bottom a layer of galvanized or copper wire mosquito net-
Florida Agricultural Experiment Station
ting. It should come up at the sides and project a couple of
inches above the ground.
Plants set out in the field may be protected by banding them.
For this purpose, melt off the tops and bottoms of tin cans and
place the cylinder over each plant, sinking it into the earth to
some depth. Instead of the tin cans, tarred paper may be used.
Like other insects which live in the
ground, mole-crickets may be poisoned
by carbon bisulphide. Sink into the in-
fested garden several holes to the square
yard. These can be made with a cane,
if the soil is a bit moist, and should go
down to a depth of one foot. Pour into
each hole an ounce of the liquid, and
quickly cover the hole. Care must be
taken to keep the liquid away from the
plants or they also will be killed; also
keep the liquid away from fire or lights
as it is very inflammable.
Another and cheaper liquid which can
be used in the same manner is a solution
of sodium cyanide in water, about an
ounce to two gallons of water. Calcium
cyanide flakes or granules can be used also.
If the garden is known to be infested at planting time it
should be treated before it is planted. For this purpose scatter
calcium cyanide in the furrow or treat it with sodium cyanide
and ammonium sulphate as advised for root-knot. Or the garden
may be treated as follows: Plow it and level it off smooth and
compact the surface with a roller or the back of a shovel. If the
soil is dry, first wet it. Leave it over night. The following
morning go out with a solution of cyanide in water. The pres-
ence of the mole crickets will be revealed by their galleries and
by little piles of soil freshly thrown up. Wherever such signs
are seen punch a hole to a depth of a few inches and pour into
it a fluid ounce or two of the sodium cyanide solution or a table-
spoonful of carbon bisulphide. Repeat the operation every night
until no more signs of their presence are seen.
To reduce the number of mole-crickets in badly infested
ground, plow deeply several times in the spring, from March to
June, when they are breeding most actively. Allow chickens,
and especially turkeys, to follow the plow for they are very
Fig. 3. "Chana" or West
Indian mole-cricket. Natu-
ral size. (Porto Rico ExP.
Sta.)
Bulletin 232, Truck and Garden Insects
fond of these insects. Pasture hogs on the field when possible.
When mole-crickets are flying during March or April (they do
not fly much at other seasons) great numbers can be caught
in light traps. Suspend a lantern in the field and place under
it a pan of water on the surface of which there is a thin layer
of kerosene.
We have had the best success in killing mole-crickets with a
poisoned bran bait made up according to the grasshopper bait
but substituting one of the commercial poultry egg mashes for
the bran in that formula. Apparently any commercial egg mash
which contains considerable dried milk is effective. It is appar-
ently the dried milk in the egg mash which makes this very
much more effective than the ordinary grasshopper bait made
up of the bran. This mixture will of course kill grasshoppers
and cutworms as well as mole-crickets, but because of the great-
er expense this is recommended only for mole-crickets.
Baits will remain attractive longer and hence prove more ef-
fective, especially in dry weather, if buried to a depth of an inch
or two in the soil.
MOLES
Moles are a nuisance in lawns and gardens because of the
extensive tunnels they make beneath the surface of the soil.
In making these tunnels they break off the roots of the plants
and cause the soil over the tunnels to dry out. Contrary to
common opinion, they do not feed extensively on vegetation but
are mostly insectivorous in their diet. They are fond of "white
grubs" which are the larvae of May-beetles or June-bugs. These
white grubs are most abundant on land that has been allowed
to grow up in grass during the summer. The first step in fight-
ing moles is to get rid of the white grubs. This can be done by
raising some cover crop such as cowpeas, velvet beans or pea-
nuts on the land to keep down the grass during the summer,
and also by turning pigs in on the land for a few weeks before
the garden is plowed. (See white grubs under potatoes, page 81,
for further suggestions.) Although, by eating the white grubs,
moles perform a good service to the grower, like some other
troubles, the remedy is often worse than the disease.
Control. Moles may be discouraged from burrowing in
the garden by tramping the soil solidly into their runways or
crowding a brick or a stone into it where it enters the garden
from the outside, making sure of course, that the mole is not
Florida Agricultural Experiment Station
in the garden when this is done. The presence of the mole is
best detected in the early morning by the ridges of fresh dirt
or the movement of the soil as he forces his way through it. In
the latter case the mole can at once be dug out and either killed
or, better, carried off to some pasture or waste land where its
activities will be beneficial rather than harmful.
Moles make two types of tunnels. One is the feeding tun-
nel which is but a few inches below the surface of the ground.
The other is larger and located much deeper, a foot or more.
This is the main highway for the moles in going from one end
of their range to the other. There are several mole traps on
the market and moles may be trapped by uncovering their main
roadway and placing in the breach a mole trap. A handful of cal-
cium cyanide may be placed in the opening thus formed instead
of a trap.
The prevalent idea that moles feed largely on the roots
of plants arises from the fact that their runways are commonly
used by field mice which do the damage. Stopping up the run-
ways will discourage the mice as well as the moles. In the
kitchen garden both moles and mice may often be drowned out
by turning the garden hose into the runway. The mice may be
poisoned by putting in the runways some corn that has been
soaked in arsenic, paris green, or strychnine.
ANTS
One of the nuisances with which the gardeners and truckers
have to contend is ants. The amount of damage they will do
depends to a large extent on the species. Following are men-
tioned some of the ways in which they are annoying in a garden.
They eat off growing plants such as cabbage. Most species
feed to a limited extent only on growing vegetables, but many
species seem to object to the presence of vegetation about their
nests. This is particularly true of the large yellow agricul-
tural ants which will keep a space many feet in diameter about
their nests absolutely free from vegetation. The leaf-cutting
ants which are found in the southern part of the State, cut off
and remove to their nests a large number of leaves. They do
not use these directly for food, but to grow a kind of fungus
of which they are particularly fond. They were the first mush-
room growers. They are particularly annoying to citrus trees
in the tropics where they abound.
Bulletin 232, Truck and Garden Insects
One of the most annoying habits of ants is that of carrying
away seeds from seedbeds. They are particularly fond of let-
tuce and romaine seed. They use the seeds for food and will be-
gin to carry them to their nests as soon as the seeds are planted
and will continue their pernicious activities all through the ger-
mination period and until the young seedlings have used up all
of the material in the seeds. Ants often cover up plants by build-
ing mounds over them.
Ants are very fond of the honeydew given off by aphids.
some jassids, mealybugs and other scale-insects. For the sake
of this substance many kinds will tend those insects, sometimes
driving away their enemies and more commonly carrying those
pests from one plant to another. (See garden aphid under
cabbage plant lice, page 41.)
Ants in the truck patch and garden, especially those that
sting, are somewhat annoying to workers.
Control. Ants are best destroyed in their nests. For this
purpose carbon bisulphide can be used but sodium cyanide is
cheaper and more efficient. Dissolve the cyanide in water, an
ounce to two quarts of water. With a cane or sharp stick punch
a hole to the depth of a foot or more in the center of the hill
and pour into it a few ounces of the solution. The dosage to be
given as well as the depth of the hole will depend upon the size
and depth of the nest. As soon as the liquid has soaked away,
cover up the hole with dirt and tramp it solid. The gas given
off will penetrate the galleries of the nest and kill most of the
ants and their young. It is best to do this in the early morning
when most of the ants are "at home." All of the nests within
50 or 60 feet of the seedbed should be treated. As recorded
under the head of fumigation, cyanide is one of the most pow-
erful poisons known, when either inhaled or swallowed. It
should also be kept out of open sores. Some ants will probably
escape the first treatment. These will, however, lose all interest
in the seedbed and will go slowly about, cleaning the dead ants
out of the nest. Their slow and languid motions are in sharp con-
trast to their feverish activity of the previous day. The sur-
vivors will probably, in the course of a few days, start small new
nests in the vicinity. These in turn may be treated.
The following formula first used at the Potter Palmer Estates
to drive ants away from the bases of citrus trees has been found
effective for hardier vegetables:
Florida Agricultural Experiment Station
Crude carbolic acid.......................................... 1 pint
W hale oil soap ........................................ ..... 1 pound
W ater .................................. ...... ....... 3 gallons
This is emulsified by forcing it through a spray pump several
times until an even mixture is obtained. Pour around base of
plant in shallow basin.
Another mixture which has been used in repelling ants from
the bases of plants like strawberries, is made by dissolving half
a teaspoonful of creolin in a gallon of water.
VEGETABLE WEEVIL (Listroderes obliquus Gyll.)
This weevil (Fig. 4), which is very destructive to a large num-
ber of vegetable crops, is invading Florida from the west. It is
now found in small numbers as far east as Gadsden County. The
weevil can be poisoned by ar-
senicals.
The insect is about five-
eighths of an inch long, gray in
color, mottled with numerous
small black areas and with lar-
t I ger light gray spots and lines,
Fig. 4.-Dorsal view of the vegetable
weevil (enlarged). Original by
J. W. Wilson.
Fig. 5.-Head and prothorax of the vegetable
weevil (greatly enlarged). Original by
J. W. Wilson.
two on the posterior halves of the elytra are especially promi-
nent. Near the posterior end of each elytron a rather promi-
nent papilla projects horizontally. The snout is broad and
short. (Fig. 5).
ROOT-KNOT
This is a disease characterized by knot-like swellings on
the roots. Severely infested plants fail to make proper growth
and often turn yellow and die prematurely.
The cause is a minute round-worm or nematode (Caconema
Bulletin 232, Truck and Garden Insects
radicicola) which bores into the roots to feed. It gives off a
poison which causes the plant to make the swelling. It affects
nearly all garden and truck crops, except corn, to a varying de-
gree. The worms are not very active during the winter, but dur-
ing the warmer weather from April to October they often make
it impossible to grow a profitable crop of certain plants on the
infested land. Newly-cleared land is usually free from these
worms, but most sandy soils of Florida, when cleared and culti-
vated for a number of years, become infested.
The following plants commonly grown in Florida are subject
to infestation. Those most liable to severe attack come first in
the list:
1. Okra 15. Dasheens 30. Cabbage
2. Tomatoes 16. Peppers 31. Cauliflower
3. Eggplant 17. Squash 32. Collards
4. Cucumbers 18. Lettuce 33. Soybeans
5. Cantaloupes 19. Beans 34. Mustard
6. Amaranth 20. Rape 35. Pecans
(careless weed) 21. Papaya 36. Japanese persimmon
7. Celery 22. Carrot 37. Violets
8. Tobacco 23. Pineapples 38. Old World grapes
9. Peas 24. Sunflowers 39. Sugarcane
10. Peaches 25. Bananas 40. Peanuts
11. Figs 26. Cotton 41. Catalpa
12. Irish potatoes 27. Radishes 42. Quince
13. Watermelons 28. Sweet potatoes 43. Kudzu
14. Beets 29. Asparagus
On land which has been heavily infested it is impossible to
grow profitably the plants at the head of this list. They may
grow well at first but soon become stunted and fail to bear well.
Control--The usual way to free infested land is to raise
only non-susceptible crops on it for three years and thus starve
out the worms. Among such immune or partly immune plants,
are, most of the true grasses, including crab-grass and Bermuda,
most varieties of corn and wheat, rye, and some varieties of
oats, velvet beans, beggarweed, and the Crotalarias. Iron and
Brabham cowpeas are usually resistant. Onions, parsnips,
strawberries and turnips are but slightly affected. While grow-
ing any of these crops to free the land of nematodes it is im-
portant that weeds should not be allowed to grow there as the
nematodes are abundant on many of them. This is especially
true of some species of Amaranth or "careless weed."
However, most truckers cannot afford to plant their fields to
such relatively cheap crops for a series of years. For such
truckers the following method is recommended: As soon as the
crop is off in the spring plant infested land to Crotalaria spec-
Florida Agricultural Experiment Station
tabilis. Plant it in rows about three feet apart. The exact width
will depend upon the cultivating instruments. Cultivate fre-
quently, at least after heavy rains, to prevent any crust from
forming on the soil to the exclusion of air, and keep it free of
all weeds. This will necessitate one or two hoeings and maybe
some weeds pulled by hand. If this is thoroughly done it will
usually practically eliminate the nematodes in one summer.
Velvet beans can be substituted for the Crotalaria, but they do
not grow as well on the more moist truck lands, and their twin-
ing habit of growth makes it difficult to cultivate the land prop-
erly. Crotalaria striata may be used, but the growing season is
longer and its more woody stems make it more difficult to
break it up the following fall. Moreover we have seen some root-
knot on Crotalaria striata but none on C. spectabilis.
For a quick cleanup the land may be treated with a double
treatment of sodium cyanide and ammonium sulphate, but this
method is so expensive that it is recommended only for seedbeds.
Full directions for this treatment and also other methods for
combatting nematodes will be found in the root-knot bulletin of
the Experiment Station.
OTHER GENERAL PESTS
The following named pests attack a large number of vege-
tables and could have been treated appropriately under this
general heading. They are: Fall army worm or grass worm
(see under corn, page 55); red spiders (see under peas, page
77); garden aphid (see under cabbage, page 41); and cut-
worms (see under cabbage, page 35).
BEANS
BEAN LEAF-HOPPER (Empoasca fabae)
Several species of jassids severely attack snap beans, espe-
cially those planted early in the fall. Their ravages are often
so severe as to discourage the planting of beans at that season.
Jassids obtain their food by sucking the juices of plants.
If the insects attack in sufficient numbers the plants will be-
come stunted in growth, fail to bear well, turn yellow and
finally die.
Several species are concerned in this injury. The most
abundant is Empoasca fabae or bean leaf-hopper. This is also
called the potato leaf-hopper in the North because it is there es-
Bulletin 232, Truck and Garden Insects
pecially injurious to potatoes. It is a light green insect, 1/i
inch long. Under a lens the eyes of the living insect are white
but they quickly turn brown after death. The bug lives on a
variety of plants but is partial to cowpeas and beans. There are
many generations a year.
Control. These insects can be killed by a strong tobacco
extract. A successful one is:
Black leaf 40...................... .................. 2/5 pint
Bordeaux ............................ ........... 50 gallons
Extracts of pyrethrum, of which there are several brands on
the market, will give better kill of these insects, particularly of
the adults, than the tobacco extracts. Although somewhat more
expensive than the tobacco compounds, they are to be recom-
mended for this insect because of their greater efficiency.
Spraying with an ordinary nozzle is not altogether satis-
factory because so many of the bugs escape by flying away.
Much better control can be obtained by covering the discharge
nozzle of the spray with a hood. Full directions and an illustra-
tion of this apparatus can be found in Bulletin 164 of this
Station. Good results have also been obtained with a traction
sprayer by nailing burlap sacks over the top of the platform
and to the sides in such a manner as to hang down and drag on
the beans. Hoppers flying away from the spray are caught
in these sacks which are always wet with the spray. By the
use of these appliances good crops of beans have been raised
during years when surrounding fields were entirely destroyed.
In some sections a hopperdozer, constructed on the plan of a
vacuum cleaner, has given good results.
It is very important that one raising beans in the fall
should keep a belt several rods wide entirely around the bean
field clear of all herbaceous vegetation. This can be done by
either plowing the strip and giving it frequent cultivation or
cutting the vegetation off and burning it before the beans come
up. This belt around the field in which there is no vegetation
is very effective in checking the migration of the hoppers from
the surrounding vegetation.
On the lower East Coast the bean jassid is more injurious
to the winter and early spring crops of beans.
TUREE-CORNERED HOPPER (Stictocephala festina)
In addition to the smaller leaf-hopper, Empoasca fabae,
beans are commonly infested with a much larger one. This is
Florida Agricultural Experiment Station
yellowish-green in color, about a quarter of an inch long and
half as wide. As viewed from above, its outline is that of a long
triangle. This and its habit of feeding on alfalfa have resulted
in its being known in the West as the "three-cornered alfalfa
hopper." It is also a pest of tomatoes, watermelons, and cow-
peas in Florida. We have also found it common on hickory, oak,
go!denrod, and summer haw (Viburnum). Control measures
would be the same as for the smaller species.
BEAN LEAF-ROLLER (Eudamus proteus)
Another insect which is very troublesome to the early fall-
planted crop is a caterpillar which rolls up the edges of the
leaves after cutting slits in them. From these shelters the
caterpillars range over the leaves which are often so badly
eaten that no pods can be formed.
The caterpillar (Fig. 6), which grows to an inch in length,
is a light greenish-yellow, velvety insect. The brownish-yellow
Fig. 6.-Bean leaf-roller: Larva. Much enlarged. Original.
head is attached by a neck which is much narrower than usual
in caterpillars so that there is a marked constriction between
the head and thorax.
In the summer the larva will complete its growth in 14 days,
but in October and November, 30 or more days are required.
The larva then forms the pupa on the plants and in 6 days
the bluish butterfly emerges. The insect belongs to the group
of butterflies known as "skippers," doubtless because of their
habit of darting quickly from plant to plant in search of nectar
or a place for an egg. The eggs are deposited on beans in sum-
mer. Members of this group of butterflies when at rest, hold
their wings at an angle of about 45 degrees instead of horizontal
or perpendicular as do other butterflies. This species (Fig. 1)
may be distinguished from other skippers by its larger size, 2
inches across the outstretched wings, and by the prolongations
(" tails ") of the hind wings.
Bulletin 232, Truck and Garden Insects
The insects are scarce in the spring and early summer so
that early beans are not troubled. But by the first of Septem-
ber the butterflies are abundant and beans become heavily in-
fested.
Control. The insect can readily be killed by spraying with
lead arsenate. However, beans are easily injured by arsenicals
so not over 12 ounces of the powdered, or a pound and a half
of the paste, form of lead arsenate should be used to 50 gallons
of water, and to this should be added, before using, a pound of
hydrated lime or the milk obtained from slaking 2 pounds of
quick lime in water. If jassids also are present, add tobacco
to the solution.
It is sometimes desirable (up to the blooming period) to
spray beans with 4-4-50 bordeaux for fungus diseases. The
lead arsenate, and also the nicotine solution, can be placed in
the bordeaux.
BEAN WEEVIL (Acanthoscelides obtectus)
There are two or three species of weevils that infest beans.
The most common is Acanthoscelides obtectus (Fig. 7). Others
are more common on cowpeas and will be treated under that
heading. The ravages of this insect on dried beans are very
conspicuous; in fact, if not checked, it will entirely destroy
seed beans. They also damage snap beans. The infested pods
show wart-like swellings where the female punctures them to
lay eggs in the cavity of the pod. She gnaws out a narrow slit
and then inserts her ovipositor in the hole and lays the egg.
