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Group Title: lorida Agricultural Experiment Station bulletin 465.
Title: Control of insect pests of cucumber and squash /
CITATION THUMBNAILS PAGE IMAGE ZOOMABLE
Full Citation
STANDARD VIEW MARC VIEW
Permanent Link: http://ufdc.ufl.edu/UF00026938/00001
 Material Information
Title: Control of insect pests of cucumber and squash /
Series Title: Bulletin / University of Florida. Agricultural Experiment Station ;
Physical Description: 15 p. : ; 23 cm.
Language: English
Creator: Kelsheimer, E. G
Publisher: University of Florida Agricultural Experiment Station
Place of Publication: Gainesville, Fla
Publication Date: 1949
Copyright Date: 1949
 Subjects
Subject: Cucumbers -- Diseases and pests -- Florida   ( lcsh )
Cucumbers -- Diseases and pests -- Control -- Florida   ( lcsh )
Squashes -- Diseases and pests -- Florida   ( lcsh )
Squashes -- Diseases and pests -- Control -- Florida   ( lcsh )
Genre: government publication (state, provincial, terriorial, dependent)   ( marcgt )
non-fiction   ( marcgt )
 Notes
Statement of Responsibility: by E.G. Kelsheimer.
General Note: Cover title.
General Note: "A contribution from the Vegetable Crops Laboratory."
 Record Information
Bibliographic ID: UF00026938
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: ltuf - AEN6199
oclc - 18267350
alephbibnum - 000925546

Table of Contents
    Copyright
        Historic note
    Main
        Page 1
        Page 2
        Page 3
        Page 4
        Page 5
        Page 6
        Page 7
        Page 8
        Page 9
        Page 10
        Page 11
        Page 12
        Page 13
        Page 14
        Page 15
Full Text





HISTORIC NOTE


The publications in this collection do
not reflect current scientific knowledge
or recommendations. These texts
represent the historic publishing
record of the Institute for Food and
Agricultural Sciences and should be
used only to trace the historic work of
the Institute and its staff. Current IFAS
research may be found on the
Electronic Data Information Source
(EDIS)

site maintained by the Florida
Cooperative Extension Service.






Copyright 2005, Board of Trustees, University
of Florida







December, 1949


UNIVERSITY OF FLORIDA
AGRICULTURAL EXPERIMENT STATIONS
HAROLD MOWRY, Director
GAINESVILLE, FLORIDA
(A Contribution from the Vegetable Crops Laboratory)





Control of Insect Pests of

Cucumber and Squash

By E. G. KELSHEIMER
Entomologist, Vegetable Crops Laboratory, Bradenton, Florida





A cucumber field totally destroyed by melonworm attacks.


iI,


Bulletin 465










BOARD OF CONTROL
Frank M. Harris, Chairman, St. Petersburg
N. B. Jordan, Quincy
Hollis Rinehart, Miami
Eli H. Fink, Jacksonville
George J. White, Sr., Mount Dora
W. F. Powers, Secretary, Tallahassee


EXECUTIVE STAFF

J. Hillis Miller, Ph.D., President of the
University
Harold Mowry, M.S.A., Director
L. 0. Gratz, Ph.D., Asst. Dir., Research
W. M. Fifield, M. S., Asst. Dir. Admin.
Geo. F. Baughman, M.S., Business Manager3
Claranelle Alderman, Accountant3


MAIN STATION, GAINESVILLE

AGRICULTURAL ECONOMICS

C. V. Noble, Ph.D., Agri. Economist' 3
R. E. L. Greene, Ph.D., Agri. Economist
Zach Savage, M.S.A., Associate
A. H. Spurlock, M.S.A., Associate
D. E. Alleger, M.S., Associate
D. L. Brooke, M.S.A., Associate
M. R. Godwin, Ph.D., Associate
H. W. Little, M.S., Assistant
Tallmadge Bergen, B.S., Assistant
Orlando, Florida (Cooperative USDA)
G. Norman Rose, B.S., Asso. Agr. Economist
J. C. Townsend, Jr., B.S.A., Agr.
Statistician'
J. B. Owens, B.S.A., Agr. Statistician2
J. F. Steffens, Jr., B.S.A., Agr. Statistician2


AGRICULTURAL ENGINEERING

Frazier Rogers, M.S.A., Agr. Engineer' 3
J. M. Johnson, B.S.A.E., Asso. Agr.
Engineer3
J. M. Myers, B.S., Asso. Agr. Engineer
R. E. Choate, B.S.A.E., Assistant. Agr.
Engineer"
A. M. Pettis, B.S.A.E., Asst. Agr. Engineer 3

