• TABLE OF CONTENTS
HIDE
 Front Cover
 Front Matter
 Table of Contents
 Introduction
 Life history of insects
 Indirect methods of combating...
 Direct methods of combating...
 Collecting by hand
 Insecticides
 General garden insects and...
 Insects and other pests of:
 Roselle and squash
 Acknowledgement
 Index






Group Title: Bulletin - University of Florida Agricultural Experiment Station ; 370
Title: Insects and other pests of Florida vegetables
CITATION PAGE IMAGE ZOOMABLE PAGE TEXT
Full Citation
STANDARD VIEW MARC VIEW
Permanent Link: http://ufdc.ufl.edu/UF00026688/00001
 Material Information
Title: Insects and other pests of Florida vegetables
Series Title: Bulletin University of Florida. Agricultural Experiment Station
Physical Description: 118 p. : ill. ; 23 cm.
Language: English
Creator: Watson, J. R ( Joseph Ralph ), 1874-1946
Tissot, A. N ( Archie Newton ), b. 1897
Publisher: University of Florida Agricultural Experiment Station
Place of Publication: Gainesville Fla
Publication Date: 1942
 Subjects
Subject: Vegetables -- Diseases and pests -- Florida   ( lcsh )
Genre: government publication (state, provincial, terriorial, dependent)   ( marcgt )
non-fiction   ( marcgt )
 Notes
Statement of Responsibility: by J.R. Watson and A.N. Tissot.
General Note: Cover title.
General Note: Includes index.
Funding: This collection includes items related to Florida’s environments, ecosystems, and species. It includes the subcollections of Florida Cooperative Fish and Wildlife Research Unit project documents, the Florida Sea Grant technical series, the Florida Geological Survey series, the Howard T. Odum Center for Wetland technical reports, and other entities devoted to the study and preservation of Florida's natural resources.
 Record Information
Bibliographic ID: UF00026688
Volume ID: VID00001
Source Institution: University of Florida
Holding Location: University of Florida
Rights Management: All rights reserved by the source institution and holding location.
Resource Identifier: aleph - 000925171
oclc - 12335019
notis - AEN5815

Table of Contents
    Front Cover
        Page 1
    Front Matter
        Page 2
    Table of Contents
        Page 3
        Page 4
    Introduction
        Page 5
    Life history of insects
        Page 5
        Page 6
    Indirect methods of combating insects
        Page 7
        Cultural methods
            Page 7
        Destruction of crop refuse and wormy fruit, trap crops, and natural enemies
            Page 8
    Direct methods of combating insects
        Page 9
    Collecting by hand
        Page 9
    Insecticides
        Page 9
        Stomach poisons
            Page 10
            Page 11
            Page 12
        Contact insecticides
            Page 13
            Page 14
            Page 15
            Page 16
            Page 17
        Fumigation
            Page 18
        Heat
            Page 19
    General garden insects and pests
        Page 20
        Grasshoppers
            Page 20
        Mole-crickets
            Page 21
            Page 22
            Page 23
        Moles
            Page 24
        Salamanders and gophers
            Page 25
            Page 26
        Ants
            Page 27
        Vegetable weevil
            Page 28
        White-fringed beetle
            Page 29
        Seed corn maggot
            Page 30
        Root-knot
            Page 31
            Page 32
    Insects and other pests of:
        Page 33
        Bean leaf hopper
            Page 33
            Page 34
            Page 35
            Page 36
            Page 37
        Lima beans
            Page 38
            Page 39
        Cabbage
            Page 40
            Page 41
            Page 42
            Page 43
            Page 44
            Page 45
            Page 46
            Page 47
            Page 48
            Page 49
            Page 50
        Canteloupe, carrots, and celery
            Page 51
            Page 52
            Page 53
            Page 54
        Corn
            Page 55
            Page 56
            Page 57
            Page 58
            Page 59
            Page 60
            Page 61
            Page 62
            Page 63
        Cowpeas
            Page 64
            Page 65
            Page 66
            Page 67
        Cucumbers
            Page 68
            Page 69
            Page 70
            Page 71
            Page 72
        Dasheen and eggplant
            Page 73
            Page 74
            Page 75
        Lettuce, mustard, and okra
            Page 76
            Page 77
        Onions
            Page 78
            Page 79
        Parsley and English peas
            Page 80
            Page 81
            Page 82
        Peppers
            Page 83
            Page 84
            Page 85
        Potatoes
            Page 86
            Page 87
            Page 88
            Page 89
        Radish
            Page 90
    Roselle and squash
        Page 91
        Page 92
        Strawberries
            Page 93
            Page 94
            Page 95
            Page 96
            Page 97
            Page 98
        Sweet potatoes
            Page 99
            Page 100
            Page 101
            Page 102
        Tomatoes
            Page 103
            Page 104
            Page 105
            Page 106
            Page 107
            Page 108
            Page 109
            Page 110
        Turnips and watermelons
            Page 111
            Page 112
            Page 113
            Page 114
    Acknowledgement
        Page 115
    Index
        Page 116
        Page 117
        Page 118
Full Text


Bulletin 370
Bulletin 370


(A Revision of Bulletin 232)


May, 1942


UNIVERSITY OF FLORIDA ,
AGRICULTURAL EXPERIMENT STATION, .
WILMON NEWELL, Director
GAINESVILLE, FLORIDA







INSECTS AND OTHER PESTS OF
FLORIDA VEGETABLES

By J. R. WATSON and A. N. TISSOT


Fig. 1.-Bean leaf-roller: Adult. Natural Size.


Single copies free to Florida residents upon request to
AGRICULTURAL EXPERIMENT STATION
GAINESVILLE, FLORIDA


-Tj^ -







EXECUTIVE STAFF
John J. Tigert, M. A., LL. D., President
of the University3
Wilmon Newell, D.Sc., Director3
Harold Mowry, M. S. A., Asst. Dir.,
Research
W. M. Fifield, M. S., Asst. Dir., Admin.
J. Francis Cooper, M. S. A., Editors
Clyde Beale, A.B.J., Assistant Editors
Jefferson Thomas, Assistant Editor3
Ida Keeling Cresap, Librarian
Ruby Newhall, Administrative Managers
K. H. Graham, Business Managers
Rachel McQuarrie, Accountant3
MAIN STATION, GAINESVILLE
AGRONOMY
W. E. Stokes, M.S., Agronomist1
W. A. Leukel, Ph.D., Agronomist8
Fred H. Hull, Ph.D., Agronomist
G. E. Ritchey, M.S., Associate2
W. A. Carver, Ph. D., Associate
Roy E. Blaser, M.S.. Associate
G. B. Killinger, Ph.D., Associate
John P. Camp, M.S., Assistant
Fred A. Clark, B.S.A., Assistant
ANIMAL INDUSTRY
A. L. Shealy, D.V.M., An. Industrialist'.s
R. B. Becker, Ph.D., Dairy Husbandman'
E. L. Fouts, Ph.D., Dairy Technologists
D. A. Sanders, D.V.M., Veterinarian
M. W. Emmel, D.V.M., Veterinarians
L. E. Swanson, D.V.M., Parasitologist
N. R. Mehrhof, M.Agr., Poultry Husb.a
W. M. Neal. Ph.D., Asso. in An. Nutrition
T. R. Freeman, Ph.D., Asso. in Dairy Mfg.
R. S. Glascock. Ph.D., Asso. An. Husb.
D. J. Smith, B.S.A., Asst An. Husb.'
P. T. Dix Arnold, M.S.A., Asst. Dairy
Husbandmans
L. L. Rusoff, Ph.D., Asst. in An. Nutr.3
L. E. Mull, M.S,, Asst. in Dairy Tech.
0. K. Moore, M.S., Asst. Poultry Hush.
ECONOMICS, AGRICULTURE
C. V. Noble, Ph.D., Agr. Economists,3
Zach Savage, M.S.A., Associate
A. H. Spurlock, M.S.A., Associate
Max E. Brunk, M.S., Assistant
ECONOMICS, HOME
Ouida D. Abbott, Ph.D., Home Econ.'
Ruth Overstreet, R.N., Assistant
R. B. French, Ph.D., Asso. Chemist
ENTOMOLOGY
J. R. Watson, A.M., Entomologist'
A. N. Tissot, Ph.D., Associate
H. E. Bratley, M.S.A., Assistant
HORTICULTURE
G. H. Blackmon, M.S.A., Horticulturist'
A. L. Stahl, Ph.D., Associate
F. S. Jamison, Ph.D., Truck Hort.
R. J. Wilmot, M.S.A., Asst. Hort.
R. D. Dickey, M.S.A., Asst. Horticulturist
J. Carlton Cain, B.S.A., Asst. Hort.'
Victor F. Nettles, M.S.A., Asst. Hort.'
F. S. Lagasse, Ph.D., Asso. Horticulturist2
H. M. Sell, Ph.D., Asso. Horticulturist3
PLANT PATHOLOGY
W. B. Tisdale, Ph.D., Plant Pathologist'.3
George F. Weber, Ph.D., Plant Path.3
L. O. Gratz, Ph.D., Plant Pathologist
Erdman West, M.S., Mycologist
Lillian E. Arnold, M.S., Asst. Botanist
SOILS
R. V. Allison, Ph.D., Chemistl,s
Gaylord M. Volk, M.S., Chemist
F. B. Smith, Ph.D., Microbiologists
C. E. Bell, Ph.D., Associate Chemist
H. W. Winsor, B.S.A., Assistant Chemist
J. Russell Henderson, M.S.A., Associates
L. H. Rogers, Ph.D., Asso. Biochemist
Richard A. Carrigan. B.S., Asst. Chemist
Geo. D. Thornton, M.S., Asst. Chemist
R. E. Caldwell, M.S.A., Soil Surveyor
Olaf C. Olson, B.S., Soil Surveyor


BOARD OF CONTROL
H. P. Adair, Chairman, Jacksonville
R. H. Gore, Fort Lauderdale
N. B. Jordan, Quincy
T. T. Scott, Live Oak
Thos. W. Bryant, Lakeland
J. T. Diamond, Secretary, Tallahassee
BRANCH STATIONS
NORTH FLORIDA STATION, QUINCY
J. D. Warner, M.S. Agron. in Charge
R. R. Kinkaid, Ph.D., Asso. Plant Path.
R. W. Wallace, B.S., Asso. Agron.
Elliott Whitehurst, B.S.A., Assistant An.
Husbandman4
Jesse Reeves, Asst. Agron., Tobacco
W. H. Chapman M.S., Asst. Agron.
CITRUS STATION, LAKE ALFRED
A. F. Camp, Ph.D.. Horticulturist in Chg.
Chas. K. Clark, Ph.D., Chemist
V. C. Jamison, Ph.D., Soils Chemist
B. R. Fudge, Ph.D., Associate Chemist
W. L. Thompson, B.S., Associate Ento.
F. F. Cowart, Ph.D., Asso. Horticulturist
W. W. Lawless, B.S., Asst. Horticulturist
R. K. Voorhees, Ph.D., Asso. Plant Path.
T. W. Young,, Ph.D., Asso. Hort., Coastal
EVERGLADES STA., BELLE GLADE
J. R. Neller, Ph.D., Biochemist in Chg.
J. W. Wilson, Sc.D., Entomologist
F. D. Stevens, B.S., Sugarcane Agron.
Thomas Bregger, Ph.D., Sugarcane
Physiologist
G. R. Townsend, Ph.D., Plant Pathologist
R. W. Kidder, M.S., Asst. An. Husb.
W. T. Forsee, Ph.D., Asso. Chemist
B. S. Clayton, B.S.C.E., Drainage Eng.2
F. S. Andrews, Ph. D., Asso Truck Hort.4
Roy A. Bair, Ph.D., Asst. Agron.
SUB-TROPICAL STA., HOMESTEAD
Geo. D. Huehle, Ph.D., Plant Pathologist
in Charge
S. J. Lynch., B.S.A., Asst. Horticulturist
E. M. Andersen, Ph.D., Asst. Hort.
W. CENT. FLA. STA., BROOKSVILLE
W. F. Ward, M.S., Asst. An. Husband-
man in Charges
RANGE CATTLE STA., ONA
W. G. Kirk, Ph. D., An. Husb. in Charge
E. M. Hodges, Ph.D., Asso. Agron.
Gilbert A. Tucker, B.S.A. Asst. An. Husb.

FIELD STATIONS
Leesburg
M. N. Walker, Ph.D., Plant Pathologist
in Charge
K. W. Loucks, M.S., Asst. Plant Path.
Plant City
A. N. Brooks, Ph.D., Plant Pathologist
Hastings
A. H. Eddins, Ph.D., Plant Pathologist
E. N. McCubbin, Ph.D., Asso. Truck
Horticulturist
Monticello
A. M. Phillips, B.S., Asst. Entomologist'
Bradenton
Jos. R. Beckenbach, Ph.D.. Truck Horti-
culturist in Charge
David G. Kelbert, Asst. Plant Pathologist
Sanford
R. W. Ruprecht, Ph.D., Chemist in
Charge, Celery Investigations
W. B. Shippy, Ph.D., Asso. Plant Path.
Lakeland
E. S. Ellison, Meteorologists
'Head of Department
2In cooperation with U. S.
sCooperative, other divisions. U. of F.
4On leave for military service.


ift ol









CONTENTS
Page
Introduction _--_-- ---_----....._ ------------ 5
Life History of Insects ...---__. .-----------.- ----.--..- 5
Indirect Methods of Combating Insects-----------------..----- 7
Cultural Methods -----..-.-..-- ------------ 7
Destruction of Crop Refuse and Wormy Fruit---_--- -------- 8
Trap Crops -.........------------.--------- 8
Natural Enemies ---------- -------- 8
Direct Methods of Combating Insects ------ ---- 9
Collecting by Hand _9___-__ ---- -----------9
Insecticides --....... _-__- ...------------------- 9
Stomach Poisons ------------------------- --.----- 10
Contact Insecticides ...-------------..---------.---- ---- 13
Fumigation --..------------- 18
Heat .... -----.......... --------_ ---------- 19
General Garden Insects and Pests_ -_- ------ 20
Grasshoppers ....-----...-.... -----------------------------..------ ....20
Mole-Crickets ._-.. _--_- ---- ------- 21
Moles ___-_____--------------- 24
Salamanders and Gophers --. --..---------.....--. 25
Ants ----.. --------...-.-.-------------.. 27
Vegetable Weevil ..- ------------. 28
White Fringed Beetle ----------- .-------29
Seed Corn Maggot --------------------. ------ 30
Root-Knot --- ----------------- 31
Insects and Other Pests of: Beans------- 33
Lima Beans .----. -- --------- ------------------ 38
Beets --_. .....__ ----------.. ------------- 38
Cabbage ----_.. ....-------------.------ .. 40
Cantaloupe -----...--- ----------------------- 51
Carrots --------------------__---- ---------- -------.. 51
Celery ------.......---------------....-- 51
Corn --_..------ ----------. -..---------- 55
Cowpeas ---.. --..-..---------------------..- 64
Cucumbers -.........-----------.-------------------- 68














Dasheen -----------

Eggplant ....-... ....----------

Lettuce -..-_..- ----------....

Mustard ------------.........

Okra ..---...----...- ---------..

Onions -----.... ----...-... .--

Parsley ---..-.....----------.

Peas, English --------__.. ..--

Peppers --..-...... .-------..-.

Potatoes ---- ---------

Radish -__..----- ---.........----

Roselle ..---..--... -----.-

Squash -------.... .. ------..-....

Strawberries -......--

Sweet Potatoes ---..._-... _..

Tomatoes ..-------


Turnips -- --- ...- -- ....... ----------

Watermelons ------------.

Acknowledgements -------------------..

Index .-.-------.... ----.---...---...--------------


Page

--.---------- 75

-..---------------------------------- 75


----- 76
-------------- 76

........ .--- .- 76



.. ---- 78

-..-.....----- 80

-.......------ 80

-........----- 83

------ 86

..------------ 90

....-------.-- -- 91

-..----------- 91

-----.--- 93

------ 99

------ 103


111
-- Ill----

--. 111

........115

----- 116


---------------------------------

---------------------------------

--------------------------------


- --- -- -


--------------

--------------

-------------


------------------

-----------------

-----------------

-----------------

-----------------

-----------------

---------------


-- -- -


.-.


--------------------------

--------------------------

---------------------------

---------------------------

---------------------------

---------------------------









INSECTS AND OTHER PESTS OF
FLORIDA VEGETABLES
By J. R. WATSON and A. N. TISSOT

INTRODUCTION
Commercial vegetable growers and home gardeners will find
in this bulletin a short description, in many cases with an illus-
tration, a brief life history, and a statement of the best known
methods for the control of each insect which commonly causes
trouble. Mites, nematodes, moles, "gophers" and "salamanders"
are also discussed as pests of vegetable crops. Only those in-
sects are considered which attack crops during the season when
they are commonly grown in Florida. The vegetable grower in
this state escapes many insect attacks that trouble the more
northern growers because he raises many of his crops in the win-
ter when insect life is somewhat dormant. This dormancy is due
mostly to the lower temperatures, but in part to the comparative
dryness of the Florida winter. The early fall crops suffer severe-
ly because insect life has been stimulated to rapid development
by the hot, moist summer. Some insects, however, thrive better
in dry weather and they are most troublesome in the spring.
Much of the information in this bulletin is new and is taken
from records of recent experiments by the writers; the remainder
is taken from other publications of this Station, of other
experiment stations, and of the United States Department of
Agriculture.
The truck or garden crops are discussed in alphabetical order.
Under each crop will be found the description and control meas-
ures of the more important insects which attack it. Insects which
commonly attack more than one crop are listed under each one
but are discussed only under the name of the crop on which they
are most commonly found or on which they inflict the most ser-
ious damage.
Under the heading "General Garden Insects and Pests" will
be found discussions of several enemies of the garden in general,
which usually are no more severe on one crop than on another.
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 in-









INSECTS AND OTHER PESTS OF
FLORIDA VEGETABLES
By J. R. WATSON and A. N. TISSOT

INTRODUCTION
Commercial vegetable growers and home gardeners will find
in this bulletin a short description, in many cases with an illus-
tration, a brief life history, and a statement of the best known
methods for the control of each insect which commonly causes
trouble. Mites, nematodes, moles, "gophers" and "salamanders"
are also discussed as pests of vegetable crops. Only those in-
sects are considered which attack crops during the season when
they are commonly grown in Florida. The vegetable grower in
this state escapes many insect attacks that trouble the more
northern growers because he raises many of his crops in the win-
ter when insect life is somewhat dormant. This dormancy is due
mostly to the lower temperatures, but in part to the comparative
dryness of the Florida winter. The early fall crops suffer severe-
ly because insect life has been stimulated to rapid development
by the hot, moist summer. Some insects, however, thrive better
in dry weather and they are most troublesome in the spring.
Much of the information in this bulletin is new and is taken
from records of recent experiments by the writers; the remainder
is taken from other publications of this Station, of other
experiment stations, and of the United States Department of
Agriculture.
The truck or garden crops are discussed in alphabetical order.
Under each crop will be found the description and control meas-
ures of the more important insects which attack it. Insects which
commonly attack more than one crop are listed under each one
but are discussed only under the name of the crop on which they
are most commonly found or on which they inflict the most ser-
ious damage.
Under the heading "General Garden Insects and Pests" will
be found discussions of several enemies of the garden in general,
which usually are no more severe on one crop than on another.
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 in-






Florida Agricultural Experiment Station


sect, 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 more or less
well marked stages and the changes undergone in passing from
one stage to the next are collectively known as metamorphosis.
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. With
such insects, the larva, when it has completed its growth, goes
into the pupal or resting stage. The pupa is enclosed in a rigid
case and is incapable of motion except for a turning and twisting
of the body. No food is eaten during this stage. Such insects are
said to have a complete metamorphosis. In the life history of
others, such as the true bugs, thrips, and grasshoppers, the im-
mature stages, commonly called nymphs, resemble the adult in-
sects but are usually smaller, have no wings and the organs of
reproduction are but partly developed. They have no true pupal
stage but are active and most of them take food in all stages.
During the later nymphal stages the future wings are indicated
by small pads on each side of the body. Such insects are said to
have an incomplete or gradual metamorphosis.
Many kinds of larvae and especially the hairless caterpillars
are often called "worms," although they are very different from
the true worms as represented by earthworms fishwormsms"),
tape-worms, and nematodes.
It is important that one know something of the life history
of insect pests because nearly all insects have some stage in which
they are more easily controlled than at other times. Thus, some
are most easily controlled during the egg stage, others in the
larval, pupal, or adult stages. The control measures given in this
bulletin are designed to take advantage of any vulnerable periods
in the life cycle of the insects concerned.
Insects may be divided according to their method of taking
food into two classes, biting and sucking. 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. In the case of
some insects, for instance moths and butterflies, the larvae may






Insects and Other Pests of Florida Vegetables


have biting mouth-parts, while the adults have mouth-parts of the
sucking type.

INDIRECT METHODS OF COMBATING INSECTS
Ravages of insects may be controlled by either direct or in-
direct methods. Direct methods include the application of in-
secticides or poison baits, hand picking and collecting in pans,
traps, or with special appliances. Indirect methods refer to cul-
tural practices, the use of trap crops, and the protection of the
enemies of insects. Since "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 would be more ex-
pensive 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 modifica-
tions of farm practice may be beneficial to the soil in addition to
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 moisture, add humus to the soil, and stop
the breeding of many insect pests by burying them. Many insects
spend the quiescent or pupal stage in the ground. If the land is
plowed and harrowed many 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 may be buried so
deeply that emergence is impossible.
Cover crops are usually grown on truck land during summer.
A cover crop should be chosen which will not harbor the same
pests that infested the previous crop, and not build up a large
population of pests that may attack the crop that is to follow.
For example cowpeas should not be used as a summer cover crop
on land on which beans will be planted in the fall, as cowpeas and
beans have many insects in common. If the land is permitted to
grow grass and weeds during the summer it often gets thoroughly
stocked with cutworms, white grubs, and a great variety of other
undesirable inhabitants.
Rotation of crops is important from the standpoint of insect
control. If crop after crop of the same plant is grown, there is
likely to be such a serious accumulation in the soil of insect pests






Insects and Other Pests of Florida Vegetables


have biting mouth-parts, while the adults have mouth-parts of the
sucking type.