These speckled" pods should not be
confused with those h a v i n g spots
caused by the fungus, Colletotrichum. \
Those spots caused by the fungus are
sunken instead of elevated and attain
a much larger size. The egg hatches /
in from 1 to 3 weeks, according to the 6
prevailing temperature, into a small, F. 7.--n-weevil (Aehos
Fig. 7.-Bean-weevil (Acanthns-
worm-like larva. This requires from celides obtectus): a. Adult
beetle much enlarged; b, in-
11 days to 6 weeks to become full tested bean. (From u. s.
Bur. of Ent.)
grown and then changes into the pupa.
From 5 to 18 days later the adult emerges. This is an ashy-
black beetle about a tenth of an jnch long with hard wing-cases
and somewhat flattened body.
Nothing can be done to protect beans in the field from
Florida Agricultural Experiment Station
the ravages of this insect. The best method of control is to
plant clean seed in a field that has not recently produced a crop
of cowpeas or beans. Breeding in dried beans can be prevented
by keeping the beans in cold storage (32 to 34 degrees F.) for
two months or more, or they may be fumigated as recommended
for stored seeds.
LESSER CORN STALK-BORER (Elasmopalpus lignosellus)
This insect is injurious to corn in the states farther north;
in Florida it does more damage to cowpeas and beans, although
it is injurious to corn. Next to the bean-jassid it is the most in-
jurious insect on fall-planted beans. It often destroys almost the
entire stand if control measures are not adopted. The insect
is a bluish-green caterpillar (Fig. 8, d) which bores into the
stem at the surface of the ground and tunnels up and down in
it, causing the young plant to wilt and die quickly. If the
cowpea-plant gets a good start before it is attacked it is not
easily killed and may produce some pods, so that the damage
is not as noticeable, but a bean is usually killed outright. The
full-grown caterpillar is about a half-inch long. It is quite
smooth; i. e., it is not noticeably hairy. There is a large brown
spot on the back of each segment (joint). The head is brown
and hard and the first joint of the thorax is black. The adult
Fig. 8.-Lesser corn stalk-borer (Elasmopalpus lignosellus): a, Male moth;
b, wing of female moth; c, moth, showing the resting position of the
wings; d, caterpillar: f, pupa. About three times natural size. (From
U. S. Bur. of Ent.)
is a small, brownish moth with cream-colored markings (Fig.
8, a). It belongs to the same family as Crambus (see root web-
worms, under corn, page 56) and rolls its wings about its abdo-
men in the same manner (Fig. 8, c).
Bulletin 232, Truck and Garden Insects
The female lays her eggs on the stem near the surface of the
soil and the caterpillar feeds on the surface of the roots until
about half-grown, when it bores into the stem.
Control. The caterpillars, working inside of the stems, are
safe from any poison that could be applied to the crop. The
young on the roots are also safe. The only means of prevent-
ing their spread through a field is to pull up and destroy all in-
fested plants. Rotation of crops should he practiced. Beans
should not be planted on land that has just grown beans, pea-
nuts. cowpeas, turnips, or corn, as they are all host plants.
OTHER BEAN PESTS
Other insect-pests attacking beans are: Root-knot nema-
tode (see under general garden pests, page 24) ; cutworms (see
under cabbage, page 35) ; the corn ear-worm (see under corn,
page 50) sometimes mines the pods: the cabbage looper (see
under cabbage, page 37) sometimes eats the leaves; cowpea
pod-weevil (see under cowpeas, page 60) ; grasshoppers (see
under general garden pests, page 18) are troublesome in the
fall; pumpkin bug (see under cowpeas, page 61) and other
plant-bugs (see under potatoes, page 80) are among the most
troublesome enemies of the bean grower; garden aphid (see
under cabbage, page 41) ; wireworms (see under corn, page
53) ; flea-beetles (see under beets, page 33) ; and striped cu-
cumber-beetle (see under cucumbers, page 66).
LIMA BEANS
GALL-WORM (Monoptiloba sp.)
In addition to the pests of other beans, lima beans are at-
tacked by a caterpillar that bores into the stems. The plant
thus attacked forms a large swelling or gall about the larva.
In this gall the larva lives, feeding on the tissue until its growth
is complete. The adult insect emerges as a small moth, and
lays eggs on the stems of the plant. These galls are very com-
mon on lima beans in Florida.
The attacks of this caterpillar do not usually become se-
vere until summer, hence lima beans planted early usually pro-
duce a fair crop. The only practical means of preventing this
injury seems to be to plant as early as possible and fertilize
and cultivate well.
Bush lima beans are not as much injured as the climbing var-
ieties.
Florida Agriciltural Experiment Station
BEETS
BLISTER-BEETLES
These long, slender beetles feed on a variety of truck plants,
including beets, tomatoes, and potatoes. In the Northern
States these insects are known as old-fashioned potato bugs "
to distinguish them from the more recently introduced Colo-
rado potato-beetles." They are known in parts of Florida as
"Yankee bugs," perhaps from the bluish color of certain species.
The adult beetle crushed against the skin causes a blister, hence
the name blister-beetle." It is also called Spanish fly," cer-
tain species being the source of the drug of that name.
Eight species of blister-beetles are more or less trouble-
some to vegetation in Florida. The most common one is the
gray blister-beetle (Epicauta heterodera) which has no stripes.
The striped blister-beetle (E. vittata) (Fig. 9) is frequently
seen.
The work of all the species is about the same, except that
they show preferences for different plants. They strip all
Sthe softer parts of the leaves, leaving only the mid-
ribs. The beetles usually feed in colonies, some-
times so large that they quickly strip and ruin a
patch or an entire field.
If the colony is small the quickest way to ex-
terminate it is to collect the beetles in a pan of
Fig. 9.-Strip- kerosene. They are quick to take alarm and the
ed blister-
beetle; Nat- collector must work rapidly. If the colony is large
u r a l size.
rom U. S. the plants should be sprayed with lead arsenate.
The larvae feed on the eggs of grasshoppers and
are beneficial to agriculture. For this reason it is better, wher-
ever possible, to drive the beetles from the field rather than to
poison them. To do this, use a bundle of twigs with which to
whip the plants and work with the wind, driving the beetles
quite a distance from the field to prevent their quick return. It
may be necessary to repeat this driving frequently.
BEET LEAF-MINER (Pegomyia vicina)
This insect belongs to a large class made up of small pests
which often escape the notice of the trucker because of the
small size of the insect and the wound inflicted, while the un-
thrifty condition of the injured plants is laid to a lack of fer-
tilizer or water. Collectively they inflict severe damage.
Bulletin 232, Truck and Garden Insects
This maggot-like larva of a two-winged fly frequently bur-
rows in the tissue of beet leaves. If they become numerous they
will materially check the growth of the plants.
In its protected position, the grub cannot be reached by
any insecticide, but the grower can check an outbreak by de-
stroying all infested leaves. This at least should be done when
the beets are gathered, if not before. If the infested leaves are
left in the field the grubs have opportunity to enter the ground,
go into the pupal stage and emerge later as flies.
FLEA-BEETLES
These are small oval beetles (Fig. 10) that get their name
from the habit of quickly springing several inches when dis-
turbed. Two species are more or less troublesome in Florida to
beets, cabbage,
cucumbers, to-
matoes, and re-
lated plants.
They eat the
epidermis o n
one side of the
leaf and the soft
interior cells but
leave the veins
and other hard f
parts. a
Bordeaux
mixture is usu-
ally efficacious
in preventings 4
injury by these b
e
insects. The Fig. 10.-Strawberry flea-beetle: a, Adult; b, eggs on leaf;
mixture can be c. s'de-view o, young larva; e dorsal view of larva; f, pupa.
Greatly enlarged. (From U. S. Bur. of Ent.)
made more effi-
cient by the addition of from 8 to 16 ounces of powdered lead
arsenate (or 1 to 2 pounds of the paste) to 50 gallons of the
bordeaux.
One common species of flea-beet'e is usually very abundant
on evening primrose (Oenothera sp.) from which they often
spread to cultivated crops. These weeds should be destroyed
around the edges of truck fields as well as in the fields.
Florida Agricultural Experiment Station
STRIPED MORNING-SPHINX (Celerio lineata)
The larva of this very common hawk-moth feeds occasion-
ally on beets, although its common host plant in Florida is purs-
lane. It has the size and general appearance of the tomato-worm
and belongs to the same family. Its life history is similar and
the control measures are the same.
LARGER BEET WEBWORM
There are two species of small moths of the genus Hymenia
(or Zinckenia) whose caterpillars attack the beet. The larger
one is the spotted beet webworm (Hymenia perspectalis). Thia
larva is a small green caterpillar with purplish dots on its head.
The adult moth is a little over an inch in width across the
wings. It is cinnamon-brown in color with narrow white bands
in the middle of the front wings. The eggs are about 1/50 of
an inch in diameter and are laid on the leaves of the beets and,
particularly, carelessweed (amaranth). The latter is probably
its original host plant.
SMALL BEET WEBWORM (Hymenia fascialis)
This small webworm is much more abundant than Hymenia
perspectalis. During July the moths collect about the blossoms
of catnip and other plants in great numbers. As with the other
species the beet is a minor host plant for this insect, whose
larvae live chiefly on wild plants. The moth is smaller than
the other species and the white bands of the wings are larger.
Either species can be controlled with lead arsenate.
CUTWORMS
These greedy pests seem to be especially fond of beets, the
leaves of which they cut off. If this is repeated continuously
the plant is unable to grow. For control, see cabbage.
OTHER BEET PESTS
Other insects which attack beets are: Wireworms (see un-
der corn, page 53) ; white grubs (see under potatoes, page 81);
bean-jassid (see bean leaf-hopper under beans, page 26);
harlequin cabbage-bug (see under cabbage, page 45); false
chinch-bug (see tarnished plant-bug under celery, page 48);
sweet-potato caterpillar (see under sweet potatoes, page 93);
12-spotted Diabrotica or corn root-worm (see under corn, page
58); and cabbage looper (see under cabbage, page 37).
Bulletin 232, Truck and Garden Insects
CABBAGE
(Many cabbage insects also attack collards, cauliflower,
brussels sprouts, kohlrabi, and Chinese cabbage.)
CUTWORMS
Cutworms are very fond of any succulent plant, and are
troublesome to most truck and garden crops. Cabbage is one of
the chief sufferers from their attacks. They gnaw off the young
plants just above the ground, making them worthless.
Cutworms are the almost hairless larvae (Fig. 11, a, b,) of
any of several species of moths of the Noctuid family. The
moths are night-fliers and are commonly seen about lights. They
are grayish or brownish in color and most of them have on their
fore wings small silvery markings, dots, dashes, or commas (Fig.
11, d, e).
In Florida they do not hibernate but are active and breed
throughout the year, although neither the moths nor the cater-
pillars are active during the coldest nights of the winter. The
caterpillars will remain active
at a lower temperature than the
moths, but the latter are to be
seen about lights during warm
evenings even in midwinter.
The worms suspend operations
during the coldest nights only, d
when the temperature drops c
below 45 degrees.
There are no definite broods,
caterpillars of all sizes, eggs, a
one and the same time.
Control. The moths by
preference lay their eggs (Fig.
12) on grasses in heavy sod
land. The larvae feed on the Fig. 11.-Cutworm moth (Mamnetrm ckeno-
grasses. Consequently, on land iiof ao:. enlarva; e pua d. moth: a.
that has h a d considerable (From U. S. Bur. of Ent)
grass, the cut-worms are most troublesome. As long as the
grass is available there is so much food in proportion to the
number of worms that their feeding is scarcely noticeable. But
Florida Agricultural Experiment Station
when such land is plowed, the normal food supply of the cater-
pillars is cut off and they are concentrated upon the relatively
small amount of vegetation of the farmer's crop.
When grass land is plowed measures should
Sbe taken to kill the cutworms present before
a crop is planted. To do this, prepare the land
ten days or two weeks before the cabbages are
to be set out. During that time many of the
cutworms will leave or die of starvation and
the remainder develop a good appetite. A day
or two before the crop is to be set out, cut some
green and succulent plants such as col'ards,
rape, cowpeas, etc., and dip them into a strong
solution of paris green; about an ounce to a
Fig. 12.-Eeas of cut- gallon of water. Scatter this about the field
worm moth (Aprotis
saucia): a, sin-"e after sunset, for the hungry cutworms to feed
egg, greatly enlarg-
ed: b, exg mass on upon during the night. Instead of the green
twig. Natural size.
(From U. s. ur. of material the following poisoned bait may be
Ent.)
used.
Bran ...-............................................-----...... .... 20 pounds
Cottcnseed meal ............................................. 5 pounds
Paris green .......................... ..................... 1 pound
W ater ..................................................... ... 2 gallons
Mix the bran, cottonseed meal and paris green thoroughly
while still dry; then moisten with water until it is decidedly
damp, but not sloppy, and of such consistency that it will fall in
fine flakes when sown broadcast over the land. This should be
put out after sunset so that it will be fresh and attractive when
the worms come out to feed in the night. If the following day is
cloudy, the bait will remain attractive for the second night,
otherwise it will need to be renewed if the cutworms have not
been brought under control. If properly sown it will fall in
such small flakes that fowls or other birds will not pick it up.
In a cabbage field, better protection will be given to the plants
at a smaller expenditure for material if, instead of being sown
broadcast, the bait is placed in small piles about the stalks of
the cabbage. For protecting other crops it may be scattered
along the rows. Instead of both cottonseed meal and bran,
either may be used alone, in which case 25 pounds is used.
Stale bran or meal should not be used in making this bait. The
mixture must be made up fresh each day from sweet fresh
material.
Bulletin 232, Truck and Garden Insects
In a small garden or in afield where there are but few
cutworms, the easiest, quickest and cheapest method of dealing
with them is to walk through the patch in the early morning and
look for plants which were cut off during the preceding night.
By scratching the earth away from the base of the plant the
culprit will usually be found at a depth of not more than an
inch. They may be collected and fed to chickens.
CABBAGE WORMS
At least five species of caterpillars feed on cabbages and re-
lated plants in Florida. The most common one during the cab-
bage growing season, the winter, is the cabbage looper.
CABBAGE LOOPER (Autographa brassicae).-This larva (Fig.
13, a) of a Noctuid moth is closely related to cutworms, which
it resembles in general shape. It does not have the cutworm
manner of feeding but
works on the surface of
the cabbage leaves both
day and night. It in-
jures the leaves by eat-
ing holes in them and
also damages the ap-
pearance of the heads
by soiling them with its
excrement. The cater-
pillar is light green in
color and grows to a
length of more than an
inch.
The eggs, yellowish-
green in color and about
Fig. 13.-Cabbare looper: a, larva; b, pupa; c, adult.
Natural size. (From U. S. Bur. of Ent.)
a fiftieth of an inch in diameter, are scattered over the surface
of the leaves. The caterpillar requires about 3 weeks for
growth and spends about 2 weeks in the pupa stage.
The adult moth (Fig. 13, c) also looks much like those of cut-
worms, and, in the latitude of Gainesville, may be active all
winter.
THE CABBAGE PLUTELLA (Plutella maculipennis).-The cab-
bage plutella (Fig. 14, a), a much smaller caterpillar than
the looper, is common on cabbages. It is less than a half-inch
long and is much more hairy in appearance than the looper.
When disturbed it drops quickly from the plant, spinning a
Florida Agricultural Experiment Station
silken thread which it uses to remount when the danger is over.
On the under side of the leaf, it makes small round holes, rare-
ly extending through. Like the looper, this caterpillar is active
Fig. 14.-Cabbage plutella: a, Larva; d, e, pupa; f,
moth; h, moth at rest. Two and one-half times
natural size. (From U. S. Bur. of Ent.)
all winter in the latitude
of Gainesville and south.
The cocoon placed on the
leaf is a loosely-woven af-
fair through which the
pupa (Fig. 14, e) may be
seen plainly.
The adult (Fig. 14, f)
is a small moth 5/8 inch
across the expanded
wings, which are gray
with a border of lighter
areas. When the wings are folded in the resting position (Fig.
14, h) these areas form diamond-shaped patches along the back.
For this reason the moth is also called the "diamond-back" moth.
The life history occupies from two to three weeks in sum-
mer. It spends about three days in the egg stage, from one to
two weeks in the larval, and from four to eight days in the pupal
stage. Therefore, if one wishes to effect a thorough clean-up of a
heavy infestation of this insect, he should give the
plants a second spraying about ten days after the
first (two weeks in winter.)
CABBAGE BUTTERFLIES
The caterpillars of these white butterflies are a
injurious to late cabbage and collards. They do
not seriously trouble the main winter-grown crop
of cabbage because they are not active at that sea-
son.
IMPORTED CABBAGE-WORM (Pontia rapae). -
In the northern and western parts of the State Fig. 15.-Imort-
ed cabbage but-
the most common cabbage butterfly is the im- terfly: a. lar-
va; b, pupa.
ported cabbage-worm, a pest which was brought Natural size.
to this country about 1856. It has since spread Bur. of Ent.)
over the entire country, reaching Florida about
1890, but has never become as abundant as in the Northern
States.
The full-grown caterpillar (Fig. 15, a) is about 11/4 inches
long, bright green with a yellowish line down the middle of its
Bulletin 232, Truck and Garden Insects
back and a row of spots of the same color along its sides. Two
or three weeks are required for its growth. It then crawls to
some sheltered place and there transforms into the pupa (Fig.
/ __
Fig. 16 -Imported cabbage butterfly: Fig. 17.-Imported cabbage butterfly:
Female. Natural size. (From U. S. Male. Natural size. (From U. S.
Bur. of Ent.) Bur. of Ent.)
15, b) and 8 or 10 days later, in warm weather, the butterfly
(Figs. 16, 17) emerges. But those which enter the pupa stage
in the late fall remain there all winter, at least in the northern
part of the State. The eggs are white or yellow in color and are
scattered over the surface of the leaf.
NATIVE OR SOUTHERN CABBAGE-WORM (Pontia protodice). -
This worm (Fig. 20, a) is similar in appearance to the import-
ed worm but has four longitudinal yellow bands. The butterflies
can be distinguished by comparing the illustrations (Figs. 16,
17, 18, 19). The nature of the injury it inflicts is identical with
that of the species last named.
GULF WHITE (Pontia monuste).- This butterfly has a yel-
low caterpillar (Fig. 21, a) with four lorgitudinal stripes of a
Fig. 18.-Southern cabbage butterfly: Fig. 19.-Sout'ern cabbage butterfly: Fe-
Male. Natural size. (From U. S. Bur. male. Natural size. (From U. S. Bur.
of Ent.) of Ent.)
purplish hue. It is 11/2 inches long. The butterfly (Fig. 21, c)
is the largest of the group, measuring nearly 3 inches across
the expanded wings. This is by far the most common and
troublesome caterpillar on cabbage and collards grown during
the late spring and summer in the southern part of the State.
