Historic, archived document

Do not assume content reflects current
scientific knowledge, policies, or practices.

*

oe G AR D EN
nsect
lide

Ss

"Zz = ; L i
US. Department of Agriculture? Ne

AWI—95

All Vegetables

Blister beetles . . ..
Calkwortist ss ase ee
Grasshoppers ....
Sunkbugs’:>%,.. 7.
White grubs. .-—.- >

Wireworms ......

Beans

Beetles: ies srerss cee

Leafhoppers .
Magcots s: Seana

Plant lice (aphids) .

Broccoli, Cabbage, Cauliflower,
Collards, Kale, Radishes,

Turnips

Beetles .
Caterpillars .

Cubwormss.: (ais sean
Harlequin bugs .. .

Maggots

Plant lice . : fos eae

2

. . . .

i ON a 4 gtk ae

ot ul. ja) ee) ce

Crops and Pests

Page
Corn )
Borers...

Maggots

Peas
Maggots .
Plant lice .

Crue Teo se er ae) ae |. ee

Com: carwonmus.- . “certusms | tees

10

S

12 Cumyrorms:.. 3".
9

7

Z

a © cat) Si ei es ee ae oe

Eggplant, Potatoes, Tomatoes

—

OmWvO°O

Beetles ..
Borers

Cutworms
Flea beetles

Caterpillars .

6 ee let eP | tee 6. ee

ee ee ee me

Leafhoppers . pa:
Tomato fruitworms . .:.....

Cucumbers, Melons, Pumpkin,

SE, selene ~, Maggots .
SET Sioa 6 Plant lice .
Ph eA: 8 Sguash bugs

oe ~ “oe: 20 ee er ia ee

ace, Je Vea ae tebe! ee (oe eee

INSECTS IN THE VICTORY GARDEN

Now, in time of war, the need for
maximum production of food is more
important than ever before. Our
Government is asking urban as well
as rural people to contribute their
share again this year in meeting our
huge food requirements. They can
do this by growing Victory Gardens
to supply their home needs for veg-
etables, thus releasing food pro-
duced from other sources to feed our
fighters, our allies, and our workers
on the home front.

Twenty-two million Victory Gar-
dens is the goal set tor 1944. This
means that we need about 16 mil-
lion city, town, and _ suburban
gardens.

Insects that feed on garden crops

584186°—44

must be controlled. In this guide the

gardener will find a general discus-
sion of insects and their control.
Insects having the same or similar
habits are listed together, and
methods for combating them are
given. No attempt is made to discuss
each insect separately, or to give as
wide a variety of control measures
as commercial growers would need.

A knowledge of insects and their
food habits will be useful in applying
control measures and will alsolessen
the sometimes groundless fear of
damage they may cause. For ex-
ample, many insects that will not
cause crop damage will be found
in the garden, their presence being
merely incidental.

On the other hand, some insects,
such as blister beetles, grasshop-
pers, and cutworms, feed on a wide
variety of plants. Others, such as
cabbage worms (caterpillars) and
harlequin bugs, feed on closely
related crops like cabbage, col-
lards, kale, and broccoli. The Mex-
ican bean beetle feeds only on
beans, the striped cucumber beetle
on squash and other members of the
sguash family, such as pumpkins
and melons.

Insects feed on plants by chewing

holes in the leaves, sucking plant
juices, or tunneling into the roots,
stems, or leaves. The presence of
the chewers is easy to detect; the
injury caused by the other kinds
shows up as wilting, curling, or
stunting of the different parts of the
plants.

Some insects are beneficial, be-
cause they feed on other insects that
are pests. Some of the beneficial
insects are ladybeetles, wasps, syr-
phid flies, and lacewings.

CUTWORMS atiack the young
plants of cabbage, collards, toma-
toes, corn, and almost all other gar-
den plants. They cut these plants off
at the surface of the ground. These
insects are likely to be present in
soil that was in grass and weeds the

year before. Newly set plants should
be protected by collars at the time
of planting. The collars should be
made of paper and should be about
the size and weight of a 1-cent post
card. Wrap the paper around the
plant as illustrated. Leave ample
space for air to circulate between
the collar and the plant, and allow
the collar to extend into the soil
about 1 inch. Cutworms will crawl
from plant to plant, and each
worm may cut off several plants.
For this reason, any cutworms found
should be killed. A pinch of poisoned
bait placed at the base of each
plant will prevent further damage.
Also, a poison bait scattered thinly
on the ground just before the plants
are set will attract the cutworms,and
the small amount of bait they eat
will kill them.