INDIRECT METHODS OF COMBATING INSECTS
Ravages of insects may be controlled by either direct or in-
direct methods. Direct methods include the application of in-
secticides or poison baits, hand picking and collecting in pans,
traps, or with special appliances. Indirect methods refer to cul-
tural practices, the use of trap crops, and the protection of the
enemies of insects. Since "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 would be more ex-
pensive 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 modifica-
tions of farm practice may be beneficial to the soil in addition to
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 moisture, add humus to the soil, and stop
the breeding of many insect pests by burying them. Many insects
spend the quiescent or pupal stage in the ground. If the land is
plowed and harrowed many 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 may be buried so
deeply that emergence is impossible.
Cover crops are usually grown on truck land during summer.
A cover crop should be chosen which will not harbor the same
pests that infested the previous crop, and not build up a large
population of pests that may attack the crop that is to follow.
For example cowpeas should not be used as a summer cover crop
on land on which beans will be planted in the fall, as cowpeas and
beans have many insects in common. If the land is permitted to
grow grass and weeds during the summer it often gets thoroughly
stocked with cutworms, white grubs, and a great variety of other
undesirable inhabitants.
Rotation of crops is important from the standpoint of insect
control. If crop after crop of the same plant is grown, there is
likely to be such a serious accumulation in the soil of insect pests






8 Florida Agricultural Experiment Station

of that crop as to make its culture unprofitable. Furthermore,
closely related plants should not follow each other in the rotation,
as their insect enemies often are similar.

DESTRUCTION OF CROP REFUSE AND WORMY FRUIT
Wormy fruit should be disposed of, usually by being picked
with the marketable fruit and sorted out at the packinghouse.
Too often it is left in the field. However, if the picking season is
short 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 re-
mainder of the refuse at the end of the season. When harvesting
of the crop is finished the crop residue should be destroyed rather
promptly. This may be done by plowing or disking the land or
in some instances by turning livestock into the field to eat the
refuse. If the plants are allowed to stand until they die they may
breed large numbers of insect pests which will menace the crop
that follows.
TRAP CROPS
The best way to prevent an insect from attacking 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 it is 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 some natural enemies. Some animals prey
on insects in general and others on certain families of insects.
Such animals are often of great value in preventing insect out-
breaks and it is very important that they be protected by vege-
table growers. Many enemies of insects are other insects. With
the exception of wasps, these are not generally molested by man,
but many higher animals which prey on insects are. Insects
make up a large proportion 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.
Most birds are valuable allies of man in the fight against in-
sects and as such merit more rigid protection than is now afforded







Insects and Other Pests of Florida Vegetables


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

COLLECTING BY HAND
Among the direct methods of controlling insects the primitive
one of collecting them by hand may be found the most satisfactory
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 containing a little water covered with a film of kerosene,
or 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
Where large acreages are involved, and for all the smaller
insects, even in small plantings, hand collecting is impractical and
often impossible. Under these circumstances the grower can best
cope with the insects by means of insecticides.
With reference to the use of insecticides, insects may, as
stated previously, be divided into two groups-those that have
biting mouth-parts and chew their food and those that have suck-
ing mouth-parts and get their nourishment by sucking the juices
of their food plants. The kind 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 insects
have jaws or the plant has pieces chewed out of it, the insects
belong to the biting group. If the mouth-parts are in the nature
of a lance or sucking tube, or if the plant curls, wilts, or turns
yellow or is dwarfed, without any external injury other than
small punctures, the insect belongs to the sucking group. It may
be necessary, however, to examine the underground parts of the
plant, as well as those above ground, because injury to the roots
also may cause withering and yellowing of the plant.
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







Insects and Other Pests of Florida Vegetables


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

COLLECTING BY HAND
Among the direct methods of controlling insects the primitive
one of collecting them by hand may be found the most satisfactory
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 containing a little water covered with a film of kerosene,
or 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
Where large acreages are involved, and for all the smaller
insects, even in small plantings, hand collecting is impractical and
often impossible. Under these circumstances the grower can best
cope with the insects by means of insecticides.
With reference to the use of insecticides, insects may, as
stated previously, be divided into two groups-those that have
biting mouth-parts and chew their food and those that have suck-
ing mouth-parts and get their nourishment by sucking the juices
of their food plants. The kind 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 insects
have jaws or the plant has pieces chewed out of it, the insects
belong to the biting group. If the mouth-parts are in the nature
of a lance or sucking tube, or if the plant curls, wilts, or turns
yellow or is dwarfed, without any external injury other than
small punctures, the insect belongs to the sucking group. It may
be necessary, however, to examine the underground parts of the
plant, as well as those above ground, because injury to the roots
also may cause withering and yellowing of the plant.
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







Insects and Other Pests of Florida Vegetables


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

COLLECTING BY HAND
Among the direct methods of controlling insects the primitive
one of collecting them by hand may be found the most satisfactory
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 containing a little water covered with a film of kerosene,
or 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
Where large acreages are involved, and for all the smaller
insects, even in small plantings, hand collecting is impractical and
often impossible. Under these circumstances the grower can best
cope with the insects by means of insecticides.
With reference to the use of insecticides, insects may, as
stated previously, be divided into two groups-those that have
biting mouth-parts and chew their food and those that have suck-
ing mouth-parts and get their nourishment by sucking the juices
of their food plants. The kind 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 insects
have jaws or the plant has pieces chewed out of it, the insects
belong to the biting group. If the mouth-parts are in the nature
of a lance or sucking tube, or if the plant curls, wilts, or turns
yellow or is dwarfed, without any external injury other than
small punctures, the insect belongs to the sucking group. It may
be necessary, however, to examine the underground parts of the
plant, as well as those above ground, because injury to the roots
also may cause withering and yellowing of the plant.
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







10 Florida Agricultural Experiment Station

a contact insecticide-some substance that kills the insects by a
caustic action on their body or by being drawn into their spiracles.
Insects do not possess lungs as do the higher animals, but they
take in air through very small openings in their sides called
spiracles. From these spiracles air is carried to all parts of the
insect's body through a system of small tubes.
Insecticides may be applied to plants in the form of either
liquid or dust. Some can be used both ways while others can be
used only in one form. Where the grower has a choice of either
dusting or spraying the form which he should use will depend
upon his equipment, distance to water, weather conditions at the
time, supply and cost of labor, and other factors.
One of the essentials of satisfactory insect control is the ap-
plication of a suitable insecticide when the insects first appear in
dangerous numbers. If they are allowed to become too numerous
it will not only be more difficult to get a complete cleanup but
they may have caused so much injury that the plants will not
recover even though the insects may be killed.


STOMACH POISONS
ARSENICALS
The stomach poisons in most common use are compounds of
arsenic. The three most used are paris green, lead arsenate, and
calcium arsenate.
Paris Green.-The oldest of the arsenicals, paris green, is not
used as extensively as formerly on truck crops, chiefly because
of its tendency to burn tender foliage. One can diminish this
danger by adding to the solution hydrated lime or the milk ob-
tained from slaking quick lime. A good formula is:
Paris green ..----_------ 1 pound
Lime ---....-------------- 2 pounds
Water _..... ..... .....---------------50 gallons

The lime should be slaked in a little water and then strained
to remove all particles that might clog a spray nozzle; this milk is
then added to the 50 gallons of water. If hard water must be used
for spraying more lime should be used.
Lead Arsenate.-The arsenical now most used on truck crops
is lead arsenate, which is sold as a finely ground powder. It is not
as likely to burn plants as paris green. One pound of the powder
to 50 gallons of water makes a spray about as strong as it is or-







Insects and Other Pests of Florida Vegetables


dinarily necessary to use. Lime should be used as with paris
green.
Lead arsenate can be used also as a dust. It is never used
alone but is mixed with hydrated lime, talc, fullers' earth, flour
or other inert material. The proportions ordinarily used are 1
pound of the poison to 6 or 8 pounds of the carrier. The mixing
must be very thoroughly done so that a uniform product will be
obtained.
Calcium Arsenate.-This arsenical, commonly used on cotton
to combat the boll weevil, can be used on the more hardy truck
crops. Cheaper than lead arsenate, it is more liable to burn tender
foliage. It is lighter, and consequently goes through a dusting
machine more easily. For dusting vegetables calcium arsenate
should never be used alone but should be mixed with some carrier
as suggested for lead arsenate. Because of the danger of burning,
calcium arsenate is not often used in liquid sprays, but when it is
used in this way it is mixed in the same proportions as lead
arsenate.
Magnesium Arsenate.-This arsenical is commonly recom-
mended for the Mexical bean beetle. It is substituted for lead
and calcium arsenate on beans because beans are so easily burned
by these arsenicals. It is used as is lead arsenate.

MIXING LIQUID SPRAYS
In making up any of these substances in sprays the proper
amount should first be mixed in a small amount of water until
all lumps have disappeared and then added to the bulk of the
water. It is necessary 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 cause the insecticide to stick
better. In spraying glossy plants like cabbage this is imperative.
Principal spreaders are:
Milk of Lime.-(See under paris green).
Calcium Caseinate.-This is a commercial product prepared
from skimmilk, and is sold under various trade names.
Flour Paste.-A good spreader can be made by boiling 2
pounds of flour, corn meal, or starch in 2 gallons of water. This
will suffice for 50 gallons of spray.
Bordeaux Mixture.-This common fungicide sometimes 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







Florida Agricultural Experiment Station


with most arsenicals and is a good spreader. This makes a spray
that will control most fungi and biting insects. Nicotine com-
pounds also can be mixed with bordeaux to combat many suck-
ing insects. In mixing these insecticides with bordeaux the bor-
deaux solution takes the place of the water called for in the
formula.
When insecticides are used with bordeaux mixture first mix
the insecticides with a little water and add this solution to the
bordeaux after it is completely made up.

FLOURINE COMPOUNDS
Because the arsenicals are poisonous to man and the higher
animals, much work has been done in an attempt to find sub-
stitutes for them that will be safer to use on plants that are to be
used for food. For a time it was thought that the fluosilicates and
fluorides could be substituted for arsenicals on parts of plants
which were going to market, but thorough research has indicated'
that these compounds may be as injurious to health as arsenicals
and the restrictions on their use are fully as severe. For this
reason they are not in general use, although they are used on
special crops where for some reason or other arsenicals are not
advisable.
Various compounds of fluorine have been tested for use as in-
secticides but the fluosilicates have been most generally used.
Unlike the arsenicals, most fluorine compounds cannot be used
satisfactorily as liquid sprays. Sodium fluosilicate was first used
as a control for the Mexican bean beetle. For use as a dust 1 part
of the powder is mixed with 4 or 5 parts of hydrated lime or other
carrier. Calcium fluosilicate has been used in much the same way
but it has generally proven less satisfactory than the sodium.
Barium fluosilicate and natural cryolite are the compounds of
fluorine that have proven most efficient as insecticides. Gener-
ally they are sold under trade names and are ready to apply. In
some cases it is necessary to add a carrier or diluting agent and
one should always follow the directions given by the manu-
facturer for applying the insecticide. Under certain conditions
the fluorine insecticides seem a little more likely to burn tender
vegetation than do the arsenicals.

ROTENONE
On parts of the plants which are to be marketed, when ar-
senicals and fluorine compounds cannot be used, rotenone com-






Insects and Other Pests of Florida Vegetables 13

pounds may be substituted. Though they are not as efficient in
killing insects and are somewhat more expensive, when used on
plants they are not poisonous to man and higher animals and for
that reason there is no objection to their presence on vegetables
or fruits going to market.
Rotenone is a toxic substance found in the roots of many
plants. The commercial product is extracted chiefly from derris
and cube, two tropical leguminous plants. Derris is grown prin-
cipally in the East Indies and cube is produced in South America.
The crushed roots of these plants were formerly used by the
natives of the regions where they grow as poisons to stun fish so
they could more easily be captured. This practice led entomolo-
gists to investigate their possibilities as insecticides.
Rotenone insecticides are best known as contact insecticides
but recent work has shown that they also have a definite stomach
poison action. The insecticides containing rotenone are marketed
for use as liquid sprays or as dusts. The spray materials consist
of root extract combined with some spreading agent that will
cause them to mix easily with water. The dusts usually consist of
the finely ground roots, with or without the addition of a carrier,
though some dusts are made by adding rotenone extracts to some
inert ingredient. There are a great many commercial brands of
rotenone insecticides which vary greatly in their rotenone con-
tent and in using them one should carefully follow the directions
given on the container in which they are purchased.
CONTACT INSECTICIDES
Nicotine.-This is one of the most common contact insecti-
cides used against small and delicate insects. It is also one of the
safest, for in excessive dosages only is there any danger of burn-
ing tender plants. Nicotine is sold in several forms. That most
commonly used is a concentrated nicotine sulfate containing 40
percent of nicotine. It may be used either in liquid sprays or
mixed with hydrated lime as a dust.
When used as a spray it should be mixed with a spreader,
since the nicotine alone in water will not wet the insects well and
a poor kill usually will result. Soap is the spreader most com-
monly used. Fish oil soap ("whale oil") is the form most used,
but any cheap alkaline laundry soap or powdered soap will do.
Washing powders composed mostly of soda are unsatisfactory.
From 1 to 3 pounds of soap per 50 gallons of soft water is suffi-
cient; more soap is necessary for use with hard water. Soap






Florida Agricultural Experiment Station


should never be used in a spray which contains an arsenical, since
soap renders some of the arsenic soluble and this is almost cer-
tain to burn tender plants. When spraying with bordeaux mix-
ture for control of fungous diseases the nicotine may simply be
added to the bordeaux.
Within the past few years there have been placed on the mar-
ket a number of new spreaders which are much more effective
than ordinary soap. Among the better known of these are so-
dium oleate and potassium oleate. They are made in semi-solid
and liquid forms and are sold under various trade names. The
liquid form is preferable for use in sprays, since it mixes readily
in cold water. Others of the newer spreaders are oil derivatives.
The principal advantage of these spreaders is that by their
use the nicotine can be used at much greater dilutions than is
possible with soap. With some of them the nicotine can be re-
duced to a dilution of 1 part to 3,000 of water and still give good
control of aphids. Since the spreaders cost less than the nicotine
which they replace, their use will materially reduce the cost
of the spray.
Nicotine sulfate-lime dust is the most widely used of the
nicotine bearing dusts. For small insects, such as aphids, a 3%
dust is effective if weather conditions are satisfactory. A dust of
this strength can be
purchased from
most dealers in in-
secticides or it can
be made by the
grower himself. To
obtain a dust of this
strength 7' pounds
of 40% nicotine sul-
fate is thoroughly
mixed with 92y'
pounds of hydrated
lime. A satisfactory
type of home mixer
made from a wood-
en barrel is illus-
trated (Fig. 2). A
tightly fitting door
about eight inches
Fig. 2.--Barrel mixer for making dusts. square is placed in







Insects and Other Pests of Florida Vegetables


one end or side of the barrel for filling and emptying. It is
essential that each lime particle carry a little of the nicotine;
consequently the mixing must be done very thoroughly. To facil-
iate mixing, about a peck of small rounded stones or a few short
lengths of heavy chain should be placed in the barrel with the
dust ingredients. Unless the dust is to be used at once it should
be stored in tight containers, since it quickly loses its strength on
exposure to the air.
The addition of a pound of ammonium sulfate or a pint of
liquid ammonia to 100 pounds of this mixture will hasten the kill
of insects. The ammonia 'has a stimulating effect on the insects,
increasing the rapidity of their breathing, so that the nicotine
fumes act upon them more quickly.
There is now on the market a product containing 50 percent
of nicotine in the form of free nicotine dissolved in water. The
price per unit of the nicotine is about the same as in nicotine
sulfate. By the use of free nicotine one can make a considerably
cheaper dust because this nicotine is so quickly volatile. A 2
percent dust has been found effective, and so instead of 72
pounds of nicotine sulfate in 92 2 pounds of hydrated lime, 4
pounds of 50 percent free nicotine are added to 96 pounds of lime.
Some types of dusters are so constructed that these materials
can be mixed in the hopper. Such machines avoid a considerable
loss in nicotine which occurs when the dusts are transferred from
the mixing machine to the hopper of the duster. By the use of
this self-mixing duster the amount of nicotine can be consid-
erably reduced.
For small acreages where limited quantities of dust are
needed the saving in cost may hardly justify the trouble of mixing
the dust at home but when large quantities are used home mixing
will result in an appreciable saving in expense.
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 as a repellant. They stick better if applied when the plants
are wet with dew or rain. Twenty-five pounds of finely ground
tobacco dust can be mixed with 75 pounds of the nicotine sul-
fate-lime dust without appreciably reducing its efficiency. This
reduces the cost of the dust.
To get a good kill of insects with nicotine dusts it is quite
important that favorable weather conditions exist at the time the






Florida Agricultural Experiment Station


application is made. Low temperature retards the action of the
nicotine and one should not attempt to dust if the temperature
is below 70 degrees Fahrenheit. It is essential that the air be
quiet when the dust is applied or a poor kill will result. If there
is a perceptible breeze the dust will drift away from the plants
so quickly that many of the insects will escape. When a power
duster is used the discharge nozzles can be enclosed in a cover
made of waxed muslin or similar material which will confine the
dust and prevent it from drifting away so quickly. This cover
may be extended behind as a long trailing sheet which will keep
the dust in contact with the plants for a longer time. This ar-
rangement cannot be used on some crops, but where it can be
used it greatly increases the effectiveness of the dust.
Pyrethrum.-This is the name commonly given to certain
species of Chrysanthemum grown principally in Dalmatia and
Japan, and the finely ground dried flower heads of these plants.
The powdered flowers, and extracts containing their active agents
known as pyrethrins I and II, are much used in contact insecti-
cides. Pyrethrum powder mixed with talc, sulfur, or other car-
rier and used as a dust is very effective in controlling many suck-
ing insects as well as some of the smaller chewing insects. Lime
should not be used as a carrier with pyrethrum, since it quickly
destroys the pyrethrins and renders the dust ineffective. Extracts
containing pyrethrins I and II as generally sold are combined
with miscible oils, soaps, or other spreaders. For use as liquid
sprays it is necessary only to mix them with water. Commercial
pyrethrum products which are sold under many different trade
names contain varying proportions of the toxic agents, so
one should make up the spray according to directions on the con-
tainer.
Though the pyrethrins are very toxic to most insects they are
not at all harmful to human beings and warm blooded animals,
in amounts likely to be found on sprayed or dusted plants. The
pyrethurm insecticides are more expensive than nicotine com-
pounds but they have the advantage of killing many insects, such
as the bean leafhopper, blister beetles, young grasshoppers,
strawberry pameras, and others which are killed with difficulty
if at all with nicotine.
Rotenone.-Rotenone, the active agent in the roots of derris
and cube, is discussed under stomach poisons but it is also much
used as a contact insecticide. The action of rotenone is similar
to, though slower than, that of the pyrethrins. Against most in-






Insects and Other Pests of Florida Vegetables


sects rotenone is much more toxic than the pyrethrins but in some
cases the reverse is true.
Aliphatic Thiocyanates.-Within the last few years there have
been placed on the market synthetic compounds known as ali-
phatic thiocyanates. Though still somewhat in an experimental
stage they appear to have a specific toxicity to certain pests, such
as spider-mites, mealybugs, and thrips. They are harmless to
human beings and warm blooded animals. They are somewhat
more likely to cause injury to plants than are the nicotine, pyre-
thrum and rotenone sprays.
Sulfur.-This is an excellent material for use against members
of the spider tribe, especially red spiders and other mites. On
vegetable crops sulfur usually is put on as a dust, since the lime-
sulfur spray commonly used on citrus trees is not safe on many
truck crops. As a dust, sulfur is commonly mixed with about 5%
of lime to lighten it and allow it to go through a dusting machine
better. This lime must be omitted if the sulfur is to be combined
with pyrethrum compounds, where the lime is not needed any-
way, since the pyrethrum itself adds lightness to the dust mix-
ture. Sulfur is sometimes mixed with tobacco dust. This makes
a good dust for strawberries and other plants growing close to
the ground. The more finely ground the sulfur is, the better. The
kill is produced by the volatilization of the sulfur, and this pro-
cess goes on more rapidly when the particles are extremely small.
Kerosene Emulsion.-Kerosene emulsion is an old remedy
for sucking insects. It will kill some insects which are resistant
to weaker insecticides, but unless made and applied carefully it
is likely to burn tender foliage. The stock solution is:
Hard soap --- ------ --------- pound
Hot water (soft) .......------- 1 gallon
Kerosene (coal oil) ..---.- ---_--- 2 gallons
Shave the laundry soap into the soft water which should be
near the boiling point and stir 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 by forcing it through
a spray nozzle at rather high pressure two or three times, or until
a smooth, creamy mixture is formed. If this is done properly no
free oil will collect on the surface when the solution cools.
For vegetable crops, the solution should be diluted with 10
to 15 parts of water, depending on the insect to be killed and the
tenderness of the plants. The 1 to 15 dilution will kill most aphids
and certain other soft-bodied insects.