Florida Agricultural Experiment Station
Control.-Any or all of these caterpillars are easily controlled
by means of arsenicals. One can use paris green but either lead
''Ii,,,/u ,. a
0 1
Fig. 20.-Southern cabbage butterfly: a, larva:
b, pupa. Natural size. (From U. S. Bur. of
Ent.)
or calcium arsenate is
preferable. One pound of
paris green or 2 pounds of
lead or calcium arsenate
powder is put into 50 gal-
lons of water. This liquid
usually does not stick well
to cabbage plants on ac-
count of the "bloom," a
waxy coating. To make it
stick, add lime when the
mixture is made, at the
rate of 2 or 3 pounds for 50 gallons of water, according to
whether the water is hard or soft. Flour-paste is also a good
substance to make the arsenic compound stick to cabbage leaves.
A paste made by boiling 2 pounds of flour in 2 gallons of water
may be added to 50 gallons of the arsenical solution.
A spreader recommended by the Illinois Agricultural Experi-
ment Station is made by dissolving 5 pounds rosin and 1 pint
fish-oil soap in a gallon of water in an iron kettle. Then add
4 gallons of water and 1 pound of concentrated lye or potash
and boil for a few minutes. When ready to spray, add to 32
gallons of water 2 gallons of the above solution, 6 gallons of milk
obtained by slaking quick lime in water (strain it so as not to
clog the sprayer), and 1/ pound of paris green or 2 pounds of
powdered lead arsenate.
A new "spreader" worked out by the U. S. Department of
Agriculture is a solution of cactus. Thirty pounds of cactus is
chopped fine and allowed to soak over night in 50 gallons of
water. This is strained and the arsenic added. In those parts
of the State where some of the wild species of prickly pears"
or spineless cactus grow, this should make a cheap sticker."
Some of the oil derivatives now on the market make most ex-
cellent spreaders, as do also some of the oleates.
Arsenical poisons may be used dry. It is well to use a filler of
cheap flour or air-slaked or hydrated lime, mixing about ten
parts of the filler to one of dry poison.
Of the three compounds, paris green is the least satisfactory.
Its arsenic content is variable and it may burn tender plants.
Bulletin 232, Truck and Garden Insects
Cabbage should not be dusted or sprayed with arsenicals within
ten days or two weeks of the time they are to be marketed. The
objection is not so much because of any danger to the consumer
as it is to the
appearance of
t h e material
on the market
product. When
is put on
younger cab-
bages it will be
found at mar-
keting time, if
at all only on
the old mature
leaves those
which are
stripped off at
the tim e of Fig. 21.-Gulf white butterfly: a, Larva; b, pupa:; adult. Natural
size. (From U. S. Bur. of Ent.)
ma rk et in f.
The common idea that cabbage "heads up" by the leaves curling
inward is a mistake. The head is formed entirely by internal
growth; in fact, it is but a big bud and is formed like other buds,
never by the folding up of leaves. Consequently, there is no
danger of the poison being carried into the interior of the head
and held there on the leaves.
If worms are troublesome within a week or two of the time
cabbages are to be marketed they can be dusted with one of the
fluosilicates or fluorides mentioned on page 11.
CABBAGE PLANT LICE
The common aphid on cabbage is the garden aphid or so-
called green peach aphid (Myzus persicae), although the cab-
bage plant-louse (Brevicoryne brassicae) (Fig. 22) and the tur-
nip louse '(Aphis pseudobrassicae) are also found.
The garden aphid is bright green in color and smooth, while
the others have a more mealy look, and the turnip louse is quite
hairy. The character of the damage, the life history, and the
means of control are the same for all three species and practi-
cally the same for all aphids.
Florida Agricultural Experiment Station
Ahpids suck the juices from the plant on which they live,
stunting its growth, causing the leaves to curl, turn yellow, and
finally, the plant to die. They multiply with great rapidity, often
beginning when only a week old and producing several young
each day. During warm weather, which means the entire year
in Florida, the individuals of most species bring forth young
parthenogenetically, that
is without mating between
Sthe sexes. Indeed, during
S. that time of the year males
"/ are usually not produced
S" at all. Usually the young
are born alive and active,
S the eggs hatching before
Fig. 22.-Cabbae-aphid: a. Wined female: b, they are laid. But with
wingless female. Greatly enlarged. (From U. the coming of winter, in
S. Bur. of Ent.)
more northern states,
males and true females are produced and eggs are laid which do
not hatch until spring. Most individuals never acquire wings,
but from time to time winged individuals are produced and
spread the species from plant to plant.
Farther north the green peach aphid spends the winter in
the egg stage on peaches, plums, etc. The first two or three
generations in the spring feed on the tender unfolding buds of
those trees. The first generation is pink in color but their
young are green and never become pink. The second or third
generations usually develop wings and leave the trees for tender
vegetables where they live all summer. This annual migration
is common among aphids, and the last generation returns to
the trees in the fall to lay eggs, enabling the species to get an
earlier start in the spring than would be possible were it neces-
sary to wait for herbs to grow.
Aphids give off a sweet substance called honeydew of which
ants are very fond. For the sake of this honeydew ants care-
fully tend aphids, often protecting them from their enemies
which they drive away. They may carry the aphids or their
eggs from place to place where the "pasture" is good, carry
the eggs into their nests to winter over, or even build adobe
sheds over them for protection from rain and enemies. For
this reason aphids are often called "ants' cows." Hence it
happens that the presence of excited ants on a plant is often
the most evident sign of the presence of aphids.
Bulletin 232, Truck and Garden Insects
Control.-Because of the difficulty of making a spray stick to
cabbages, better control is usually obtained by the nicotine dusts,
mentioned on page 12. In applying these dusts, particularly in
the winter time, it is important to pick out a warm day, as they
are not very effective during cold weather. It is even more im-
portant that the air be quiet, as any considerable amount of
wind will render the dusts ineffective. If the plants are small
this latter difficulty may be overcome by attaching a hood to
the end of the duster as recommended for watermelons. When
the cabbages are large enough to meet in the row, the use of a
hood of this kind is not so easy.
Dusting the plants with tobacco dust is of some benefit, and
will often keep down the number of aphids and prevent an
outbreak, but will not control effectively an outbreak that has
gained headway. These outbreaks often start on plants scat-
tered through a field and by pulling them up and destroying
them, a general outbreak can be forestalled or at least delayed.
Enemies.-Aphids are a very attractive article of diet to a
large number of enemies which are usually able to hold them in
check. Only the wonderful rate of reproduction of the aphids
enables them to have a surplus with which to start a destructive
outbreak after supplying the market" of their enemies.
The smaller birds such as wrens, fly-catchers, and warblers
destroy great numbers of aphids. A flock of young chickens,
if given the freedom of the garden, will do excellent work in
ridding it of aphids.
In a colony of aphids, dead ones may be found which are
so greatly swollen as to be nearly spherical in shape. These
have been killed by the larva of a minute wasp-like parasite
which lives in the interior of the aphid, consuming its vitals.
The parasite pupates in the dead aphid and when the adult
parasite is ready to emerge it bites a hole in the top of the
aphid and crawls out. The egg from which the parasitic larva
hatches is laid inside the aphid which the female parasite
pierces with her ovipositor.
Several kinds of soft-bodied larvae move among the aphids
and destroy them. Some are legless maggots which impale
aphids on their sharp anterior ends and suck the body fluids.
These are the larva of a family of two-winged flies, known as
syrphus-flies. There are many species. Several of these are fig-
ured in our Bulletin 183 on citrus insects, as they are also an
important factor in keeping down the citrus aphid.
Florida Agricultural Experiment Station
Another type of larva is flat, wedge-shaped, with well devel-
oped legs and a pair of sickle-shaped jaws with which it pierces
the aphids. These are aphid lions. Some of them have the inter-
esting habit of sticking the dead carcass of their victim to their
backs and are known as trash bugs. The adults are very delicate
lace-winged flies (illustrated in Bulletin 183). Some of these
flies (Chrysopa sp.) are green with bright golden eyes. Others
(Hemerobius sp.) are brown in color.
Aphids are the choice food of many ladybeetles and their
larvae. The species most common in Florida truck patches and
gardens are the convergent ladybeetle and the blood red lady-
beetle, although the twice-stabbed ladybeetle, so common and
beneficial in citrus groves, is occasionally found.
During the rainy season aphids are subject to attack by fungi,
particularly Empusa aphidis. This fungus often destroys in a
few days the aphids from whole fields.
The heavy rains of the Florida summer are directly destruc-
tive to aphids which are knocked off the plants and beaten to
death on the ground.
CABBAGE ROOT-MAGGOT (Hylemyia cilicrura)
These small, soft-bodied legless maggots (Fig. 23, a) which
often do great damage to the roots of cabbage and related plants
in the North are comparatively uncommon in Florida. The
first indications of their
presence on the roots are
a check to the growth of
the plants which wilt dur-
T ing the heat of the day
Sand show a bluish, sickly
color. The plants finally
turn yellow and wilt
e down completely. If these
plants are pulled up it is
found that the roots have
-_ been eaten off, and per-
haps the main stem mined,
Fig. 23.-Cabbage root-maggot (Hylemia cilierura): by t h e maggots which
a, Larva; b, pupa; c, female fly. About four are about 3/ of an inch
times natural size. (From U. S. Bur. of Ent.) are ao an
long when fully grown.
The adult (Fig. 23, c) is a two-winged fly, similar in appear-
ance to the house- or typhoid-fly but much smaller and with
Bulletin 232, Truck and Garden Insects
a proportionally longer abdomen. The female lays her eggs on
the stem of the plant or on the ground nearby.
Remedies.-Repellants placed about the roots of the plants
when first set out are of some benefit in discouraging the fe-
males from laying their eggs on the plants. Perhaps tobacco
dust is about as practicable as any. Carbo'ic acid emulsion may
be used. Liberal fertilization will enable the plants to outgrow
the damage done by a few maggots. Repeated shallow cultiva-
tion will destroy many of the eggs laid on the ground about the
bases of the plants. The grower should destroy all '.eavily-in-
fested plants and should avoid planting cabbage on land that has
just borne a crop of infested cruciferous plants whether cabbage,
cauliflower, collards, rape, mustard, or turnips. The maggot
will breed in wild plants of this family and all such found near
the field should be destroyed.
Cabbages in an infested seedbed can be treated with car-
bon bisulphide. To do this, make holes with a stick three or
four inches from the infested plant and slanting obliquely under
it. Pour in about a teaspoonful of the carbon bisulphide and
quickly tramp the soil solid to confine the fumes.
In the Northern States it has been found profitable after set-
ting the plants in the field to protect them from the attacks
of this insect by using tarred paper discs. These are cut open
along one radius and fitted closely about the plant. It is doubt-
ful if the attacks of the insect in Florida fields are sufficiently
common to make this precaution profitable except in the case
of some particularly valuable plants.
HARLEQUIN CABBAGE-BUG OR CALICO-BACK
(A1urgantia histronica)
This strikingly-colored insect, a native of the Mexican region,
has been slowly working its way eastward and northward. It is
not as yet abundant in Florida but may be seen occasionally on
late cabbage and is quite common and destructive to collards
that are carried through the summer.
The adult (Fig. 24, g) is black and orange and is 2/5 of an
inch long. Both the adult and young suck the juices of the
plants into which they inject a poison. A few bugs are suffi-
cient to cause a plant to turn yellow and die.
The eggs (Fig. 24, c, d, e) are deposited on the under side
of the leaves, usually in two rows; They are keg-shaped, white,
with black bands and a small black spot on each side, increas-
Florida Agricultural Experiment Station
ing the resemblance to a keg with its hoops and bung-hole.
They hatch in 3 or 4 days. The young are at first yellow, devel-
a V
f 0
Fig. 24.-Harlequin cabbage-bug: a, b.
Nymphs; d, e, eggs, greatly enlarged;
f, g, adults. Slightly enlarged. (From
U. S. Bur. of Ent.)
oping t h e orange markings
later.
They are usually present in
such numbers as to make hand
collecting practical, b u t hand
collecting of the young is less
satisfactory because of their
small size. Should these become
abundant they can be killed by
kerosene emulsion. Destroy all
infested, dying plants. In the
northern part of the State a
crop of late cabbage can be partly protected by planting an
early trap crop of mustard, radishes, or turnips. When this trap
crop becomes infested it may be sprayed with kerosene emul-
sion or pulled up and burned.
CABBAGE HAIR-WORM
OR CABBAGE SN&KE
(Mermis albicana)
T h i s whitish, thread like
worm (Fig. 25), which some-
times grows to be 2 to 9 inches
long, is frequently found in cab-
bage heads. It is an internal
parasite of grasshoppers and Fig. 25.-Cabbage hair-worm or cabbage
snake. (From U. S. Bur. of Ent.)
caterpillars and it gets into the
cabbage by crawling out of infested insects. It is therefore a
friend of the grower. In spite of its repulsive looks and the many
stories which are told of its poisonous nature, it is entirely
harmless to mankind.
SOUTHERN SQUASH BUG (Anasa armiger)
This insect sometimes attacks cabbage and collards. It breeds
on these plants, as eggs and nymphs are found there. Control is
similar to that of the squash bug, page 84.
OTHER CABBAGE PESTS
The following named insects also infest cabbage in Florida:
Blister-beetles (see under beets, page 32); flea-beetles (see
under beets, page 33); tarnished plant-bug (see under celery,
Bulletin 232, Truck and Garden Insects
page 48); onion thrips (see under onions, page 74); wire-
worms (see under corn, page 53); nematodes (see root-knot
under general garden pests, page 24); and grasshoppers (see
under general garden pests, page 18); serpentine leaf-miner
(see under cowpeas, page 62).
CANTALOUPE
The insect pests of this crop are identical with those of
cucumbers. (See cucumbers, page 63.) However, the pickle
worm and the melon worm are much more severe pests on
cantaloupes than they are on cucumbers, because the cantaloupes
have a longer growing season than the cucumbers and extend
further into the late spring when the pickle worm and the melon
worm become abundant. The trap crop of squashes should not
be omitted from the cantaloupe field.
CARROT
The common insect pests of this crop are: Cutworms (see
under cabbage, page 35) ; garden aphid (see cabbage plant-lice
under cabbage, page 41); black blister-beetle (Epicauta penn-
sylvanica) (see blister-beetles under beets, page 32); celery
caterpillars (see under celery, page 49) ; and carrot-beetle
(Ligyrus gibbosus) (see May-beetles under potatoes, page 81).
CELERY
CELERY LEAF-TYER (Phlyctaenia ferrugalis)
During some seasons this insect is extremely injurious to
celery. The eggs are laid on the leaves. The larvae feed chiefly
on the new and tender leaves above the "heart" of the celery.
As the caterpillars get older they descend the stalks and feed
near the bases of the stalks until ready to pupate. During the
later stages of growth the caterpillar spins a more or less con-
spicuous web of silk under which it feeds, hence the name of
webworm. The larva is a pale yellowish caterpillar and quite
hairy. The adult is a small brownish moth.
The celery leaf-tyer does not become abundant during every
season. Very much depends upon the winter weather.
Control.-HIeretofore the most effective means of control in
Florida fields has been pyrethrum powder. This is expensive. It
is quite possible that fluosilicates or the fluorides mentioned on
Bulletin 232, Truck and Garden Insects
page 48); onion thrips (see under onions, page 74); wire-
worms (see under corn, page 53); nematodes (see root-knot
under general garden pests, page 24); and grasshoppers (see
under general garden pests, page 18); serpentine leaf-miner
(see under cowpeas, page 62).
CANTALOUPE
The insect pests of this crop are identical with those of
cucumbers. (See cucumbers, page 63.) However, the pickle
worm and the melon worm are much more severe pests on
cantaloupes than they are on cucumbers, because the cantaloupes
have a longer growing season than the cucumbers and extend
further into the late spring when the pickle worm and the melon
worm become abundant. The trap crop of squashes should not
be omitted from the cantaloupe field.
CARROT
The common insect pests of this crop are: Cutworms (see
under cabbage, page 35) ; garden aphid (see cabbage plant-lice
under cabbage, page 41); black blister-beetle (Epicauta penn-
sylvanica) (see blister-beetles under beets, page 32); celery
caterpillars (see under celery, page 49) ; and carrot-beetle
(Ligyrus gibbosus) (see May-beetles under potatoes, page 81).
CELERY
CELERY LEAF-TYER (Phlyctaenia ferrugalis)
During some seasons this insect is extremely injurious to
celery. The eggs are laid on the leaves. The larvae feed chiefly
on the new and tender leaves above the "heart" of the celery.
As the caterpillars get older they descend the stalks and feed
near the bases of the stalks until ready to pupate. During the
later stages of growth the caterpillar spins a more or less con-
spicuous web of silk under which it feeds, hence the name of
webworm. The larva is a pale yellowish caterpillar and quite
hairy. The adult is a small brownish moth.
The celery leaf-tyer does not become abundant during every
season. Very much depends upon the winter weather.
Control.-HIeretofore the most effective means of control in
Florida fields has been pyrethrum powder. This is expensive. It
is quite possible that fluosilicates or the fluorides mentioned on
Bulletin 232, Truck and Garden Insects
page 48); onion thrips (see under onions, page 74); wire-
worms (see under corn, page 53); nematodes (see root-knot
under general garden pests, page 24); and grasshoppers (see
under general garden pests, page 18); serpentine leaf-miner
(see under cowpeas, page 62).
CANTALOUPE
The insect pests of this crop are identical with those of
cucumbers. (See cucumbers, page 63.) However, the pickle
worm and the melon worm are much more severe pests on
cantaloupes than they are on cucumbers, because the cantaloupes
have a longer growing season than the cucumbers and extend
further into the late spring when the pickle worm and the melon
worm become abundant. The trap crop of squashes should not
be omitted from the cantaloupe field.
CARROT
The common insect pests of this crop are: Cutworms (see
under cabbage, page 35) ; garden aphid (see cabbage plant-lice
under cabbage, page 41); black blister-beetle (Epicauta penn-
sylvanica) (see blister-beetles under beets, page 32); celery
caterpillars (see under celery, page 49) ; and carrot-beetle
(Ligyrus gibbosus) (see May-beetles under potatoes, page 81).
CELERY
CELERY LEAF-TYER (Phlyctaenia ferrugalis)
During some seasons this insect is extremely injurious to
celery. The eggs are laid on the leaves. The larvae feed chiefly
on the new and tender leaves above the "heart" of the celery.
As the caterpillars get older they descend the stalks and feed
near the bases of the stalks until ready to pupate. During the
later stages of growth the caterpillar spins a more or less con-
spicuous web of silk under which it feeds, hence the name of
webworm. The larva is a pale yellowish caterpillar and quite
hairy. The adult is a small brownish moth.
The celery leaf-tyer does not become abundant during every
season. Very much depends upon the winter weather.