AGRONOMY

Fred. H. Hull, Ph.D., Agronomist'
G. E. Ritchey, M.S., Agronomist2
G. B. Killinger, Ph.D., Agronomist3
H. C. Harris, Ph.D., Agronomist'
R. W. Bledsoe, Ph.D., Agronomist
W. A. Carver, Ph.D., Associate
Darrel D. Morey, Ph.D., Associate
Fred A. Clark, B.S., Assistant
Myron C. Grinnell, B.S.A.E., Assistant
M. N. Gist, Collaborator2

EDITORIAL

J. Francis Cooper, M.S.A., Editor3
Clyde Beale, A.B.J., Associate Editor'

ANIMAL HUSBANDRY AND NUTRITION

R. S. Glasscock, Ph.D., An. Husbandman3
J. E. Pace, B.S.A., Asst. An. Husbandman
S. John Folks, B.S.A., Asst. An.
Husbandman
T. J. Cunha, Ph.D., Assoc. An. Husbandman
G. K. Davis, Ph.D., Animal Nutritionist3
R. L. Shirley, Ph.D., Biochemist
Katherine Boney, B.S., Asst. Chem.


DAIRY HUSBANDRY AND DAIRY
MANUFACTURES
E. L. Fouts, Ph.D., Dairy Technologist1
R. B. Becker, Ph.D., Dairy Husbandman3
S. P. Marshall, Ph.D., Asso. Dairy Husb.:
W. A. Krienke, M.S., Asso. in Dairy Mfs."
P. T. Dix Arnold, M.S.A., Assistant Dairy
Hush.'
L. E. Mull, M.S., Asst. in Dairy Tech.

ENTOMOLOGY
A. N. Tissot, Ph.D., Entomologist'
L. C. Kuitert, Ph.D., Assistant
H. E. Bratley, M.S.A., Assistant

HOME ECONOMICS
Ouida D. Abbott, Ph.D., Home Econ.1
R. B. French, Ph.D., Biochemist

HORTICULTURE
G. H. Blackmon, M.S.A., Horticulturist'
F. S. Jamison, Ph.D., Horticulturist3
Albert P. Lorz, Ph.D., Asso Hort.
H. M. Reed, B. S., Chem., Veg. Processing
R. K. Showalter, M.S., Asso. Hort.
R. A. Dennison, Ph.D., Asso. Hort.
R. H. Sharpe, M. S., Asso. Hort.
R. J. Wilmot, M.S.A., Asst. Hort.
R. D. Dickey, M.S.A., Asst. Hort.
Victor F. Nettles, Ph.D., Asst. Hort.
L. H. Halsey, M.S.A., Asst. Hort.
F. S. Legasse, Ph.D., Asso. Hort.2

LIBRARY
Ida Keeling Cresap, Librarian

PLANT PATHOLOGY
W. B. Tisdale, Ph.D., Plant Patholog;st'"
Phares Decker, Ph.D., Plant Pathologist
Erdman West, M.S., Mycologist and Botanist
Howard N. Miller, Ph.D., Asso. Plant Path.
Lillian E. Arnold, M.S., Asst. Botanist
Robert W. Earhart, Ph.D., Plant Path.2

POULTRY HUSBANDRY
N. R. Mehrhof, M.Agr., Poultry Hush.' a
J. C. Driggers, Ph.D., Asst. Poultry Husb."

SOILS
F. B. Smith, Ph.D., Microbiologist' '
Gaylord M. Volk, Ph.D., Chemist
J. R. Henderson, M.S.A., Soil Technologist3
J. R. Neller, Ph.D., Soils Chemist
Nathan Gammon, Jr., Ph.D., Soils Chemist
R. A. Carrigan, Ph.D., Biochemist3
Ralph G. Leighty, B.S., Asso. Soil Surveyor
Geo. D. Thornton, Ph.D., Asso.
Microbiologist3
H. W. Winsor, B.S.A., Assistant Chemist
R. E. Caldwell, M.S.A., Asst. Chemist"
V. W. Cyzycki, B.S., Asst. Soil Surveyor
R. B. Forbes, M.S., Asst. Soils Chemist
W. L. Pritchett, M.S., Asst. Chemist4
James H. Walker, M.S.A., Asst. Soil
Surveyor
Walter J. Friedmann, M.S.A., Asst.
Biochemist
O. E. Cruz, B.S.A., Asst. Soil Surveyor