Florida Agricultural Experiment Station


Soap.-Soaps are used mostly as spreaders for contact in-
secticides but soaps alone, when dissolved in water at sufficient
strengths, have some value as contact insecticides. Fish-oil soaps
have been most widely used but they cannot always be obtained
readily and ordinary laundry soaps or soap powders are nearly as
effective. The higher priced toilet soaps are least effective as in-
secticides and their use is not recommended. Some of the com-
mercial soaps made from pine oil or pine tar have superior in-
secticidal properties. Some of these are now made in liquid form
which facilitates mixing them with water.
One pound of soap to eight gallons of soft water or six gal-
lons of hard water will give fairly good control of aphids and
other small, soft-bodied insects. Stronger solutions will increase
the killing power of the spray but little and will very likely injure
tender plants.
FUMIGATION

Vegetable growers ordinarily will use fumigation only for
killing insects and other pests in the soil and in bins or cribs
where seeds or other plant products are stored. Fumigation,
however, often is also the most effective method of controlling,
ants about seedbeds and insects in stored seed.
Carbon Bisulfide.-This is one of the older fumigants and, all
things considered, still remains about the most satisfactory ma-
terial for fumigating seeds, feeds, and other stored products. It
is easily obtained, is a uniform product, penetrates well, does not
injure the germinating power of seeds when properly used, and is
not particularly poisonous to human beings and the higher ani-
mals. The only serious objection to its use is that it is inflam-
mable and its fumes when mixed with air are highly explosive.
Carbon bisulfide also is valuable for killing certain kinds of soil-
inhabiting pests.
Carbon bisulfide is a highly volatile liquid which quickly va-
porizes on exposure to the air. The fumes are slightly heavier
than air and tend to settle into and penetrate to the bottom of a
bin of grain or other seeds. The bin or crib must be perfectly
tight and any cracks or small openings should be sealed before
the liquid is applied. The usual dosage is one pound to each 100
cubic feet of space to be fumigated. It is desirable that the gas be
given off as rapidly as possible so the necessary amount of the
liquid is poured into shallow pans placed on top of the pile of
corn or grain. An even better way to apply the liquid is to pour







Insects and Other Pests of Florida Vegetables


it on burlap sacks which are hung on a line above the grain, or
simply spread over the surface of the pile. After applying the
liquid the bin should be kept closed for 24 hours, after which it
should be opened and allowed to air out if the seed is to be used
for planting. If the seed is intended for some other purpose than
for planting, the bin may be kept closed for 48 hours or longer. A
barrel or oil drum makes an excellent container in which to fumi-
gate small quantities of seeds. An ounce of carbon bisulfide is
the proper dose for fumigating a 50 gallon barrel.
In using carbon bisulfide one should always keep in mind its
inflammability and be very careful to keep away all flames or
sparks as long as a perceptible odor of the gas remains.
Carbon Tetrachloride.-This material is sometimes used as a
substitute for carbon bisulfide. It is non-inflammable and non-
explosive and therefore safer from that standpoint, but it is less
toxic to insects.
A somewhat better fumigant consists of 1 part of carbon
tetrachloride and 3 parts of ethylene dichloride used in the same
manner as carbon bisulfide. The usual dosage is 12 pounds of the
mixture to 1,000 cubic feet, and it usually is exposed for 24 hours.
Tobacco.-Tobacco is used as a fumigant in greenhouses and
other closed places. Tobacco stems and refuse may be used. The
material is set on fire and the fumes of nicotine given off in the
burning will kill all tender insects in the space. The tobacco stems
are moistened so that they will smoulder and smoke but produce
no flames.
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, except when used in
very large amounts and for long exposures.
Paradichlorobenzene.-This material has been used for many
years in the control of peach tree borers. It is sold under several
trade names and is often known as PDB. It is an excellent mate-
rial for protecting seeds from insect attacks and will not affect
the viability of the seed unless used in very large amounts and in
very tight containers.
HEAT
A temperature of from 120 to 130 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 F. from 20 to 30






20 Florida Agricultural Experiment Station

minutes, insects in it will be killed and the germinating power
of the seeds will remain unimpaired. Temperatures above 130"
are liable to destroy the germination of many seeds.

GENERAL GARDEN INSECTS AND PESTS
There are a number of insects and other pests that attack
practically all garden crops. In order to avoid unnecessary repe-
tition they are discussed here collectively instead of under each
specific crop.
GRASSHOPPERS
These insects are particularly destructive 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 adult stages, flock to the farmers' crops.
There are many genera and species of grasshoppers. One of
the most common and troublesome is the red-legged grasshopper.
This is one of the smaller kinds but it makes up in numbers what
it lacks in size. In some sections the lubberly locust is often
troublesome. This is the largest grasshopper in Florida. The
newly hatched young are of a reddish-brown color but when they
are a day or two old they turn black with reddish markings, which
become yellow in the later stages. There are two color-forms of
the adults. Some are of a striking yellow color with reddish,
brown, and black markings and others are almost as black as the
young. These grasshoppers have very short wings and are inca-
pable of flight. The hind wings are bright red bordered with
black.
Grasshoppers lay their eggs in the ground in waste places at
a depth of one or two inches. Cultivation destroys many of the
eggs when they are laid in cultivated ground; consequently it is in
small fields surrounded by waste land that grasshoppers are most
troublesome. As the amount of land under cultivation in a neigh-
borhood increases, these insects become less of a pest.
Control.-Birds, including domestic fowls, especially turkeys,
are very fond of most grasshoppers, but the lubberly locust is dis-
tasteful to all birds and is not eaten. 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 in most vegetable
plantings and probably would do more harm than good.
The cheapest and most direct method of dealing with grass-
hoppers is by means of poisoned baits, of which the so-called






20 Florida Agricultural Experiment Station

minutes, insects in it will be killed and the germinating power
of the seeds will remain unimpaired. Temperatures above 130"
are liable to destroy the germination of many seeds.

GENERAL GARDEN INSECTS AND PESTS
There are a number of insects and other pests that attack
practically all garden crops. In order to avoid unnecessary repe-
tition they are discussed here collectively instead of under each
specific crop.
GRASSHOPPERS
These insects are particularly destructive 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 adult stages, flock to the farmers' crops.
There are many genera and species of grasshoppers. One of
the most common and troublesome is the red-legged grasshopper.
This is one of the smaller kinds but it makes up in numbers what
it lacks in size. In some sections the lubberly locust is often
troublesome. This is the largest grasshopper in Florida. The
newly hatched young are of a reddish-brown color but when they
are a day or two old they turn black with reddish markings, which
become yellow in the later stages. There are two color-forms of
the adults. Some are of a striking yellow color with reddish,
brown, and black markings and others are almost as black as the
young. These grasshoppers have very short wings and are inca-
pable of flight. The hind wings are bright red bordered with
black.
Grasshoppers lay their eggs in the ground in waste places at
a depth of one or two inches. Cultivation destroys many of the
eggs when they are laid in cultivated ground; consequently it is in
small fields surrounded by waste land that grasshoppers are most
troublesome. As the amount of land under cultivation in a neigh-
borhood increases, these insects become less of a pest.
Control.-Birds, including domestic fowls, especially turkeys,
are very fond of most grasshoppers, but the lubberly locust is dis-
tasteful to all birds and is not eaten. 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 in most vegetable
plantings and probably would do more harm than good.
The cheapest and most direct method of dealing with grass-
hoppers is by means of poisoned baits, of which the so-called







Insects and Other Pests of Florida Vegetables


"Kansas formula" is the one most used. It has proven very satis-
factory wherever tried. The bait contains the following in-
gredients:
Bran ----.........- -----......... 25 pounds
Paris green or white arsenic (oxide)-- 1 pound
Water ---. __ __ ._about 2% gallons
Lemons, oranges, or cantaloupes ___ 3 or 4
Syrup (blackstrap molasses is good)_-- 2 quarts

The paris green and bran are thoroughly mixed together
while dry. The lemons or other fruits are grated or chopped fine
and the whole mass-rind, pulp, and juice, together with the
syrup-is added to about half of the water. This liquid is slowly
added with constant stirring to the bran-paris green mixture. The
mixing is continued with the addition of water until the whole
mass is thoroughly damp but not sticky. It should be of such con-
sistency that it will fall apart in small flakes when scattered
broadcast over the land.
Grasshoppers are inactive and do not feed at night so the
best time to apply the bait is very early in the morning, before
sunrise if possible. The bait will be fresh and attractive when
the grasshoppers begin to move about and feed and most of them
will eat sufficient of the poison to be killed.
If the bait is not too damp and is scattered thinly over the
land the danger of poisoning chickens, other domestic animals,
or wild birds is negligible. Ordinarily there will be no danger
to chickens or other fowls eating the dead grasshoppers.
The above formula will make enough bait to treat from two
to five acres, depending on the amount of vegetation on the land,
the severity of the grasshopper infestation and other factors.

MOLE-CRICKETS
These insects in general body form are cylindrical like or-
dinary field crickets but they are quite different in color. They
vary from tan to light brown, with the fore wings and the middle
portion of the body darker brown. The front legs are enlarged
and much flattened and admirably fitted for burrowing in the
soil. Mole-crickets are seldom seen because they are hidden in
their burrows underground during the daytime and come to the
surface to feed only at night. They eat various kinds of tender
vegetation and are particularly destructive in seedbeds and gar-
dens. They make numerous runways just beneath the surface of
the soil. These resemble the runways of moles except that they






22 Florida Agricultural Experiment Station

are very much smaller. In making their burrows the mole-
crickets loosen and break off the roots of seedling plants and in
this way kill more plants than they actually eat.
There are at least three native species
of mole-crickets (Fig. 3) that are some-
what destructive in truck patches, es-
pecially in low ground where there is
considerable decaying organic matter. In
addition, the West Indian mole-cricket
or changea" (Fig. 4) is very troublesome
in many sections of the state. This insect
is commonly found on the higher and
S drier soils where other species are rather
scarce.
Control.-Mole-crickets may be kept
out of seedbeds by means of a screen
floor. At the time the seedbed is made,
dig out the earth to the depth of a foot
or so and place in the bottom a continuous
,layer of galvanized or copper wire screen


Fig. 3.-Native mole-cricket, and replace the
Natural size. soil. It should

bend up and the sides should project a
couple of inches above the surface of the
ground.
Plants set out in the field may be
protected by banding them. For this
purpose, melt the tops and bottoms off
of tin cans such as one quart oil cans
and place one of the resulting cylinders
over each plant, sinking it into the earth
to about half its depth. Instead of tin
cans, tarred paper may be used, but this
is more difficult to handle.
Like other insects which live in the
ground, mole-crickets may be killed by
carbon bisulfide. Sink into the infested


Fig. 4.-"Changa" or West
Indian mole-cricket. Nat-
ural siz. (Porto Rico
Exp. Sta.)


garden several holes to the square yard. These can be made with
a cane if the soil is 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







Insects and Other Pests of Florida Vegetables


plants or they also will be killed. Carbon bisulfide vaporizes
very rapidly and the fumes when mixed with air are highly in-
flammable, so one should keep away all fire or flames while it is
being used.
Another and cheaper liquid which can be used in the same
manner is a solution of sodium cyanide in water. An ounce of the
cyanide to two gallons of water gives a solution of suitable
strength. Two ounces of calcium cyanide flakes or granules can
be used also. Remember that the cyanides are poisonous to
human beings and they may injure plants with which they come
in contact.
If the garden is known to be infested at planting time it
should be treated before it is planted. 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, water it thoroughly and leave it over-
night. The following morning the presence of mole-crickets will
be revealed by their burrows and by little piles of soil freshly
thrown up. Wherever such signs are seen, punch a hole to the
depth of a few inches and pour into it a fluid ounce or two of
sodium cyanide solution or a teaspoonful of carbon bisulfide. Re-
peat the operation daily, 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 poultry and
especially turkeys to follow the plow, for they are very fond of
these insects. Pasture hogs on the field when possible and they
will dig out and eat many of the crickets. When mole-crickets
are flying during March or April (they do not fly much at other
seasons) great numbers of them can be caught in light traps.
Suspend a lantern in the field and place under it a tub of water
on the surface of which there is a thin layer of kerosene.
Where large areas are infested the most effective method of
controlling mole-crickets is by means of a poison bait made sim-
ilar to the grasshopper bait mentioned some pages back. In some
cases the substitution of laying mash for the bran has increased
the efficiency, although increasing the cost. This is also an effec-
tive bait for cutworms. An effective and even cheaper bait con-
sists of 10 pounds of calcium arsenate to 100 pounds of wheat bran,
thoroughly mixed, and moistened with water. Because mole-
crickets come to the surface only at night, the bait should be ap-
plied late in the evening. They do not come above ground when






Florida Agricultural Experiment Station


the soil is dry, so one should put out the bait just after a rain if
possible.
A bait which has proved very effective in backyard gardens,
though it is probably too expensive for any large scale use, is
made by mixing an ounce of paris green with a can of dog food
containing meat scrap. These are not easily mixed and one will
have to work hard at it for several minutes until the green color
is evenly distributed throughout the mass. The poisoned mixture
is then put out in small pellets in the runways of the mole-
crickets or scattered between the rows of plants. If domestic
animals are loose in the neighborhood it will be necessary to put
out the bait in very small pellets that are not easily picked up.
Another safe method is to place a board or brick over the bait
pellets. Baits will remain attractive longer and hence prove
more effective, especially in dry weather, if buried to a depth of
an inch or two in the soil. Baiting seems to be most effective in
the fall, with spring months second best.

MOLES
Moles are a nuisance in lawns and gardens because of the ex-
tensive tunnels they make beneath the surface of the soil. They
make two types of tunnels. One is the feeding tunnel which is
but a few inches below the surface of the ground. The other is
located much deeper, a foot or more below the surface, and is of
a more permanent nature. This is the main highway for the
moles in going from one part of their range to the other. In
making their tunnels they break off the roots of plants and cause
the soil over the tunnels to dry out. Contrary to common opinion,
they do not feed extensively on garden crops but are mostly in-
sectivorous in their diet. The prevalent idea that moles feed
largely on the roots of plants arises from the fact that their run-
ways are commonly used by field mice which do the damage.
Moles are fond of cutworms, earthworms, mole-crickets, and
"white grubs" which are the larvae of May beetles or June bugs.
The white grubs and cutworms are most abundant on land that
has been allowed to grow up in grass during the summer.
The first step in fighting moles is to get rid of the insect
larvae, for moles will not frequent a place where there is no food.
This can be done by raising some cover crop such as cowpeas,
velvet beans or crotalaria on the land to keep down the grass
during the summer, and also by turning pigs on the land for a few






Insects and Other Pests of Florida Vegetables


weeks before the garden is plowed. (See white grubs under
potatoes, page 88, for further suggestions.)
Control.-Moles may be discouraged from burrowing in the
garden by tramping the soil solidly into their runways or crowd-
ing a brick or stone into it where it enters the garden from the
outside. Stopping up the runways will discourage the mice as
well as the moles. 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. If a mole is found at
work it can at once be dug out.
There are several makes of mole traps on the market and
moles may be trapped by uncovering their main runway and
placing a trap in the opening. Some traps must be weighted
when they are used in dry sandy soil to keep them from jumping
out of the ground when sprung, and thus allowing the mole to
escape.
In the home 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 coated with white arsenic, paris green, or strychnine.

SALAMANDERS AND GOPHERS
In Florida two burrowing animals occasionally damage vege-
table and other garden crops. One, a small brown mammal, re-
sembles and is rather closely related to the pocket-gopher of the
West. It is commonly called a "salamander" in Florida. The
other, a large dull colored box turtle, is popularly called a
"gopher." The late C. C. Goff of this Station did considerable
work on these two animals and the information given here is
largely taken from his work.
"Salamanders" do not occur everywhere in Florida but are
generally abundant in areas having deep, well drained soils.
Apparently each animal has an individual burrow. The burrow
consists of winding, branching tunnels which run through the
soil at depths of a few inches to over three feet. The burrow is
from two to three inches in diameter and it may extend for
hundreds of feet. The "salamander" in digging its burrow dis-
poses of the excess soil by throwing up mounds of loose earth at
irregular intervals along its tunnel. These animals feed on the
roots of many plants and they are especially fond of sweet pota-
toes and peanuts. They also like tender vegetables and will often
pull whole plants into their burrows.






Florida Agricultural Experiment Station


Trapping is the most effective method of dealing with "sala-
manders." Goff's description of the procedure in trapping them
follows: "Locating a group of mounds, their arrangement is in-
spected to estimate the probable course of the main burrow.
Then selecting one of the fresher mounds, the sand is scraped off
level with the ground. Somewhere on the surface thus exposed
there will usually appear an area of lighter colored sand than
the rest; this is the plug of sub-surface soil filling the lateral tun-
nel that led to the mound. Digging back along this plug with a
trowel, or preferably a light trenching spade, its course can
usually be traced without difficulty until it enters the light-
colored subsurface soil. From this point on it is harder to follow
because the contrast in color between the plug and the surround-
ing soil is lost. At this stage of the work it is often helpful to test
the face of the excavation by pressing it with the finger; the plug
is usually less compact than the undisturbed soil around it. If
the plug can be traced it will eventually lead to an open burrow;
but if it makes a sudden turn to one side or downward it may
easily be lost. Even when this has happened the burrow can
often be found by digging a few feet farther in the same general
direction, and deepening the trench to two or three feet. If this
fails, time is usually saved by trying another mound.
"The hole intersecting the burrow is enlarged until the ends
of the tunnel open squarely into it. The pit should not, however,
be made larger than necessary, for it must later be covered
tightly with paper. If a trench leads into one side of the pit it
should be filled up level with the ground to complete the pit-wall.
"In each of the tunnel-mouths a pocket gopher trap is set,
and firmly staked or tethered if the trap is so constructed that it
might be dragged back into the burrow. The edges of the pit are
then smoothed off and the top is covered with a piece of heavy
wrapping paper or with several thicknesses of newspaper, around
the edges of which sand is heaped."
Boards or a piece of old metal roofing may be used in place
of paper to cover the hole that was dug into the burrow. If regu-
lar gopher traps are not available the smallest size steel trap will
do fairly well.
The "gopher" or burrowing turtle makes a large open burrow
which slopes gradually into the ground. Their food consists en-
tirely of vegetable matter and they are capable of doing con-
siderable damage' when their burrows are located in or near gar-
dens or fields of vegetables. These animals are most easily







Insects and Other Pests of Florida Vegetables 27

controlled by throwing into their burrows pieces of corn cob
which have been soaked in carbon bisulfide. The cobs should
be broken into pieces about two inches long that will roll easily
to or near the bottom of the burrow. Two or three pieces in each
burrow are usually sufficient. After putting in the pieces of cob,
the mouth of the burrow should be filled with soil. The middle
of the day is a good time to treat the burrows since the gophers
usually are in them at that time. They feed mostly in early
morning and late afternoon. Freshly dug earth at its mouth and
tracks leading into it are good indications that a burrow is in-
habited by a "gopher."
ANTS
Ants constitute one of the nuisances with which gardeners
and vegetable growers have to contend. The amount of damage
they do depends to a large extent on the species concerned. Most
species feed only to a limited extent on growing vegetables, but
some seem to object to the presence of vegetation about their
nests. This is particularly true of the large, brownish-yellow
agricultural ants which keep a space many feet in diameter about
their nests absolutely free of vegetation. The leaf-cutting ants,
found more commonly in the southern part of the state, cut off
and remove to their nests, piece by piece, 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. Ants were
the first mushroom growers. They sometimes cover up plants
by building mounds over them.
One of the most annoying habits of ants is that of carrying
away seeds from seedbeds. They are particularly fond of lettuce
and romaine seed. They use the seeds for food and begin to carry
them to their nests as soon as the seeds are planted and may con-
tinue their pernicious activities all through the germination pe-
riod and until the young seedlings have used up all of the material
in the seeds.
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 ants will tend those insects, sometimes driv-
ing away their enemies and more commonly carrying these pests
from one plant to another.
Control.-Ants are easiest destroyed in their nests and carbon
bisulfide is about the best material available. With a sharp stick
punch holes to the depth of a foot or more in the ant hill and pour
into each a tablespoonful or two of the liquid. The number and






Florida Agricultural Experiment Station


depth of the holes will depend upon the size of the nest., As soon
as the liquid has been poured in cover the holes with dirt and
tramp it solid. The gas given off will penetrate tlhe 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. Some ants will probably escape the first treatment.
These, however, will 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 contrast to their feverish activity
of the previous day. The survivors will probably, in the course of
a few days, start small new nests in the vicinity. These in turn
may be treated and destroyed.
The following formula, first used at the Potter Palmer Estates
to drive away ants that had their nests at the base of citrus trees,
has been found effective for use with the hardier vegetables:
Crude carbolic acid ___ ---_______----.1 pint
Fish oil soap 1--___- ___----- -- 1 pound
Water __-........................------ ---..---. 3 gallons
The fish oil soap is dissolved in a quart of water which should
be heated to facilitate mixing. If fish oil soap cannot be obtained
readily, ordinary laundry soap may be substituted, though it is
not quite as good. Add the carbolic acid slowly to the soap solu-
tion, stirring all the while. Emulsify the mixture by forcing it
through a spray nozzle several times until a smooth creamy con-
sistency is produced. The emulsion is then added to the water and
thoroughly mixed with it by stirring vigorously. A small amount
of the diluted mixture is poured at the base of each plant where
an ant nest is found.
Another mixture which has been used in repelling ants from
the bases of plants like strawberries is made by dissolving half a
teaspoonful of cresol in a gallon of water.
VEGETABLE WEEVIL
This weevil (Fig. 5) (Listroderes obliquus Gyll.) which is very
destructive to a large number of vegetable crops, has invaded the
northernmost tier of Florida counties from the west.
The adult insect is about 5/16 inch long, and varies in color
from light brown to dark brown. There are several small light
gray or yellowish markings with a large spot on each side near
the end of the wing covers. The head is prolonged into a short
broad snout (Fig. 6), and the mouthparts are at the end of this







Insects and Other Pests of Florida Vegetables


structure. The adults feed on the foliage of plants and cause
some damage but this is usually slight. The grubs or larvae live
in or above the soil and feed upon the roots of practically all
vegetables as well as many
*1';* weeds and other wild plants.
: .' They are particularly fond of
turnips, carrots and Chinese
cabbage.













Fig. 5.-Dorsal view of the vegetable Fig. 6.-Head and prothorax of the vegetable
weevil (enlarged). weevil (greatly enlarged).

Control.-There is no practical method of killing the larvae
in the soil. The adult beetles can be poisoned and this is best
done by spraying or dusting the plants in infested gardens or
fields with one of the arsenicals or fluorine compounds. These
chemicals must not be used within two or three weeks of the
time when the crop will be harvested.

WHITE-FRINGED BEETLE
On July 2, 1936, County Agent E. R. Nelson of Okaloosa
County sent to the Experiment Station a few specimens of a
weevil. A few days later County Agent Mitchell Wilkins of
Walton County sent in additional specimens of the same insect.
Some of the beetles were sent to Washington, where they were
identified by L. L. Buchanan of the U.S.D.A. as Naupactus leu-
coloma Boh. (the correct name has since been found to be Pan-
tomorus leucoloma). This insect is a native of South America
and the above collections constitute its first recorded occurrence
in North America. Since its discovery in 1936 the beetle has been
found in several localities in Florida, Alabama, Mississippi, and
Louisiana.