Control.-HIeretofore the most effective means of control in
Florida fields has been pyrethrum powder. This is expensive. It
is quite possible that fluosilicates or the fluorides mentioned on
Florida Agricultural Experiment Station
page 11 would be found effective. Arsenicals could be used on
very young celery but the leaf-tyer does not ordinari'y trouble
young celery. Arsenicals cannot be used on celery within sev-
eral weeks of the time of marketing on account of the residue,
which, lodging in the bases of the leaf stalks, remains for a long
time.
SEMI-TROPICAL ARMY WORM
This insect, which feeds chiefly on grasses, sometimes at-
tacks celery in injurious numbers. It is a large caterpillar with
reddish brown markings. It is closely related to the sweet
potato caterpillar. The same poison baits which are recom-
mended for that insect will also control this caterpillar.
GARDEN FLEA-HOPPER (Halticus citri)
This is a minute black plant-bug (Fig. 26) that attacks the
leaves of cowpeas, beggarweed, peppers, and a great variety of
weeds. The attacked spots turn yellow, giving the plant a
Fig. 26.-Garden flea-hopper; a, Short-winged female; b, full-winged female; c, male; d,
head of male in outline. Eight times natural size. (From U. S. Bur. of Ent.)
spotted, peppered" appearance. The insect may be con-
trolled by nicotine compounds, but the pyrethrum extracts will
be found more satisfactory.
TARNISHED PLANT-BUG (Lygus pratensis)
This bug (Fig. 28) is very common the country over in
gardens where it frequents blossom heads and other very young
and tender herbage and even the tender shoots of trees. The
succulent stalks of the celery plant afford a very acceptable
feeding place. In addition to stunting the growth of the plant,
due to the insect sucking the sap, brown spots are produced
where the punctures are made. These greatly reduce the at-
tractiveness of the produce on the market.
Bulletin 232, Truck and Garden Insects
The adult bug is only about 2/5 of an inch long. The male
*is dark reddish-brown and the female light brown with light
yellow markings. They
breed rapidly. The young
(Fig. 27) are greenish in
color. These bugs are rather
restless and are quick in
their movements. For this Fi. 27.-Tarnished plant-buT. Immature stages.
reason they are most easily Four times natural size. (From U. S. Bur. of
captured or killed in the
early morning when they are relatively sluggish. A strong
tobacco extract with plenty of soap will kill the young and most
of the adults but kerosene emulsion is better.
A number of other bugs, such as False Chinch-bug (Nysius
angustatus), frequently attack celery. The character of the
injury is similar to that of the tarnished plant-bug and the
control measures are identical.
CELERY CATERPILLAR (Papilio polyxenes)
This caterpillar sometimes strips the leaves from celery, and,
as the caterpillar is rather large, a single one can inflict
much damage. It is con-
spicuously colored in green
and black. It is a close
i relative to the common
Sr "orange dog" (Papilio
cresphontes) and, like that
species, when disturbed, it
thrusts out a yellow horn-
Fig. 28.-Tarnished plant-bug: Adult and young. like process from the head
About four times natural size. (Fiom U. S. accompanied by a strong
Bur. of Ent.)
pungent odor. This seems
to protect the insect from birds and possibly other foes. It
grows to a length of 2 inches. The pupa is fastened to a sup-
port partly by a silken thread about its middle. In from 12 to
15 days, in summer, there issues from it a swallow-tailed but-
terfly. This is smaller than the adult of the orange dog and
much darker in color. It is called the black swallow-tail.
Both the caterpillar and its work are so conspicuous that
hand-picking will usually be the most economical means of
control. As celery is commonly sprayed with bordeaux for fungus
Florida Agricultural Experiment Station
troubles, lead arsenate can be added (1 pound to 50 gallons of
bordeaux) and this, as well as all other biting insects, be killed.
Other Caterpillars.-Several other caterpillars attack celery;
among them are the celery looper (Autographa falcifera), an in-
sect closely related to the cabbage looper.
PLANT-LICE
At least two species of aphids commonly attack celery in
Florida. One is the common garden aphid or green peach-
aphid (Myzus persicae). The other, Macrosiphum lactucae, is
much larger. The control measures are the same as those given
under cabbage, page 43.
OTHER CELERY PESTS
Other insects injurious to celery are: Flea-beetle (see un-
der beets, page 33); cutworms (see under cabbage, page 35);
and cabbage root-maggot (see under cabbage, page 44); red
spider (see under peas, page 77).
FIELD CORN AND SWEET CORN
Sweet corn is attacked by all the common pests of corn and
there are many of them. Some show a decided preference for
sweet corn. Only the more important insects attacking corn
will be considered here.
CORN EAR-WORM, OR BUD-WORM (Chloridea obsoleta)
This common pest of cotton, corn, tomatoes, beggarweed,
etc., prefers sweet corn to any other of its host plants. Early
in the season the moth lays her eggs on the young corn. The
early generation of larvae which hatches from these eggs works
in the corn as a bud-worm." (At least two other caterpillars
that do very similar damage to corn are known as bud-
worms.") When mature the caterpillars enter the ground,
pupate, and in seven days emerge as moths which in turn lay
their eggs on the silk of the corn which is by this time begin-
ning to appear. The second generation of larvae on the corn
eats the silk and then enters the ear and feeds upon the devel-
oping kernels. Later generations develop on cotton, beans,
beggarweed, Crotalaria, etc. The insect also attacks tomatoes.
But whether working in corn as the "bud-worm" or "ear-worm,"
in tomatoes as the "fruit-worm," on cotton as the "bollworm,"
or fully exposed on beggarweed, it is the same insect. So abund-
ant is this pest in Florida that it is almost impossible to find an
Bulletin 232, Truck and Garden Insects
ear of sweet corn that has not been attacked by at least one of
these caterpillars.
Control.- The work of the first generation in the corn is
usually noticeable when the corn is about knee high. At this
stage it is not difficult to poison the caterpillars by spraying or
dusting some of the arsenic compounds into the infested buds.
The writer has dusted undiluted lead arsenate and zinc arsenite
powder into the buds without producing any harmful effects, but
it is safer and more economical to mix the poison with from 2
to 4 times its bulk of air-slacked or hydrated lime. The dusting
is best done in the early morning when the plants are wet with
dew. The agitation resulting from brushing against the stalks
will usually be sufficient to cause the dew to run down into the
bud, carrying the poison with it. In a small garden the poison
can be applied by means of a
tin can punched full of holes.
On a large scale the well- -
known bag-and-pole method
may be used, but the most
even distribution will be se-
cured by the use of a dusting
machine. It is important that 1
this early generation should
be destroyed, if possible. Not Fig. 29.-Corn ear-worm: Adult. One and a
only will the injury to the half times natural size. (Original.)
buds be checked, but the number of caterpillars in the following
generation, which works in the ears, will be lessened.
When the silks appear on the young ears of corn they can
be dusted by means of the same apparatus. The caterpillars feed
on the exposed silks for only a few days before entering the ear,
where they are safe from insecticides, so it will be necessary
to repeat the dusting every three or four days. This is too
expensive for a crop of field corn, but on such a high-priced
crop as sweet corn it is worth while.
Since this insect works its way into the ear from the tip, con-
suming the ear as it goes, those varieties of corn with long tips
and close-fitting husks about the ear are less severely injured
by this caterpillar, as they will often reach the marketing stage
before the caterpillar has worked far down into the ear. Sweet
corn should be pushed as rapidly as possible by liberal fertiliza-
tion and cultivation. If the ear matures rapidly it will be ready
Florida Agricultural Experiment Station
for the market before the worms have reached their full size
and before they have worked their way far down into the ear.
On the other hand, if the corn grows slowly because of poor care,
the worms will be full grown at harvest time and the damage
will be much greater.
Corn should be planted as early as weather conditions will
allow. Late-planted corn always suffers more severely from the
attacks of this insect.
In a small patch in the gardens the worms can often be
removed from the tip of the ear before they have inflicted mate-
rial damage. In removing the worms it is not well, however,
to open the ears to such an extent as to expose the kernels, as
other animals such as birds, Carpophilus and other insects will
then attack them. Woodpeckers and bluejays are occasionally
seen feeding on the worms and the ears of sweet corn.
Life History.-The eggs are whitish, oval, prominently
ribbed, and about a twentieth of an inch in diameter. They are
scattered over the corn. Those from which the bud-worm
hatches are laid on the leaves; those of the ear-worm on the
silk. They hatch in 3 or 4 days.
The caterpillars vary from a delicate pink to black. They
are marked with rather narrow longitudinal lines. They require
about 17 days for growth in summer, becoming 11/ to 2 inches
long. The caterpillar then bores a hole in the side of the ear
or stalk and enters the ground to a depth of 2 to 5 inches where
it forms the pupa. Here it remains for a week or two in summer
or all winter if it is the last fall brood.
The pupa lies in an earthen cell. It is about 3/-inch long.
It is at first green in color but soon turns to a light brown. The
moth (Fig. 29) which issues from this cocoon varies in color
from a dosky yellow to grayish and expands from 11/ to 2
inches. Unlike most moths it may fly in broad daylight, but
the eggs are usually laid at sunset.
CARPOPHILUS spp.
If the husk is removed from an ear of corn in the milk by
any cause, such as a woodpecker in his hunt for a corn ear-
worm, it is at once attacked by these scavenger beetles, which
are also common in decaying fruits. The beetles are brown
and about 1/% of an inch in length. Their wing-covers are so
short that they do not reach the end of the abdomen. The
beetles seem unable to penetrate the husk of an uninjured ear,
Bulletin 232, Truck and Garden Insects
but very commonly get into the burrows made by the corn ear-
worm and cause further damage. They often breed among the
kernels which blacken and decay, thus spoiling many ears that
would otherwise be usable. The larvae are small, whitish, and
maggot-like. Control measures are obviously those which con-
trol the corn ear-worm.
THE CORN LANTERN-FLY (Peregrinus maidis)
This insect and the bud worm are the worst enemies of late-
planted corn in Florida. In the latter part of August the lantern-
fly becomes extremely abundant and severely infests practically
every sta-k of young corn, and quickly kills it. Stalks that have
reached the tasselling stage are not severely injured.
This' lantern-fly is a slender yellowish-green insect about a
sixth of an inch long. Its wings are longer than the body, and
are clear except for some dark-brown markings near the tip.
They collect in large numbers in the bud and in the axils of
the leaves. These colonies are usually composed of numerous
young of all stages, and a few winged adults.
The most effective and the quickest means of controlling
this pest is to dust the buds of the corn with nicotine sulphate-
lime dust.
WIREWORMS, "DRILLWORMS"
These long, slender, hard, wiry "worms" are the larvae
of click-beetles. They feed below the surface of the ground on
the roots and stems of plants into which they often bore. The
infested plant is stunted, turns yellow and may die. The larvae
are particularly destructive to sprouting seed, eating the
inside.
The adults are called click-beetles from their habit of throw-
ing themselves into the air with an audible click when placed
on their backs. They are also called "skip jacks" and "snap
beetles."
There are dozens of species of wireworms in Florida and
at least a half-dozen injure corn. As their habits, life history,
type of soil infested, and control measures differ for each
species, it will be necessary to take up the more important ones
separately.
SPOTTED CLICK BEETLE. The most common wireworm in
Florida corn fields is the young of the spotted click-beetle
(Monocrepidius vespertinus) (Fig. 30). This is a thick wire-
worm about 1/< inch long and is found in both dry and wet land
Florida Agricultural Experiment Station
but is more destructive in the former. It is found also on
cowpeas.
The eggs are laid in the summer. They hatch in about 9
days according to Dr. A. F. Conradi and H. C. Edgerton (So.
Car. Agr. Exp. Sta. Bul. 179), and the larvae feed until the
following spring when they pupate in the ground at a depth of
from 3 to 5 inches, remaining.there about 2 weeks. The earliest
adults were taken at Gainesville on June 7 by Mr. Dozier. They
are from 1/5 to 1/3 inch long.
Fall plowing and frequent cultivation of the corn will de-
stroy many of these insects, particularly if chickens or other birds
Fig. 80.-Spotted click-beetle: Adult; pupa; larva; and egg, greatly enlarged.
(From So. Car. Agr. Exp. Sta.)
follow the plow. They are seldom found at a greater depth than
4 inches. A few seeds of cotton planted at the same time as the
corn is said to be of benefit. They prefer the cotton to the corn
and while they are feeding on the cotton, the corn has an oppor-
tunity to germinate and get a start.
The nighthawk is an important enemy of the beetles which
fly at dusk, the time when these birds are on the wing. Night-
hawks should be protected by the farmer.
MONOCREPIDIUS LIVIDUS. Associated with the last-named
species in about the same class of soil is Monocrepidius lividus.
This is perhaps the second most common wireworm in Florida.
Control measures are the same as for the above named species.
CORN AND COTTON WIREWORM. Unlike most wireworms,
this one (Horistonotus uhleri) works mostly in sandy, light, dry
soils. It differs also from the other species in its appearance.
It is long and white and has a soft skin instead of the hard,
chitinous covering like the others. Control measures are about
Bulletin 232, Truck and Garden Insects
the same as those used against the larva of the spotted click-
beetle.
CORN WIREWORMS (Melanotus spp.).-These are not as com-
mon as the other species. Like most species of wireworms they
are found mostly in low, poorly-drained land, especially if it
was in grass the previous year. Draining and liming the land,
with deep and thorough cultivation, are important.
The larvae are about 11/4 inches long, brown in color, and
have three small projections on the posterior end. Some species
require several years for growth. The adults are brown and
from a half to 3/ inch in length.
OTHER WIREWORMS sometimes injurious to corn in Florida
are Lacon curtus and Lacon rectangularis. The control meas-
ures are similar to those for the last-named.
FALL ARMY WORM, OR SOUTHERN GRASS WORM
(Laphygma frugiperda)
This well-known pest of grass attacks corn as a second
choice when all of the grass within easy range has been eaten.
Army worms are so named from their habit of assembling in
vast numbers and marching in mass formation to new pastures.
These marches come as a result of excessive numbers exhaust-
ing the food supply in the place where they hatched. The word
" fall was prefixed by entomologists in the Northern States
and is a misnomer in Florida. The destructive armies usually
form in July and August, but sometimes as early as April. At
other seasons, and during the years when no armies are formed,
a few of these caterpillars are found, feeding apart like cutworms.
Control.- These isolated caterpillars may get into the tips
of growing corn and become bud-worms where they may be
controlled by the same measures as given for the corn ear-
worms when working as bud worms. (See page 50.) The
armies may be repelled with fair success by the Kansas bait,"
(see page 18), or the food-plants may be sprayed or dusted
with lead arsenate, paris green or any other arsenical. This is
applied best while the caterpillars are working on grass, before
entering the cornfield. They often appear first on crab-grass.
The eggs are laid mostly on grasses in masses of 50 or more
and hatch in about 10 days. The caterpillars require about
two weeks in which to become full-size, which is about 1/
inches long. They are rather slender. Their color is brown
with a narrow yellowish-gray stripe along the middle of the
Florida Agricultural Experiment Station
back and a brownish-black one along the side. On the head the
central line branches, making a conspicuous V-shaped white
mark, which helps to identify the caterpillar. The body is
covered with small black prominences from each of which a
short, stiff, black hair arises. The adult is a moth resembling
those of cutworms, to which it is closely related.
ROOT WEBWORMS (Crambus spp.)
These also are caterpillars that often do severe damage to
young corn in the spring. In April, 1914, they destroyed many
acres about Gainesville and other places. They always do more
Fig. 31.-Bill-bug (Sphenophorus callosus): a, Larva; d, adult. Greatly enlarged.
(From U. S. Bur. of Ent.)
damage than they are charged with, much of their work being
attributed to cutworms. There are several species of these
insects, but all of the caterpillars are reddish, pinkish or brown,
with conspicuous dark spots on their backs. Like cutworms,
they feed at night, but do not cut the plant off. Instead, they
strip it of its leaves, make channels on the surface of the stalk,
or mine the center. They construct a tube of silk just below
the surface of the ground and hide in this during the day. This
will distinguish them from cutworms. Furthermore, they try
to escape when disturbed instead of curling up ain "playing
possum" like cutworms. The adult insects are small, light-col-
ored moths which are always plentiful in sod land. When at
rest they roll their wings around their bodies instead of laying
them back more or less flat as most moths.
Control.-Severe injury by these caterpillars is confined to
Bulletin 232, Truck and Garden Insects
land which had considerable grass during the preceding year.
Such land if intended for corn should be broken as early in the
fall as practicable. Aside from the matter
of insect control this is also the best pro-
cedure from the cultural standpoint, as it
conserves the moisture during dry winter.
Some relief can be obtained by dusting or
spraying the young plants with lead ar-
senate.
BILL-BUGS (Sphenophorus spp.)
Other insects
that injure young
corn are species of
snout beetles called
"bill bugs" (Fig.
31). They feed on
the young, tender
leaves, making par-
allel rows of holes,
after the pattern of
sap-suckers on trees
(Fig. 32). This is
done when the leaf
is rolled up in the
bud and each row
of holes is produced
by a single punc-
ture.
Like the la s t- Fig. 2.--njury to corn by bill-bugs. (From U. S. Bur.
named insect, this of Ent.)
one is injurious only on land that grew much grass during the
preceding year. Eggs are laid on grasses in low wet land, where
alone bill-bug injury is ever severe. The young feed chiefly on
the roots of grasses, but one species (S. robustus) may live in
the pith of the corn stalk.
The measures recommended for use against root webworms
(page 56) are also the ones to be used against bill-bugs.
CORN-LEAF BLOTCH-MINER (Agromyza parvicornis)
This larva of a minute black fly makes irregular shaped
blotches in the leaves of corn and some grasses by eating the
Florida Agricultural Experiment Station
tissue from between the lower and the upper epidermis. Its
injuries are most noticeable and serious on young corn. The egg
is laid in the corn leaf and hatches in 3 or 4 days in summer.
The larva feeds from 3 to 12 days in summer. It breeds during the
winter in southern
.~-J Florida (JI. Agr. Re-
i search, April 12,
1916).
/ The insect cannot
be reached by any in-
S' secticide. The only
[ course is to pull up
tested plants, and by
good care, keep the
others in such a vigor-
VT *" ously growing condi-
Fig. 33.-Southern corn root-worm: a. Adult beetle, tion as to overcome
about six times natural size; b, egg; c, larva; d, anal
segment of larva; e, work at base of corn stalk; f, the injury. An excess
pupa. (From U. S. Bur. of Ent.)
of corn should be
planted so that a good stand will remain after the requirements
of the flies have been met and the infested plants pulled up.
SOUTHERN CORN ROOT-WORM (Diabrotica 12-punctata)
This insect spends both its larval and adult stages on corn.
