Title: Cotton insect control
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Title: Cotton insect control
Series Title: Cotton insect control
Physical Description: Book
Creator: Brogdon, James.
Publisher: University of Florida Agricultural Extension Service
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Bibliographic ID: UF00084482
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CIRCULAR 130 MARCH 1955


COOPERATIVE EXTENSION WORK IN
AGRICULTURE AND HOME ECONOMICS
(Acts of May 8 and June 30, 1914)
Agricultural Extension Service, University of Florida
Florida State University and
United States Department of Agriculture, Cooperating
H. G. Clayton, Director



Cotton Insect Control

James E. Brogdon

Extension Entomologist


The key to successful cotton insect control is to
apply insecticides thoroughly at the right time and at
the proper interval. To know the right time to apply
insecticides, infestation counts are the best guides
and should be made at regular intervals of about five
to seven days.

HOW TO MAKE INFESTATION COUNTS

Boll Weevils
Presquare Counts for Overwintered Weevils.-
Inspect seedling cotton after chopping and before
squaring to determine abundance of overwintered
weevils. First weevils usually appear nearest wooded
areas or other places where they spend the winter.
Look for boll weevils in the buds of at least 100 plants
for every five acres of cotton and observe the number
of live adult weevils present. Pay particular attention
to cotton plants nearest areas where weevils over-
winter. Watch for other insects and damage while mak-
ing boll weevil inspections. If overwintered weevils
are numerous in an area, make at least one application
of insecticide just before the oldest squares are large
enough for the laying of eggs. Weevils prefer squares
the size of an ordinary pencil eraser or larger for egg-
laying. Use the lower rates recommended for boll
weevils in the cotton insect control chart.

Boll Weevil Square Infestation Counts.- Square
counts should be started when there is an average of
three to four squares per plant and continued at weekly
intervals until the crop is made. Weevils puncture the
squares when they feed on them. When an egg is laid




in the puncture in the square, the opening is sealed,
forming a small wart. In making weevil infestation
records, count both open and sealed punctures. Walk
diagonally across the field pulling healthy squares
(the size of an ordinary pencil eraser and larger)
equally from the upper, middle and lower parts of the
plant until 100 squares have been pulled. Examine at
least 100 squares for each five acres of cotton. Of
the 100 squares counted, the number of punctured
squares represents the percent infestation. Begin
control measures when the infestation reaches 10 to
15 percent.

Bollworm

Walk diagonally across the field and examine the
terminals (buds) of 100 plants. Look closely for boll
worm eggs and small worms on both sides of the
young leaves, on the stems and on the small squares
in the upper 3 or 4 inches of the plant. The bollworm
egg is smaller than the head of an ordinary pin and
pearly-white to dirty-gray in color. The newly hatched
worms are very tiny and close observation is neces-
sary to find them. Examine at least 100 plant terminals
for each 5 acres of cotton. Begin control measures
when eggs and 4 or 5 worms are found per 100 ter-
minals.

INSECTS

Boll Weevil.- The boll weevil is the number-one
pest of cotton in Florida. All cotton insect control
operations should center around a good boll weevil
control program. Boll weevils pass the winter as
adults in weeds, grass, woods, trash or other protected
places near cotton fields. They leave winter quarters
and move to cotton fields in the spring when the
weather is warm enough for cotton to grow and tend to
remain there until frost. Boll weevils prefer to feed
on and to lay their eggs in squares, but they also
attack bolls. Weevils puncture the squares when they
feed on them. When an egg is laid in the puncture the
opening is sealed, forming a small wart. The complete
life cycle from egg to adult requires about 3 weeks
and there may be seven or eight generations a year.
Bollworm.- This insect is also known as the corn
earworm and tomato fruitworm. Bollworm infestations
usually develop rather late in the season and are more
severe in some of the other cotton growing states than
Florida. Damage often occurs so late in the season




that the plants do not have time to mature another
crop of bolls.


The bollworm moths prefer rapidly growing, suc-
culent cotton in which to lay their eggs. The eggs are
laid singly on the tender growth and newly formed
squares. They are smaller than the head of an ordinary
pin, and pearly-white when first laid, but change to a
dark color before hatching. The small larvae or "worms"
feed for a few days on the tender buds or leaves and
on the outside of squares before burrowing into squares
or bolls, usually near the base. There may be several


broo s a year.