For making and applying bait,
see discussion of grasshoppers (p.

12).

PLANT MAGGOTS destroy roots

of cabbages, kale, radishes, and

broccoli. Other kinds feed on
sprouting beans, corn, and peas.
Plants such as cabbage on whose
roots maggots are feeding appear
stunted, and their leaves turn bluish
green. These insects cannot be

6

controlled. after plants are infested.
Preventive measures such. as treat-
ing the seed with a mercury com-
pound before planting may afford
some protection. A 3-inch tar-
paper disk (illustrated)—cut to the
center so that it will fit snugly—if
placed flat on the ground and
fitted around each newly set plant,
will afford protection. If maggots
threaten the crop, a mercury treat-
ment of calomel or corrosive subli-
mate may be applied to the soil
around the plants. Maggot injury
to newly planted beans, corn, and
melon seed: usually occurs during
cool, wet periods when seed germi-
nation is slowed down. Prepare a
good seedbed and plant shallow
during warm periods to promote
rapid germination of the seed.
Avoid breathing or getting into the mouth
dusts containing mercury compounds; avoid
storing them; and thoroughly clean all ves-

sels used in mixing and handling poisonous
compounds,

WIREWORMS (eit) and White
Grubs (right) feed on the roots of
plants. These pests are very destruc-
tive to gardens in some areas. No
means of control on the growing
crop is known, as any soil treatment
sufficient to kill the worms will injure

the plants. Some benefits can be
obtained by crushing all the pests
that are seen when the soil is being
worked. When wireworms or white
grubs are abundant, the soil should
be treated before the crop is planted.
Crude naphthalene flakes, used at
the rate of 1% pounds to 100 square
feet, worked into the soil to give
uniform distribution to a depth of
about 10 inches, will give control.
Good distribution can be had by
spreading about half the material
evenly over the soil just before spad-
ing or plowing and the other half
immediately after, while the ground
is still rough. The naphthalene
should be worked into the soil
promptly after it is applied. Do not
plant until 7 days after treatment.
To do so may injure the crop. Avoid
planting carrots, onions, and other
root crops on soil known to be
infested.

PLANT LICE or Aphids are pests
of peas, turnips, radishes, cabbages,
cucumbers, and other vegetables.
The leaves attacked sometimes curl
up, enclosing the pests. Stems and
the under side of leaves on which
they feed often become covered
with these tiny sucking insects,

8

which sap the plant's life. » Plants
infested cannot develop normally or
produce a crop. A nicotine sulfate
and soap solution is a good remedy.
Dissolve 2 teaspoonfuls of soap chips
in 1 gallon of water and add 1%
teaspoonfuls of nicotine sulfate.
Mix thoroughly, and spray to hit the
lice. If a dust is to be used, a nic-
otine-dust mixture can be made by
pouring | ounce of nicotine sulfate
into a quart of lime in a half-gallon
friction-top can. Add a few stones
to help in mixing the material, place
lid on container, and shake thor-
oughly for 10 minutes. Dust this
mixture on the plant lice. Use nico-
tine when the air is calm and the
temperature above 70° F. Remove
the unused nicotine mixture from
the sprayer or duster. Keep the
dust mixture sealed in a tight con-
tainer for later use.

ad
Avoid breathing nicotine sulfate or getting
it into the mouth,

PLANT-SUCKING BUGS feed on
many vegetables. The Squash Bug
(illustrated) feeds on vine crops,
such as squash, pumpkin, and cu-
cumbers. The Harlequin Bug feeds
primarily on leafy crops, such as
cabbage, kale, collards, and broc-
coli. The Green Stinkbug is a

general feeder. These bugs are all
larger then plant lice, and persist-
ent effort through hand-picking of
eggs and bugs will give much
control. Cleaning up and destroying
crop refuse after harvest will destroy
many bugs that otherwise would
attack. crops the next year. Leaf-
hoppers belong to another group of
sucking plant bugs and are the
small, usually pale green, very
active insects that readily fly from
the plant when they are disturbed.
They damage beans and potatoes
by sucking the juice from the plant
and cause a disease called hopper-
burn. Applications of sulfur will give
some protection. Potato growers use
bordeaux mixture to control leaf-
hoppers. Pyrethrum powder, if fresh,
used alone or mixed with dusting
sulfur, will give the best control of
leafhoppers.

(See pyrethrum, under Insecti-
cides, page 15.)