The adult (Fig. 33, a) feeds on the leaves in which it makes
small holes, but it is more common on the silk of the young ears
which it cuts off. It may attack also the tassel or the exposed
kernels of the ears. The white, grub-like larvae (Fig. 33, c)
mine the roots of the corn. The adult beetles are oblong and
about 1/4 inch long, red in color, with 12 black spots on the
wing covers. The insects are more abundant on late corn than
on early varieties and apparently are more common in the west-
ern part of the State than on the peninsula.
CORN WEEVILS (Calendra oryzae and C. granaria)
Sweet, or field corn, which is stored, is subject to attack by
these small beetles (Fig. 34) which eat the interior of the ker-
nels. As soon as weevils are noticed, the corn should be fumi-
gated with carbon bisulphide, using 10 pounds to 1,000 cubic
feet of space in the bin or crib. The material is placed in an
open dish on top of the corn and allowed to evaporate. The fumes
Bulletin 232, Truck and Garden Insects
are heavier than air and
will sink, and penetrate
the corn. The bin should
be made perfectly tight (
before the sulphide is in-
troduced, and kept closed
afterward for at least 24
hours. All fire and lights,
including lighted pipes,
should be kept away for
the fumes are inflam-
mable. A safer fumigant
is paradichlorobenzene.
It is not inflammable
and is not as dangerous c
oFig. 34.-Calendra granaris: a, Adult; b, larva; v.
to human beings who pupa; d, Calendra oryzae. About seven times nat-
bre e is f s. ural size. (From U. S. Bur. Ent.)
breathe its fumes. It is
a new material on the market and some difficulty may be met in
obtaining it. To use, dissolve in water 12 ounces for each 100
cubic feet of space. The liquid is then soaked up in a rag which
is placed in the seed box. There is less danger of injuring the
germinating ability of the corn by an overdose with this fumi-
gant than with carbon bisulphide. Even live animals, such as
dogs, cats, and chickens, can be thus fumigated safely in a box
for an hour. Either of these insecticides is more effective when
the temperature is above 60 degrees.
OTHER CORN PESTS
Other insects attacking corn are: Sweet-potato caterpillar
(see under sweet potatoes, page 93), semi-tropical army worm,
and serpentine leaf-miner (see under cowpeas, page 62). The
bean-jassid (see bean leaf-hopper, page 26),, lantern-fly (see
page 53), and the lesser corn stalk-borer (see under beans,
page 30) are particularly injurious to very late-planted corn
and, with the bud worm (see page 50), are the chief cause of
the difficulty of growing a crop of late-fall roasting ears in
central Florida.
There has become established in the northern states and Can-
ada a very severe pest of corn, namely, the European corn borer.
As its name indicates, it is an importation from Europe. It was
introduced into this country during or just before the European
Florida Agricultural Experiment Station
war. It is spreading over the corn belt and doubtless in time
will reach Florida. The caterpillar mines the corn stalk and often
enters the ear. Unlike the corn ear worm, it does not confine
its eating to the kernels but bores through and mines the im-
mature cob itself.
COWPEAS
COWPEA POD-WEEVIL, OR COWPEA CURCULIO
(Chalcodermus aeneus)
This black beetle (Fig. 35, a), except in color, resembles the
cotton boll weevil and, as it often feeds on young cotton in the
early spring, it is sometimes mistaken for that species. It is
an exceedingly severe pest on cowpeas. Early in the season it
feeds on the leaves of the plant, but as soon as the pods begin
to set it turns its attention to them. The females lay their eggs
in the developing seeds, making a puncture through the pods.
They also feed on the pods, making a feeding puncture simliar
to the egg puncture. These punctures make unsightly brown
spots on pods and seeds, but the greater injury is done by the
grubs that hatch from the eggs in from 4 to 6 days. This pale
yellow larva (Fig. 35, b) eats the seed. It requires a week or
two to reach full size. It then bores a hole in the side of the
pod and escapes to the ground. The adult is about 1/4 inch long
and has
deeply pit-
es ted wing
covers.
I Control.-
Rotation of
.... / crops should
cw N u s be practiced.
Land that
bd h as grown
Fig. 35.-Cowpea p-d-weevil: a, Adult; five times natural size; a crop of
b, larva; d. pupa. (From U. S. Bur. of Ent.)
heavily in-
fested cowpeas should not be planted at once to a late crop of
cowpeas. Neither should such land be planted to beans. When
the insects are feeding on the leaves early in the season, they
can be poisoned with lead arsenate. Use 1 pound of the powder
or 2 pounds of the paste to 50 gallons of water. The destruc-
tion of the early brood will materially reduce the number at-
Bulletin 232, Truck and Garden Insects
tacking the pods later. On a small garden patch or on other
particularly valuable fields the insects can be collected by hand
as recommended for the pumpkin bug.
Poultry, including chickens, and especially turkeys and
guineas, will eat these beetles readily. A very good way to con-
trol these pests is to allow these fowls to have the run of the
cowpea patch. Cowpeas intended for table use should be well
fertilized and cultivated so that they will grow rapidly. Rapidly
developing pods will not be exposed as long to the attacks of
these weevils as those growing more slowly. In many cases the
weevils will be in only the egg stage when the peas are har-
vested.
PUMPKIN BUG (Nezara viridula)
This pest attacks nearly all garden plants and especially
legumes, but is particularly at home on cowpeas. The adult
insects are little more than 1 inch long and nearly as broad
and are usually
light green in
color. The young
(Fig. 36) are bluish
with some reddish
markings. They are
quite unlike the
adults in appear-
ance. There are sev-
eral generations in
a year. The adults
of the last genera-
tion hibernate but
not until late in the
fall and are out
early in the spring.
These insects d o
considerable dam- Fig. 36-Pumpkin bug (Nezara viridula): Young. Six
times natural s:ze. (From U. S. Bur. of Ent.)
age to young
plants but the most severe injury is inflicted on the pods. Their
numerous feeding punctures make unsightly brown tough dots.
They will also dwarf the pods and if sufficiently numerous cause
them to drop.
Control.-This is a difficult pest to control. Being a suck-
ing insect, arsenicals or other stomach poisons are of no avail.
Florida Agricultural Experiment Station
The young can be killed by kerosene emulsion or a strong soap
solution, but the adults are too robust to be killed by these com-
pounds except at strengths that would be dangerous to the
plants. The only means of combating them seems to be hand-
collecting. On an ordinary field crop of cowpeas, it is ques-
tionable whether the operation would pay. It is perhaps best
to plant enough for both bugs and planter and, by good cultural
methods, to keep the vines in such vigorous growing condition
that they will bear peas in spite of the bugs. In a garden, on a
particularly valuable patch of cowpeas, or on such valuable
crops as beans, tomatoes, potatoes, etc., hand-picking will pay
well. For this purpose take a pan or other wide-mouthed dish,
pour into it an inch or less of water and on this a film of
kerosene. In the early morning or on a cold rainy day when
the bugs are sluggish, walk along the rows and knock'the bugs
into the pan. This is not as slow a process as it may seem at
first. An active boy can collect most of the bugs from an acre
of beans or several acres of potatoes in an hour.
iChickens, turkeys, and guineas will
also eat this bug, and in a small patch
about the house will often give com-
plete control.
The smaller but closely related Ne-
zara hilaris does about the same char-
acter of damage, but is comparatively
rare in Florida.
Fig. 37. (Mylabris 4 macu-
latus): a. Adult; b, c, egg
from above and below; d,
head of ma'ure larva. Great-
ly enlarged. (From U. S.
Bur. of Ent.)
SERPENTINE LEAF-MINER
(Agromyza pusilla)
This is a near relative of the corn-
leaf blotch-miner. (See under corn,
page 57.) Like that species, the larva
works in the central tissue of the leaf,
but its burrow is long and narrow,
with many bends, hence the name ser-
pentine. It is plentiful in many wild
plants, especially such legumes as beg-
garweed and coffeeweed, and it is com-
mon in cowpeas. Its life history is
similar to that of the corn-leaf blotch-
miner and it may likewise work all win-
ter in the southern part of the State.
Bulletin 232, Truck and Garden Insects
The greatest damage is done to the first two leaves cotyledonss)
of very young seedlings before the true leaves are put out. Both
of these leaf-miners have numerous parasitic enemies which
generally keep them under fair control.
COWPEA SEED-WEEVILS
Two species of weevils, the four-spotted weevil (Mylabris
4-maculatus) (Fig. 37) and the Chinese weevil (Mylabris
chinensis) (Fig. 38), both
closely related to the bean- / _
weevil (see under beans,
page 29), do about the
same character of damage d
to cowpeas as their relative
does to beans. The bean-
weevil also occasionally at- 6
tacks cowpeas and either or Fig. 38.-Mylabria chinensis: a, Adult; b, egg;
both f the cowpea weevils c, larva. About seven times natural size.
both of te cowpeaee (From U. S. Bur. of Ent.)
often attack beans. They
begin their work in the field but it is in stored peas that they
are especially injurious. These should be fumigated or heated
following directions for stored seeds. If cowpeas are kept in
cold storage at a temperature below 34 degrees for 2 or 3 months,
the eggs, as well as weevils, are destroyed.
OTHER COWPEA PESTS
Other insects attacking cowpeas are: Wireworms (see
page 53); cutworms (see page 35); leaf-footed plant-bugs (see
page 81); and lesser corn stalk-borer (see page 30), and the
garden flea-hopper (see under Celery, page 48). The harlequin
cabbage bug (see page 45) attacks the pods.
CUCUMBERS
PICKLE WORM (Diaphania nitidalis)
Cucumbers and cantaloupes with holes bored into them (Fig.
39) are common to Florida growers, more common some years
than others. Two species of insects are responsible for this
damage, the pickle worm and the melon worm. They are closely
related, very similar in appearance, and usually not distinguished
by the trucker. Either or both species may be found on cucum-
bers, melons, squashes, and gourds. They differ in their habits;
consequently methods of control must be different.
Florida Agricultural Experiment Station
The more common of the two is the pickle worm. This is
a whitish caterpillar with conspicuous black dots on each seg-
ment. In the early part of the season it bores into the buds,
blossoms, stems, and leaf-stalks, but as the fruits form, it con-
fines its attentions to them, always entering from the side near
the ground. In addition to the injury caused by the worm feed-
ing on the tissue of the cucumber, the entrance hole affords an
entry for various molds and other organisms of decay which
quickly spoil the cucumber.
The eggs are laid on the parts of the plant used for food
by the caterpillars. After the fruits are formed most of the
Fig. 39.-Injury by pickle worm to ripening cantaloupes. (From No. Car. Agr. Exp. Sta.)
eggs are laid on the under side of them, hatching in 3 or 4 days.
The larva feeds and grows for about 2 weeks, after which time
it turns a coppery color and the black dots become less con-
spicuous. It soon pupates in a dried leaf and in about another
week the moth comes forth. This moth (Fig. 40) has wings
which are clear white in the middle with a broad black border
around the margins. It measures from 1 to 11/4 inches across
the outstretched wings. This insect is commonly seen about
lights, and it may fly in the daytime.
Control.- The pickle worm, because it feeds in the interior
of the buds, blossoms and fruits, cannot be reached by arsenical
sprays. The grower should carefully collect and destroy all
wormy fruit. If these wormy cucumbers and melons are left in
the field the caterpillars will enter fresh ones, or complete their
Bulletin 232, Truck and Garden Insects
growth and enter the ground to emerge as moths in a week or
two. The moth lays enough eggs to hatch into about 300 more
worms.
The best preventive measure against both of these worms is
a trap crop. For this purpose plant -r
from 4 to 8 rows of early summer crook-
necked squash for each acre of cucum-
bers or cantaloupes. (Fig. 41.) The
large blossoms and leaves and the ten-
der fruits of the squash are preferred
by the moths to either cucumbers or t
melons, and most of the eggs will be Fig. 40.-Pickle worm Moth.
About natural size. (Original.)
laid on the squash. It is better to make
several plantings of the squash to provide a succession of blos-
soms and fruits attractive to the moths. The first planting
should be made at the same time as that of the cucumbers or
Fig. 41.-Trap crop of squash for pickle and melon worms in cantaloupe field. (From
Bur. Ent., U.S.D.A.)
melons, and other plantings at intervals of a week. The last
planting may be placed in the hills from which the cucumbers
are missing.
The infested squash blossoms and fruit may be picked and
destroyed and if the melon worm is abundant, the vines should
i
Florida Agricultural Experiment Station
be sprayed with one of the arsenicals. The quickest way to
destroy the pests on the trap crop is to pull up and burn each
lot of trap plants as soon as it has become thoroughly infested
and before the worms have reached their full size. If this is
neg ected, the trap crop is worse than useless.
Clean culture shou d be practiced, not only on account of these
insects, but also to keep down fungus diseases. As soon as the
grower is through picking, the vines, fallen leaves, and other
refuse should be raked up and burned or plowed under.
MELON-WORM (Diaphania hyalinata)
In addition to boring into the cucumbers, this caterpillar
feeds extensively on the leaves of the plants attacked, which is
a habit not possessed by the pickle worm. But the melon worm
does not often bore into the vines or leaf stalks. This worm
has longitudinal stripes instead of the black dots of the pickle
worm. It never becomes coppery-colored. The moth is larger
than the other, about 13/1 inches in expanse, and the white area
on the wings is proportionately much larger, covering all but
a narrow margin. The eggs are laid chiefly on the young leaves.
Control.- This species can be reached by arsenical sprays
because it feeds partly on the foliage. A pound and a half of lead
arsenate should be used to 50 gallons of water. Paris green may
be used at the rate of 1/2 pound to 50 gallons of water, but it
does not stick as well as the lead arsenate and is more likely to
burn the foliage. To the 50 gallons of insecticide should be
added 3 pounds of hydrated lime, or the milk obtained by slak-
ing 3 pounds of fresh quick lime in warm water. The lime is to
prevent burning the foliage. If the vines are sprayed regularly
with bordeaux mixture for blight or other fungus diseases, as
they should be, the arsenical may be placed in the bordeaux,
in which case the lime is omitted.
STRIPED CUCUMBER-BEETLE (Diabrotica vittata)
This very troublesome enemy of the northern grower of
cucurbits is usually entirely absent from the central part of
Florida, although it is present in the western and southern parts
of the State. As has been shown by the Entomologist of Arkan-
sas (Ark. Bul. 216), this beetle will nct breed in sandy soils.
This is undoubtedly the reason for its complete absence in most
sections of peninsula Florida.
The adult (Fig. 42, a), a yellow beetle striped with black,
Bulletin 232, Truck and Garden Insects
measuring about 2/5 inch long, eats the leaves of cucumbers,
squashes, melons, beans, watermelons, okra, and even those
of citrus trees. The slender white larvae (Fig. 42, b) feed on
the roots of these plants into which they tunnel, sometimes
reaching the base of the stems. In the North the adults are
troublesome to young plants only, but in South Florida they
attack and kill quickly full-grown, bearing vines. Consequently
the northern practice
of covering the young
p plants with cheese
cloth for a few weeks is
Snot effective in Florida.
The female lays
about a hundred eggs
during her lifetime of
c one month. They are
laid on the surface of
the ground where they
b a d hatch in about a week.
Fig. 42.-S'riped cucumber-beetle: a, Adult, six times In Kentucky, the larva
natural size; b, larva; c, pupa. (From U. S. Bur. requiresaboutamonth
of Ent.)
for growth and the
insect lies in the pupa, which is placed just below the surface
of the ground, for a week or two. The entire life history occu-
pies but 39 days. The life history of the insect in Florida has
not been worked out, but it is probable that the life cycle is
shorter in the summer.
Control.-Where abundant, as it is in the Everglades, this
insect is very difficult to control. Mr. C. C. Goff, Assistant Ento-
mologist of this Station, secured the best control by alternately
spraying the plants with lead arsenate in bordeaux and dusting
with one of the fluosilicates or fluorides. A pound of lead arsen-
ate was added to ordinary bordeaux and the plants sprayed with
this about once a week. Three or four days later they were
dusted with a fluosilicate or a fluoride. The bordeaux not only
acts as a spreader for the lead arsenate but has a tendency in
itself to repel this beetle. Spraying twice a week, as is neces-
sary to give protection with the bordeaux-lead arsenate alone,
was injurious to the p'ants; hence the recommendation of a
spray once a week with the bordeaux-lead arsenate and a dust
once a week with a fluosilicate or fluoride. A trap crop of sum-
fer squashes, as recommended for the pickle worm, will also
Florida Agricultural Experiment Station
have a tendency to attract these beetles away from cucumbers
or cantaloupes, as the beetles prefer the squashes, but only
when they are older. We therefore recommend that the trap
crop be planted somewhat earlier than the cucumbers.
OTHER CUCUMBER PESTS
Other insects attacking cucumbers are: Melon-aphid, a seri-
ous enemy of all cucurbits (see page 106) ; cutworms (see page
35); thrips (see page 74); tarnished plant-bug (see page 48);
and red spiders (see page 77) ; wireworms (see page 53) ; and
cabbage root-maggot (see page 44).
DASHEEN
This plant seems to be almost immune to insect attacks.
The writer has seen the tubers of plants growing in a very
damp place attacked by the larvae of a crane-fly. Some of the
tubers were half-eaten and in the hollows were found empty
pupa cases of the crane-flies. This damage would not occur on
well-drained soils. The larvae are legless, dirty-white, soft-
bodied, worm-like grubs. The adults are large, long-winged,
slender-bodied flies having exceedingly long and slender legs.
They are commonly seen hovering over springs or hanging by
their hind legs from limbs of trees or the walls of houses. They
are commonly confused with mosquitoes, especially with the
large "gallinipers," but are incapable of injuring man.
Dasheens are also attacked by the rotten-log caterpillar, and
quite seriously by the root-knot nematodes (see under general
garden pests, page 24).
EGGPLANT
The most destructive pests of eggplant in Florida are plant
lice, especially the garden plant louse (Myzus persicae). Con-
trol measures are the same as those given under cabbage, page
41.
Plant-bugs are as common on eggplant as they are on most
succulent truck crops. Their ravages are most severe in the
late fall just before the first cold weather drives them into
hibernation and when native vegetation is becoming dry and
unattractive; and also in the early spring when they first
emerge from their winter quarters. The most common of these
bugs are: Pumpkin bug (see under cowpeas, page 61); big-
Florida Agricultural Experiment Station
have a tendency to attract these beetles away from cucumbers
or cantaloupes, as the beetles prefer the squashes, but only
when they are older. We therefore recommend that the trap
crop be planted somewhat earlier than the cucumbers.
OTHER CUCUMBER PESTS
Other insects attacking cucumbers are: Melon-aphid, a seri-
ous enemy of all cucurbits (see page 106) ; cutworms (see page
35); thrips (see page 74); tarnished plant-bug (see page 48);
and red spiders (see page 77) ; wireworms (see page 53) ; and
cabbage root-maggot (see page 44).
DASHEEN
This plant seems to be almost immune to insect attacks.