Aphids (Plant Lice).- Aphids secrete a sticl
substance known as honeydew which drops on tl
leaves and bolls and gives the plants a glossy a
pearance. They are usually found on the undersid,
of the young leaves and clustered around the tend
branches of the bud. Aphids are capable of causing
curling and wrinkling of the leaves and stunting <
the plant. Aphid infestations often follow application
of calcium arsenate, DDT and certain other insect.
cides used for the control of cotton pests.


3% BHC + 5% DDT


2.5% aldrin + 5% DDT
or
3% BHC + 5% DDT
alternated with
calcium arsenate
or
1.5% dieldrin + 5%
DDT
or
2.5% heptachlor +
5% DDT
or
20% toxaphene
or
2% endrin


10 to 20 lbs.

10 to 20 lbs.

10 to 20 lbs.

10 to 15 lbs.


10 to 20 lbs.


10 to 20 lbs.

10 to 20 lbs.

10 to 20 lbs.


Any dust recommended for Boll
Weevils (except calcium arsenate)
at 15 to 20 lbs. per acre. For heavy
infestations, apply 10% DDT* or 3%
BHC + 10% DDT at 15 to 20 lbs.


BOLL WEEVILS


















BOLLWORMS





APHIDS (PLANT
LICE)






RED SPIDER
MITES






THRIPS


10 to 20 lbs.

10 to 20 lbs.

10 to 15 lbs.



10 to 15 lbs.

10 to 20 lbs.

10 to 20 lbs.

20 to 30 lbs.


Any dust (with or without DDT)
recommended above for boll weevils
(except calcium arsenate) at 6 to 8
lbs. per acre.


toxaphene

toxaphene

aldrin


2 to 3 lbs.
or
2 lbs. + DDT 1/2 lb.
or
1/4 to 1/2 lb. + DDT 1/2 lb.


or
dieldrin 1/6 to 1/4 lb. + DDT 1/2 lb.
or
heptachlor 1/4 to 1/2 lb. + DDT 1/2 lb.
or
BHC (gamma) 1/3 to 1/2 lb. + DDT 1/2 lb.
or
endrin 1/4 to 1/2 lb.

Read labels on containers of cotton sprays
to determine quantities needed for the
amounts of active ingredient.
Use any of above mixtures. For heavy
infestation, use DDT* alone at 1 to 2
lbs. or add DDT to above mixtures to
give 1 lb. DDT per acre.


BHC (gamma) 1/3 to 1/2 lb. + DDT 1/2 lb.
or
parathion 1/8 to 1/4 lb.
or
malathion 1/2 lb.
or
demeton 1/8 to 1/4 lb.
malathion 1/2 lb.
or
parathion 1/8 to 1/4 lb.
or
aramite 1/2 to 1 lb.
or
demeton 1/8 to 1/4 lb.
Any of the sprays (with or without DDT)
recommended above for boll weevils at
2/3 the rate.


When infestation reaches 10 to 15%
punctured squares, make 3 or 4 ap-
plications at 5-day intervals. Repea
as necessary. Additional applica-
tions should be made at 5-day inter-
vals when infestation again rises to
10 to 15%. Read "HOW TO MAKE
INFESTATION COUNTS." Vary
amounts per acre with size of plants
Large plants have more surface to
be protected and require more mate-
rial for good coverage than do small
plants.





When bollworm eggs and 4 or 5
small worms are found per 100 ter-
minals, apply at 5-day intervals
until controlled. Vary amount per
acre with size of plants.
When leaves begin to appear sticky
and glossy. Vary amount per acre
with size of plants.





Treat entire field when leaves begin
to redden and mites are numerous in
small areas or along margins of fields
Vary amount per acre with size of
plants.



When stands of young cotton are
threatened.


*When DDT is applied alone, no weevil control is obtained and heavy aphid infestations are likely to build up.