30 Florida Agricultural Experiment Station

The adult beetles are three-eights to one-half inch in length.
They are dark gray in color with a pale stripe along the lower
edge of each wing cover, and two pale lines on each side of the
head and thorax. The body and legs are covered with long pale
hair. The larvae are short, thick-bodied grubs without legs.
The body is yellowish-white and the head is brown.
This is a very destructive insect not only to practically all
vegetable crops but also to field crops such as cotton, corn, pea-
nuts, and cowpeas. The adult beetles cause some injury by eating
the leaves of various plants but the most severe damage is done
by the grubs which attach themselves to the roots of the plants
and gouge out holes, either killing the plant outright or severely
stunting it. They are particularly destructive to such vegetable
crops as potatoes, beans, and corn.
Most of the eggs are laid during July and August, though egg
laying may continue until late in the fall. The eggs begin to
hatch about two weeks after they are laid and continue hatching
until late fall or early winter. The larvae at once begin to feed
and partially complete their development, passing the winter in
various stages of growth. Little apparent damage results from
this summer and fall feeding of the larvae. With the coming of
warm weather in spring the larvae again begin to feed actively
and their growth is rapid. This is when greatest damage is done
to young plants of cotton, corn, and other crops.
Control.-The Bureau of Entomology and Plant Quarantine
of the United States Department of Agriculture has been carrying
on extensive research on this insect in the infested areas since
July 1937. Some of the measures they have found effective in
controlling or holding the insect in check are: Destruction of all
vegetation in the most heavily infested areas; application of in-
secticides (arsenicals or fluorine compounds) on vegetation to
kill the adults; construction of barriers to prevent migration of
the adults during the egg-laying period; and the use of certain
quarantine measures to prevent the spread of the insect into
uninfested regions.
SEED CORN MAGGOT
This pest (Hylemya cilicrura Rond.) of planted seeds and
young seedlings is rather serious in many parts of the United
States. Ordinarily it causes little or no injury in Florida, but in
the winter and spring of 1941 it caused considerable damage in
several places in the state. First reported on lupines, it was later







Insects and Other Pests of Florida Vegetables


found on cucumbers and beans. Some cucumber plantings had
the stand seriously reduced and some bean fields were almost
totally destroyed.
The adult is a small gray fly about 1/5 inch long, somewhat
resembling a miniature house fly. The eggs are laid in the soil
or on the seed or young plants. The larvae or maggots are a
dirty yellowish-white, and are about one-fourth inch long when
fully grown. They burrow into the seed or the stem or roots of
the young plants. They change to the brown puparium or resting
stage in the soil and from these the adults emerge in about two
weeks. These flies develop at rather low temperatures. Low
temperatures delay the germination of plants, thus extending the
period when they are susceptible to attack by the flies. This may
account for their destructiveness in 1941.
Control.-There is no way of controlling this pest by the use
of insecticides but certain precautions may be taken to reduce
the danger of infestation. The flies prefer to lay their eggs in
soil containing an abundance of decaying vegetable matter, so
the land should be plowed well in advance of planting time and
the seedbed well prepared. Anything that will hasten the ger-
mination of the seed and the growth of the young plants will be
of benefit.
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 roundworm or nematode, Heterodera
marioni, 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 truck crops but to varying degrees. The worms are not
very active in winter, but during the warmer weather from April
to October they often make it impossible to grow a profitable
crop of certain plants on infested land. Newly cleared land is
usually free from these worms, but most sandy soils of Florida,
when cleared and cultivated for a number of years, become in-
fested.
The following list of plants includes most of the farm and
garden crops commonly grown in Florida, given in the approxi-
mate order of their susceptibility to damage from root-knot,
which is not necessarily an indication of the abundance of nema-
todes in their roots. It is not advisable to attempt to grow, on in-
fested land, plants near the head of the list.






Florida Agricultural Experiment Station


1. Okra 12. Peas 23. Papaya 33. Radishes
2. Tomatoes 13. Peaches 24. Cabbage 34. Pecans
3. Eggplant 14. Roses 25. Cauliflower 35. Sugarcane
4. Cucumbers 15. Tobacco 26. Collards 36. Mustard
5. Cantaloupes 16. Irish potatoes 27. Sunflower 37. Violets
6. Celery 17. Watermelons 28. Bananas 38. Japanese
7. Beans 18. Lettuce 29. Carrots persimmons
8. Dasheens 19. Soybeans 30. Rape 39. Catalpa
9. Peppers 22. Beets 31. Sweet 40. Kudzu
10. Squash 21. Pineapples potatoes 41. Quince
11. Figs 22. Cotton 32. Asparagus 42. Peanuts
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 nearly immune plants are
most of the true grasses, including crab-grass and bermuda, most
varieties of corn, wheat, rye, and some varieties of oats, velvet
beans, beggarweed, and the crotalarias. Iron, Brabham, and
Suwanee cowpeas usually are resistant. Onions, parsnips and
strawberries grown during the winter are but slightly affected.
While growing any of these crops to free the land of nematodes it
is important 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."
Although this method of freeing land of nematodes is fairly
effective, most truck growers cannot afford to plant their fields
to such relatively cheap crops for a series of years. For such
growers the following method is recommended. As soon as the
crop is off in the spring, plant the infested land to Crotalaria
spectabilis. Plant it in rows about three feet apart. The exact
width will depend upon the cultivating implements. Cultivate
frequently, at least after heavy rains, to prevent a crust from
forming on the soil which would tend to exclude air, and keep it
free of all weeds. This will necessitate one or two hoeings and
maybe some weeds will need to be pulled up by hand. If this is
thoroughly done it will usually practically eliminate the nema-
todes 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 twining habit of growth makes it difficult to cul-
tivate the land properly. Crotalaria striata may be used but its
growing season is longer and its more woody stems are more dif-
ficult to break up the following fall. Moreover, some root-knot
has been seen 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 sulfate, but this
method is so expensive that it is recommended only for seedbeds







Insects and Other Pests of Florida Vegetables


and small gardens. Full directions for this treatment and also
other methods for combating nematodes will be found in Florida
Agricultural Experiment Station Bulletin 311.

INSECTS AND OTHER PESTS OF BEANS
BEAN LEAF HOPPER
The bean leaf hopper (Empoasca fabae Harris) is easily the
worst pest of beans in Florida and each year does considerable
damage in some sections of the state.
The adult leaf hopper is a pale green, wedge-shaped insect
about 1/8 inch long. It is broadest at the head and tapers back
to the tip of the folded wings. The young resemble the adults in
color and shape but are smaller and lack wings. The eggs are
laid in tiny slits in the leaves. There are several generations a
year, the length of the life cycle varying with temperature and
other factors. The food of leaf hoppers is plant sap which they get
by piercing the leaves with their needle-like mouth parts. The
feeding of the insects causes the leaves to be small, crinkled, and
often yellow. They may later turn brown, and in severe infesta-
tions the plants will be much dwarfed and will produce no pods.
Control.-Several precautions may be taken to prevent in-
festations of this insect. The land should be plowed well in ad-
vance of planting time to starve out any leaf hoppers that may be
present. The vegetation along fence rows and ditch banks bor-
dering the bean field should be destroyed by mowing and burn-
ing or by some other means. One should avoid planting beans in
the vicinity of cowpeas, as they often harbor leafhoppers which
will migrate to the beans.
The most effective insecticides for the control of leaf hoppers
are dust mixtures composed of sulfur and pyrethrum, sulfur and
rotenone, or combinations of all three. The pyrethrum gives a very
quick and complete kill but remains effective only a short time.
Rotenone is slower in its action but remains effective longer. The
sulfur has some insecticidal value and tends to delay reinfesta-
tion. There are many different brands of pyrethrum and rote-
none and since these vary in content of active agents one should
always follow directions for use indicated on the container.
Dusting for the control of leaf hoppers should be undertaken only
when the air is auiet. If there is a breeze the dust will drift
away so quickly that a poor kill will result.







Insects and Other Pests of Florida Vegetables


and small gardens. Full directions for this treatment and also
other methods for combating nematodes will be found in Florida
Agricultural Experiment Station Bulletin 311.

INSECTS AND OTHER PESTS OF BEANS
BEAN LEAF HOPPER
The bean leaf hopper (Empoasca fabae Harris) is easily the
worst pest of beans in Florida and each year does considerable
damage in some sections of the state.
The adult leaf hopper is a pale green, wedge-shaped insect
about 1/8 inch long. It is broadest at the head and tapers back
to the tip of the folded wings. The young resemble the adults in
color and shape but are smaller and lack wings. The eggs are
laid in tiny slits in the leaves. There are several generations a
year, the length of the life cycle varying with temperature and
other factors. The food of leaf hoppers is plant sap which they get
by piercing the leaves with their needle-like mouth parts. The
feeding of the insects causes the leaves to be small, crinkled, and
often yellow. They may later turn brown, and in severe infesta-
tions the plants will be much dwarfed and will produce no pods.
Control.-Several precautions may be taken to prevent in-
festations of this insect. The land should be plowed well in ad-
vance of planting time to starve out any leaf hoppers that may be
present. The vegetation along fence rows and ditch banks bor-
dering the bean field should be destroyed by mowing and burn-
ing or by some other means. One should avoid planting beans in
the vicinity of cowpeas, as they often harbor leafhoppers which
will migrate to the beans.
The most effective insecticides for the control of leaf hoppers
are dust mixtures composed of sulfur and pyrethrum, sulfur and
rotenone, or combinations of all three. The pyrethrum gives a very
quick and complete kill but remains effective only a short time.
Rotenone is slower in its action but remains effective longer. The
sulfur has some insecticidal value and tends to delay reinfesta-
tion. There are many different brands of pyrethrum and rote-
none and since these vary in content of active agents one should
always follow directions for use indicated on the container.
Dusting for the control of leaf hoppers should be undertaken only
when the air is auiet. If there is a breeze the dust will drift
away so quickly that a poor kill will result.






Florida Agricultural Experiment Station


BEAN LEAF ROLLER
Another very troublesome insect in the early fall crop is a
caterpillar (Eudamus proteus (Linn.) ) that rolls up the edges of
the leaves after cutting slits in them. From these shelters the
caterpillars range over the leaves and often eat them so badly
that no pods can be formed. The insects are scarce in spring and
early summer so that early beans are not much troubled, but by
the first of September the butterflies are abundant and the beans
become heavily infested.
The caterpillar (Fig. 7), which grows to an inch in length,
is a light greenish-yellow, velvety insect. It differs from most
caterpil ars
which attack
vegetables in
I. that it has a
marked con-
___ striction be-
Fig. 7.-Bean leaf roller: Larva. Much enlarged. t w een the
brownish-
yellow head and the rest of the body. The eggs are deposited on
the leaves of beans and hatch in a few days. In summer the
larvae complete their growth in about 14 days but in October and
November 30 or more days are required. When fully grown the
larvae pupate on the plants and in about a week the bluish but-
terflies emerge. The insect belongs to the group of butterflies
known as "skippers," from their habit of darting quickly from
plant to plant in search of nectar or a place to lay their eggs.
Members of this group of butterflies when at rest hold their
wings at an angle of about 45 degrees instead of horizontal or per-
pendicular as do other butterflies. .This species (Fig. 1) may be
distinguished from other skippers found in Florida by its larger
size, two inches across the outstretched wings, and by the pro-
longations ("tails") of the hind wings.
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 lead arsenate should be used to 50 gallons
of water, and to this should be added the milk obtained by slaking
2 pounds of quick lime or 3 pounds of hydrated lime in a small
amount of water. It is sometimes desirable (up to the blooming
period) to spray beans with 4-4-50 bordeaux to control fungous
diseases, and the lead arsenate can be added to the bordeaux at
the rate of 12 ounces to 50 gallons. On some of the muck soils of







Insects and Other Pests of Florida Vegetables


the Everglades beans are especially susceptible to arsenical burn-
ing and there the dosage should be reduced to 8 ounces to 50
gallons.
If a dust is preferred to a spray, a fairly effective one is made
by thoroughly mixing 1 pound of lead arsenate with 8 to 10 pounds
of hydrated lime. The sulfur-rotenone dusts recommended for
controlling the leaf hopper will also kill many of the younger
stages of the leaf-roller caterpillars.

BEAN WEEVIL
There are two or three species of weevils that infest beans in
Florida. The most common is Acanthoscelides obtectus (Say)
(Fig. 8). Others are more common on cowpeas and will be treated
under that heading. The ravages of
this insect on dried beans are very con-
spicuous; in fact, if not checked it will
entirely destroy seed beans. It also
damages snap beans in the field. The
Infested pods show wart-like swellings
S, where the female punctures them to
Fig. 8.-Bean weevil (Acanthos- lay eggs in the cavity of the pod. She
ceelde s oect):arged; dul gnaws out a narrow slit and then in-
fested ofbt. (From U. S. serts her ovipositor in the hole and
lays the egg. These "speckled" pods
should not be confused with those affected by anthracnose. An-
thracnose spots are sunken instead of elevated and attain a much
larger size. The egg of this weevil hatches in from one to three
weeks, depending on the prevailing temperatures, into a small,
grub-like larva. This requires from 11 days to six weeks to be-
come full grown and then changes into the pupa. From five to
18 days later the adult emerges through a circular hole. The
presence of this hole is characteristic of infested beans. The
adult is a grayish beetle about 0.1 inch long with hard wing-cases
and a short, thick body.
Control.-Little can be done to protect beans in the field
from 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 F.) for two months
or more, or they may be fumigated as recommended for stored
seeds. Beans that have been fumigated must be kept in heavy
paper bags or other containers or they may become reinfested.







Florida Agricultural Experiment Station


LESSER CORN STALK BORER
Corn is the crop most injured by this insect (Elasmopalpus
lignosellus (Zell.) ) in the states farther north. In Florida it
does more damage to cowpeas and beans, although it is also inju-
rious to corn. Next to the bean leaf hopper it is often the most







..





I I .----_

Fig. 9.-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.)

injurious insect on beans. It sometimes destroys almost the en-
tire stand if preventive measures are not adopted. The destruc-
tive stage is the bluish-green caterpillar (Fig. 9, 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
a cowpea plant gets a good start before it is attacked it may not
be killed and may produce some pods, so that the damage is not
so noticeable, but a bean plant is usually killed outright. The
full grown caterpillar is about 1/2 inch long and appears quite
smooth, without noticeable hairs. There is a large brown spot
on the back of each body segment or joint. The head is brown
and hard and the first joint of the thorax is black. The adult
is a small, brownish moth with cream-colored markings (Fig. 9,
a). It belongs to the same family as Crambus (see root web-
worms, page 61) and rolls its wings about its abdomen in the
same manner (Fig. 9, c).
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.







Insects and Other Pests of Florida Vegetables


Control.-The caterpillars, working inside the stems, are
safe from any poison that could be applied to the crop. The
younger stages on the roots are also safe. The only means of pre-
venting their spread through a field is to pull up and destroy
all infested plants. Rotation of crops should be practiced. Beans
should not be planted on land that has just grown beans, peanuts,
cowpeas, turnips, or corn, as they are all host plants of the insect.

MEXICAN BEAN BEETLE
This beetle (Epilachna varivestris Muls.), which is a very severe
pest of beans in most of the Eastern states, is present in extreme
northern Florida. Both the larvae and the adult beetles feed
upon the bean plant, skeletonizing the leaves by eating off tender
parts and leaving the veins. The beetle belongs to the ladybeetle
family and is one of the few species of this family which is de-
structive to vegetation. The vast majority of the ladybeetles
feed upon aphids, scales and other soft-bodied insects.
This insect has been recognized as a pest of beans in Colo-
rado and other Western states for at least 75 years. It was first
found in the East near Montgomery, Alabama, in 1920. From this
original locality it has spread throughout practically all the East-
ern states but has made its way southward very slowly. Several
years ago it appeared at Monticello, Florida, but the infestation
apparently died out. Within recent years there has been a rather
well established infestation in Gadsden County.
In states where this pest does a great deal of damage it is
controlled by dusting the beans with magnesium arsenate, mag-
nesium being used because it is less likely to burn the tender fo-
liage of the beans than are other arsenicals. Fluorine insecti-
cides also have been used rather extensively for controlling the
beetle.
OTHER BEAN PESTS
Other pests attacking beans are: Root-knot nematodes, page
31; the corn earworm which sometimes mines the pods, page 55;
cutworms, page 41; the cabbage looper which sometimes eats the
leaves, page 43; the cowpea pod-weevil, page 64; grasshoppers are
troublesome in the fall, page 20; pumpkin bugs, page 65, and
other plant bugs, page 86, are among the more troublesome
enemies of the bean grower; wireworms, page 59; thrips, page
106; flea beetles, page 39; and cucumber beetles, pages 71 and 72,
are less commonly troublesome though they sometimes cause
some damage.







Florida Agricultural Experiment Station


LIMA BEANS
LIMA BEAN VINE BORER
In addition to the other pests of beans, pole lima beans are
attacked by a caterpillar (Monoptilota sp.) 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 completed. The adult insect is a small moth
which lays its eggs on the stems of the plant. These galls are very
common on pole lima beans in Florida.
Control.-The attacks of this caterpillar do not usually be-
come severe until summer, hence lima beans planted early usually
produce a fair crop. The only practical means of preventing in-
jury seems to be to plant as early as possible. Bush lima beans
are seldom injured by this insect.

INSECTS AND OTHER PESTS OF BEETS
BLISTER BEETLES
These long, slender beetles feed on a variety of truck crops,
including beets, tomatoes, and potatoes. In the Northern states
they are known as "old fashioned potato beetles," to distinguish
them from the more recently introduced Colorado
potato beetle. 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." Eight species of blister beetles are more
or less troublesome to vegetation in Florida. The
Fig. 10.-Strip- most common ones are the grayish-black beetle,
ed blister
beetle; nat- Macrobasis unicolor (Kby.), which has no stripes,
ural size.
(From U. S. and the striped blister beetle, Epicauta vittata (Fab.)
Bur. of Ent.)
(Fig. 10).
The work of all the species is about the same, except that they
may show preference for different plants. They strip all the
softer parts of the leaves, leaving only the midribs. The beetles
usually feed in droves, sometimes so large that they quickly strip
and ruin a patch or an entire field. Only the adult stage is de-
structive, as the larvae feed on grasshopper eggs and are thus
beneficial.
If the drove is small the quickest way to exterminate it is to
collect the beetles in a pan of kerosene. They are quick to take
alarm and the collector must work rapidly. If the drove is large







Insects and Other Pests of Florida Vegetables


the plants should be sprayed with lead arsenate or one of the
pyrethrum compounds. Because of the food habits of the larvae
it is better, whenever practical, to drive the beetles from the
field rather than to poison them. To do this, arm several persons
with loose bundles of small branches with which to brush the
beetles from the plants and start them moving along the ground.
Advantage should be taken of any wind that may be blowing as
the beetles move better with the wind. Drive them to some dis-
ance from the field so they will not return to it.

FLEA BEETLES
These are small oval beetles (Fig. 11) belonging to the family
Chrysomelidae. They get their name from their habit of quickly
springing away
when disturbed.
Several species
are more or less
troublesome in
Florida on beets,
cabbage, cucum-
bers, tomatoes,
s t r a w berries,
and related
plants. They eat
the epidermis on f
one side of the a
leaf and the soft
interior cells but
leave the veins
and other hard
parts. One com- b
mon species of Fig. 1l.-Strawberry flea beetle: a, Adult; b, eggs on leaf;
flea beetle usu- c, side view of young larva; e, dorsal view of larva; f, pupa.
Greatly enlarged. (From U. S. Bur. of Ent.)
ally is very
abundant on evening primrose, Oenothera sp., from which it often
spreads to cultivated crops. These weeds should be destroyed
around the edges of vegetable fields as well as in the field itself.
Bordeaux mixture usually is efficacious in preventing injury
by these insects, acting as a repellant and tending to keep them
off the plants. The mixture can be made more efficient by the
addition of a pound of lead arsenate to 50 gallons of the bordeaux.







Florida Agricultural Experiment Station


Sprays containing extracts of pyrethrum are also effective if used
as directed by the manufacturers.
WHITE-LINE SPHINX
The larva of this very common hawk-moth (Sphinx lineata
Fab.) feeds occasionally on beets, although its natural host plant
in Florida is purslane. It belongs to the same family as the to-
mato hornworm and the larvae of the two insects are similar in
size, general appearance and habits. In small plantings hand
collecting is often the most satisfactory means of control. For
larger areas dusting or spraying the plants with arsenate of lead
while they are small, or with one of the rotenone compounds as
harvest time approaches, will prove effective.
BEET WEBWORMS
There are two species of moths belonging to the genus Loxo-
stege whose larvae attack and occasionally injure the leaves of
beets. These larvae normally feed on wild vegetation, especially the
"careless weed," and it is only in seasons of unusual abundance
that they attack beets and other garden crops. Fully grown larvae
may be nearly an inch long and vary much in color, being various
shades of green and yellow. The larvae spin a silken web wher-
ever they go and they often make silken shelters in which to hide.
Control.-Destruction of weeds in and about the beet field
will usually serve to prevent infestation by these insects. In
case they become numerous enough to require control measures
they can easily be killed by means of arsenical or rotenone in-
secticides.
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, below.
OTHER BEET PESTS
Other insects which attack beets are: Wireworms, page 59;
white grubs, page 87; bean jassids, page 33; harlequin cabbage
bugs, page 49; the false cinch bug (see tarnished plant bug),
page 54; sweet potato caterpillar, page 99; 12-spotted Diabrotica
or corn root worm, page 63; and cabbage loopers, page 43.

INSECTS AND OTHER PESTS OF CABBAGE
The insects here discussed also attack and injure related
crops such as brussels sprouts, cauliflower, collards and kohlrabi.






Insects and Other Pests of Florida Vegetables 41

Control measures recommended for use on cabbage will be ef-
fective on these related crops as well.
CUTWORMS
Cutworms are the almost hairless larvae (Fig. 12, a, b) of
several species of moths of the Noctuid family. The moths are
night fliers and are commonly seen about lights. They are gray-
ish or brownish in color and most of them have small silvery
markings, dots, dashes, or com-
mas on their fore wings (Fig.
12, d, e).
Cutworms are very fond of
-S any succulent plant and are
troublesome to most truck and
d / garden crops, including cab-
"fe bage. They gnaw off the young
plants just above the surface
of the ground, and a single lar-
va may cut off and kill several
a .b plants during its development-
al period. Sometimes cut-
worms feed inside the growing
heads of cabbage and lettuce
and do not enter the soil after
feeding.
Fig. 12.-Cutworm moth (Mamestra cheno- In Florida many cutworms
podii): a, b, larva, c, pupa; d, moth; e, are active and breed through-
wing of moth, enlarged. Natural size.
(From U. s. Bur. of Ent.) out the year, although neither
the moths nor the caterpillars are active during
the coldest nights of the winter. The worms re-
main active at a lower temperature than the
moths, but the latter may be seen about lights
on warm evenings, even in midwinter. The
worms suspend operations during the coldest
nights only, when the temperature drops be-
low 45. There are no definite broods but all
stages of the insects may be found at almost
any time.
Control.-The moths by preference lay b
their eggs (Fig. 13) on grasses in sod land. Con- Fig. 13.-Eggs of cut-
sequently the cutworms usually are most trou- worm moth (Arotis
saucia): a, Single
blesome on land that has been in grass for egg, greatly enlarged;
b. egg mass on twig.
some time. As long as the grass is available Natural size. (From
U. S. Bur. of Ent.)