VETERINARY SCIENCE
D. A. Sanders, D.V.M., Veterinarian'
M. W. Emmel, D.V.M., Veterinarian3
C. F. Simpson, D.V.M., Asso. Veterinarian
L. E. Swanson, D.V.M., Parasitologist
Glenn Van Ness, D.V.M., Asso. Poultry
Pathologist
G. E. Batte, D.V.M., Asso. Parasitologist









BRANCH STATIONS

NORTH FLORIDA STATION, QUINCY
J. D. Warner, M.S., Vice-Director in Charge
R. R. Kincaid, Ph.D., Plant Pathologist
L. G. Thompson, Ph.D., Soils Chemist
W. C. Rhoads, M.S., Entomologist
W. H. Chapman, M. S., Asso. Agron.
Frank S. Baker, Jr., B.S., Asst. An. Husb.
Mobile Unit, Monticello
R. W. Wallace, B.S., Associate Agronomist
Mobile Unit, Marianna
R. W. Lipscomb, M.S., Associate Agronomist
Mobile Unit, Chipley
J. B. White, B.S.A., Associate Agronomist
Mobile Unit, Pensacola
R. L. Smith, M.S., Associate Agronomist

CITRUS STATION, LAKE ALFRED
A. F. Camp, Ph.D., Vice-Director in Charge
W. L. Thompson, B.S., Entomologist
J. T. Griffiths, Ph.D., Asso. Entomologist
R. F. Suit, Ph.D., Plant Pathologist
E. P. Ducharme, M.S., Asso. Plant Patho.4
R. K. Voorhees, Ph.D., Asso. Horticulturist
C. R. Stearns, Jr., B.S.A., Asso. Chemist
J. W. Sites, M.S.A., Horticulturist
H. 0. Sterling, B.S., Asst. Horticulturist
J. A. Granger, B.S.A., Asst. Horticulturist
H. J. Reitz, M.S., Asso. Horticulturist
Francine Fisher, M.S., Asst. Plant Path.
I. W. Wander, Ph.D., Soils Chemist.
A. E. Wilson, B.S.A., Asso. Biochemist
J. W. Kesterson, M.S., Asso. Chemist
R. N. Hendrickson, B.S., Asst. Chemist
Wallace T. Long, M.S.A., Asst. Hort.
J. C. Bowers, B.S., Asst. Chemist
D. S. Prosser, Jr., B.S., Asst. Horticulturist
R. W. Olsen, B.S., Biochemist
F. W. Wenzel, Jr., Ph.D., Supervisory Chem
Alvin H Rouse, M.S., Asso. Chemist
L. W. Faville, Ph.D., Asst. Chemist

EVERGLADES STATION, BELLE GLADE
R. V. Allison, Ph.D., Vice-Director in Charge
F. D. Stevens, B.S., Sugarcane Agronomist
Thomas Bregger, Ph.D., Sugarcane
Physiologist
J. W. Randolph, M.S., Agricultural Engineer
W. T. Forsee, Jr., Ph.D., Chemist
R. W. Kidder, M.S., Asso. Animal Hush.
T. C. Erwin, Assistant Chemist
Roy A. Bair, Ph.D., Agronomist
C. C. Scale, Asso. Agronomist
N. C. Hayslip, B.S.A., Asso. Entomologist
E. H. Wolf, Ph.D., Asst. Horticulturist
W. H. Thames, M.S., Asst. Entomologist
W. N. Stoner, Ph.D., Asst. Plant Path.
W. A. Hills, M.S., Asso. Horticulturist
W. G. Genung, B.S.A., Asst. Entomologist
Daniel W. Beardsley, B.S., Asst. An. Husb.
W. D. Hogan, M. S., Asst. Plant Path.


SUB-TROPICAL STATION, HOMESTEAD

Geo. D. Ruehle, Ph.D., Vice-Dir. in Charge
D. 0. Wolfenbarger, Ph.D., Entomologist
Francis B. Lincoln, Ph.D., Horticulturist
Robt. A. Conover, Ph.D., Asso. Plant Path.
Milton Cobin, B.S., Asso. Horticulturist
R. W. Harkness, Ph.D., Asst. Chemist

W. CENT. FLA. STATION, BROOKSVILLE

William Jackson, B.S.A., Animal Husband-
man in Charge"

RANGE CATTLE STATION, ONA

W. G. Kirk, Ph.D., Vice-Director in Charge
E. M. Hodges, Ph.D., Agronomist
D. W. Jones, B.S., Asst. Soil Technologist
E. M. Kelly, B.S.A., Asst. An. Husb.

CENTRAL FLORIDA STATION, SANFORD

R. W. Ruprecht, Ph.D., Vice-Dir. in Charge
J. W. Wilson, Sc.D., Entomologist
Ben. F. Whitner, Jr., B.S.A., Asst. Hort.
P. J. Westgate, Ph.D., Asso. Hort.