COTTON INSECT CONTROL CHART

INSECTS DUSTS SPRAYS APPLICATION
(Amount finished dust per acre) (Amount active ingredient per acre)


3% BHC + 5% DDT
or

1% parathion
or
4 or 5% malathion



4 or 5% malathion
or
1% parathion
or
3% aramite
or
sulfur




ed Spider Mites.- Hed spiders are so small that
they can hardly be seen without a magnifying glass.
They may be greenish or yellowish in color, but the
Females are usually reddish and the smaller males
*eddish yellow. Red spiders multiply rapidly. There
nay be as many as 17 generations a year in some
cotton areas. Infestations usually develop around
:he margins of fields, near ditch banks or weed patches
md along dusty roads. Red spiders live on the under-
sides of the leaves, where they lay their eggs and
spin delicate webs. Yellowish or whitish speckling
)f the leaves usually shows that red spiders are
amaging cotton. The entire leaf may redden or turn
sty brown, curl and drop off if damage is severe.
ed spiders are more injurious during hot, dry weather
d a heavy rain often checks an outbreak.
Thrips.- Thrips are not a serious pest of cotton
n Florida. These small, elongated, yellow-to-almost-
lack insects are about 1/25 inch long and may attack
eedling plants as soon as they are out of the ground.
heir injury causes a ragging and crinkling of the
eaves, retards growth and may damage the young
stand. Cotton outgrows this injury and there is usually
little effect on the yield. Thrips control may occa-
ionally be justified because it allows plants to grow
ff more rapidly and uniformly, which may be an aid
n cultivation. To find thrips, pull a plant or two from
he soil and shake over a white paper or handkerchief.
f treatment is deemed necessary, application should
e made when the cotton is in the 2- to 4-leaf stage,
r just after chopping is completed.
Miscellaneous Insects.- Fleahoppers, fleabeetles,
utworms, cotton leaf worms and tarnished plant bugs
ay infest cotton, but usually are not considered to
e major pests of cotton in Florida. They generally do
ot cause much damage when a program is carried out
Keep boll weevils, bollworms, aphids and red
spiders under control.
EARLY-SEASON BOLL WEEVIL CONTROL
If overwintered boll weevils are numerous in the
ea, make at least one application of insecticide
st before the oldest squares are large enough for
e laying of eggs. Weevils prefer squares the size
f an ordinary pencil eraser or larger for egg-laying.
DT usually is not needed in this application. Use
e lower rates recommended for boll weevils in the
hart.
MID- AND LATE-SEASON INSECT CONTROL
Read Carefully "Hlow To Make Infestation Counts."
ake weekly infestation counts for boll weevils and




bollworms. Also examine cotton plants for red spider
mites, aphids and other pests. They can build up
rapidly.
Boll weevils will migrate late in the season when
squares and young bolls become scarce. At this time,
large numbers of weevils may move into fields every
day from other areas. During this period, it is essen-
tial that heavy and thorough applications of insecti-
cides be kept on the cotton to prevent serious damage
to the bolls. Many farmers make the serious error of
stopping their control program too soon. Bolls must
also be protected from bollworms as long as worms
are present or until cotton opens.
APPLICATION OF INSECTICIDES
Amount of Spray or Dust per Acre.- The amounts
per acre shown in the insect control chart are recom-
mended amounts. Good coverage is necessary for
satisfactory control and the amount of spray or dust
material applied per acre to obtain good coverage
varies with the size of the plants.
Dusts.- Apply dusts during calm periods when the
the wind velocity is less than 5 miles per hour. The
best hours for dusting are usually between 5 p.m. and
9 a.m.
Sprays.- The amount of the actual insecticide
contained in different emulsifiable concentrate spray
formulations may vary between materials and also
formulations of the same material. In using a spray
concentrate, the actual number of pounds of the in-
secticide there is per gallon must be known in order
to determine the amount of concentrate to use per
acre. The number of pounds of actual insecticide
contained per gallon is given on the label of most of
the spray concentrates offered for sale for cotton
insect control. The quantity of finished spray applied
per acre will vary with the type and speed of the
equipment. Sprays can be applied effectively in wind
up to 15 to 20 miles per hour.
PRECAUTIONS
All insecticides used for the control of cotton
insects are poisonous and should be handled with
caution. Parathion and demeton are especially toxic
to human beings. The materials are poisonous if
swallowed, inhaled or absorbed through the skin.
Follow carefully the precautions printed on the con-
tainer.

Because of the relatively small acreage of cotton grown in Florida,
there has been only limited research carried out on cotton pests in
the State. Most of the information in this circular is adapted from
recommendations from neighboring cotton growing states.




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