Florida Agricultural Experiment Station


there is so rimuch food in proportion to the number of worms that
their feeding is scarcely noticed, but when such land is plowed
and planted the normal food supply of the caterpillars is cut off
and they are concentrated upon the relatively small amount of
vegetation of the crop.
When grass land is plowed measures should be taken to kill
the cutworms present before a crop is planted. To do this, pre-
pare the land 10 days or two weeks before the crop is to be set.
During that time many of the cutworms will leave or die of
starvation. A day or two before the crop is to be set, cut up some
green and succulent plants such as collards, rape, or cowpeas,
and dip them in a strong solution of paris green-about an ounce
to a gallon of water. Scatter these poisoned plants about the
field after sunset for the hungry cutworms to feed upon during
the night. Instead of the green material the following poison
bait may be used.
Bran ..---------.....-------...- --........... ....20 pounds
Cottonseed meal _---...--__.... -------.._ ....... 5 pounds
Paris green ...... . ..------...___ .. _._.. ........ 1 pound
Water ___..--------..____-.......-..--------...- 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 bait should
be put out after sunset so that it will be fresh and attractive
when the worms come out to feed during the night. If the fol-
lowing day is cloudy the bait will remain attractive the second
night. If properly sown it will fall in such small flakes that
fowls and other birds will not pick it up. In a field already
planted better protection will often be given to the plants at
a smaller expenditure for material if, instead of being sown
broadcast, the bait is placed in small pinches about the stems
of the plant. For protecting some crops it may be scattered
along the rows.
In small gardens or in a field where there are but few cut-
worms the easiest, quickest and cheapest method of dealing with
them is to walk through the patch in the early morning and look
for plants that were cut off during the preceding night. By
scratching the earth away from the base of the plant the worm
will usually be found at a depth of not more than an inch. They
may be collected and fed tu chickens or otherwise destroyed.






Insects and Other Pests of Florida Vegetables


CABBAGE WORMS
At least five species of caterpillars feed on cabbage and re-
lated plants in Florida. Control measures are similar for all five,
and are discussed on page 46.
Cabbage Looper, Autographa brassicae (Riley).-This larva (Fig.
14, a) of a Noctuid moth is the most common worm during the


ba




Fig. 14--Cabbage looper: a, larva; b, pupa; c, adult.
Natural size. (From U. S. Bur. of Ent.)


winter. It is closely re-
lated 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 injures the
leaves by eating holes
in them and also dam-
ages the appearance of
the heads by soiling
them with its excrement.
The caterpillar is light


green in color and grows to a length of more than an inch. It
requires about three weeks for growth and spends about two
weeks in the pupa stage. The eggs, yellowish-green in color and
about a fiftieth of an inch in diameter, are scattered over the
surface of the leaves. The adult moth (Fig. 14, c) also looks much
like those of cutworms. In peninsular Florida it is usually active
all winter.
The Cabbage Plutella, Plutella maculipennis (Curt.).-The cab-
bage plutella (Fig. 15, a), a much smaller caterpillar than the
looper, is common on cab-
bages. It is less than 1/2
inch long and is much
more hairy in appearance
S ff than the looper. When
7 .. disturbed it drops quickly
i from the plant, spinning
a silken thread which it
)e uses to remount the plant
Fig. 15.-Cabbage plutella: a, Larva; d, e, pupa; f, when danger is past. On
moth; h, moth at rest. Two and one-half times the under side of the leaf
natural size. (From U. S. Bur. of Ent.)






Florida Agricultural Experiment Station


it makes small round holes, which rarely extend through to the
upper surface. Like the looper, this caterpillar is active all win-
ter in the latitude of Gainesville and southward. The cocoon is
a loosely-woven affair through which the pupa (Fig. 15, e) may
be plainly seen. The cocoons are attached to the leaves or stems
of the plants.
The adult (Fig. 15, f) is a small moth % inch across the ex-
panded wings, which are gray with a border of lighter areas.
When the wings are folded in the resting position (Fig. 15, 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. About three days are spent in the egg stage, from one to
two weeks in the larval, and from four to eight days in the pu-
pal stage. Therefore, to effect a thorough cleanup of a heavy
infestation of this insect the plants should be given two applica-
tions of an insecticide, with an interval between sprays of about
10 days in warm weather and two weeks in winter.

CABBAGE BUTTERFLIES
The caterpillars of three white butterflies are injurious to
late cabbage and collards. They do not seriously trouble the
main winter-grown crop of cabbage because they are not very
active at that season.
Imported Cabbage Worm, Pieris rapae (L.).-In the northern
and western parts of the state the most common cabbage butter-
fly is the imported cabbage worm, a pest which was brought to
this country about 1856. It has since spread ov-
er the entire country, reaching Florida about
1890. Here it has never become abundant as in
the Northern states.
The full-grown caterpillar (Fig 16, a) is about
S1/4 inches long, bright green with a yellowish line
down the middle of its 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. 16, b), and eight or ten days later,
Fig. 16.-Import- in warm weather, the butterfly (Figs. 17, 18)
terfba, but: emerges. Those which enter the pupal stage in
Vaturalb s tpupa late fall may remain there all winter, at least in
From Ut.) the northern part of the state. The eggs are white
Bir. of Ent.)







Insects and Other Pests of Florida Vegetables


!

Fig. 17.-Imported cabbage butterfly:
Female. Natural size. (From U. S.
Bur. of Ent.)


Fig. 19.-Southern cabbage butterfly: Male.
Natural size. (From U. S. Bur. of
Ent.)


*i'. '

~X~Z __ ". .-A
Fig. 18.-Imported cabbage butterfly:
Male. Natural size. (From U. S.
Bur. of Ent.)


Fig. 20.-Southern cabbage butterfly: Fe-
male. Natural size. (From U. S. Bur.
of Ent.)


or yellow and are scattered
Over the surface of the
leaves.
Native or Southern Cab-
Sbage Worm, Pieris protodice
r /' (B. & Lec.): This worm
(Fig. 21, a) is similar in ap-
Fig. 21.-Southern cabbage butterfly: a, larva: pearance to the imported
b, pupa. Natural size. (From U. S., Bur. of rm but has four longi-
EntS) worm but has four longi-
tudinal yellow bands. The
butterflies can be distinguished by comparing the illustrations
(Figs. 17, 18, 19, 20). The nature of the injury it inflicts is identi-
cal with that of the species last named.
Gulf White, Pieris monuste L.-The larva of this butterfly is
greenish-yellow with four longitudinal stripes of a purplish hue
(Fig. 22, a). It is about 11/2 inches long. The butterfly (Fig. 22, c)
is the largest of the group, measuring nearly three inches across
the expanded wings. This is by far the most common and trouble-
some caterpillar on cabbage and collards grown during the late
spring and summer in the southern part of the state.







Florida Agricultural Experiment Station


Control.-On
young cabbage
which has not
begun to head
all of these cat-
erpillars a r e
easily controlled
by means of
arsenicals or
fluorine com-
4 pounds. Paris
green can be
used, but either
lead arsenate or
calcium ars e-
nate is prefer-
Fig. 22.-Gulf white butterfly: a, Larva; b, pupa; c, adult. Natural able. One pound
size. (From U. S. Bur. of Ent.) of paris green or
11/2 pounds of lead or calcium arsenate is added to 50 gallons of
water. The arsenicals alone in water do not stick well to cab-
bage because of the waxy coating or "bloom" of the leaves. To
make them stick better some other materials are added to the
spray. Two or three pounds of hydrated lime to each 50 gallons
make a fair sticker. A better one is calcium caseinate used at
the strength recommended by the manufacturers. A paste made by
boiling 2 pounds of flour in 2 gallons of water and added to 50
gallons of the spray makes an effective sticker.
A "spreader" developed by the U. S. Department of Agri-
culture consists of an infusion of cactus. Thirty pounds of cac-
tus is chopped fine and allowed to soak over night in 50 gallons of
water. This is strained and the arsenical is 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."
Arsenicals may also be used dry. It is well to use a filler of
cheap flour or hydrated lime, mixing about 10 parts of the filler
to 1 of the poison. The fluorine compounds are used almost en-
tirely in dust form. Natural cryolite and barium fluosilicate are
perhaps best suited for use on cabbage and related crops. Talc
or other inert materials are commonly mixed with these insecti-
cides, but lime should never be used.
Cabbages should not be dusted or sprayed with poisons after







Insects and Other Pests of Florida Vegetables


they start to head. When an arsenical is put on younger cabbage
it will be found at marketing time, if at all, only on the old ma-
ture leaves-those which are stripped off at the time of harvest-
ing... The common idea that cabbage "heads up" by the leaves
curling inward is a mistake. The head is formed entirely by in-
ternal growth; it is but a big bud and is formed like other buds,
never by 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. After the cabbage begins to head rotenone
compounds should be substituted for arsenicals.

APHIDS
Cabbage is very commonly infested with aphids or plant lice.
Four species have been found on this crop in Florida but only
two, the cabbage aphid,
Brevicoryne brassicae (L.)
(Fig. 23), and the turnip
S/ aphid, Rhopalasiphum pseudo-
S brassicae (Davis); ordinarily
S' become numerous enough
to cause any damage.
Aphids are small, soft-
bodied insects which live to-
Fig. 23.-Cabbage aphid: a, Winged female; b, gether in dense colonies
wingless female. Greatly enlarged. (From U.
S. Bur. of Ent.) that may contain thousands
of individuals. Many aphids are green in color and both of the
above species are green beneath the waxy or powdery coating
that covers them. Due to this coating the colonies of aphids ap-
pear as light gray patches on the surface of the leaves.
The life history, habits, and effect on the plants of these two
species are very similar to those of all aphids found on vegetable
crops in Florida. Control measures recommended here likewise
will apply in general to aphids on other crops, though some slight
modifications may be needed due to the nature of the crop or
other factors.
Unlike most insects, aphids do not lay eggs except for one
generation in the fall. The young of the remaining generations
are all born alive. The mild winters in Florida enable aphids to
remain active throughout the year and most species do not lay
eggs at any time, the young of all generations being born alive.
Another peculiarity of reproduction in the aphids is that the
young are produced parthenogenetically, that is, without mating.






Florida Agricultural Experiment Station


In most species of aphids only females have been found in Flori-
da and it seems probable that males occur very rarely if at all.
Aphids multiply with extreme rapidity when conditions are
favorable for their development. An aphid may begin to produce
young when it is less than a week old and it may produce five or
six young a day during the reproductive period of two or three
weeks. In very cool weather development and reproduction are
much retarded. With an abundance of succulent plants on which
to feed, and other conditions favorable, nearly all the aphids are
wingless. If the plants begin to harden or the aphids are greatly
crowded, most of them will be winged. This enables them to fly
away in search of a more suitable environment.
Aphids are sucking insects and their food consists of plant
juices which they get from tender, succulent portions of plants.
They are most injurious during periods of drouth when they
cause a noticeable wilting and yellowing of the plants.
Many species cause a curling or crinkling of the leaves of
their host plants but that is not the case with the species feeding
on cabbage.
Ants are very commonly found associated with aphids. The
aphids give off a sweet liquid-honeydew-of which ants are
very fond. In return for this honeydew the ants care for the
aphids and often drive away any enemies that would molest
them. The presence of numbers of ants on a plant should lead
one to investigate further. In this way one can often detect
a developing aphid infestation which would otherwise remain
undiscovered.
There are many natural factors that tend to hold aphids in
check. Among the more important of these are unfavorable
weather conditions, such as dashing rains which beat many
aphids from the plants to the ground where they are killed;
small insect-eating birds which destroy many of them; and other
insects that prey upon them. The more important of the insects
that destroy aphids are ladybeetles, syrphid flies, aphid lions, and
hymenopterous parasites. Both the adult ladybeetles, with which
everyone is familiar, and their larvae consume aphids. In the
case of syrphid flies, only the larvae eat aphids, the adults feed-
ing on nectar, honeydew or other liquids. Syrphid fly larvae are
slug-like or grub-like creatures with piercing mouthparts at the
pointed front end of the body. They puncture the aphids and
suck out their body fluids. Aphid lions are the larvae of lace-






Insects and Other Pests of Florida Vegetables 49
wing flies, small insects with delicate, lace-like, green or brown
wings. Their larvae are spindle-shaped and have very large
sickle-shaped jaws. They also feed on the body fluids of the
aphids.
The hymenopterous parasites are very small, dark colored
insects that are seldom noticed. The female punctures the skin
of the aphid and lays a tiny egg in its body. From the egg hatches
a small, legless grub that lives inside the aphid's body, feeding on
the soft tissues and eventually killing it. Parasitized aphids are
greatly swollen and nearly spherical in shape and are easily
noticed in a colony. When the parasite is fully mature it cuts a
circular hole in the skin of the dead aphid and emerges to seek
other aphids in which to lay its eggs.
Control.-Artificial control of cabbage aphids can be accom-
plished by means of contact insecticides, which may be applied as
either sprays or dusts. Nicotine sulfate is the most widely used
spray material. The waxy nature of the cabbage leaves makes
effective spraying rather difficult because the spray tends to
run off instead of wetting the leaves and the aphids. The use of
the better spreaders, such as sodium or potassium oleate, will
largely overcome this difficulty and make effective control pos-
sible. Nicotine sulfate-lime dust gives very good control of aphids
on cabbage, provided weather conditions are satisfactory. The
air must be quiet and the temperature should be above 70 F., as
nicotine dust is not effective at lower temperatures. The dusts
containing rotenone, though more expensive than nicotine sul-
fate-lime dust, will kill aphids at somewhat lower temperatures
than the nicotine. The rotenone dusts will also kill many of the
younger stages of the cabbage caterpillars.


HARLEQUIN BUG OR CALICO
BACK
This strikingly-colored insect
(Murgantia histronica (Hahn) ),
a native of the Mexican region,
has been slowly working its way
eastward and northward. It is
not as yet generally abundant in
Florida but may be seen occas-
ionally on late cabbage and it is
quite common and destructive to
collards that are carried through
the summer.


a ; --- 10








f &

Fig. 24.-Harlequin cabbage bug: a, b,
Nymphs; d, c, eggs, greatly enlarged;
f, g, adults. Slightly enlarged. (From
U. S. Bur. of Ent.)






Florida Agricultural Experiment Station


The adult (Fig 24, g) is black and orange, and is % inch
long. Both the adults and the young suck the juices of the plants.
A poison is injected into the feeding punctures and a few of these
bugs are sufficient 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, giving
them a striking resemblance to a keg with its hoops and bung-
hole. They hatch in three or four days. The young are at first
yellow, developing the orange markings later.
Control.-They are usually present in such small numbers as
to make hand collecting of the adults practical, but hand collect-
ing of the young is less satisfactory because of their small size.
If these become abundant they can be killed by spraying with
kerosene emulsion. All infested, dying plants should be pulled
and destroyed, as they may bear eggs or young bugs. In the
northern part of the state a crop of late cabbage can be partially
protected by planting an early trap crop of mustard, radishes, or
turnips. When this trap crop becomes infested it may be sprayed
with kerosene emulsion or pulled up and burned.
CABBAGE HAIR-WORM OR CABBAGE SNAKE
This whitish, thread like
worm (Mermis albicans) (Fig. 25),
which sometimes grows to a
length of nine inches, is occas-
ionally found in cabbage heads.
It is an internal parasite of grass-
hoppers and caterpillars and is
therefore a friend of the grow-
er. It gets into the cabbage by
crawling out of infested insects.
In spite of its repulsive looks
Fig. 25.-Cabbage hair-worm or cabbage I pite of its repulsive looks
snake. (From U. S. Bur. of Ent.) and the many stories which are
told of its poisonous nature, it is entirely harmless. Aside from
the elimination of grasshoppers, control measures are impractical.
SOUTHERN SQUASH BUG
This insect (Anasa armigera (Say) ) sometimes attacks cabbage
and collards. It breeds on these plants, as eggs and nymphs are
found there. Control is similar to that for the squash bug, page
92.







Insects and Other Pests of Florida Vegetables


OTHER CABBAGE PESTS
The following insects also infest cabbage in Florida: Blister
beetles, page 38; flea beetles, page 39; tarnished plant bug, page
54; onion thrips, page 78; wireworms, page 59; nematodes (root-
knot), page 31; grasshoppers, page 20; and the serpentine leaf
miner, page 66.

INSECTS AND OTHER PESTS OF CANTALOUPE
The insect pests of this crop are almost identical with those
of cucumbers, and since cucumbers are more generally grown
in Florida the insects are discussed under that crop. (See cucum-
bers, page 68). The pickleworm and the melonworm, how-
ever, are much more severe pests on cantaloupes than on cucum-
bers, because cantaloupes have a longer growing season than cu-
cumbers and extend into late spring when the pickle worm and
the melon worm become abundant. The trap crop of squash
recommended for controlling these insects in cucumbers should
never be omitted from the cantaloupe field.

INSECTS AND OTHER PESTS OF CARROTS
The more common pests of carrots are all discussed else-
where in connection with other crops and so they are merely men-
tioned here. The common pests of this crop are cutworms, page
41; blister beetles, page 38; celery caterpillars, page 54; car-
rot-beetle, Ligyrus gibbosus DeG., (see May-beetles under potatoes,
page 88; and root-knot, page 31.

INSECTS AND OTHER PESTS OF CELERY
CELERY LEAF-TIER
The celery leaf-tier (Phlyctaenia rubigalis (Guen.) ) (Fig. 26) is
considered the major insect pest of celery in Florida, though it is
not present in destructive numbers every year. Cool weather
retards its development and it is only in seasons of high temper-
atures that it seriously damages the celery crop.
The adult is a small brownish moth with darker cross lines on
the wings. The eggs are laid on the leaves and the young larvae
feed for a time on the under sides of the leaves. As they get old-
er they move toward the heart of the plant and feed on the ten-
der leaves there. Sometimes they feed on the stalks of the celery
near the base of the plants. The older larvae have the habit of
binding together with a web of silk parts of one or more leaves
and thus forming a shelter within which they feed. The young





Florida Agricultural Experiment Station


^ .B













C D

Fig. 26.-The celery leaf tier, a, eggs; b, mature larva; c, pupae; d, adult, a, highly mag-
nified; others magnified from 2 to 3 times.
caterpillars are green, the fully matured ones yellow with a
bright green line bordered on each side by a white stripe running
along the middle of the back.
Control.-The most effective method of controlling this pest
consists of dusting the plants with pyrethrum powder, either
alone or mixed with sulfur. If a good grade of pyrethrum is
used it can be mixed with an equal weight of sulfur without re-







Insects and Other Pests of Florida Vegetables


during its effectiveness. The sulfur in this mixture will also con-
trol any red spiders that may be on the celery. It is essential
that the dust be forced into the hearts of the plants. The younger
larvae are much more easily killed than the older ones and for
this reason control measures should be started before the infesta-
tion has developed too far.
The use of arsenicals for the control of this pest is not recom-
mended. They are not very effective in killing the caterpillars,
and poisonous residues in dangerous amounts are very likely to
be found at the bases of the stalks at harvest time.
For fuller discussion of this insect see Bulletin 251 of this
Station.
SEMI-TROPICAL ARMY WORM
This insect (Xylomyges eridania Cramer), which feeds chiefly
on grasses, sometimes attacks celery in injurious numbers. A
large caterpillar with reddish brown markings, it is closely related
to the sweet potato caterpillar. The same poison baits which are
recommended for that insect will also control this caterpillar.

GARDEN FLEAHOPPER
This is a minute black plant bug (Halticus citri (Ashmd.) ) (Fig.
27) that attacks the leaves of celery, cowpeas, beggarweed, pep-
pers, and a great variety of weeds. Pale spots often appear at











Fig. 27.-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.)

the points where feeding punctures have been made, giving the
plants a spotted appearance.. In severe infestations the leaves or
even whole plants may be killed. The insect may be controlled
with nicotine compounds but pyrethrum extracts are more effec-
tive.






Florida Agricultural Experiment Station


TARNISHED PLANT BUG
This bug (Lygus pratensis (L.) ) (Fig. 29) is very common
throughout the country in gardens, where it frequents blossom
heads and other very young
and tender herbage and
even the tender shoots of
Streets. The succulent stalks
\ / of celery plants afford a
Fig. 28.-Tarnished plant bug: Adult and young. very acceptable f oo d.
About four times natural size. (From U. S.
Bur. of Ent.) Growth is stunted by the
sucking of sap and brown spots are produced where the punc-
tures are made. These greatly reduce the attractiveness of the
celery on the market.
The adult bug is only about 1/4 inch long. The male is dark
reddish-brown and the female light brown with light yellow
markings. The young (Fig.
28) are greenish in color.
These bugs are rather rest-
less and are quick in their
movements. For this rea-
son they are most easily
killed in the early morning
when they are relatively
sluggish. Nicotine sulfate Fig. 29.-Tarnished plant bug. Immature stages.
Four times natural size. (From U. S. Bur. of
with soap or other spreader Ent.)
will kill the young and most of the adults but sprays containing
pyrethrum or rotenone are more effective.
A number of other bugs, including the false chinch bug,
Nysius ericae (Sch.)- frequently attack celery. The character of the
injury is similar to that of the tarnished plant bug and the same
control measures may be used.
CELERY CATERPILLAR
This conspicuous green caterpillar (Papilio polyxenes Fabr.)
with black cross bands is a rather common feeder on celery and
related crops. It strips the leaves clean as it goes and since it
grows to the rather large size of two inches in length a single
individual can do considerable damage when the plants are
small. It is a close relative of the "orange dog", Papilio cresphontes,
and like that species, when disturbed, thrusts out a yellow horn-
like process from the head that gives off a strong, sickening odor.