WEST FLORIDA STATION, MILTON

C. E. Hutton, Ph.D. Agronomist'
H. W. Lundy, B.S.A., Associate Agronomist


FIELD STATIONS

Leesburg

G. K. Parris, Ph.D., Plant Path. in Charge

Plant City

A. N. Brooks, Ph.D., Plant Pathologist

Hastings

A. H. Eddins, Ph.D., Plant Path. in Charge
E. N. McCubbin, Ph.D., Horticulturist

Monticello

A. M. Phillips, B.S., Asso. Entomologist2
John R. Large, M.S., Asso. Plant Path.

Bradenton
J. R. Beckenbach, Ph.D., Hort. in Charge
E. G. Kelsheimer, Ph.D., Entomologist
David G. Kelbert, Asso. Horticulturist
E. L. Spencer, Ph.D., Soils Chemist
Robert O. Magie, Ph.D., Gladioli Hort.
J. M. Walter, Ph.D., Plant Pathologist
Donald S. Burgis, M.S.A., Asst. Hort.

Lakeland

Warren O. Johnson, B.S., Meterologist2

Head of Department.
'In cooperation with U. S.
3 Cooperative, other divisions, U. of F.
On leave.

























CONTENTS



INTRODUCTION ..------ -----------... ............ .. -....... 5

INSECT PESTS ----- ...... ...... ... .... 5

OUTLINE OF EXPERIMENTS -.. ..... .- -------_.................... 7

DISCUSSION ........---. ............ 10

TIME OF APPLICATION 12

RECOMMENDATIONS ------ .. 13

SUMMARY --_---- ---__- .. 14

PRECAUTIONS 14









Control of Insect Pests of

Cucumber and Squash

By E. G. KELSHEIMER

Cucumbers and squash are important crops in Florida. In
1948 (1)1 the harvested acreage of cucumbers was 14,560, with a
valuation of $6,149,000. The first published data on squash
acreage and production in Florida was for 1948, showing 7900
harvested acres with a valuation of $1,839,250. These two crops
are subject to attack from a number of insects, the more im-
portant of which are briefly described.
Banded Cucumber Beetle.-The banded cucumber beetle,
Diabrotica balteata Lec., occurs in destructive numbers on
squash, cucumber and cantaloupe and is general in its feeding
habits on tomato plants. It injures the plant by destroying the
foliage and feeding on the flower and flower buds. The adult
beetle is yellowish green with three bright green stripes or bands
running across the wing covers. Its distribution is general over
the state.
Florida Flower Thrips.-This insect, Frankliniella cephalica
Crawford, is found in considerable numbers on the stamens of
the cucurbit flowers. Generally little damage is done by these
insects because there is always more than enough pollen, but
occasionally they occur in numbers sufficient to prevent pollina-
tion. The insects are minute, soft bodied, yellowish in color and
quite active.
Serpentine Leaf Miner.-This leaf-mining insect, Liriomyza
pusilla (Meig.), has of recent years become a major pest not only
to cucurbits but to many other of our vegetable crops. Both the
adult and the larvae produce injury to the leaves of the plant.
The larvae are the "miners" in the leaves which destroy tissue,
and if not controlled, cause the leaf to dry up and die. 'The
adults puncture the leaf surface and feed upon the plant juice.
The adult fly is tiny, shining black and marked with yellow in
various ways. The larvae are yellowish colored.


1 Italic figures in parentheses refer to Literature Cited.







Florida Agricultural Experiment Stations


Melonworm.-The melonworm, Diaphania hyalinata (L.),
is the principal enemy of cucurbits. The adult is a small, clear-
winged moth with a light brown and glistening white body bor-
dered by a brownish-black band. The larvae are green worms
approximately an inch in length when full grown and are charac-
terized by a thin white stripe down the middle of the back. The
larvae feed extensively upon the leaves, later boring into the
stem and fruit.
Pickleworm.-The adult or moth of the pickleworm, Dia-
phania nitidalis (Stoll), differs from the adult of the melonworm
in that it has purplish-brown wings with a clear area in the
middle of the front wings. The larvae at first are whitish cater-
pillars with prominent black dots on each segment. Later they
change to a coppery color with the black dots becoming less con-
spicuous. This pest is harder to control than the melonworm
because it bores into the stem and growing bud of the plant,
often killing it. For this reason, it is sometimes called a "vine
borer." It also bores into the fruit.
Cutworms.-There are many species of these soft bodied
caterpillars that may feed upon cucurbits, so no attempt will be
made to describe them separately. Injury is caused by cutting
off the young plants at ground level or feeding upon the leaves
and fruit.
Striped Cucumber Beetle.-The striped cucumber beetle,
Diabrotica vittata (F.), is seldom found on the west coast of
Florida, due probably to its inability to reproduce in sandy soils
(2). The adult is a yellow beetle striped longitudinally with
black, which causes damage by eating the leaves. It occurs in
some locations on the east coast of Florida, and in the everglades
in large numbers.
Squash Bug.-This insect, Anasa tristis (Deg.), like the
striped cucumber beetle, is seldom found on the west coast of
Florida but occurs on the east coast and other sections. These
large brownish-black oblong bugs frequent the under sides of
the leaves and stems where they suck the sap, causing the plant
to wilt and die.
Leaf-footed Plant Bug.-This bug, Leptoglossus phyllopus
(L.), is a brown bug with a yellow line running across the wing
cover. The hind legs are flattened, which gives its name. They