The writer has seen the tubers of plants growing in a very
damp place attacked by the larvae of a crane-fly. Some of the
tubers were half-eaten and in the hollows were found empty
pupa cases of the crane-flies. This damage would not occur on
well-drained soils. The larvae are legless, dirty-white, soft-
bodied, worm-like grubs. The adults are large, long-winged,
slender-bodied flies having exceedingly long and slender legs.
They are commonly seen hovering over springs or hanging by
their hind legs from limbs of trees or the walls of houses. They
are commonly confused with mosquitoes, especially with the
large "gallinipers," but are incapable of injuring man.
Dasheens are also attacked by the rotten-log caterpillar, and
quite seriously by the root-knot nematodes (see under general
garden pests, page 24).
EGGPLANT
The most destructive pests of eggplant in Florida are plant
lice, especially the garden plant louse (Myzus persicae). Con-
trol measures are the same as those given under cabbage, page
41.
Plant-bugs are as common on eggplant as they are on most
succulent truck crops. Their ravages are most severe in the
late fall just before the first cold weather drives them into
hibernation and when native vegetation is becoming dry and
unattractive; and also in the early spring when they first
emerge from their winter quarters. The most common of these
bugs are: Pumpkin bug (see under cowpeas, page 61); big-
Bulletin 232, Truck and Garden Insects
footed plant-bug (see under potatoes, page 80) ; and leaf-footed
plant-bug (see under potatoes, page 81). A fourth one, the
cotton-stainer, may be treated here. Its name is derived from
the nature of the damage done to cotton. As a result of the
feeding of the bugs, the lint is stained yellow.
COTTON-STAINER (Dysdercus suturellus)
Like the leaf-footed plant-bug this insect is occasionally
injurious to citrus fruits, but neither is as common in groves
as the pumpkin bug. The cotton-stainer has a marked tendency
to be gregarious. Although it is usually entirely absent from
groves, truck, and cotton fields, it sometimes occurs in large
numbers and does much damage.
The cotton-stainer, like the other plant bugs, injures plants
with its sucking beak. When a puncture is made in the fruit of
an eggplant, a hard, brown spot develops and if the fruit is
young it will probably be deformed. If punctures are numerous
the fruit turns yellow and falls off. But the chief damage is
done to the stems of the young plant.
The adult is a dull red bug about a half inch long and oblong-
ovate in shape. The young is similar in color and shape, but
is smaller and lacks wings.
Like the other large plant-bugs, the young of the cotton-
stainer can be killed by strong contact insecticides (see pump-
kin bug under cowpeas, page 61), but in the adult stage it
is better to collect them. The cotton-stainers are very fond
of cottonseed meal and advantage may be taken of this to
trap them. Small piles of the meal are placed about in the
field. As the bugs gather, the piles are from time to time
sprayed with pure kerosene or a strong emulsion of kerosene
and water. The Spanish cocklebur (Urena lobata) is one of
the favorite host plants of this insect and should be destroyed
when growing about the edges of truck patches.
BROWN STINKBUGS (Euschistus variolarius and E. sayi)
These bugs are commonly associated with the other large
plant-bugs on eggplant and other plants. They have the general
shape of the pumpkin bug but are only half as large and are
grayish-brown instead of green in color. The nature of the
damage and the control measures are identical with those of
the pumpkin bug (see under cowpeas, page 61).
Florida Agricultural Experiment Station
THE CRANE-FLY BUG (Leptocorisa tipuloides)
This is a slender light-brown bug about 5/g inch long, and
only about 1/12 of an inch w:de. Its slender body and long legs
suggest a crane-fly, hence the name. It can be killed by a strong
soap and tobacco solution, using about 5 pounds of soap and a
half pint of 40 percent nicotine sulphate to each 50 gallons of
water. It is a common insect on grass in Florida.
THE BIG CONVICT BUG (Corecoris confluentus)
This insect is brownish yellow in color and grows to be
nearly an inch long and a half inch wide. Its abdomen is crossed
by a number of wide stripes, strongly suggesting the clothing of
a convict. It is common in the southern part of the state and
does about the same character of damage as the pumpkin bug. It
inflicts severe damage on the fruit, which turns yellow about the
punctures and soon drops. It also attacks tomatoes.
LACE BUGS
These are tiny sucking insects which sometimes heavily at-
tack eggplant. They derive their name from the character of
the wings. Thickened raised veins form a conspicuous network
over wings and thorax, so that the whole bug as viewed from
above seems covered with the most delicate lace. There are
several species found on eggplant, none of them much over 1/8
inch long. These insects can be controlled by tobacco sprays.
The Colorado potato beetle (see page 82) also attacks egg-
plant.
OTHER EGGPLANT PESTS
Other insects attacking eggplant are: Flea-beetle (see
under beets, page 33); harlequin cabbage bug (see under cab-
bage, page 45); serpentine leaf-miner (see under cowpeas,
page 62) ; and red spiders (see under peas, page 77).
LETTUCE
The cabbage looper (see under cabbage, page 37) is the
most troublesome insect enemy of winter-grown lettuce. A sin-
gle larva may eat out the bud and destroy the value of a plant
although not killing it outright.
Aph:ds are very commonly present on lettuce. The most
common species is the garden aphid but occasionally a large
red aphid (Macros'phum rudbeckiae) is found. For remedies,
see cabbage plant-lice, page 41.
Bulletin 232, Truck and Garden Insects
LEAF-HOPPEPS
The bean leaf-hopper, Empoasca fabae, and other leaf-hop-
pers are quite common on lettuce even during tl'e coldest months.
In add tion to sucking the sap of the plants these insects, and
also flies which breed in the decaying heads of lettuce, spread
several destructive fungus diseases of lettuce. These diseases
are usually much more serious t9 winter-grown lettuce than the
direct attacks of insects. When spraying lettuce with bordeaux
for fungus diseases it would be well to add nicotine or pyre-
thrum compounds to kill the leaf-hoppers. During the winter
the fie d will not be as quickly reinfested from surrounding fields
as would a field of beans in the fall. All dead and diseased let-
tuce should be removed from the field at once. This will not only
lessen the amount of spores to spread contagion, but will also
stop the breeding of the flies.
THE PITTED LYGAEID (Geocoris punctipes)
This is a small (1/6 inch long) dark brown insect which
works on lettuce very much as does the tarnished plant-bug. It
is related to the chinch bug which is the common cause of the
yellow and dead spots in our St. Augustine grass lawns. Like
its relative, it works all winter except during the coldest days.
It is larger than the chinch bug, especially the head. Its light
brown thorax is thickly covered with shallow black pits. It is
also a pest of cotton.
The best spray for lettuce is one composed of 1 pound lead
arsenate and 2/5 pint of 40 percent nicotine sulphate in 50 gal-
lons of bordeaux mixture. This will control most insect enemies
and fungi. The lead arsenate should not be used within a month
of the marketing date.
Should caterpillars, or other chewing insects, become trouble-
some during this period, lettuce can be dusted with one of the
fluosilicates or fluorides.
OTHER LETTUCE PESTS
Other insects attacking lettuce are: Tarnished plant-bug
(see under celery, page 48) ; cutworms (see under cabbage,
page 35).
MUSKMELONS
The insects attacking this crop are the same as those dis-
cussed under cucumbers (see pege 63); and watermelons (see
page 106). The pickle worm and the melcn worm are much more
Florida Agricultural Experiment Station
troublesome than on cucumbers. The trap crop of summer
squash should never be neglected when planting melons.
MUSTARD
The insects attacking this crop are the same as those dis-
cussed under cabbage (see page 35).
OKRA
The chief insect enemies of okra are: Flea-beetles (see
under beets, page 33) ; the garden aphid (see plant lice under
cabbage, page 41); red spiders (see under peas, page 77); cut-
worms (see under cabbage, page 35) ; pumpkin'bugs (see under
cowpeas, page 61); striped cucumber-beetle (see under cucum-
bers, page 66); and whitefly (see under sweet potatoes,
page 94.) Others are discussed
here.
OKRA CATERPILLAR, OR
ABUTILON MOTH
(Cosmophila erosa)
Okra leaves are often eaten
by a light-green caterpillar (Fig.
43) which has no conspicuous
markings. (The.moth, Fig. 44.)
Like the cabbage looper, this in-
sect is a semi-looper. It grows to
Fig. 43.-Okra caterpillar: Larva. Nat- a length of 13/ inches and then
ural size. (Original.)
rolls up the edge of the leaf and
pupates in the fold. According to H. L. Dozier, formerly of the
department of entomology, Florida Agri-
cultural Experiment Station who worked
out the life history, it spends from 5 to 6
days in the pupa. The egg hatches in /
from 3 to 4 days and the larva requires
about 24 days for growth, making a gen-
eration require about 34 days.
The caterpillar is attacked by a little
wasp-like parasitic insect (Chalcis ovata)
which prevents it fr om becoming a Fig 44.-Okra caterpillar:
a, adult male; b, adult fe-
greater pest. The caterpillar is easily con- !n.Natural size. (Orig.
Florida Agricultural Experiment Station
troublesome than on cucumbers. The trap crop of summer
squash should never be neglected when planting melons.
MUSTARD
The insects attacking this crop are the same as those dis-
cussed under cabbage (see page 35).
OKRA
The chief insect enemies of okra are: Flea-beetles (see
under beets, page 33) ; the garden aphid (see plant lice under
cabbage, page 41); red spiders (see under peas, page 77); cut-
worms (see under cabbage, page 35) ; pumpkin'bugs (see under
cowpeas, page 61); striped cucumber-beetle (see under cucum-
bers, page 66); and whitefly (see under sweet potatoes,
page 94.) Others are discussed
here.
OKRA CATERPILLAR, OR
ABUTILON MOTH
(Cosmophila erosa)
Okra leaves are often eaten
by a light-green caterpillar (Fig.
43) which has no conspicuous
markings. (The.moth, Fig. 44.)
Like the cabbage looper, this in-
sect is a semi-looper. It grows to
Fig. 43.-Okra caterpillar: Larva. Nat- a length of 13/ inches and then
ural size. (Original.)
rolls up the edge of the leaf and
pupates in the fold. According to H. L. Dozier, formerly of the
department of entomology, Florida Agri-
cultural Experiment Station who worked
out the life history, it spends from 5 to 6
days in the pupa. The egg hatches in /
from 3 to 4 days and the larva requires
about 24 days for growth, making a gen-
eration require about 34 days.
The caterpillar is attacked by a little
wasp-like parasitic insect (Chalcis ovata)
which prevents it fr om becoming a Fig 44.-Okra caterpillar:
a, adult male; b, adult fe-
greater pest. The caterpillar is easily con- !n.Natural size. (Orig.
Bulletin 232, Truck and Garden Insects
trolled by lead arsenate. The sprayed pods should be thorough-
ly washed before they are cooked.
Okra intended for market, or which cannot readily be washed,
can be dusted with one
of the fluosilicates or
fluorides, which are non-
poisonous.
CORN EAR-WORM
The corn ear-worm at-
tacks the pods of okra
much as it does cotton
bolls, or seed-pods of to-
bacco (Fig. 45), that is,
it bores into the pods
and feeds on the inte-
rior. Control measures
are the same as those
used against this insect
on tomatoes, page 96.
COTTON SQUARE-BORER
(Uranotes mellinus)
This butterfly, called Fig. 45. Corn ear-worm on tobacco seed pods.
the "gray hair-streak", About natural size. (Fla. Agr. Exp. Sta. Bul. 48.)
deposits eggs on okra.
The larva, a green caterpillar, eats the leaves and bores into
the buds. The purplish butterfly has a small narrow tail-
like appendage projecting from its hind wings. It is this ap-
pendage that suggests the name of "hair streak." The butter-
fly measures about 21/2 inches across the wings. Besides attack-
ing cotton, where it mines into the squares, the caterpillar at-
tacks loquats, where it mines into the blossom buds. (See An.
Rep. Fla. Agr. Exp. Sta., 1913, page Ixx.)
ROOT-KNOT
Of all the common hosts of root-knot nematodes, okra is per-
haps the most sensitive to their attacks. It is useless to attempt
to grow okra on any land which is infested with root-knot nema-
todes.
Florida Agricultural Experiment Station
ONIONS
ONION THRIPS (Thrips tabaci Lind)
These thrips (Fig. 46) are responsible for the blanching
and withering of the tips of onion leaves. They are always pres-
ent in onion fields in Florida, working throughout the season,
except during the cold-
est days of winter.
Like other thrips, they
are always more abun-
\dant in continued dry
weather, and compar-
atively scarce after a
prolonged rainy pe-
'- riod. They are deli-
cate insects, about
S1/25 inch long, and
are knocked off the
plants and killed
by heavy rains.
Thrips belong to the
sucking class of in-
Fig. 46.-Onion thrips (Thrips tabaci) Greatly magni- sects. Their punctures
fied. (Fla. Agr. Exp. Sta. Eul. 46.) are not deep but are
very numerous so that the plant tissue, when the fresh wound is
examined, has the appearance of having been rasped. Later, the
tip of the leaf whitens and shrives. This continuous killing of
leaves greatly interferes with the growth of the onions, and
control measures used will repay their cost many times over.
This insect attacks cabbage, cauliflower, tobacco, turnips, mus-
tard, and many other plants (see Fla. Agr. Exp. Sta. Bul. 26,
p. 105) but is most serious on onions.
Eggs are placed singly in the leaf tissue just below its sur-
face. They hatch in about 4 days. The larval stages last from
7 to 9 days, the insect molting twice. Then follows the nymphal
stage during which the insect is dormant and takes no food.
The wings show for the first time during this stage which lasts
4 days.
The insects can be killed by whale-oil soap, 1 pound to 4
gallons of water, or by any of the tobacco extracts.recommended
for the flower thrips. A half-pint of 40 percent nicotine sul-
phate and 3 or 4 pounds of soap to 50 gallons of water is suf-
ficient.
Bulletin 232, Truck and Garden Insects
A more economical and efficient spray will be obtained by sub-
stituting some of the better spreaders for the soap, such as the
oil derivatives or the oleates. The use of these spreaders will
also enable one to cut down the amount of nicotine necessary,
therefore lessening the cost.
In spraying for the onion thrips, it is very important to have
a gcod pressure so as to force the spray down into the axils of
the leaves where the thrips hide. In planting a field of any con-
siderable size roadways should be left every 100 feet so that a
power sprayer may be driven through the patch, this to obtain
the necessary pressure. It may be necessary to spray a second
time in order to get the nymphs and eggs that are hidden in the
bases of the leaves or elsewhere at the time of the first spraying.
ONION ROOT-MAGGOT (Hylemia spp.)
The onion root-maggot (Fig. 23) begins its depredations
early in the season on the young and tender onion plants. "The
eggs are deposited loosely above the surface of the ground
on the stem and basal leaves. Usually 5 or 6 eggs are deposited
on the plant. In about a week these eggs hatch and the young
maggots burrow downward within the leaf sheath, leaving dis-
colored streaks to mark their passage; penetrating the soft cylin-
drical root, they greedily devour the interior, leaving the outer
skin. Having consumed one plant, it is abandoned and another
is attacked. About 2 weeks is required for the maggot to com-
plete its growth, when it usually leaves the onion and, retiring
into the neighboring soil, forms the pupa, from which it
emerges as an adult fly in about a fortnight. The winter is
probably passed in the pupa state in the ground." (Fla. Agr.
Exp. Sta. Bul. 34, p. 306.) Pegomya cepetorum, the Northern
imported onion maggot, is not known to occur in Florida.
Control-The maggots in the bulbs are out of reach of any
insecticides and all efforts must be aimed at preventing them
from reaching the plants. As many of the eggs are deposited
on the ground near the plants, or are loosely attached, frequent
cultivation will break many of them and remove others to such
a distance that the newly-hatched maggots will fail to reach the
plants.
Onions should not be planted on land that has had a crop
of cabbage, cauliflower, collards, turnips, mustard, or other
plants of this family during the summer or early fall. All
wild crucifers in or near the field should be destroyed. In an
Florida Agricultural Experiment Station
infested field of onions or cabbages all refuse of the crop should
be pulled and burned as soon as the crop is harvested.
Several of the Northern stations report success in poison-
ing the flies of the onion root-maggot before they have had op-
portunity to lay many eggs. The following poisoned bait was
prescribed by the Wisconsin Station. Five grams of sodium
arsenite are dissolved in a gallon of boiling water and a pint of
cheap molasses is added. This solution is sprayed on the plants
with a coarse nozzle so that it will fall in large drops. It must
be renewed after every heavy rain or once a week in dry
weather. Another method is to distribute the poison in from
15 to 20 small pans for each acre of onions. These need to be
renewed only after heavy rains or when dried out. During the
dry weather of the average spring this method would probably
be more economical than spraying.
OTHER ONION PESTS
Other insects attacking onions are: Fall army worm (see
under corn, page 55); wireworms (see under corn, page 53);
and cutworms (see under cabbage, page 35).
PARSLEY
Two insects attack this crop quite commonly in Florida.
They are: Celery worm (see celery caterpillar, page 49), and
cutworms (see under cabbage, page 35).
PEAS
Peas, or English peas, also sometimes called garden peas,
are attacked by about the same pests as the sweet, or flowering,
peas. Their pests are discussed here. Cowpeas, or field peas,
are sometimes called peas. Their pests are discussed under the
heading of cowpeas in an earlier part of this bulletin.
PEA-APHID (Illinoia pisi)
This green plant louse is much larger than the garden aphid,
measuring 3/16 inch long. They collect on the young and ten-
der portions of the vines near the growing tip which they may
cover completely. They commonly collect also in the bud where
they are concealed by the bracts.
There are usually a few of these insects on peas and as the
hot dry weather of spring comes on they multiply so rapidly
that they kill the vines in a few days.
The life history and remedies are so similar to those of
Florida Agricultural Experiment Station
infested field of onions or cabbages all refuse of the crop should
be pulled and burned as soon as the crop is harvested.
Several of the Northern stations report success in poison-
ing the flies of the onion root-maggot before they have had op-
portunity to lay many eggs. The following poisoned bait was
prescribed by the Wisconsin Station. Five grams of sodium
arsenite are dissolved in a gallon of boiling water and a pint of
cheap molasses is added. This solution is sprayed on the plants
with a coarse nozzle so that it will fall in large drops. It must
be renewed after every heavy rain or once a week in dry
weather. Another method is to distribute the poison in from
15 to 20 small pans for each acre of onions. These need to be
renewed only after heavy rains or when dried out. During the
dry weather of the average spring this method would probably
be more economical than spraying.
OTHER ONION PESTS
Other insects attacking onions are: Fall army worm (see
under corn, page 55); wireworms (see under corn, page 53);
and cutworms (see under cabbage, page 35).
PARSLEY
Two insects attack this crop quite commonly in Florida.