Insects and Other Pests of Florida Vegetables


This seems to protect the insect from birds and possibly other
foes. The pupa is fastened to some support by a silken thread
about its middle. In from nine to'12 days there issues from it a
swallow-tailed butterfly. 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 con-
trol. As celery is commonly sprayed with bordeaux for fungous
troubles, a pound of lead arsenate added to 50 gallons of the
bordeaux will control this caterpillar. However, this can be used
only on small plants as there would be danger of poisonous resi-
due remaining at harvest time if used on older celery.
Other Caterpillars.-Several other caterpillars attack celery,
among them the celery looper, Autographa falcifera (Kby.), an in-
sect closely related to the cabbage looper.
MOLE-CRICKETS
Mole-crickets sometime cause severe injury to celery in seed-
beds. In the Sanford area the principal species concerned is the
Southern mole-cricket, Scapteriscus acletus R. & H. For control
measures see page 22.
OTHER CELERY PESTS
Other insects injurious to celery are: Fleabeetle, page 39;
cutworms, page 41; and red spider, page 81.
INSECTS AND OTHER PESTS OF CORN
Sweet corn is attacked by the many common pests of corn.
Some show a decided preference for sweet corn. Only the more
important insects attacking corn will be considered here.
CORN EARWORM OR BUDWORM
This common pest of cotton, corn, tomatoes, beggarweed, and
beans (Heliothis obsoleta (Fab.) ) prefers sweet corn to any other
of its host plants. Early in the season the moths lay their eggs
on the young corn. The larvae hatching from these eggs work
in the corn as budwormss." (At least two other caterpillars that
do very similar damage to corn are also known as budwormss.")
When mature the caterpillars enter the ground and pupate, and
in about seven days the moths emerge. The moths of this gen-
eration lay their eggs principally on the silks of the ears. The
second generation larvae eat the silks and make their way into
the ear, where they feed upon the developing kernels. Later gen-
erations develop on cotton, beans, beggarweed, crotalaria and






Florida Agricultural Experiment Station


other plants. Whether working in corn as the "budworm" or
"earworm," in tomatoes as the "fruit worm," on cotton as the
"bollworm," or fully exposed on beggarweed, it is the same in-
sect. So abundant is this pest in Florida that it is difficult to
find an ear of sweet corn that has not been attacked by at least
one of these caterpillars.
Life History.-The eggs are whitish, oval, prominently ribbed,
and about 1/20 inch in diameter. They hatch in three or four
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 1/4 to 2 inches
long. The full grown caterpillar eats its way out of the ear or
stalk and enters the ground to a depth of two to five inches,
where it forms the pupa. Here it remains for two or three weeks
in summer, or all winter if it is the last fall brood. The pupa lies
in an earthen cell. It is
about 34 inch long and is at
Fr first green in color but soon
turns to a light brown. The
Smooth (Fig. 30) which issues
from this cocoon varies in
color from dusky yellow to
grayish and expands from
11/2 to 2 inches. Unlike most
Smooths, it may fly in broad
Fig.a30o-Corn earth wrm Adult. One and a daylight but the eggs are
half times natural size.
mostly laid about sunset.
Control.-The work of the first generation in the corn is
usually noticeable when the corn is about knee high. It is im-
portant that this early generation be destroyed, if possible. Not
only will the injury to the buds be checked but the number of
caterpillars in the following generation which works in the ears,
will be lessened. At this stage some degree of control may be
obtained by spraying or dusting some of the arsenical compounds
into the infested buds. The senior author has dusted undiluted
lead arsenate and zinc arsenate 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 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







Insects and Other Pests of Florida Vegetables


the bud, carrying the poison with it. In a small garden the poison
can be applied by means of a tin can with holes punched in the
bottom. On a larger scale the well known bag-and-pole method
may be used, but the most even distribution will be secured by the
use of a dusting machine.
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 a short time 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 treatment is too ex-
pensive for a crop of field corn but on such a valuable crop as
sweet corn it is worth while.
This insect works its way into the ear from the tip, consum-
ing the silk as it goes, so varieties of corn with long, close-fitting
husks are less severely injured by this caterpillar, as the ears will
often reach the marketing stage before the caterpillar has worked
far down into the kernels. If the ear matures rapidly it will be
ready for 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,
or for other reasons, 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, since late planted corn always suffers more severely from
the attacks of this insect.
In a small patch in the garden the worms can often be re-
moved from the tip of the ear before they have inflicted material
damage. In removing the worms one should not, however, open
the ears to such an extent as to expose the kernels, as birds, corn
sap beetles, and other insects will then attack them. Wood-
peckers and bluejays are occasionally seen eating the worms
which they have removed from the ears of sweet corn.
Recently workers in the U.S.D.A. Bureau of Entomology have
developed a method that seems to be very effective in combat-
ing the earworm. The material used is a light, highly refined oil
having a viscosity of about 200. This must be introduced into the
ear at a very definite stage of its development. The procedure is
as follows: From 1/2 to 1 cubic centimeter of this oil (approxi-
mately a thimble full) is injected into the ear. An ordinary oil
can with a sharp pointed spout makes a satisfactory instrument
for applying the oil. Push the tip of the spout into the husk and
silk about midway between the tip of the husk and the end of the







Florida Agricultural Experiment Station


ear and squirt in the proper amount of oil. By experimenting
one can learn how hard to press the bottom of the can to force out
the right amount. It is very important that the oil should be
put into the ear after the silk has withered but before it has be-
come dry. The reason for this is that the eggs are laid on the
silks and the young caterpillars hatching from these eggs eat
their way through the silks down into the ear. When they meet
the barrier of oil they cannot eat through it and if the oil touches
them they are killed. If the oil is put in too soon, before the silk
has performed its function in the fertilization of the ovules, there
will be no kernels; on the other hand, if one waits too long the
worms will have eaten through the silk and into the ear and will
not be killed. The effectiveness of the treatment is increased by
the addition to the oil of sufficient pyrethrum extract to give a
concentration of 1/2 to 1 percent of pyrethrins I and II. This
mixture is much more toxic to the caterpillars than is the oil
alone. This treatment costs only a cent or two per dozen ears
and is therefore very practical for use on sweet corn.

CORN SAP BEETLES
If the husk on an ear of corn is torn or broken in the soft or
milk stage the exposed kernels are almost certain to be attacked
by small brown beetles (Carpophilus spp.). These beetles feed on
fermenting sap or plant juices and are common in decaying fruit.
They are about %s inch long. Their wing covers are so short that
they do not reach the end of the abdomen. The beetles seem un-
able to penetrate the husk of an uninjured ear, but very com-
monly get into the burrows made by the corn earworm 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. It is
obvious that any measures that control the corn earworm and
keep the end of the husks intact will effectively prevent injury
by the sap beetles.
THE CORN LANTERN-FLY
This insect (Peregrinus maidis (Ashm.) ) and the budworm are
the worst enemies of late planted corn in Florida. In summer the
lantern-fly becomes extremely abundant and often infests prac-
tically every stalk of corn. The young plants are quickly killed
but stalks that have reached the tasselling stage are less severely
injured. The lantern-fly is a slender yellowish-green insect
about 1/6 inch long. Its wings are longer than the body, and are







Insects and Other Pests of Florida Vegetables


clear except for some dark brown markings near the tip. These
insects collect in large numbers in the buds and in the axils of
the leaves. The colonies usually contain numerous young of all
sizes and a few winged adults.
Control.-The most effective and quick means of controlling
this pest is to dust the buds of the corn with nicotine sulfate-lime
dust, or with dusts containing pyrethrum or rotenone.

WIREWORMS, "DRILLWORMS"
Wireworms are long, slender, smooth, hard-bodied larvae
that feed on the roots of plants or on germinating seeds. Most of
them are brown in color, though some species are soft-bodied and
white or yellow. These larvae are the young of click beetles, so
called because of their habit of throwing themselves into the air
with an audible click when they are placed on their backs. They
also are called "skip jacks" and snap beetles. These beetles (Fig.
31) usually are rather slender insects with bodies tapering at






\







Fig. 31.-Spotted click-beetle: Adult; pupa; larva; and egg, greatly enlarged.
(From So. Car. Exp. Sta.)

each end. Most of them are a rather uniform brown or gray,
though some have lighter or darker markings.
There are many kinds of wireworms in Florida and several
of them are injurious to corn. They are more or less similar in
habits, life history and nature of injury. For convenience they
are discussed together. The adult beetles by preference lay their
eggs in the soil about the roots of grasses. The larvae hatching
from the eggs feed upon the roots of the grasses or other plants,
sometimes boring or tunneling in the larger roots. When corn is
planted on infested land the larvae sometimes eat out the in-







Florida Agricultural Experiment Station


terior of the sprouting seeds so that they fail to come up. If the
corn gets a few inches high before it is attacked the larvae eat the
young roots or bore into the tender stem and the plant withers and
dies. Length of the life cycle varies in different species but
those with the shortest cycle spend nearly a year in the larval
stage. Some species spend two years or even longer in this stage.
Control.-No satisfactory method of controlling the larvae
in the soil has yet been found. Some materials when added to the
soil will kill the worms but their cost is prohibitive. Seed treat-
ments to repel the larvae have been tried but to no avail.
Most wireworms are more prevalent on low, poorly drained
land, though the corn and cotton wireworm, Horistanotus uhleri
Horn, is found mainly in light sandy soils. Larvae of the spotted
click beetle, Monocrepidius vespertinus (Fabr.), are found in both
dry and wet soils, though more prevalent in the former. Draining
the low, wet soils will often greatly reduce the wireworm popu-
lation.
Crop rotation is of value in reducing wireworm damage. One
should avoid planting corn, cotton, or similar crops on land that
has recently been in grass. Early plowing would help in many
cases.
FALL ARMY WORM OR SOUTHERN GRASS WORM
This well known pest of grass (Laphygma frugiperda (S. & A.) )
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 forma-
tion to new pastures. These marches come as a result of excessive
numbers exhausting 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 in small
numbers or individually.
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 to attain full size, about 11/4 inches long. They are rather
slender. Their color is brown with a narrow yellowish-gray
stripe along the middle of the back and a brownish-black one
along each side. The middle line branches on the head, forming
a conspicuous V-shaped white mark, which helps to identify the







Insects and Other Pests of Florida Vegetables


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 re-
lated.
Control.-The isolated caterpillars may get into the tips of
growing corn and become budwormss," where they may be con-
trolled by the same measures as given for the corn earworms
when working as budworms. (See page 56). A crop can often
be protected from an advancing army of the caterpillars by the
use of the cutworm bait described on page 42. This is sown
broadcast over a strip about a rod wide along the threatened sides
of the field. As the caterpillars advance they pick up enough of
the poison to kill them before they do much damage to the crop.
They move mostly in the daytime so the bait should be applied
early in the morning. In dry weather daily applications will be
needed as the bait is not very attractive to them after it has dried
out. Threatened crops may be protected by spraying or dusting
them with lead arsenate, other arsenicals, or fluorine compounds.

ROOT WEBWORMS
These also are caterpillars (Crambus spp.) that often do se-
vere damage to young corn in the spring. They always do more
damage than they are charged with, much of their work being
attributed to cutworms. There are several species 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 off the plants. 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 cut-
worms. Furthermore, they try to escape when disturbed in-
stead of curling up and "playing possum" as do cutworms. The
adult insects are small, light colored 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 do
most moths.
Control.-Severe injury by these caterpillars is confined to
land which had considerable grass during the preceding year.
Such land if intended for corn should be broken as early as prac-
ticable in the fall. Some relief can be obtained by dusting or
spraying the young plants with lead arsenate.







Florida Agricultural Experiment Station


BILLBUGS
Other insects that injure young corn are snout beetles com-
monly called billbugss" (Fig. 32). There are several species of



r














Fig. 32.-Billbug (Calandra callouss: a, Larva; right, adult. Greatly enlarged.
(From U. S. Bur. of Ent.)

these beetles but the most common in Florida is the Southern
corn billbug, Calandra callosus Oliv. These insects normally feed
on grasses; among cultivated crops corn suffers most. They feed
on the young, tender leaves, making parallel rows of holes, after
the pattern of sap-suckers on trees (Fig. 33). This is done while
the leaf is rolled up in the bud and each row of holes is produced
by a single puncture. Eggs are laid in punctures in the stalks
near the surface of the ground. The legless grubs burrow inside
the stalks, causing them to be twisted and dwarfed.
Control.-Like root webworms, billbugs usually are inju-
rious only on land that carried much grass during the preceding
year. Eggs are laid on grasses in low wet land where billbug in-
jury is often severe. The measures recommended for use against
root webworms (page 61) are also effective against billbugs.

CORN LEAF BLOTCH MINER
This larva of a minute black fly (Agromyza parvicornis) (Lw.) )
makes irregular shaped blotches in the leaves of corn and some
grasses by eating the 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 three or four






Insects and Other Pests of Florida Vegetables


days in summer. The larval stage occupies from three to 12
days in summer. It breeds during the winter in southern Florida
(Journ. Agr. Res., April 12, 1916), but in the central and northern
parts of the state is inactive during the cool
part of the year.
Control.-The insects cannot be reached
economically with an insecticide. The only
course is to pull up and destroy badly in-
fested plants, and by good care keep the
others growing so vigorously as to overcome
the injury.
SOUTHERN CORN ROOTWORM
This insect,
(Diabrotica
12-punctata (Fab.)) ,
in both the larval .-
and adult stages,
attacks corn. The
adult (Fig. 34, a) __ -,
feeds on the leaves I'l,.
in which it makes 'i i
small holes, but is /
more common on'
the silk of the
young ears. It may *
attack also the tas-
sel or exposed ker-
nels of the ears. .,
The white, grub-
like larvae (Fig. .' ) t
34, c) mine the
roots of the corn. Fig. 33.-Injury to corn by biltbugs. (From U. S. Bur.
of Ent.)
The adult beetles
are oblong and about /4 inch long, yellowish-green in color, with
black spots on the wing covers. It sometimes is called the spotted
cucumber beetle.
Control.-No satisfactory method of control has yet been
found for this beetle when working on corn; and neither is there
any very effective method of preventing infestations by it. Plow-
ing the land well in advance of planting time and destroying
weeds and other wild vegetation around the edges of the field
will usually give some measure of protection.






Florida Agricultural Experiment Station


OTHER CORN PESTS
Other insects attacking corn are: Sweetpotato caterpillar page
99; semi-tropical army worm, page 99; and serpentine leaf-miner,
page 66. The lesser
corn stalk borer,
S( page 63, is particu-
i. larly injurious to
very late planted
S.' corn and, with the
I /'' a I budworm, is the
3\ ',i chief cause of the
Difficulty of grow-
Sing a crop of late
-fL q3 fall roasting ears in
central Florida.
S'. There has be-
d d come established in
Fig. 34.-Southern corn rootworm: a, Adult beetle, the Northern states
about six times natural size; b, egg; c, larva; d, anal
segment of larva; e, work at base of corn stalk; f, and Canada a very
pupa. (From U. S. Bur. of Ent.) 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 First World War. It is spreading over
the corn belt and may in time reach Florida. The caterpillar
mines the corn stalk and often enters the ear. Unlike the corn
earworm, it does not confine its eating to the kernels but bores
through and mines the immature cob as well.

INSECTS AND OTHER PESTS OF COWPEAS
COWPEA POD WEEVIL OR COWPEA CURCULIO
This black beetle (Chalcodermus aeneus (Boh.) ) (Fig. 35, a) re-
sembles, except in color, the cotton boll weevil and as it feeds on
young cotton in early spring it is sometimes mistaken for that spe-
cies. It is an exceedingly severe pest of cowpeas. Early in the sea-
son it feeds on the leaves, but as soon as the pods begin to form it
turns its attention to them. The females lay their eggs in the
developing seeds, making punctures through the pods. They also
feed on the pods, the feeding punctures being similar in ap-
pearance to the egg punctures. These punctures make unsightly
brown spots on pods and seeds, but the greater injury is done by







Insects and Other Pests of Florida Vegetables


the grubs that hatch from the eggs in from four to six days. The
pale yellow larvae (Fig. 35, b) eat the seeds. They require a
week or two to reach full size, then bore holes in the sides of the
pod and es-
cape to the
ground. The ,
adult is
about /4 in.
long and has :- -
deeply pit-
ted wing ;
covers.
Control. b
Rotation d
Of Fig. 35.-Cowpea pod weevil: a, Adult: five times natural size;
0o cropS b, larva; d, pupa. (From U. S. Bur. of Ent.)
should be
practiced. Land that has grown an early crop of 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 lead arsenate
and 2 pounds of hydrated lime to 50 gallons of water. The de-
struction of the early brood will materially reduce the number of
attacking the pods later. On a small garden patch or on other
particularly valuable fields the adult insects can be collected by
hand as recommended for the pumpkin bug. Rotenone sprays
are also recommended.
Poultry, especially turkeys and guineas, eat these beetles
readily. A very good way to control this pest is to allow these
fowls to have the run of the cowpea patch. Rapidly developing
pods will not be exposed as long to the attacks of these weevils
as those growing more slowly. In rapidly growing pods the eggs
may not even have hatched when the peas are harvested.

PUMPKIN BUG
This pest (Nezara viridula (L) ) attacks nearly all garden plants,
especially legumes, and is particularly at home on cowpeas. The
adult insects (Fig. 36) are a little more than % inch long, nearly as
*broad, and usually are light green in color. The young are bluish
with some white and reddish markings. They are quite unlike the
adults in appearance. There are several generations a year. Some






Florida Agricultural Experiment Station


adults of the last annual generation hibernate late in the fall and
are active again early in the spring. These insects do considerable
damage to young cowpes- but the most severe injury is inflicted
on the pods. Their nu-
merous feeding punc-
tures make unsightly
tough brown dots. They
also dwarf the pods and
if sufficiently numerous
may cause them to drop.
Control.-This is a
difficult pest to control.
Being a sucking insect,
arsenicals and other
stomach poisons are of
Fig. 36.-Pumpkin bugs. Natural size. no avail. The young
can be killed with kero-
sene emulsion or pyrethrum and rotenone sprays, but the adults
are too robust to be killed by these compounds except at strengths
that would be dangerous to the plants. The only means of com-
bating them seems to be hand collecting. On an ordinary field
crop of cowpeas it is questionable whether this 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
condition that they will bear peas in spite of the bugs. In a
garden or a particularly valuable patch of cowpeas and on such
valuable crops as beans, tomatoes, and potatoes, hand collecting
will prove profitable. For hand collecting use a shallow pan and
pour into it an inch or so of water and on this a film of kerosene.
In the early morning or on a cool rainy day when the bugs are
sluggish walk along the rows and knock them into the pan. This
is not as slow a process as it may seem at first. An alert boy can
collect most of the bugs from an acre of beans or cowpeas in an
hour or two.
SERPENTINE LEAF MINER
This (Agromyza pusilla Meig.) is a near relative of the corn leaf
blotch miner, page 62. Like that species, the larva works in the
inner tissue of the leaf but its burrow is long and narrow with
many bends, hence the name serpentine. This insect often injures
cowpeas and is also prevalent in many wild plants, especially
beggarweed and coffeeweed. Its life history is similar to that of







Insects and Other Pests of Florida Vegetables


the corn leaf blotch miner and it likewise may work all winter in
the southern part of the state. The greatest damage is done to the
first two leaves cotyledonss) of very
p young seedlings before the true leaves
appear. Both of these leaf miners have
numerous parasitic enemies which gen-
erally keep them under fair control.
Application of insecticides has not
proved of any value.


COWPEA SEED WEEVILS


Two species of weevils, the four-
spotted weevil, Callosobruchus maculatus
C (F.), (Fig. 37) and the Chinese weevil,
Mylabris chinensis (L.) (Fig. 38), both
t closely related to the bean weevil (page
35), do about the same type of damage
to cowpeas as their relative does to
beans. The bean weevil also occasion-
ally attacks cowpeas and either or both
:0 of the cowpea weevils often attack beans.
d V They may begin their work in the field
but it is in stored peas that they are es-
Fig. 37Calosobrusa specially injurious. These should be
latus (F.): a, Adult; b, c, egg specially These should be
from above and below; d, fumigated or treated, following direc-
head of mature larva. Great-
ly enlarged. (From U. s. tions for stored seeds. If cowpeas are
Bur. of Ent.)
kept in cold storage at a temperature
below 34 degrees for two or three months the eggs as well as the
weevils are destroyed.


OTHER COWPEA PESTS
Other insects attacking
cowpeas are: Wireworms,
page 59; cutworms, page 41;
leaf-footed plant bugs, page
87; lesser corn stalk borer,
page 36; and the garden flea
hopper, page 53. The harle-
quin cabbage bug attacks the
pods, page 49.


d



Fig. 38.-Mylabris chinensis: a, Adult; b,
egg; c, larva. About seven times natural
size. (From U. S. Bur. of Ent.)







Florida Agricultural Experiment Station


INSECTS AND OTHER PESTS OF CUCUMBERS

PICKLEWORMS
Cucumbers and cantaloupes with holes bored in them (Fig.
39) are familiar to Florida growers though more common some


















Fig. 39.-Injury by pickle worm to ripening cantaloupes. (From No. Car. Agr. Exp. Sta.)

years than others. Two species of insect are responsible for this
damage, the pickleworm (Diaphania nitidalis (Stoll) ) and the
melonworm. They are closely related, very similar in appear-
ance, and usually are not differentiated by the trucker. Either or
both species may be found on cucumbers, melons, squashes, and
gourds. They differ in their habits; consequently methods of con-
trol must differ.
The more common of the two is the pickle worm. This is a
whitish caterpillar with conspicuous black dots on each segment.
In the early part of the season it bores into the buds, blossoms,
stems, and leaf stalks, but as the fruits form it confines its atten-
tion largely to them, usually entering from the side near the
ground. In addition to the injury caused by the worms feeding
on the tissue of the cucumber, the entrance hole affords a point
of entry for various molds and other organisms of decay which
quickly spoil the fruit.
The eggs are laid on the parts of the plant used for food by
the caterpillars. After the fruits are formed most of the eggs are







Insects and Other Pests of Florida Vegetables


laid on them, usually on the underside. The eggs hatch in three
or four days. The larva bores into the plant, feeds and grows for
about two weeks, after which it becomes coppery in color and
the black dots become less conspicuous. It soon pupates in a dried
leaf or other shelter and in about a week or 10 days the moth
(Fig. 40) comes forth. The moth has a brown body and the wings
are purplish-brown, with an area in the
middle of the front wings and the basal
half of the hind wings clear yellow. At
the end of the body is a conspicuous
brush of black hairs. It measures about
one inch across the outstretched wings.
This insect is commonly seen about
and it may fly in the daytime. The .,.
moth lays 300 or more eggs during its Fig. 4.- Ploe.rm moth.
lifetime.
Control.-The pickleworm, because it feeds in the interior of
the buds, blossoms and fruits, cannot effectively be reached by
dusts or sprays. This means that the grower must depend upon in-
direct methods of control. He should carefully collect and destroy
all wormy fruit. If these wormy cucumbers and melons are left in


Fig. 41.-Trap crop of squash for pickle and melon worms in cantaloupe field. (From
Bur. Ent., U.S.D.A.)