6







Control of Insect Pests of Cucumber and Squash


may occur in great numbers, producing damage by sucking plant
juices.
The Melon Aphid.-The melon aphid, Aphis gossypii Glov.,
may be destructive to cucurbit plants in all stages of growth.
The most serious damage is done when the plants are small.
This sucking insect causes dwarfing and sometimes the death of
the plant, and is instrumental in spreading certain viruses, such
as cucumber mosaic.

Outline of Experiments
Many control measures have been used against the chewing
and sucking insects attacking cucurbits. Much of the earlier
experimental data secured from test plots have been discarded
since the new organic insecticides have become so generally used.
Of the insects previously listed, the melonworms, pickleworms,
leafminers and aphids are usually the principal pests, and the
control studies have been conducted with these insects in mind.

Table 1.-CONTROL OF SQUASH INSECTS, BRADENTON, FLA.,
SPRING 1947, AS REFLECTED BY YIELDS.
Wt. in Lbs.
of No. of
How Marketable Wormy
Class* Treatment Used Strength Squash Squash
I Chlordane Dust 5% 67.3 14
BHC 43 gamma Spray 0.75 Lbs-100 66.1 17
Chlordane 50W Spray 2 Lbs.-100 63.1 27
Cryolite Dust 30-70 62.8 7
Piperonyl butoxide Dust Mfg. 59.7 19
BHC 50W (low gamma) Spray 3 Lb.-100 59.3 11
Methoxychlor Dust 3% 59.1 20
BHC (low gamma) Dust 1.5 gamma 58.7 4
DDT 50W Spray 1 Lb.-100 57.3 18
Pipernoyl cyclo-
hexenone Dust Mfg. 55.8 24
II DDT 50W Spray 2 Lbs.-100 48.0 28
Methoxychlor 50W Spray 2 Lbs.-100 40.1 24
Check (no treatment) 40.1 40
DDT Dust 3% 39.0 15
Methoxychlor 50W Spray 1 Lb.-100 36.9 44
Difference required for
significance, odds 19:1 I 17.6 14.0
The first-listed treatment in Class I gave yields significantly superior to the first-listed
treatment in Class II. For other comparisons, see "difference required for significance."
Note: This experiment was conducted with five replications; insecti-
cides were applied weekly for three weeks.







8


Florida Agricultural Experiment Stations


The data from one fall and one spring experiment on straight-
neck squash are given in Table 1 and Table 2. In the spring test,
14 materials and a check were tested, with five replications.
There were three applications of material spaced one week apart.
Only 1.6 inches of rain fell during this entire period, and all came
on the day following the second application. In the fall test, 26
materials were compared; these were replicated eight times.
Three applications of materials were made at two-week intervals.
The rainfall for the period of October 22 to November 18, 1947,

TABLE 2.-CONTROL OF INSECTS, BRADENTON, FLA., FALL 1947,
AS REFLECTED BY YIELDS.

Wt. in Lbs.
of No. of
How Marketable Wormy
Class Treatment Used Strength Squash Squash
I Parathion Dust 1% 259.8 2
Methoxychlor 50W Spray 2 Lbs.-100 252.0 19
Parathion 15W Spray 2 Lbs.-100 250.5 6
Chlordane 50W Spray 2 Lbs.-100 249.6 6
BHC (low gamma) Spray 3 Lbs.-100 247.7 2
Cryolite Dust 30-70 246.8 9
Cyclohexenone T65 Dust 245.9 8
Check (no treatment) 242.6 24
Lindane Dust 1 gamma 242.1 5
Lindane* 25 gamma Spray 1 Lb.-100 240.0 2
Cryolite Spray 6 Lbs.-100 236.1 17
DDT Colloidal 25% Spray I Qt.-100 235.5 10
BHC 12 gamma Spray 1.5 Lbs.-100 233.4 None
Butoxide T66 Spray 1-400 233.3 19
Parathion Dust 0.5% 231.1 7