They are: Celery worm (see celery caterpillar, page 49), and
cutworms (see under cabbage, page 35).
PEAS
Peas, or English peas, also sometimes called garden peas,
are attacked by about the same pests as the sweet, or flowering,
peas. Their pests are discussed here. Cowpeas, or field peas,
are sometimes called peas. Their pests are discussed under the
heading of cowpeas in an earlier part of this bulletin.
PEA-APHID (Illinoia pisi)
This green plant louse is much larger than the garden aphid,
measuring 3/16 inch long. They collect on the young and ten-
der portions of the vines near the growing tip which they may
cover completely. They commonly collect also in the bud where
they are concealed by the bracts.
There are usually a few of these insects on peas and as the
hot dry weather of spring comes on they multiply so rapidly
that they kill the vines in a few days.
The life history and remedies are so similar to those of
Bulletin 232, Truck and Garden Insects
the garden aphid (see cabbage plant-lice, page 41), which also
is common on peas, as to need no restatement. The lice in the
bud have better protection than those on cabbages and it is
necessary to use strong pressure in order to force the buds open
so that the liquids can reach the aphids.
Instead of liquid sprays the peas may be dusted with nico-
tine sulphate-lime dusts. This large aphid is more difficult to
kill than most aphids, and it is well to use 4 percent dust instead
of 3 percent, especially during cool weather in early spring or
winter.
During cool weather a better kill will be obtained with extracts
of derris or especially pyrethrum.
RED SPIDER (Tetranychus telarius)
Another pest that becomes a serious menace to peas in dry
spring weather is the 2-spotted mite (Tetranychus telarius).
Either this or the aphid or both usually destroy the late winter-
planted crop of peas.
Peas when attacked become dry, mealy or cobwebbyy" in
appearance, cease to grow, wilt down, and soon die. So rapidly
does an infestation develop that in a few days from the time
damage is first noticed the vines are dead.
This pest is not a true insect but belongs to the spider
class of animals and to a subdivision distinct from the large
garden spiders, being more closely related to red bugs."
Members of this group are often called spider mites" and
also spinning mites" from the habit many of them have of
spinning a silken web over the host plant or a part of it.
" Spinning mites" would be the most nearly correct popular
name. The name red spider is misapplied as these pests are not
true spiders and are not usually red; they are often yellow and
sometimes green.
The red spiders are usually round in outline, small, and
have eight legs when full grown. This characteristic at once
serves to distinguish spiders from insects, which never have
more than six legs.
Although they are troublesome out of doors only in dry
weather, they may be troublesome throughout the year in green-
houses, on house plants and in other places sheltered from rain.
Life History.--The egg hatches in from 3 to 5 days. The
young mites require about 10 days during warm weather for
growth and the adults are about 4 days old before they begin
Florida Agricultural Experiment Station
to lay eggs. Between 2 and 3 weeks is the time usually re-
quired for a generation but it has been found to be as short as
10 and as long as 35 days.
These mites spin irregular strands of silk all over the host
plant so that a severely-infested plant is well-webbed. They
use this web as a road over which to travel, but it also serves
to hold the eggs to the leaves and perhaps tends to lessen the
danger of the mites being washed off by heavy rains. They
spread by crawling from place to place, although they may be
carried by the wind.
They damage the plant by sucking the sap from the leaves.
Each puncture is extremely minute but in the case of a severe
infestation the plant becomes white, the chlorophyll or green
coloring matter being removed with the sap.
Control.- As these mites are dry weather creatures, one of
the most effective means of control is frequent and heavy
sprinkling, especially if strong pressure can be had. A field
supplied with the common system of overhead irrigation also
supplies a fairly satisfactory means of control. A stream of
water not only knocks off many of the mites, but the moisture
aids their numerous enemies.
If a sprinkling system is not available, recourse must be
had to insecticides. The best are those containing sulphur in
some form. Free sulphur or some of its compounds may be
used, being applied either dry, or in the form of a spray. Free
sulphur is one of the best remedies for red spiders or mites. It
is somewhat slower in its action than some compounds of sul-
phur, taking often 2 or 3 days or more to do its work, but it
remains active for a long time, frequently 2 or 3 weeks, and
usually kills the mites. Sulphur can be applied dry, and driven
into the vines by a hand duster, or shaken into the vines through
a closely woven cloth or a perforated can.
It is better to mix 3 pounds of dry sulphur with 1 pound of
hydrated lime. The lime can be bought or made by adding 32
pounds (4 gallons) of water to each 100 pounds of quicklime.
Mix hydrated lime and sulphur thoroughly. The best results will
be obtained by applying the dust at night or in the early morn-
ing when the air is quiet and the plants are wet with dew, as
the dust sticks better then. It works better when the nights
are moist and the days bright and sunny, for under these con-
ditions the oxidation of the sulphur takes place more rapidly.
As a spray from 1 to 5 pounds of sulphur to 50 gallons of
water can be used.
Bulletin 232, Truck and Garden Insects
Whether the grower can use the dust or the spray most
economically will depend on a number of things, such as the
outfit that he can obtain, the distance the water must be hauled,
and the severity of the infestation, the spray being a little
quicker in its action, particularly in cold or wet weather, than
the dust.
Of the compounds of sulphur, lime-sulphur is one of the
best. Use about 1 gallon to 70 gallons of water. Use either
the commercial product, or mix 8 pounds of lime and 8 pounds
of sulphur. Cover the lime with about 6 quarts of water, and as
the mixture becomes heated, add the sulphur slowly. When thp
slaking is over, quickly cool the mass by pouring cold water into it.
A compound that will act quickly and can usually be bought
at drug stores is potassium sulphide (liver of sulphur). Une
pound of this to 50 gal-
lons of water will prove
satisfactory, especially if
from 2 to 5 pounds of
flour are added.
PEA-WEEVIL
(Mylabris pisorum)
This weevil (Fig. 47)
works in dried peas in FFig. 47.-Pea-weevil (Mylabris )isorum): b. Adult, c,
Ork in drie pe i fu 1-grown larva; d, pua ; g, pea s'owin- exit
the same manner that h;ce, na ural size. Much enlarged. (From U. S.
Lur. of Ent.)
the bean-weevil works in
beans. It is closely related to that species and the treatment of
infested seeds is the same. (See bean-weevil, page 29.)
OTHER PESTS OF PEAS
Other pests of peas are: Onion root-maggot (see under
onions, page 75); and plant-bugs (see under potatoes, page
80, and pumpkin bug under cowpeas, page 61). The bugs at-
tack chiefly the young pods.
The corn ear-worm (see page 50) frequently mines the pods
of peas. Should it become sufficiently abundant to make control
measures necessary, peas can be sprayed or dusted with lead
arsenate or dusted with one of the fluosi:icates or fluorides.
PEPPER
The insect pests common to the pepper are: Garden aphid
(see plant lice, page 41); flea-beetles (see page 33) ; pump-
Florida Agricultural Experiment Station
kin-bug (see page 61); leaf-footed plant-bug (see page 81);
flea-hopper (see page 48) ; and blister beetles (see page 32);
corn ear-worm (see under tomatoes, page 96).
Wireworms often attack peppers which are resting on the
ground. They bore into the pepper and of course ruin it for the
market, as fungus diseases gain entrance through the opening.
It is only the earlier peppers on the plants which usually touch
the ground that are attacked, but as these are often the most
profitable part of the crop the loss is sometimes serious. This
damage can be largely prevented by placing a piece of bark,
shingle, heavy piece of paper or thick layer of straw under the
pepper to keep it off of the ground.
POTATOES
BIG-FOOTED PLANT-BUG (Acanthocephala femorata)
This big brown bug (Fig. 48) with club-shaped leg-joints is
quite common on early potatoes especially when planted near
hammocks, in which they hibernate. It is by far the largest
plant bug in Florida, being more than an inch long. Like the
other plant-bugs, these use for food the juices of succulent,
quickly growing plants. The potato is a favorite. It is not
only very succulent, but its large stems furnish sufficient sup-
port for these heavy bugs." The insects usually settle 3 or 4
inches below the top and the withdrawal of sap causes the tip
of the plant to wilt, markedly. If the attack is persistent the
top will die. It is possible that the damage this bug, as well as
the other plant-bugs, inflicts is not entirely due to the loss of
sap. They may inject a poison into the
puncture.
S Control.-These insects are so large and
S their effects on the plant so conspicuous
That collecting them by hand is an easy
matter. The wilted tops show the location
of the bugs. Two or three collections dur-
ing the season usually suffice.
This bug is particularly abundant in the
Early spring on thistles. These weeds
Fig. s.-mg-footed pant- should be cut down when around the mar-
bug. Natural size.
(Original.) gin of truck fields.
During the past several seasons the writer successfully used
sunflowers as a trap crop to keep these bugs off of Irish pota-
Bulletin 232, Truck and Garden Insects
toes in the spring. Young sunflower plants will stand a light
frost and can be planted nearly as early as potatoes. A row or
two of sunflowers around the edge and every hundred feet
through the field will afford almost complete protection to the
potatoes.
LEAF-FOOTED PLANT-BUG (Leptoglossus phyllopus)
This bug attacks the great majority of truck and garden
crops, but potatoes, beans, cowpeas, and tomatoes are favorites.
Fig. 49. Leaf footed
plant bug. Enlarged.
(From Fla. Agr. Exp.
Sta. Bul. 112.)
It is not as large as the big-footed
plant-bug, but makes up in numbers
what it lacks in size. Next to the
pumpkin bug it is the most common of
the larger plant-bugs. It also attacks
citrus. It is readily recognized by the
yellow line running across the wing
covers and the peculiar expansion of its
hind tibiae which suggests its name
(Fig. 49).
Control measures are the same as
those for the pumpkin bug (see under
cowpeas, page 61).
MAY-BEETLES, OR WHITE GRUBS
(Phyllophaga spp.)
These large fleshy-white grubs (Fig. 50) which are so injuri-
ous to grass lands do some damage to potatoes when planted on
land that was previously in grass. They eat the tubers. They do
not usually eat more than half of the potato, hollowing it out on
one side. They seldom eat the main stem of the plant. These
grubs are a fa-
vorite food of
moles which in
tunneling the c
ground for the
grubs, do more
damage to the e ab
potato than do Fig. 50.-May-beetle or June-bug (Phyllophaga fervida): a,
h Adult: b, pupa; c, egg; d, young grub; e, full-grown grub.
the grubs. BY Natural size. (From U. S. Bur. of Ent.)
ridding his fields
of white grubs the farmer will greatly lessen the number of moles.
White grubs are slow-growing and very long-lived. All spend
many months in the larval stage, some spend 3 years.
Florida Agricultural Experiment Station
When full-grown the grubs form pupae (Fig. 50, b) in
earthen cells in the ground. The adults (Fig. 50, a) are the
well-known June-bugs" or May-beetles" which are so
abundant about lights. Like the cutworms, the white grubs
are active throughout the year in Florida.
Control.- The only practical control measure is to rid the
ground of the grubs as thoroughly as possible before the crop is
planted. This is best done when the ground is plowed. En-
courage chickens and turkeys and such wild birds as crows and
grackles to follow the plow, or turn pigs into the field. It is
particularly important to take these precautions if there has
been much grass on the land. Skunks are persistent enemies
of white grubs as well as other insects and should be protected
by the farmers.
The large Carrot-beetle (Ligyrus gibbosits) does about the
same damage as whiie grubs, has a similar life history, and calls
for identical control measures.
COLORADO POTATO-BEETLE (Leptinotarsa decemlineata)
This notorious pest of the Northern potato grower fortun-
ate'y has not yet made its appearance in numbers in the main
potato-growing sections of our State. This beetle is present in
the northern counties of Florida as far south as Alachua County.
It is slowly spreading south, and has appeared in the neighbor-
hood of Hastings, the main potato producing center of the state.
In the northern and western parts of the State, during the
summer when there are no potatoes, it feeds on tomatoes and
wild sFecies of Solanum. The latter should be destroyed if
found near potato fields in those parts of the State.
The insect is easily controlled by lead arsenate. When pota-
toes are regularly sprayed with bordeaux as a precaution against
blight, the lead arsenate can be added to that solution.
APHIDS
In the main potato growing sections of the state the aphid Mac-
rosiphum so'anifolii is the most injurious insect. There are two
color phases of this aphid, one brown and one green. In a patch
of potatoes which are small, good control can be obtained by
spraying with nicotine compounds in bordeaux, but when the
potatoes are large it is difficult to reach the aphids down among
the vines. At this stage best control will be obtained by dusting
the potatoes with a nicotine compound, either a 3 percent dust
Bulletin 2-32, Truck and Garden Insects
of nicotine sulphate, or a 2 percent dust of free nicotine. As in
all dusts with nicotine, a time must be chosen when there is no
strong wind blowing, or a sheet of cloth may be fastened over
the duster as a protection against wind.
MEALYBUGS (Psendococcus citri)
When potatoes are kept in a dry place and allowed to sprout
slowly they frequently become heavily infested with mealy
bugs. They are most noticeable on spring-grown potatoes
which are kept through the summer for planting the fall crop.
They collect in the eyes and about the bases of the sprouts.
Mealybugs give off a copious secretion of honeydew, in which a
black fungus called sooty mold grows, as on a citrus tree infested
with whitefly (see Bulletin 183). Mealybugs are sucking insects
and the presence of a numerous company on the sprouts inter-
feres with their proper development. Unless the soil is very dry
they do not multiply to any marked extent after the potatoes are
planted.
One of the best ways of dealing with mealybugs on potatoes
is to spray them with heavy pressure and wash them off. If one
is not equipped with a source of water with high pressure, pota-
toes may be dipped either in nicotine sulphate with one of the
oil derivatives as spreaders, or in one of the pyrethrum com-
pounds now on the market.
The Experiment Station has introduced from California a
ladybeetle which feeds on mealybugs. It may at some time be
possible for the Experiment Station to supply a colony of these
beetles to any one wishing to carry potatoes through the sum-
mer.
OTHER POTATO PESTS
Other insects attacking potatoes are: Flea-beetles (see under
beets, page 33) ; pumpkin bugs (see under cowpeas, page 61);
blister-beetles (see under beets, page 32).
RADISHES
The insects commonly attacking radishes are: Garden aphid
(see plant-lice under cabbage, page 41) ; cabbage root-maggot
(see under cabbage, page 44); and flea-beetles (see under
beets, page 33).
ROSELLE
The chief insect pests of this crop are the okra caterpillar
(see page 72), the corn earworms (see page 50), and the cot-
ton stainer (see page 69).
Bulletin 2-32, Truck and Garden Insects
of nicotine sulphate, or a 2 percent dust of free nicotine. As in
all dusts with nicotine, a time must be chosen when there is no
strong wind blowing, or a sheet of cloth may be fastened over
the duster as a protection against wind.
MEALYBUGS (Psendococcus citri)
When potatoes are kept in a dry place and allowed to sprout
slowly they frequently become heavily infested with mealy
bugs. They are most noticeable on spring-grown potatoes
which are kept through the summer for planting the fall crop.
They collect in the eyes and about the bases of the sprouts.
Mealybugs give off a copious secretion of honeydew, in which a
black fungus called sooty mold grows, as on a citrus tree infested
with whitefly (see Bulletin 183). Mealybugs are sucking insects
and the presence of a numerous company on the sprouts inter-
feres with their proper development. Unless the soil is very dry
they do not multiply to any marked extent after the potatoes are
planted.
One of the best ways of dealing with mealybugs on potatoes
is to spray them with heavy pressure and wash them off. If one
is not equipped with a source of water with high pressure, pota-
toes may be dipped either in nicotine sulphate with one of the
oil derivatives as spreaders, or in one of the pyrethrum com-
pounds now on the market.
The Experiment Station has introduced from California a
ladybeetle which feeds on mealybugs. It may at some time be
possible for the Experiment Station to supply a colony of these
beetles to any one wishing to carry potatoes through the sum-
mer.
OTHER POTATO PESTS
Other insects attacking potatoes are: Flea-beetles (see under
beets, page 33) ; pumpkin bugs (see under cowpeas, page 61);
blister-beetles (see under beets, page 32).
RADISHES
The insects commonly attacking radishes are: Garden aphid
(see plant-lice under cabbage, page 41) ; cabbage root-maggot
(see under cabbage, page 44); and flea-beetles (see under
beets, page 33).
ROSELLE
The chief insect pests of this crop are the okra caterpillar
(see page 72), the corn earworms (see page 50), and the cot-
ton stainer (see page 69).
Florida Agricultural Experiment Station
SQUASH
VINE BORER (Melittia satyriniformis)
The larva of this moth mines into,,the interior of the vine
and causes it to wilt and finally to die. The grub (Fig. 51, d) is
whitish in color, somewhat flattened, and is about an inch long.
After completing its growth, the larva leaves the plant and en-
ters the ground to pupate. The adult, a moth (Fig. 51, a),
measures 114 inches across the wings. It is an attractive in-
sect with its hind-wings transparent in the centers and mar-
gined with brown; fore-wings olive-brown, olive-green thorax,
and orange abdomen. The eggs are laid on the vines near the
ground, hatch in 7 days and the grub at once bores into the
stem of the plant.
A wilted vine
S9 should be inves-
Stigated and if the
entrance hole
Made by the
worm, about
b which there is
usually a little
fras, is found the
Svine should be
d cut open and the
Fig. 51.-Squash-vine borer: a, Adult; b, adult with wings w or m removed.
folded; c, eggs on stalk; d, larva at work; e, pupa; f, co-
coon. One-third larger than natural size. (From U. S. Bur. Be sure to cut the
of Ent.)
stem only length-
wise and never across the fibers and the vine probably will re-
cover. To induce it to take root beyond the injury, cover the
vine with dirt.
SQUASH-BUG (Anasa tristis)
These squash-bugs (Fig. 52) are large brownish-black, ob-
long bugs, somewhat over a half inch long, which frequent in
groups the under sides of the stems of squashes, suck the sap,
cause the plants to wilt and perhaps die. They are shy crea-
tures and when approached move to the other side of the stem
out of sight. They are not nearly so destructive to squashes in
Florida as in more northern states, perhaps because they do
not become active in the spring until the main crop of squashes
is too nearly mature to be seriously damaged. The adults are
common in summer, feeding on various wild plants.
Bulletin 232, Truck and Garden Insects
The eggs are laid in bunches on the under side of the leaves
and commonly in the angles formed by the larger veins. They
are brownish in color and quite conspicuous. The newly-hatched
nymph (Fig. 52) is oval with yellow abdomen, black thorax,
and pink feelers (antennae). After the first molting the nymphs
become black with gray thorax.
Hand picking is about the only practical
method of control, although the young may
be killed by tobacco sprays. The egg masses
should also be picked off or crushed.