. .- 11 I







Florida Agricultural Experiment Station


the field the caterpillars will leave them and enter fresh ones,
or complete their growth and emerge as moths in a week or two.
Field sanitation should be practiced, not only on account of
these insects but also to keep down fungous diseases. As soon as
the crop is harvested, vines, fallen leaves, and other refuse should
be raked up and burned or plowed under.
The best preventive measure against these worms is a trap
crop. For this purpose plant from four to eight rows of early
summer crook-neck squash in each acre of cucumbers or canta-
loupe (Fig. 41). The large blossoms and leaves and the tender
fruits of the squash are preferred by the moths to either cucum-
bers or melons, and most of the eggs will be laid on the squash.
It is better to make several plantings of the squash to provide
a succession of blossoms and fruits attractive to the moths. The
first planting should be made at the same time the cucumbers
or melons are planted, followed by other plantings at intervals of
a week. The last planting may be placed in hills where cucum-
ber plants are missing. The infested squash blossoms and fruit
may be picked and destroyed, or if the melon worm is abundant,
the vines should be sprayed with one of the arsenicals. The quick-
est way to destroy the pests on the trap plant is to pull up and
burn each lot of trap plants as soon as it has become heavily in-
fested and before the worms have reached their full size. If this
is neglected the trap crop will serve as a breeding ground for the
moths and thus be a menace rather than a protection to the main
crop. The spring crop of cucumbers and melons should be planted
as early as weather conditions will allow. These insects, as well
as melon worms, become more numerous as the season advances.

MELONWORM

The melonworm (Diaphania hyalinata (L.) ), in addition to
boring into the fruits and stems, feeds extensively on the leaves
of the plants attacked before the fruits are formed, thus differing
from the pickleworm. The melonworm has longitudinal stripes
instead of the black dots of the pickleworm and it never becomes
coppery-colored. The moth, which is slightly larger than the
pickleworm moth, is an insect of striking appearance, with a light
brown body ending in a large brush of dark or yellowish hairs,
and pearly white wings bordered by a broad, even band of brown-
ish-black. The eggs are laid chiefly on the young leaves.







Insects and Other Pests of Florida Vegetables


Control.-This species can be controlled with arsenical -and
other poison sprays because it feeds partly on the foliage. A
pound of lead arsenate should be used to 50 gallons of water. To
the 50 gallons of spray should be added 2 pounds of hydrated
lime, or the milk obtained by slaking 2 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 fungous diseases, the arsenical may be added to the bor-
deaux, in which case the lime is omitted.
The trap crop of squash suggested as a means of protection
against the pickle worm is also strongly recommended in the case
of the melon worm.

STRIPED CUCUMBER BEETLE
This very troublesome enemy (Diabrotica vittata (F.) ) of
the Northern grower of cucurbits is usually entirely absent in
central Florida, although it is present in the western and southern
parts of the state. Apparently this beetle will not breed in sandy
soils (Arkansas Exp. Sta. Bul. 216). This is undoubtedly the
reason for its complete absence in most sections of peninsular
Florida.
The adult (Fig. 42, a), is a yellow beetle striped with black,
measuring about 1/4 inch long. It eats the leaves of cucumbers,
squash, melons, beans, watermelons, okra, and even those of cit-
rus trees. The slender
white larvae (Fig. 42, 41-
b) feed on the roots of 'i -,'
these plants into which
they tunnel, some-
times reaching the
base of the stems. In
the North the adults
are troublesome to c
young plants only but 'R i"
in southern Florida
they attack and kill d
full grown, bearing Fig. 42.-Striped cucumber-beetle: a, Adult, six times
vine s. Consequently, natural size; b, larva; c, pupa. (From U. S. Bur.
of Ent.)
the northern practice
of covering the young plants with cheesecloth for a few weeks is
not effective in Florida.







Florida Agricultural Experiment Station


The female lays about 100 eggs during her lifetime of about
a month. They are laid on the surface of the ground near the base
of the plants, and hatch in about a week. The larval stage lasts
about a week, and the complete cycle from egg to adult can take
place in a month or five weeks under favorable conditions.
Control.-Where abundant, as it is in the Everglades, this in-
sect is very difficult to control. The late C. C. Goff, assistant
entomologist of this Station, obtained the best control by alter-
nately spraying the plants with lead arsenate in bordeaux and
dusting with a fluosilicate or fluoride. A pound of lead arsenate
was added to 50 gallons of bordeaux and the plants were 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 it has a tendency to
repel the beetles. Spraying twice a week, which is necessary to
give protection with the bordeaux-lead arsenate alone, was in-
jurious to the plants; hence the recommendation of a spray once
a week with the bordeaux-lead arsenate and a dust once a week
with a fluosilicate or fuloride.
A trap crop of summer squash as recommended for the pickle-
worm will also have a tendency to attract these beetles away
from the cucumbers or cantaloupes, as the beetles prefer the
squash, but only when the squash is older. Therefore, it is recom-
mended that the trap crop be planted somewhat earlier than the
cucumbers.
BANDED CUCUMBER BEETLE
This insect (Diabrotica balteata Lec.), a close relative of the
striped cucumber beetle, is becoming very common on many
truck crops, including cucumbers. The adult beetle is yellowish-
green with three bright green stripes or bands running across
the wing covers. It is more general in its feeding habits than
the striped cucumber beetle but it has not been as numerous on
any one crop as that species often is. It is a comparatively recent
immigrant from the West and seems to be getting more abundant
year by year. It is not confined to any certain sections of the
state but it has been taken in many different localities.
Control.-This insect will yield to the control measures
advocated for the striped cucumber beetle, but it will seldom
be necessary to spray or dust as often as for that species.







Insects and Other Pests of Florida Vegetables


MELON APHID
This plant louse (Aphis gossypii Glov.) is nearly as destructive
to cucumbers as to melons. It attacks the plants in all stages of
growth but does the greatest damage while the plants are small.
Control measures suggested for aphids on watermelons (page
112) .will prove effective on cucumbers also.
OTHER CUCUMBER PESTS
Other pests attacking cucumbers are: Cutworms, page 41;
thrips, page 106; tarnished plant bug, page 54; wireworms, page
59; red spiders, page 81; root-knot, page 31; and 12-spotted cu-
cumber beetle, page 63.

INSECTS AND OTHER PESTS OF DASHEEN
This plant seems to be almost immune to insect attacks. The
senior author has seen the tubers of plants growing in a very
wet place attacked by the larvae of a crane-fly. Some of the
tubers were half eaten and in the hollows were found empty
pupal cases of the crane-flies. 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
gallinippers, but are incapable of injuring man. Injury to dash-
eens by this insect has not been observed where crops are grown
on properly drained soils.
Dasheens are also attacked by the rotton-log caterpillar, and
quite seriously by root-knot nematodes (see page 31).

INSECTS AND OTHER PESTS OF EGGPLANT
Many of the insects that attack eggplant in Florida are like-
wise pests of potatoes and tomatoes and are discussed under those
crops. A few insects, however, are rather peculiar to eggplant
and are discussed here.
EGGPLANT LEAF MINER
This insect (Gnorimoschema glochinella (Zell.) ), closely related
to the potato tuber worm and the tomato pinworm, is similar to
them in appearance and habits. As its name indicates, it mines
in the leaves of eggplant, eating the soft inner tissue of the leaves






Florida Agricultural Experiment Station


but leaving the upper and lower epidermises. The mines are
almost entirely confined to the edges of the leaves. These appear
as irregular, light colored areas which later turn brown. The
eggs are laid on either the upper or lower side of the leaves. The
young caterpillars are whitish at first but later become brown or
bluish-green. The pupae are found in the dried remnants of
fallen leaves or sometimes in the soil very near the surface. The
adult is a small, gray, inconspicuous moth that is seldom noticed.
The exact life history of the insect in Florida is not known but it
probably can complete its life cycle in about a month.
Control.-Because it feeds entirely within the leaves, control
of this insect by means of insecticides is not practical. Some
measure of protection is possible through crop rotation and sani-
tation. One should not plant two successive crops of eggplant
on the same land, particularly if the first crop is infested with
leaf miners. After harvest of the crop is completed the plants
should be destroyed. This may be done by pulling them up and
burning them after they are dried or the land may be disked and
plowed, taking care that all crop residue is well covered.

COTTON STAINER AND OTHER PLANT BUGS
The cotton stainer (Dysdercus suturellus (H.-S.) ) feeds on
cotton, hibiscus and related crops, often occurring in fairly large
colonies. When it feeds on the bolls of cotton the lint is stained
an indelible yellow, whence its common name. Occasionally it
attacks eggplant, feeding on and injuring the young plants and
later feeding on the young fruits. A hard brown spot develops
where a feeding puncture has been made in a fruit and if the fruit
is very young it may be deformed. Numerous punctures in a
small fruit may even cause it to become yellow and fall off.
The adult bugs are somewhat over 1/2 inch long, with a red
body and head, and dark brown wings bordered with white.
The young or nymphs are a brilliant shining red and very con-
spicuous against green vegetation.
Control.-The younger stages of this insect can be killed
with sprays containing pyrethrum or rotenone'but the older
nymphs and the adults are more resistant. Hand collecting is
practicable for gardens or small truck patches. These insects feed
regularly on cottonseed meal and advantage can be taken of this







Insects and Other Pests of Florida Vegetables


habit to trap them. Small piles of the meal are placed about in
the field and when the bugs gather on it to feed they may be
collected or sprayed with kerosene and killed. The Spanish
cocklebur, Urena lobata, is one of the favorite wild host plants of
the cotton stainer and it should be destroyed when growing in the
vicinity of vegetable fields as well as around cotton fields or
citrus groves.
Other plant bugs that occasionally attack eggplant are: Brown
stink bugs, Euschistus spp., which resemble the pumpkin bug in size
and general appearance but are brown instead of green; the big
convict bug, Corecoris fuscus (Thun.), a broad, flattened insect with
alternating black and yellow bands on each side of the body; and
the crane-fly bug, Leptocorisa tipuloides (DeG.), a long slender
insect with long delicate legs. These insects normally feed on
weeds and other wild vegetation. Though a few of them can be
found in most truck fields they do not often get abundant enough
to cause serious damage. When present in sufficient numbers to
be injurious the younger nymphs can be killed with pyrethrum
or rotenone sprays, but hand collecting is the only method of deal-
ing with the adults.

APHIDS
Three species of aphids have been taken on eggplant in
Florida. They are the melon aphid, Aphis gossypii Glov.; the potato
aphid, Macarosiphum gei (Koch); and the green peach aphid, Myzus
persicae (Sulz.). All of these species may at times become nu-
merous enough to damage the crop. Control measures recom-
mended for use against cabbage aphids will prove effective against
the aphids of eggplant.

PEPPER WEEVIL
The pepper weevil (Anthonomus eugenii Cano.) feeds on egg-
plant but rarely breeds there. In the region where this insect
occurs, eggplant should be destroyed after harvesting is com-
pleted, as is recommended for peppers.

OTHER EGGPLANT PESTS
Other pests of eggplant are: Flea beetles, page 39; garden
flea hopper, page 53; Colorado potato beetle, page 88; harlequin
cabbage bug, page 49; red spiders, page 81; and root-knot, page 31.






76 Florida Agricultural Experiment Station

INSECTS AND OTHER PESTS OF LETTUCE
Lettuce has no serious insect pests peculiar to itself. There
are, however, several kinds of insects which normally attack other
crops that occasionally do some damage to lettuce.
The cabbage looper, page 43, and the imported cabbage worm,
page 44, sometimes injure lettuce rather seriously. A single larva
of either of these insects, feeding in the heart or bud, may com-
pletely ruin a lettuce plant. Control measures suggested for
cabbage are satisfactory on lettuce also.
Various species of leaf hoppers and plant bugs feed on
lettuce, occasionally causing some damage. The smaller forms
can be controlled by the use of pyrethrum or rotenone sprays or
dusts. Hand picking is the most effective method of dealing with
the larger, more resistant plant bugs.

OTHER LETTUCE PESTS
Other pests attacking lettuce are: The corn earworm, page 55;
tarnished plant bug, page 54; banded cucumber bettle, page 72;
cutworms, page 41; aphids, page 47; and root-knot, page 31.

INSECTS AND OTHER PESTS OF MUSTARD'
The insect pests of mustard are almost exactly the same as
those attacking turnips, and both of these crops have many pests
in common with cabbage. All the caterpillars that are discussed
under cabbage feed upon mustard, though they inflict less dam-
age here than on cabbage. Control measures are the same, but
one must be more cautious in using arsenicals, as practically the
whole of the mustard plant is used for food. The turnip aphid,
Rhopalosiphum pseudobrassicae (Davis), is more of a pest on mustard
than on cabbage. Varieties with broad and relatively smooth
leaves appear to be less heavily infested than the smaller leaved,
rough varieties.

INSECTS AND OTHER PESTS OF OKRA

OKRA CATERPILLAR
Okra leoves often are eaten by light green caterpillars (Anomis
erosa Hubn.) without conspicuous markings (Fig. 43). The moth
(Fig. 44), has a wing spread of about one inch. The front wings
are yellow at the base and brown toward the end, the hind wings
are light at the base and brown toward the outer end. The eggs,






Insects and Other Pests of Florida Vegetables


which are laid on the leaves, hatch in three or four days and the
larvae require a little over three weeks to reach their full size
of about 14 inches. A little less
than a week is spent in the pupal
stage, the entire life cycle from
egg to adult thus requiring slight-
ly over a month.
C o n t r o1 .-The caterpillar
stage is attacked by a small wasp-
like parasite, Brachymeria ovata
Say, which doubtless prevents it
from becoming a greater pest.
When the caterpillars attack the
okra before the pods begin to form
Fig. 43.-Okra caterpillar: Larva. Nat- they are easily controlled by
ural size.
spraying or dusting with lead ar-
senate, as indicated for the control of cabbage worms, page 46. In
case of later infestations when the plants are producing pods it is
unsafe to use arsenicals and rotenone compounds must be resorted
to for controlling the caterpillars.

CORN EARWORM
The corn earworm attacks the nods of okra much as it does
cotton bolls, or seedpods of tobacco (Fig. 45); that is, it bores into
the pods and feeds on the interior. Control measures are the same
as those used against this insect on tomatoes, page 103.

COTTON-SQUARE BORER
Young okra pods sometimes are bored into by thick-bodied
green caterpillars (Strymon melinus Hbn.) about a half inch long
when fully grown. This insect is not par-
ticularly destructive but it is of interest
because it is about the only member of the
family of butterflies known as hair
streaks that is of any economic im-
portance. The adult is a fragile insect
with a wing-spread of about 1Y4 inches
and it has the delicate hair-like tails
on the hind wings which give to the fam-
ily the name of hair streak. The cat- Fig. 44.-Okra caterpillar:
erpillars attack young cotton squares at a, adult male; b, adult fe-
male. Natural size.






Florida Agricultural Experiment Station


times and they have also been found boring into the blossom
buds of loquats.
Control.-If the caterpillars become numerous enough to war-
rant control measures, the rotenone compounds should be used.

A. *-- ^ ROOT-KNOT
Of all the common
hosts of root-knot nema-
todes, okra is without
doubt the most seriously
injured by their attacks.
SThe young plants very
quickly show the charac-
teristic galls and this
e x t r e m e susceptibility
makes okra an excellent
test plant for growing on
land to determine
whether or not it is in-
fested with nematodes.
It is useless to attempt to
grow okra on land that
is known to be infested,
as the crop will not only
-.. .:W be a failure but the num-
b-- ers of nematodes in the
Fig. 45.-Corn ear-worm on tobacco seed pods. oil will be greatly in-
About natural size. d il will be greatly in-
creased.

OTHER OKRA PESTS
Other pests of okra are: Aphids, page 47; flea beetles, page
39; cutworms, page 41; pumpkin bugs, page 65; and red spiders,
page 81.
INSECT AND OTHER PESTS OF ONIONS
ONION THRIPS
These thrips (Thrips tabaci Lind.) (Fig. 46) are responsible
for the blanching and withering of the tips of onion leaves. They
are very scarce in the fall of the year when the onions are com-
monly planted. The heavy summer rains are very hard on this
thrips and it is difficult to find any specimens whatever during
the latter part of the summer.






Insects and Other Pests of Florida Vegetables


Investigation of onion sets bought in Florida seed stores have
shown an average of about 75 of these insects per quart, which is
sufficient to start an infestation. It is evident that onion sets put
out in the fall are an important source of infestation of this thrips.
During the fall and
winter they gradually
build up to large num-
bers and by spring
they are almost uni-
versally present in all
onion fields. Like
other thrips, they are
Always more abundant
in dry weather and
S- comparatively scarce
after a rainy period.
Thrips have
mouthparts of the
sucking type. Their
shallow feeding punc-
tures are very numer-
Fig. 46.-Onion thrips (Thrips tabaci). Greatly magni- ous and close together
fied.
so that the surface of
the fresh wound has the appearance of having been rasped. Later,
the tip of the leaf whitens and shrivels. This continuous killing
of leaves greatly interferes with the growth of.the onions, and
effective control measures will repay their cost many times over.
This insect attacks cabbage, cauliflower, tobacco, turnips, mustard,
and many other plants, but is most serious on onions.
Eggs are placed singly in the leaf tissue just below the sur-
face. They hatch in about four days. The larval stages last from
seven to nine days, the insect molting twice. Then follows the
nymphal stage during which the insect is dormant and takes no
food. The wing pads first appear during this stage, which lasts
four days.
Control.-By destroying the thrips on onion sets before they
are planted one can often prevent an infestation of the insects on
the crop. This may be accomplished by soaking the sets for a few
minutes in a solution containing pyrethrum or rotenone com-
pounds, at the dilution indicated on the container.
Thrips on the growing crop can be controlled by the use of a
good contact insecticide. One half-pint of 40 percent nicotine






Florida Agricultural Experiment Station


sulfate and 3 or 4 pounds of soap to 50 gallons of water makes
a spray that has long been used for controlling thrips. A more
economical and efficient spray will be obtained by substituting
for the soap some of the better spreaders such as oil derivatives
or the oleates. The use of these spreaders permits a reduction in
the amount of nicotine necessary, thereby lessening the cost.
In spraying for the onion thrips it is very important to have
good pressure to force the spray down into the axils of the leaves
where the thrips hide. When planting a field of any considerable
size, roadways should be left every 100 feet so that a power
sprayer may be driven through the patch. Because it is difficult
to get the nymphs and eggs that are hidden in the bases of the
leaves or elsewhere at the time of spraying, a second application
may be needed in some cases.

OTHER ONION PESTS
Other insects attacking onions are: Fall army worm, page
60; wireworms, page 59; and cutworms, page 41.

INSECTS AND OTHER PESTS OF PARSLEY
Parsley is not grown very extensively in Florida and neither
is it subject to severe injury from insect attacks. There are, how-
ever, two pests that occasionally cause some damage to the crop.
These are celery caterpillars, page 54, and cutworms, page 41.

INSECTS AND OTHER PESTS OF ENGLISH PEAS

PEA APHID
This (Macrosiphum pisi (Kalt.) ) is by far the most serious pest
of peas in Florida. The plants may be attacked at almost any
stage of growth, the aphids being largely confined to the growing
tips and the young pods on the older plants. An infestation at any
time causes some injury but the most severe damage occurs dur-
ing periods of drouth when a heavy infestation may kill a whole
field of peas within a few days.
This is one of the largest aphids commonly found on vege-
table crops. When fully grown they are about Vs inch long and
those with wings measure nearly %/ inch from tip to tip of the
spread wings. They are pale green in color and blend so well
with plant foliage that even a heavy infestation may escape notice.
They multiply very rapidly and an extremely heavy infestation







Insects and Other Pests of Florida Vegetables


can develop from a few small colonies in the course of two or
three weeks. While the plants are succulent and growing rapidly
nearly all the aphids will be wingless, but if they become very
crowded or if the plants begin to wither most of the insects will
develop wings.
Control.-The large size of this aphid and the fact that many
of them are well protected under the blossom bracts or in the
growing tips make control more difficult than for most aphids
found on truck crops. Nicotine sulfate-lime dust is fairly effec-
tive when conditions are favorable for its use. A 4 percent dust
is preferable to the 3 percent dust ordinarily used for controlling
aphids, however. If the air is very quiet and the temperature is
above 70 degrees F. good results can be obtained from dusting in
the open. It is usually rather windy in early spring when the
peas are grown so that effective dusting is often difficult. If a
power duster is used this difficulty can be largely overcome by
enclosing the discharge nozzles under a cover of waxed muslin
or similar material and extending this cover backward as a trail-
ing sheet 50 to 100 feet long. This contrivance prevents the dust
from blowing away so quickly. It remains in contact with the
aphids for several seconds so that a very good kill results. Ex-
cellent results have been obtained when some of the rotenone-
bearing dusts have been substituted for the nicotine sulfate-lime
dust. More expensive than nicotine, these dusts remain effective
longer so that reinfestation is delayed and fewer applications are
necessary. They also are more effective than nicotine in cool
weather.
RED SPIDER
Another pest that becomes a serious menace to peas in dry
spring weather is the common red spider, Tetranychus telarius (L.).
Either the red spider or the aphid or both usually destroy the late
winter crop of peas unless control measures are taken. They
damage the plant by sucking the sap from the leaves. Each punc-
ture is extremely minute but in severe infestations the plants
become white, the chlorophyll or green coloring matter being re-
moved with the sap. Peas attacked by this pest 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 after the damage is first noticed the vines may be dead.