II DDD 50W Spray 2Lbs.-100 227.4 3
Parathion Dust 2% 227.1 None
Cyclohexenone T65 Spray 1-400 226.1 21
Butoxide T66 Dust 224.5 9
Rhothane-DDD Dust 3% 218.6 10
DDT Dust 3% 213.8 7
Methoxychlor Dust 3% 210.5 9
DDT 50W Spray 2 Lbs.-100 206.7 1
Chlordane Dust 5% 202.5 6

III Toxaphene Dust 10% 186.7 9

IV BHC (low gamma) Dust 1.5 gamma 126.9 None

Difference required
for significance,
odds 19:1 30.8 8


Used first time at late of 4P per 100
Toxaphene 10% dust stopped after first application.
This experiment was conducted with eight replications; insecticides.
were applied every two weeks for three applications.







Control of Insect Pests of Cucumber and Squash


9


totalled 4.08 inches, of which 1.20 inches fell the day after the
first application of material. A rainfall of 2.46 inches fell on
November 8, four days after the second application of insecti-
cides.
Cucumbers were used as the test crop in the spring and fall
tests for 1948. Fifteen materials (including parathion2 for the
first time) were tested in six replications of the Marketer va-
riety in the spring of 1948. Data are presented in Table 3. Only
two applications were made, spaced two weeks apart. A total of
.77 inches of rain fell during the testing period, all of which fell
after the first application.

TABLE 3.-CONTROL OF CUCUMBER INSECTS, BRADENTON, FLA.,
SPRING 1948, AS REFLECTED BY YIELDS.
Wt. in Lbs.
of No. of
How Marketable Wormy
Class Treatment Used IStrength Cucumbers Cucumbers
I Parathion Dust 1% 350 9
Parathion 25W Spray 1-100 289 19
Methoxychlor Dust 3% 259 9
Lindane Dust 1 gamma 245 6
II Chlordane Dust 5% 231 10
Methoxychlor 50W Spray 2 Lbs.-100 186 16
Cryolite Dust 30-70 181
Lindane 25 gamma Spray 1 Lb.-100 176 6
DDD Dust 3% 167 6
Chlordane 50W Spray 2 Lbs.-100 156 11
Cryolite Spray 6 Lbs.-100 151 5
DDD 50W Spray 2 Lbs.-100 148 5
DDT Emulsion 25 Spray 1/ pt.-100 142 9
Check (no treatment) 107
7
Difference required,
odds 19:1 137 N. S.
This experiment was conducted with six replications; insecticides were
applied twice at two-week intervals.

In the fall of 1948, the best five materials from the previous
spring trials were compared. The yield data are presented in
Table 4. Five replications were given two insecticidal treatments
at two-week intervals. There was a total of 8.55 inches rainfall
during the month of September. The rainy season made it dif-
ficult to apply insecticides. Insect infestation was general over
the entire planting before the first application was made. A


2 O,0-diethyl O-p-nitrophenyl thiophosphate.







10


Florida Agricultural Experiment Stations


rainfall of .75 inches fell ten days after the first application, and
a rain started one hour after the second application was made.
The total for this rain was 2.78 inches.
Standard fungicidal sprays were used on all plantings. The
1948 fall treatments were on disease-resistant varieties, so less
attention was given to fungicidal treatment.

Discussion
Growers have been able to successfully raise and market
cucurbits using cryolite for the control of chewing insects. Cryo-
lite-bran bait is a good control for the cutworms that attack the
young plants. The introduction of the chlorinated and phos-
phatic groups of insecticides has provided some good worm and
aphid controls. It is these new compounds that will be discussed.
As indicated in Tables 1-4, inclusive, many compounds and
various formulations have been tested. No attempt will be made
to discuss all of these individually.

TABLE 4.-CONTROL OF CUCUMBER INSECTS, BRADENTON, FLA., FALL 1948,
AS REFLECTED BY YIELDS.
Wt. in Lbs.
of No. of
How Marketable Wormy
Class Treatment Used Strength Cucumbers Cucumbers
I Lindane Dust 1 gamma 371.8 36
Parathion Dust 1% 324.7 95
II Parathion 15W Spray 1 Lb.-100 258.8 108
Methoxychlor Dust 3% 255.2 138
Check (no treatment) 227.6 166
Chlordane Dust 5% 195.3 134
Difference required,
odds 19:1 75.4 40
This experiment was conducted with five replications; insecticides were
applied twice at two-week intervals.