OTHER SQUASH PESTS
Fig. 52. Squash-bug:
Other insects attacking the squash are Youn nymphs and
adult. Natural sz e.
Pickle worm and melon worm (see under cu- (From u. S. Bur. of
cumbers, pages 63 and 66). The grower
can use no trap crop to attract these insects away from squashes.
He must plant enough for both himself and the moths. All in-
fested fruits should be destroyed. The melon aphid (see under
watermelons, page 106), also attacks squash.
STRAWBERRIES
RED SPIDER (Tetranychus telarius)
Red spiders frequently become very prevalent upon straw-
berry plants in the spring of the year when the weather is dry
and warm. They breed less rapidly in cool weather and the
heavy rains of summer usually very quickly bring them under
control; but during the spring when the weather is dry, they
often cause heavy losses. They attack both leaves and fruit. The
leaves turn a pale color and, if the infestation is heavy, become
dry and shrivel up and die. The young unripe berries take on a
brown color and also become hard and dry and fail to develop.
The injury is caused by the red spiders sucking the sap out of
the foliage and fruit. For description and life history of this
pest see under peas, page 77.
Like all members of the spider class, they are best controlled
by sulphur. If the weather is reasonably warm, one can ordi-
narily get satisfactory control by simply dusting the plants with
flowers of sulphur. This is, by all means, the quickest and most
economical way of combating red spiders. Sulphur is best
spread with a dust gun but may be applied by hand. In order
to make it go through a dust gun more readily sulphur is often
Florida Agricultural Experiment Station
mixed with 5 to 10 percent of hydrated lime, but the lime is not
necessary to kill the spiders. If this dust is applied in the morn-
ing when the plants are wet with dew, it will stick somewhat
better; but it can be applied any time during the day when there
is not a heavy wind blowing.
During cold weather better control will be obtained by spray-
ing the plants with lime-sulphur. One gallon of lime-sulphur to
50 gallons of water is used. However, this spray will taint the
berries and should not be used during the picking season, al-
though there will be no danger to the consumer. Nicotine sul-
phate and derris compounds (see below) are also good insecti-
cides for red spiders, but nicotine compounds also would be
objectionable during the picking season.
In small dooryard patches which can be reached with the hose
or in a field provided with irrigation, a liberal sprinkling with
water will check these pests. The water should be applied with
as great a pressure as the plants will stand.
FLORIDA FLOWER THRIPS (Frankliiella bispinosa)
This orange-yellow insect, about 1/25 inch long, is often very
injurious to strawberries in the spring. Its attacks are confined
entirely to blossoms where it feeds on stamens and young ber-
ries. Like the red spiders, these are sucking insects but their
punctures are very shallow and very numerous. The action on
the berries resembles much that of the red spider but is more
largely confined to very young berries than is the case in attacks
by the red spider. As a result of their feeding the blossoms
drop off, or the young berry may remain hard and brown, fail-
ing to grow. In cases of less severe infestation the berry may
be deformed, due to the fact that it was injured on one side and
not on the other. These insects frequently seriously shorten the
bearing season of the vines as they are usually more abundant
in the later blossoms.
Control.-One of the best sprays for thrips is nicotine sulphate
(one part of nicotine sulphate to 600 parts of water). To make
the solution spread better one of the oleates or oil derivatives
or a little soap should be added to the solution (2 or 3 pounds
to 50 gallons, more if the water is hard). This should be applied
in the heat of the day as its strength is soon dissipated after
the application and the kill is much better when the weather is
Bulletin 232, Truck and Garden Insects
warm. In fact, at a temperature below 60 degrees it is apt to
be unsatisfactory. The spray should be applied with as much
force as possible as the thrips have a tendency to hide down
among the stamens and other parts of the flower and will not
be reached by the spray unless good pressure is employed.
As this solution will taint the berries, it should be applied
immediately after picking. After 48 hours the odor and taste
will have disappeared from the berries.
A satisfactory dust for controlling this insect can be made by
mixing a very finely ground tobacco dust, such as snuff No. 2,
with an equal quantity of sulphur. This is not likely to taint
the fruit, as the dust wil. be knocked off in picking, and it has
the added advantage in that it will also control red spiders.
Preventive Measures.-Weeds and ether plants in bloom about
the strawberry patch should be destroyed as the thrips will
spread from these to the strawberry blossoms. This destruction
should take place some weeks or a month before the strawber-
ries bloom. The white-blcssomed Spanish reedle (Bidens leu-
cantha), a common plant about strawberry patches in the
southern part of the state, is a favorite host plant of thrips, as
are also roses.
Life History.-The life history of this insect is very short-
two or three weeks when the weather is warm. The eggs are
laid in shallow slits in the stem just below the blossom. They
hatch out in three days into a light yellow nymph without wings
which continues to feed on the young berry and other tender
parts of the plant.
PAMERAS
Other very destructive insects which are liable to attack
strawberry plants in the spring are the pameras. Fortunately
they do not make their appearance in destructive numbers until
the bearing season is nearly over, but growers who attempt to
carry their vines through the summer almost invariably have
trouble with these insects. They breed so rapidly and are so
inconspicuous in color, size, and habits that they often become
very abundant before they are noticed. The young, in size and
color, resemble small yellow ants but they are much more rapid
in their movements than ants and the presence of the darker
winged adults will readily identify them.
Florida Agricultural Experiment Station
This insect causes "buttons"-berries that in some early stage
of development cease to grow and become hard, dry, and brown.
A very young berry will turn brown and dry up. Later the in-
sects attack the crown of the plant which withers rapidly and
dies if the bugs are numerous.
There are three species of these insects. The smallest of these,
Orthaea vincta, is black with yellow markings and about 1/5
inch long. This is the most common of the three. The larger
ones, Orthaea bilobata and Orthaea longulus, are much longer.
These bugs belong to the same family as the chinch bugs, the
most destructive enemy of the St. Augustine grass in Florida,
and they have the same "buggy" odor.
Control.-The most effective insecticide is the tobacco extract
recommended for thrips. This must be applied with strong pres-
sure so that the liquid will be forced down into the crowns of the
plants where the bugs congregate, usually just at the surface of
the ground. In small garden patches, particularly after the pick-
ing season, these insects can be brought under control by allow-
ing young chickens to have the run of the strawberry patch.
Like red spiders and thrips these insects tend to disappear as
the rainy season comes on. Many of them are killed by the
heavy, dashing rains. The insects are very abundant on wild
spurge (Euphorbia sp.). This not uncommon weed, which is
light colored and lies very flat on the ground and has a milky
juice, should be destroyed when in the neighborhood of a straw-
berry patch as a precautionary measure.
CUTWORMS
Following their usual habit of severing succulent stems, these
caterpillars often cut off the petioles of the leaves of strawberry
plants or the stems of the young fruit. They also inflict another
type of injury by attacking the green but well grown fruit from
below, often hollowing it out until nothing but the shell of the
berry is left, or they may make only a small hollow in it. This
is done without severing the berry from the vine.
Control.-One of the best insecticides for cutworms and one
of the most cheaply applied is the poisoned bran bait. (See
page 36.) This bait should be put out in the evening after
the sun has set so that it will not dry out and a few flakes should
be distributed around each plant. The 25 pounds should suffice
to cover four or five acres.
Bulletin 232, Truck and Garden Insects
If cutworms are not sufficiently numerous to make this worth
while, they can be dug up and destroyed. If one will go through
the patch early in the morning and dig down an inch or so
under all severed leaves or berries he sees, he will usually dis-
cover the culprits without much trouble.
Preventive Measures.-Cutworms are always worse in beds
made up on ground which was occupied by heavy sod. If such
land is to be used for making the strawberry beds, it should be
plowed two or three weeks before the berries are set. Then, 10
days or two weeks after plowing, the poisoned bran bait recom-
mended above should be sown broadcast over the land in the
evening. The cutworms, rendered very hungry by their long
fast caused by the destruction of the grass, will eat this poisoned
bait eagerly and a thorough clean-up should result. Instead of
the poisoned bran mash one may scatter over the ground leaves
of mustard or collards or even grass which have been dipped in
a strong solution of lead arsenate, using an ounce or two to
three gallons of water.
WHITE GRUBS
Sometimes the roots of strawberry plants are eaten off by
large white grubs, the larvae of June bugs or May beetles. This
type of injury will be found most frequently where heavy sod
land has been plowed up for strawberry beds. If many of these
grubs are found in the soil when the beds are being made up,
the grubs should be exterminated before the plants are set out.
This can be done by allowing hogs to run in the field for a few
weeks or the ground may be treated with calcium cyanide. This
should be spread at the rate of about 300 pounds per acre in
front of the plow when the bed is being plowed. It should be
laid down in the bottom of the furrow, immediately in front of
the plow which will promptly cover it over.
EARWIGS
These dark colored insects with a pair of pincher-like organs
on the end of the body are often very abundant in low grounds.
They feed on the roots of the plants and often come out at night
and feed on the foliage and berries. The poisoned bran bait
recommended for grasshoppers is perhaps the best means of
control.
Florida Agricultural Experiment Station
FLEA-BEETLES
Several species of flea-beetles, more especially the straw-
berry flea-beetle, Haltica ignita, a ye low-bronze inse-t about
1/5 inch long, attacks strawberry leaves, eating round holes in
them.
Control.-The best control for these insects is to spray the
plants with bordeaux, to each 50 gallons of which a pound of
lead arsenate has been added. If the attack occurs during the
picking season, the use of arsenic in any form should be avoided.
A good insecticide to use under those circumstances would be
one of the pyrethrum compounds.
One of the favorite food plants of this beetle is the orna-
mental, crape myrtle. This plant shou d not be grown in close
proximity to a strawberry bed or at least it should be watched
closely during the spring and sprayed with lead arsenate in case
the beetles appear on it.
COWPEA POD WEEVIL (Chalcodermus aeneus)
This black weevil, about the size of a boll weevil, is a very gen-
eral feeder and sometimes in the early spring attacks the straw-
berry plants. If the attack does not occur during the picking
season, a spray with lead arsenate will afford protection. If the
attack does occur during the picking season, the best plan is to
go through the patch in the early morning when the weevils
are sluggish and, with the hand or a stick, knock the beetles off
into a flat dish containing a little kerosene in the bottom.
APHIDS
The strawberry root aphid, Aphis forbesi Weed, sometimes at-
tacks strawberry plants, sucking the sap from the roots. It
can be controlled by punching holes slantingly under the plants
and pouring in a tablespoonful or so of carbon bisulphide. The
hole should be several inches from the plant, but both the dis-
tance from the plant and amount of carbon bisulphide to use
will vary with the character of the soil. In heavy, dense soils
more of the material will be needed and the distance from the
plant will need to be shortened as the gas does not penetrate
heavy soils as well as light, open, sandy ones.
O.her species of aphids will attack the part of the plant above
ground, the crown, etc. They are best controlled by tobacco ex-
Bulletin 232, Truck and Garden Insects
tracts, such as nicotine sulphate. This may be applied either
as a dust mixed with lime or as a liquid spray. Dusting will be
much quicker but it will take more of Ihe material. A good dust
is made by thoroughly mixing three and three-fourths pounds of
nicotine sulphate with 50 pounds of hydrated lime. The mixing
must be thorough. It should be done in a barrel rigged up for
this purpose (see Bulletin 183, Fla. Agr. Exp. Sta). This dust
should be applied in the heat of a good, warm day and when
there is not much wind blowing.
If the spray is used, one part of nicotine sulphate should be
used to 600 parts of water and to every 50 gallons, three or four
pounds of soap should be added to make it spread and stick bet-
ter, or the nicotine sulphate may be added to the bordeaux mix-
ture. Derris or pyrethrum compounds may be used instead of
nicotine sulphate.
NEGRO BUGS OR BURROW BUGS
(Corimelaena (Thyreocoris) pulicarius and Pangaeus bilneatus)
These are small, roundish, shiny black bugs which are some-
times found damaging the roots of
strawberries or they may attack the
berries, whose juices they suck. They
have a very nauseous odor, suggesting
that of bedbugs. The adult bugs are
about 1/8 inch long. The middle piece
of the back is enlarged so that it cov-
ers the entire abdomen, which makes
the insect look more like a beetle than
a bug; the sucking mouth parts, how-
ever, readily distinguish it as a bug.
Control.-A spray of crude carbolic
acid, a tablespoonful to two gallons of
water, has been found to be very ef-
fective in driving these bugs away;
but if they occur during the picking
season it should be applied just after
the berries have been picked.
FIELD CRICKET (Gryll,/s a..imilis)
The field cricket (Fig. 53) is com-
Fig. F3.-Fiel cricket (fCrillus
assimilis). Slightly enlarged.
(From Fla. Agr. Exp. Sta. Bul.
42.)
only found under the mulch in strawberry beds. Prof. A. L.
J
C~1~~
Florida Agricultural Experiment Station
Quaintance, who made a study of them in Lake City, found them
very injurious. The following is quoted from his Bulletin 42 of
this Station, p. 596.
"From the slyness and alertness of these insects, they can rarely be
approached unawares, and studied in their normal mode of living. Exam-
inations of many different plants from which crickets have been fright-
ened led me to believe that the cricket must undoubtedly be classed as an
enemy to the strawberry grower. In the majority of cases where crickets
were frightened from plants, much of the ripe fruit has been eaten into in
such a way that decay would soon result. A hole an eighth of an inch
thick or more is sometimes eaten into the fruit, but more usually several
smaller pits are eaten out. If an individual cricket were to confine its at-
tention to one berry, the damage would not be so great, but it does not
seem to do this, but attacks several different berries. In this way a single
insect is able to occasion the destruction of a considerable number of ripe
fruit in a short while."
Young chickens in a patch will quickly destroy these insects.
The poisoned bran bait is very effective.
OTHER STRAWBERRY PESTS
Other insects more or less injurious to strawberries are
Greenhouse whitefly (see under sweet potatoes, page 94) ; leaf-
footed plant-bug (see under potatoes, page 81); and grasshop-
pers (see under general garden pests, page 18) ; webworms (see
under corn) ; and mole-crickets (see page 19).
SUNFLOWER
This common garden annual is severely attacked by plant-
bugs. They first attack the stem of the young plant and when
the head is formed shift their attention to that. They suck the
juices from the forming seeds and continue their attacks until
the seeds are quite mature. By harvest time many seeds are
empty shells, valueless as poultry food. The most common of
these bugs is the leaf-footed plant-bug (see under potatoes, page
81), the pumpkin bug (see under cowpeas, page 61), and the
big-footed plant-bug (see under potatoes, page 80).
Hand-collecting is a comparatively simple matter as the
bugs are massed on the heads of the plants. One should use a
net, or a pan of kerosene. If the pan is held under the head
which is then given a sharp jar, most of the bugs will fall into
the kerosene and be killed.
Other insects attacking sunflowers are: Red spiders (see
under peas, page 77) ; and cutworms (see under cabbage, page
35); and jassids (see under beans, page 26).
Bulletin 232, Truck and Garden Insects
SWEET POTATOES
SWEET-POTATO CATERPILLARS (Prodenia spp.)
Several species of caterpillars are likely to attack this plant,
particularly during August and July. If not combated they
often defoliate an entire field. They are velvety-looking cater-
pillars which belong to the cutworm family but have more of
the habits of army worms as they feed during the day, and
have a strong tendency to collect in colonies so that defoliation
commonly begins in one of two places in a field. Indeed, one
species, Xylomyges eridania (Fig. 54, a) is called "the semi-trop-
ical army worm." The most com-
mon species, Prodenia ornitho- g
galli, is about 2 inches long be-
fore it enters the ground to pu-
pate. (Fig. 54, b.) In color it is
a dark, rich velvety brown, al-
most black. The life history of A
these caterpillars is similar to
that of cutworms.
ControL-The most thorough
method of killing these worms is B
to spray with lead arsenate, us-
ing 1 pound of the powder to 50
Fig. 54.-Sweet-potato caterpillar moths:
gallons of water. Two pounds of a, Xylomyges eridania: b, Prodenia
quick lime added will prevent any onithogai. Natural size. (Original.)
quick lime added will prevent any
burning effects. The spraying should be done in the early morn-
ing so that the spray will evaporate quickly. A cheaper method
is to dust the plants in the early morning when the dew is on
them. For this purpose use a mixture of 1 part of lead or cal-
cium arsenate to from 1 to 3 of air-slaked or hydrated lime.
This can be applied by means of a coarse burlap bag shaken
over the vines, but a better method is to use a dusting machine.
The cheapest method of dealing with the caterpillars and
one that has been entirely successful in many cases, is to poison
them with the Kansas bait; directions for making it are given
under cutworms. (See under cabbage, page 36). The bait
should be put out about sunset or on cloudy days so that it will
not dry out quickly.
Birds, including chickens and turkeys, are very fond of these
caterpillars. They are also attacked by parasitic flies and wasp-
like enemies and preyed upon by true wasps.
Florida Agricultural Experiment Station
FALL ARMY WORM
The fall army worm often attacks sweet potatoes. It is a
smaller, slimmer caterpillar than the sweet potato caterpillar
and control measures are the same. Its description and life
history will be found under corn. (See page 55.)
HORNWORMS
The larvae of several hawk-moths or sphinx-moths, also
called "humming-bird moths" from their habit of hovering
over flowers, often attack sweet potatoes. These do not work
in armies" but they are so large that a few scattered in-
dividuals can do considerable damage and should be collected
by hand. For the life history and enemies of these insects see
under tomatoes, page 101.
GOLDBUGS, OR TORTOISE-BEETLES
These are pretty little beetles which eat holes in the leaves
of sweet potatoes. They are usually common but are seldom
present in sufficient number to be considered a troublesome pest.
Nevertheless, the entire damage amounts to considerable. The
beetles are round to oblong in shape and about 1/4 inch long.
Two species are common in Florida. The more abundant
(Metriona bicolor) is of a beautiful iridescent, golden color.
It looks like a drop of gold against the deep green of the leaf,
on the upper surface of which it is commonly found. The other
(Chirida guttata) has a ground color of duller yellow with a
harp-shaped black pattern stretching completely across the back.
These beetles can be poisoned readily with lead arsenate.
SWEET-POTATO WHITEFLY (Bemisia inconspicua)
This relative of the destructive citrus whitefly is a severe
pest to sweet potatoes especially in the southern part of the
State, particularly to late-planted vines. Farmers in some com-
munities have abandoned the attempt to grow a late crop on ac-
count of the ravages of this pest. With this insect, like all white-
flies, it is the larva which does the damage by sucking the sap
from the leaves. The adult, which is smaller than the citrus
wh tefly, lays her eggs on the under side of the leaves. These
hatch in about a week. The young crawl about until they find a
suitaLle place to insert their probosces or beaks. Having once in-
serted them, they are unable to withdraw and are anchored firm-
ly for the remainder of their larval days. If the beak is pulled out
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