Florida Agricultural Experiment Station


This pest is not a true insect but belongs to the spider class
of animals, though to a subdivision distinct from the large garden
spiders. It is more closely related to the "red bugs." Members
of this group are called "spider mites" and also "spinning mites"
from the habit many of them have of spinning a silken web over
the host plant. "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 always red, but are often yellow
and sometimes green. They spin irregular strands of silk all over
the infested part of the host plant, using this web as a road over
which to travel. The web also serves to hold the eggs to the
leaves and perhaps it tends to lessen the danger of the mites being
washed off by heavy rains. They spread principally by crawling
from place to place, but they may be carried by the wind.
The spinning mites are usually round in outline, small, and
have eight legs when full grown. This number of legs at once
serves to distinguish spiders from insects, which always have
six legs in the adult stage. Although they are troublesome out of
doors only in dry weather, they may be troublesome throughout
the year in greenhouses, on house plants, and in other places
sheltered from rain.
The eggs hatch in from three to five days. The young mites
require about 10 days during warm weather for growth and the
adults are about four days old before they begin to lay eggs. Be-
tween two and three weeks is the time usually required for a
generation but it has been found to be as short as 10 days and as
long as 35 days.
Control.-As these mites are dry weather creatures, one of
the most effective means of control is frequent and heavy sprink-
ling, especially if strong pressure can be used. The common sys-
tem of overhead irrigation supplies a fairly satisfactory means of
control. A stream of water knocks off many of the mites and the
moisture aids their numerous natural enemies. If a sprinkling
system is not available, recourse must be had to insecticides.
The best are those containing sulfur in some form, or
some of its compounds may be used, as either dusts or sprays.
Free sulfur is one of the best remedies for spinning mites. It is
somewhat slower in its action than some compounds of sulfur,
often taking two or three days or more to do its work, but it
remains active for a long time (frequently two or three weeks)
and usually kills all the mites. Sulfur can be applied dry and







Insects and Other Pests- of Florida Vegetables


blown into the vines with a hand duster or shaken through a
closely woven cloth bag or a perforated can. Sulfur alone does
not dust very well, so it is better to mix 9 pounds of dry sulfur
with 1 pound of hydrated lime. A satisfactory spray consists
of 5 pounds of wettable sulfur in 50 gallons of water.
Whether the grower can use the dust or the spray most
economically will depend on a number of things, such as the outfit
that may be available, the distance the water must be hauled,
and the severity of the infestation. The spray is a little quicker
acting than the dust, particularly in cold or wet weather. Best
results will be obtained by applying the dust at night or in the
early morning 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
conditions the vaporization of the sulfur takes place more rapidly,
and it is these vaporization products that are most effective in
killing the mites. The
S plants should be dry
when the spray is used.

f !PEA WEEVIL
c This weevil (Bruchus
pisorum (L.)) (Fig. 47)
works in dried peas in
SSthe same manner that
the bean weevil works
Fig. 47.-Pea weevil (Bruchus pisorum): b, Adult; c, in beans. It is closely
full-grown larva; d, pupa; g, pea showing exit
hou: natural size. Much enlarged. (From U. S. related to that species
Bur. of Ent.)
and the treatment of in-
fested seeds is the same. (See bean weevil, page 35.)

OTHER PESTS OF PEAS
Other pests of peas are: Plant bugs, page'86; pumpkin bugs,
page 65; and banded cucumber beetle, page 72. The corn ear-
worm, page 55, frequently mines the pods of peas.

INSECTS AND OTHER PESTS OF PEPPERS
The insects attacking peppers are mostly those found also
on eggplant, potatoes, and related plants but two pests, the pepper
weevil and the pepper stem weevil, are largely confined to
peppers.







Florida Agricultural Experiment Station


PEPPER WEEVIL
In 1935, this insect (Anthonomus eugenii Cano.), which has long
been known as a pepper pest in Mexico and the Southwest, was
discovered in Manatee County, Florida. Since that time it has
spread to adjoining counties and it seems likely to spread to other
pepper growing sections. There are two methods by which it
principally spreads to new territory. The adults are rather good
fliers but their spread in this manner is relatively slow. They
may easily be carried over much greater distances through the
agency of man. In one recorded instance a live weevil traveled
15 miles on the windshield of an automobile. In the early part of
the season, before the pepper plants begin to bear fruit, the wee-
vils feed on the leaves and may be carried from place to place on
young plants. Field boxes and implements used in infested fields
may also carry weevils to new localities.
This weevil is capable of doing much damage. This was
clearly shown in the infested region where it completely ruined
the crop in several fields. The pepper weevil is closely related
to the boll weevil and resembles it in general appearance, though
it is much smaller. Both insects attack their host plants in a
similar manner but the pepper weevil never feeds or breeds in
cotton and the boll weevil never bothers peppers. The adult
pepper weevil is about 1/s inch long and the head is prolonged
in a long slender snout (Fig. 48). The body of freshly emerged


















Fig. 48.-a, dorsal view of the pepper weevil; b, side
A view of pepper weevil's front leg, showing the
single spine on the femur. (From Bul. 310.)






Insects and Other Pests of Florida Vegetables


adults is rather thickly covered with flattened pale scales which
give it a grayish appearance. As the insects get older many of the
scales are rubbed off, particularly on the back, leaving a shining
dark brown body color.
The eggs are laid in small punctures made by the females in
the unopened blossom buds or in young peppers. The short, thick,
grub-like larvae feed either in the interior of the bud or in the
central seed mass in the center of the young fruit. When the
larvae are full grown they pupate where they have been feeding
and a little later the adults emerge. The eggs hatch in about
three days, the larvae become full grown in six to nine days and
the pupal stage lasts four days. This short life cycle of just a
little over two weeks accounts for the very rapid multiplication
of the insect.
The first indication of the presence of this weevil in a pepper
field is the excessive dropping of the blossom buds and of the
young peppers up to an inch long. If some of these are broken
open one can usually find some of the larvae, pupae or adults.
Control.-Because the larvae feed entirely within the buds
and fruits, control by means of insecticides is not practicable. The
most satisfactory and effective method of control for succeeding
crops consists of thoroughly cleaning up and destroying all the
crop residue when the picking season is over. Although the
adults feed to a limited extent on a wild Solanum in Florida, they
apparently breed only in peppers and occasionally in eggplants.
A thorough clean-up of the pepper fields will thus result in al-
most complete destruction of the insect. If the complete de-
struction of all peppers and eggplants, including the hot peppers
grown for pickles, could be accomplished this this pest might very
probably be exterminated. Unfortunately, a few hot peppers
grown in dooryards or gardens usually escape and these serve to
carry the weevil through the summer until the next crop is
planted in the fall. Even though this is the case, the individual
farmer can, through a thorough clean-up of his own fields, be
reasonably sure that he will not be much troubled by this pest
the following year.
PEPPER STEM WEEVIL
Early in 1934 this weevil (Collabismodes cubae Boh.) was found
attacking peppers in the southeastern part of the state. It differs
markedly from the other weevil in habits and it is somewhat
larger. It is yellow and dark brown and there are a few scattered






Florida Agricultural Experiment Station


white scales that give it a roughened appearance. The snout is
shorter and thicker than in the other species.
The larvae of this insect bore in the stems of peppers and
tomatoes, attacking any portion of the stem from the taproot to
the tips of the branches. Seldom does it enter the fruits. Pupa-
tion takes place in the mines in the stems and the adults emerge
from small openings made in the side of the stem. Peppers and es-
pecially tomatoes are the principal food plants of this insect but
it has been reared from potato stems, in small numbers from
eggplant, and once from a wild nightshade.
Control.-Hidden as it is in the stems, this weevil cannot be
reached with insecticides. A thorough destruction of all pepper
and tomato plants at the close of the picking season has given
very good control the following year. The adult is not a very
strong flier and if the growers will systematically clean up and
destroy their pepper and tomato crop residue they should be able
to hold the insect well in check.

OTHER PESTS OF PEPPER
Other insects attacking peppers are: Aphids, page 47; flea
beetles, page 39; garden flea hopper, page 53; pumpkin bug, page
65; blister beetles, page 38; corn earworm, page 55; and banded
cucumber beetle, page 72.

INSECTS AND OTHER PESTS OF POTATOES
BIG-LEGGED PLANT BUG
This big brown bug (Acanthocephala femorata (Fab.) ) (Fig. 49)
with the much enlarged hind legs is quite common on early
potatoes, especially those planted near the
~ hammocks in which the bugs hibernate. It
Sis by far the largest plant bug in Florida,
being more than an inch long. Like the other
S plant bugs, its food is the juices of succu-
Slent, rapidly growing plants, especially the
potato. Not only is the potato plant very
succulent, but its large stems furnish suffi-
cient support for these heavy bugs. The in-
.. sects usually settle to feed three or four in-
Fig. 49.-Big-legged plant- ches below the top and withdrawal of sap
causes the tip of the plant to wilt markedly.
If feeding continues the top will die.







Insects and Other Pests of Florida Vegetables


Control.-These insects are so large and.their effects on the
plants so conspicuous that collecting them by hand is an easy
matter. The wilted tops show the location of the bugs. Two or
three collections during the season will usually suffice.
This bug and the leaf-footed plant bug are particularly
abundant in early spring on thistles. These weeds should be cut
down when growing within several hundred feet of truck fields.
Otherwise, when they mature and die down the bugs may migrate
to potatoes and other crops.
The senior author has successfully used sunflowers as a trap
crop to keep these bugs off of Irish potatoes. 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 100 feet through the field will afford fair protection to the
potatoes. The bugs that gather on the sunflowers should be col-
lected and destroyed at frequent intervals.

LEAF-FOOTED PLANT BUG
This bug (Leptoglossus phyllopus (L.) ) attacks the great ma-
jority of truck and garden crops, but potatoes, beans, cowpeas,


and tomatoes are favorites. .It also
attacks citrus. It is not as large as
the big-legged 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 is readily recognized by
the yellow line running across the wing
covers and the peculiar flattening of its
hind legs, which suggests its name
(Fig. 50).
Control measures suggested for use
against the preceding species will also
prove effective against this insect.


MAY BEETLES OR WHITE GRUBS
These large fleshy white grubs (Phyllophaga spp.) (Fig. 51)
which are so injurious in grass lands do some damage to potatoes
planted on land that was previously in grass. They feed on the
tubers but usually do not eat more than half of the potato, hol-
lowing it out on one side. They seldom eat the main stem of


Fig. 50.-Leaf-footed plant-
bug. Enlarged.







Florida Agricultural Experiment Station


the plant. These grubs are a favorite food item of moles, which
in tunneling the ground for the grubs may do more damage to
the potatoes than do the grubs. Ridding a field of white grubs
will greatly lessen the number of moles.
White grubs
are slow growing
and very long
lived. All spend .,Q-
many months in
the larval stage,
some three years '
or more. When --- e b
full gro w n the Fig. 51.-May-beetle or June-bug (Phyllophaga fervida): a,
grubs form pupae Adult; b, pupa; c, egg; d, young grub; e, full-grown grub.
grubs form pupae Natural size. (From U. S. Bur. of Ent.)
(Fig. 51, b) in
earthern cells in the ground. The adults (Fig. 51, a) are the well
known "June bugs" or "May beetles" which occasionally are so
abundant about lights. Like the cutworms, 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. Allow
chickens and turkeys and such wild birds as crows and grackles
to follow the plow, or turn pigs into the field for a few weeks be-
fore plowing. It is particularly important to take these precau-
tions if there has been much grass on the land. Skunks are per-
sistent enemies of white grubs as well as other insects and they
should be protected by farmers.
The large carrot beetle, Ligyrus gibbosus (DeG.), does about
the same damage as white grubs, has a similar life history, and
will yield to the same control measures.

COLORADO POTATO BEETLE
This important potato pest (Leptinotarsa decemlineata (Say))
which is so well known to Northern potato growers has become
established in much of Florida. In some fields it has become nu-
merous enough to cause an appreciable amount of damage, but in
Florida it is nowhere near as destructive as in the North.
The adult is an elongated-oval insect about 3/ inch long. Its
wing covers are striped with yellow and black, the 10 black stripes
giving it its specific name which means "10-lined." The larvae







Insects and Other Pests of Florida Vegetables


or grubs are a deep brick red with black spots on the sides. When
the larvae become full grown they burrow into the ground to
pupate. Both the adults and the larvae feed on potato leaves,
though the larvae are much more destructive. Potatoes are the
favorite food plant of this insect but it also attacks tomatoes,
eggplant, peppers, and to a slight extent several other plants.
Control.-The insect is easily controlled by the use of arseni-
cals. When potatoes are sprayed regularly with bordeaux mix-
ture for disease control, 1 pound of lead arsenate added to each
50 gallons of bordeaux will control the beetle. Many growers use
copper-lime dust for disease control and the lead arsenate can
very well be added to this, in fact, some of the commercial copper-
lime dusts have the arsenical included at the mixing plant.
APHIDS
Aphids (Macrosiphum gei (Koch) ) are a rather severe pest of
potatoes in some sections of the state. The most prevalent species
is the one named above, commonly called the potato aphid. This
is a large green plant louse which rather closely resembles the pea
aphid. In the North, pink and green forms of this aphid occur
but the pink form has not been found in Florida. Other aphids
found on potatoes here are: The melon aphid, Aphis gossypii Glov.,
the green peach aphid, Myzus persicae (Sulz.), and Myzus convolvuli
(Kalt.), that appears to have no common name.
Control.-The control measures recommended for the pea
aphid will also prove effective when used on potatoes.
MEALYBUGS
When potatoes are kept in a dry place and allowed to sprout
slowly they frequently become infested with mealybugs (Pseu-
dococcus citri Risso). They are most noticeable on spring-grown
potatoes which are kept through the summer for planting in the
fall. They collect in the eyes and about the bases of the sprouts.
Mealybugs give off a copious excretion of honeydew, in which a
black fungus called sooty mold grows, as on a citrus tree infested
with whitefly (See Fla. Ext. Bul. 88). Mealybugs are sucking in-
sects and their presence in large numbers on the sprouts interferes
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 seed
potatoes is to wash them off with a strong spray of water. If one







Florida Agricultural Experiment Station


does not have a source of water at high pressure, the potatoes may
be dipped in a contact insecticide. Nicotine sulfate with a good
spreader, or one of the pyrethrum or rotenone sprays, will prove
effective. One of the synthetic insecticides known as aliphatic
thiocyanates appears to be particularly efficient in killing mealy-
bugs. A spray containing this should make an excellent dip for
ridding potatoes of mealybugs at planting time.

POTATO TUBER WORM
This insect (Gnorimoschema operculella (Zell.) ), which is a very
close relative of the eggplant leaf miner, is principally a pest of
potatoes in storage, though it also works as a leaf miner in pota-
toes, tomato, tobacco, eggplant and related crops.
The adult is a small, inconspicuous gray moth. The larvae
are pinkish-white and a little over 1/4 inch long when fully grown.
Their burrows in the tubers are often lined with dirty looking
silk. One generation may follow another in stored potatoes and
as the entire life cycle may require less than a month the pota-
toes may be totally destroyed in a few months during summer.
Control.-Unless precautions are taken to prevent infesta-
tion, potatoes carried over summer in Florida for fall planting
are very likely to be severely damaged by this insect. At digging
time the potatoes should not remain uncovered in the late evening
or over night when the moths are laying eggs. The potatoes
should be stored in a screened inclosure, since infestation may
occur at any time. If the potatoes become infested the larvae
can be killed by fumigating the potatoes with carbon bisulfide,
using 5 pounds to each 1,000 cubic feet of space, with an exposure
of 48 hours.
OTHER POTATO PESTS
Other insects attacking potatoes are: Flea beetles, page 39;
pumpkin bugs, page 65; blister beetles, page 38; cutworms, page
41; wireworms, page 59; army worms, page 60; and cucumber
beetles, page 71.


INSECTS AND OTHER PESTS OF RADISH
The insect pests of radish are the same ones that commonly
attack mustard and turnips. For control see the measures recom-
mended under those crops.







Insects and Other Pests of Florida Vegetables


INSECTS AND OTHER PESTS OF ROSELLE
This plant is related to okra and cotton and is attacked by
many insects commonly found on those plants. Those most likely
to injure roselle are: The okra caterpillar, page 76; the corn ear-
worm, page 55; and the cotton stainer, page 74.

INSECTS AND OTHER PESTS OF SQUASH
PICKLEWORM AND MELONWORM
The fact that squash is used as a trap crop to protect cucum-
bers and cantaloupes from the pickleworm and the melonworm
is very good evidence that these insects attack it freely. This
is indeed the case, and at times it is well nigh impossible, espec-
ially in the fall, to produce a crop of squash, particularly of
summer crook-neck type, due to the ravages of these pests.
Control.-Because squash is their favorite food plant the
grower cannot use a trap crop to protect them. There are, how-
ever, some measures that will help to lessen the severity of the
infestation. If all wormy fruits are picked up and destroyed and
the crop residue is destroyed at the close of the picking season
the numbers of moths in the neighborhood will be reduced and
the worms should be less troublesome on future crops. Squash
grown in early spring and late fall usually is less severely in-
jured than that grown during warmer weather. In those cases
where the melonworm is the more prevalent of the two insects
some measure of control is possible through the use of insecti-
cides as indicated on page 71. Squashes with a hard rind such
as the Table Queen or Acorn varieties are not much troubled
by these borers. These borers also attack chayotes.

SQUASH VINE BORER
This insect (Melittia satyriniformis Hubner), a very severe pest
of squash in the North, is less prevalent in Florida but occasionally
causes some damage.
The adult moth (Fig. 52), which has a wing spread of about
114 inches, is a beautiful insect. The front wings are dark green
and the hind wings are clear, with a black fringe around the edge.
The body is dark green, red and orange. The moths lay their
eggs on the stems, usually near the ground. The larvae hatching
from the eggs at once bore into the stem and feed inside of it.
The full grown larva is short, thick-bodied and dirty white in
color. It crawls out of the plant and pupates in the soil.






Florida Agricultural Experiment Station


Control.-Feeding inside the plant, this insect can hardly
be reached with any insecticide. The larvae tunneling in the
stems often cause
the plant to wilt.
When one finds a
wilted plant he
should examine it
closely and try to
a find the point of
S entry. The bur-
S.. -. row is often indi-
i '-...:. '* ^ cated by moist,
-._ green, sawdust-
"-~---~-A :. like material
f which is forced
Fig. 52.-Squash vine borer; a, Adult; b, adult with wings out by the larva.
folded; c,'eggs on stalk; d, larva at work; e, pupa; f, co-
coon. One-third larger than natural size. (From U. S. Bur. When a burrow is
of Ent.)
located, slit the
stem with a knife and remove the larva. If the slit is made
lengthwise of the stem the plant will not be much injured and
will probably recover.
SQUASH BUG
Squash bugs (Anasa tristis (DeG.) ) (Fig. 53) are large brown-
ish-black, oblong bugs, nearly an inch long. They frequent the
under sides of the stems and leaves of squash,
W sucking the sap and causing the plants to wilt
and perhaps die. They are shy creatures and
when approached move to the other side of
the stem out of sight. Like the vine borer,
they are not nearly as destructive in Florida
as in the more Northern states.
Fng ny 3.Squash bdg; The eggs are laid in clusters on the under
adult. Natural size.
(From s. Bur. of side of the leaves, rather frequently in the
Ent.) angles formed by the larger veins. When
first laid they are yellow but soon turn brown. They are always
conspicuous against the green of the leaves and are rather easily
located. The newly hatched nymphs are yellowish but after the
first molt are dark ashy-gray in color. The bugs feed together in
groups and the combined feeding of several on one leaf will often
cause it to wither.
Control.-The younger stages of the nymphs can be killed
with pyrethrum or rotenone sprays but hand collecting is the only







Insects and Other Pests of Florida Vegetables


effective control for the adults. Destroying the egg clusters also
aids in control.
OTHER SQUASH PESTS
Other insects attacking squash are: The melon aphid, page
111; and the banded cucumber beetle, page 72.

INSECTS AND OTHER PESTS OF STRAWBERRIES
COMMON RED SPIDER
Red spiders (Tetranychus telarius (L.) ) frequently become
very prevalent upon strawberry plants in the spring when the
weather is dry and warm. They breed less rapidly in cool weather
and the heavy rains of summer usually bring them under control
very quickly, but during the spring when the weather is dry
they often cause heavy losses. They attack both leaves and fruit.
Attacked leaves assume 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, become hard and dry and fail to
develop. The injury is caused by the red spiders sucking the sap
from the foliage and fruit. For description and life history of
this pest see page 81.
Control.-Like most members of the spider class, they are
best controlled by sulfur. If the weather is reasonably warm
one can ordinarily get satisfactory control by simply dusting the
plants with sulfur. This is by all means the quickest and most
economical way of combating red spiders. Sulfur is best put on
with a dust gun but may be applied by hand. In order to make
it go through the duster more readily sulfur is often mixed with
inert clay or other materials. Dusting sulfurs commonly sold
by insecticide dealers already carry some such material and noth-
ing more need be added. If this dust is applied in the morning
when the plants are wet with dew it will stick better; but it can
be applied any time during the day when the wind is not blowing.
During cold weather better control will be obtained by spray-
ing the plants with lime-sulfur or wettable sulfur. One gallon of
concentrated lime-sulfur or 5 pounds of wettable sulfur in 50
gallons of water is used. Lime-sulfur spray will taint the berries
and should not be used during the picking season, although there
would be no danger to the consumer. Wettable sulfur will not
taint the berries as seriously.
In small dooryard patches that can be reached with the hose
and in fields provided with overhead irrigation, frequent sprink-







Florida Agricultural Experiment Station


ling with water may check these pests. The water should be ap-
plied with as much pressure as the plants will stand.

FLORIDA FLOWER THRIPS
This orange-yellow insect (Frankliniella cephalica (Crawford) ),
about 1/25 inch long, is often very injurious to strawberries in
the spring. Its attacks are confined mostly to the blossoms, where
it feeds on stamens and other soft parts. These thrips are suck-
ing insects but their punctures are very shallow and very nu-
merous. The action on the berries much resembles that of the
red spider but is more largely confined to very young berries.
As a result of this feeding, the blossoms drop off or the young
berries may remain hard and brown, failing to grow. In cases of
less severe infestation the berries may be deformed, due to the
fact that they were injured on only one side. These insects fre-
quently seriously shorten the bearing season of the plants, as they
are usually more abundant in the later blossoms.
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 in three
days into light yellow nymphs without wings, which continue to
feed on the young berries and other tender parts of the plant.
Control.-One of the best sprays for thrips is nicotine sulfate
(1 part of nicotine sulfate to 600 parts of water). To make the
solution spread better one of the oleates, an oil derivative, or a
little soap (2 or 3 pounds to 50 gallons, more if the water is hard)
should be added to the solution. This spray 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 warm.
In fact, at an air temperature below 60 degrees it is apt to be un-
satisfactory. 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. Since this solution
will taint the berries it should be applied immediately after pick-
ing. 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 containing at least 1
percent of nicotine with an equal quantity of sulfur. This is not
likely to taint the fruit, as the dust will be knocked off in picking,




University of Florida Home Page
© 2004 - 2010 University of Florida George A. Smathers Libraries.
All rights reserved.

Acceptable Use, Copyright, and Disclaimer Statement
Last updated October 10, 2010 - - mvs