Lindane3 made from essentially pure gamma isomer-base
material has been used since the fall test of 1947. A benzene
hexachloride of 43 percent gamma was used in the spring of
1947 with good results. This was a fore-runner of the high
gamma isomer content made from essentially pure base material.

3 The coined name "Lindane" is established for gamma isomer of the
chemical 1, 2, 3, 4, 4, 6-hexachlorocyclohexane of a purity not less than 99
percent.







Control of Insect Pests of Cucumber and Squash


Lindane has consistently been in the top group of insecticides in
each trial. No explanation can be given at this time why the
high gamma material is only one of the chlorinated series that
controls insects without reducing yields. It has been one of the
outstanding insect controls.
Parathion, one of the new phosphatic insecticides, was first
used in the fall of 1947 on squash. It is considered to be an aphi-
cide primarily, and was used incidentally in the tests as a worm
control because some of the earlier phosphatic materials such as
hexaethyl tetraphosphate (and later the current formulation
tetraethyl pyrophosphate) were effective worm controls. Para-
thion apparently has some fumigating effect, because it has
killed larvae of the melonworm that have webbed on the under
side of the leaf as well as those that the material hit directly.
Plots of squash treated with parathion presented a greener,
healthier, canopy of foliage. This might mean that certain in-
sects generally considered of no economic importance were con-
trolled, or that the response was nutritional. Wolfenbarger (3)
has conducted some tests which substantiate the nutritional
angle. These same conditions were evident in the cucumber
plots as well as the 1948 fall tomato plots. Growers have re-
ported a similar luxuriant canopy of foliage on their cucurbits.
Although parathion is thought of primarily as an aphicide,
the data in Tables 2, 3, and 4 show that parathion is a good larva-
cide. Parathion loses its insecticidal effectiveness after two
weeks in the field.
A question that is frequently asked concerns the advisability
of using DDT as a control measure for certain insects attacking
cucurbits. Under some conditions, DDT will burn cucurbits, but
generally no visible damage results and worms are controlled.
However, DDT definitely reduced the yield of squash as shown in
Tables 1 and 2, and of cucumbers, as indicated in Table 3. DDT
significantly reduced the yield of squash and cucumbers, though
this would not be noticeable unless the grower ran check plots.
Some growers realize this but accept the lower yield, figuring
that the clean fruit saves them enough in sorting and grading
to offset the reduced yield.
Several formulations of DDT other than the regular dust and
spray have been tested, including colloidal and emulsifiable ma-


11







Florida Agricultural Experiment Stations


trials. All forms tested have reduced yields of squash and
cucumber.
Methoxychlor, in both the spray and dust forms, showed good
promise under grower conditions, but in controlled experiments
has proven erratic. Yields were not reduced, but worm control
was generally inferior.
Dichlorodiphenyl dichloroethane (DDD or TDE), was avail-
able for experimental use in the fall test of 1947. Both the dust
and the spray were good worm controls but significantly reduced
yields of both squash and cucumbers (Tables 2 and 3).
Benzene hexachloride (low gamma) was an excellent worm
control and in the spring 1947 tests did not reduce yields (Table
1). In Table 2, the fall tests show that the spray did not reduce
the yield, but the 1.5 percent gamma dust was at the bottom of
the list for yield. Low gamma benzene hexachloride was not
included in further tests because of this yield reduction and be-
cause of the danger of off-flavors that attend its use.
Toxaphene in some preliminary tests severely burned squash
and cucumbers, but was tried again in the fall of 1947. The 10
percent dust was applied once and greatly reduced the yield as
shown in Table 2. This material was omitted in subsequent
tests.
Chlordane reduced yields in some experiments, and did not
affect them in others. (Tables 1-4.) Tests in the fall of 1947
(Table 2), indicated that the spray was superior to the dust,
since the dust applications reduced the yields. The worm con-
trols at this time were about equal for either dust or spray. In
Table 4, materials from the spring test are compared, and here
chlordane dust reduced the yield below that of the check plot re-
ceiving no treatment. The worm control was also poor. Part of
this was attributed to wet weather. These tests indicate that
chlordane should certainly not be used on cucurbits in wet
weather, and its general use is not recommended. Lindane and
parathion are superior in insect control of cucurbits without the
hazards of reduced yields.

Time of Applications
Cucurbits are dependent upon bees for pollination, hence it is
advisable to have a few hives of bees in the field or nearby. All
of the new insecticides are toxic to honey bees, so it is suggested


12







Control of Insect Pests of Cucumber and Squash


that applications of spray or dust be applied in the late afternoon
or evening when the flowers are not fresh and the bees are less
active. The plants are usually dry at this time of day and there
is less chance of burning the foliage. Foliage burn may be pro-
duced on wet plants, especially if a heavy dust application re-
mains on the plant.

Recommendations
Control of cutworms and armyworms is usually necessary to
insure a crop. Cryolite bran bait has been an old favorite and is
still used in large quantities in some areas. DDT or chlordane-
bait containing one pound of the actual poison to 100 pounds of
carrier and applied at the rate of 30 pounds per acre; DDT and
chlordane spray containing one pound of the actual ingredient
(two pounds of 50W or two and one half pounds of 40W) to 100
gallons of water applied at the rate of 50 gallons per acre; DDT
3 percent or chlordane 5 percent dust applied at the rate
of 15 pounds per acre have proven quite effective because of their
wider range of insect killing. If the plants are up, care should
be taken that heavy applications of DDT or chlordane do not
come in contact with the plant or burn will result. Both can
burn the foliage when the leaves are tender and wet.
There are two possible approaches to the problem of insect
control on cucurbits, 1) the prevention of any build-up in popula-
tion by applying insecticides on schedule, or 2) the use of in-
secticides for control only when needed, as determined by careful
inspection of the plants. The former approach is recommended
-that of applying insecticides on schedule.
Beginning when the plants are in the first and second true
leaves, apply lindane spray at the rate of 50 gallons per acre or
less, made up from a formulation of one pound of the 25 gamma to
100 gallons of water. As the plants grow and spread, increasing
quantities will be required, up to a maximum of 200 gallons per
acre. If a dust is preferred, apply a 1 percent gamma dust at
the rate of 10 to 15 pounds per acre when the plants are small,
increasing to a maximum of 30 pounds per acre for ground
application and 40 pounds by airplane. These applications should
control all of the insects mentioned. Make regular applications
throughout the growing season or every 10 to 14 days.


13







Florida Agricultural Experiment Stations


An alternative method is offered to the grower who prefers
to apply insecticides only as needed. Inspection of the plants
will determine the time of application of insecticide. Generally,
insect populations are established under this method, so if
aphids, leaf miners and worms are present, apply parathion as
a spray or dust. The spray is made with one pound of 15W to 100
gallons of water; the dust is 1 percent. Parathion should not
be used within 30 days of picking so one application when the
plants are in the 4th to 6th true leaf is all that should be used.
After this application use lindane at the rates prescribed above
every two weeks as long as needed.
Parathion is more effective than lindane in cleaning out
established infestations of aphids and leaf miners. Care should
be used in the application of parathion on young plants as it will
cause a burn under certain conditions.

Summary
Tests of the new organic insecticides for controlling pests of
cucurbits are reported in detail. The principal insects that at-
tack cucurbits are the melonworm, pickleworm, aphids and ser-
pentine leaf miner, although some insects of lesser importance
are pests at times and may occur in damaging numbers. All of
these can now be controlled on a field scale. Parathion, in a
limited way, and lindane, used either as a dust or as a spray, are
recommended for the control of the major pests of the cucurbits.
Applying insecticides on a regular schedule is recommended.

Precautions
All insecticides are poisonous. Do not work with the material
in a confined area. Do not permit any operator of a spray rig or
dust machine to remain in the spray or dust for prolonged
periods, nor to inhale fumes. Operators of spray machines
usually become thoroughly wet before the spraying is over. A
bath and a complete change of clothing should be required of
the operator. This precaution should also be followed with other
new organic insecticides. Manufacturers of these materials
issue precautionary instructions which should be followed care-
fully.


14







Control of Insect Pests of Cucumber and Squash 15

Avoid the use of insecticides on edible portions of the crop
where there is a possibility of toxic residues remaining at
harvest.
Honeybees are necessary for pollination of cucurbits and
these insecticides are poisonous to honeybees, but if the time of
application is adhered to, these new poisons are far less toxic to
bees than the arsenicals formerly used.

Literature Cited
1. Owens, J. B. et al. Vegetable crops in Florida. USDA and FAE
Station Crop and Livestock Reporting Service, Orlando. Vol. LV. Dec. 1948.
2. Watson, J. R. Florida truck and garden insects. Fla. Agr. Exp. Sta.
Bul. 232, 1931.
3. Wolfenbarger, D. O. Nutritional value of phosphatic insecticides.
Jour. Ec. Ent. 41: 5: 818-19. October 1948.




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