¢
a

in Ws
aR .

BEETLES chew holes in the leaves
of plants such as beans, potatoes,
eggplants, turnips, cucumbers, and
melons. The Bean Beetle (illus-
trated) and the Potato Beetle in both
the hard-shell and the young stage
eat the plant leaves. Blister Beetles,

10

Cucumber Beetles, and Flea Beetles,
feed on the leaves of plants only
when in the hard-shell (adult) stage.
Flea beetles are small, dark insects,
and move so rapidly they often pass
unnoticed. They riddle the leaves of
plants with small holes. Newly set
plants such as tomatoes and egg-
plants, especially while wilted, are
attractive to flea beetles. Eggplants
and potatoes are subject to flea
beetle attack at all times, whereas
cabbage, kale, radish, and turnip
seedlings are more susceptible to
damage as they come through the
ground. The small gardener can
pick the larger beetles off the plants
by hand and thus protect his crops.
Rotenone or cryolite applied lightly
but thoroughly to both the upper
and lower surfaces of the leaves
will afford protection from beetles.
Cryolite can be used until the edible
parts of plants begin to form (see
caution on page 15).

CATERPILLARS eéai the leaves
of garden plants, especially cab-
bage, kale, collards, cauliflower,

and broccoli; also tomatoes. If
these “‘worms’’ are not checked,
they may ruin the crop. Pick off the
pests by hand and destroy them. A

mixture of cryolite, dusted or
sprayed on plants at weekly in-
tervals as long as necessary will
control these insects. Care should
be taken to cover both surfaces of
the leaves. Cryolite should not be
used on cabbage, cauliflower, or
heading broccoli after the head
begins to form, nor should it be used
on any leafy vegetable intended for
immediate consumption. If cater-
pillar control becomes necessary
after heading or fruiting begins,
dust crops such as cabbage with
rotenone dust. Reach the innermost
parts of the plants as well as both
sides of the leaves. Rotenone is of
little or no value for ‘‘worms’’ that
feed on tomatoes. If treatment of
tomatoes is necessay after plants
have fruited, use cryolite, but be
sure to wipe or wash the fruit
carefully before it is eaten or
marketed.

ll

GRASSHOPPERS chew the leaves

and fruits of practically all vege-

tables. In some areas they are
destructive almost every year, in
others they seldom cause damage.
Grasshoppers can be controlled by
the use of poison baits. Inthe Western

12

and Great Plains States, where
extensive grasshopper control pro-
grams are carried on, ready-mixed
baits are available. Where ready-
mixed baits cannot be procured, a
bait can be prepared by mixing—

1 guart of wheat bran or rolled oats.

2 level teaspoonfuls of paris green.
When these dry materials are
thoroughly mixed, add enough water
slowly while mixing to make a
crumbly mash in which every flake
is moist and carries some poison.
About 1 pint of water will be re-
quired. The bait should be scattered
thinly over the ground. One quart
of mixed bait is enough for one
application to 2,000 square feet.
Apply the bait in the morning when
the temperature reaches 68° F. or
higher. Since grasshoppers usually
come from uncultivated areas out-
side the garden, these areas as well
as the garden should be baited.

BORERS tunnel! into the stems and
roots of squash, pumpkins, cucum-
bers, melons, corn, and other plants.
Some borers hatch from eggs laid

on plants; others migrate from
weeds in the garden. Therefore keep
the weeds down. Squash borers
(illustrated) tunnel into vines and

cause them to wilt and die. Reduce
damage by spraying plants four
times, at weekly intervals, with a
strong solution of 1 part nicotine to
100 parts of water, when the first
blossoms appear. Borers can often
be located in wilted vines by the
yellow, waxy material near the
point where they cut through the
stem. Slit the stem at this point with a
sharp knife, and crush or remove the
borers. Immediately cover the stem
with moist earth to prevent drying
of the injured plant tissue. Water
the vines frequently until new roots
begin to form. Damage to corn by
the European Corn Borer can be
reduced by the application of rote-
none spray: or dust. Get the insecti-
cide into the center of the plant
where the tassel forms, and between
each leaf and the stalk. Four appli-
cations 5 days apart, beginning
about June 15, should be made on
corn knee high or higher.

13

Ss “a! ioe

SIM, =FT

i iif

CORN EARWORM or Tomato
Fruitworm (illustrated) feeds on
tomato fruits and corn ears. The
larger worms make holes about as
big around as a lead pencil in the
fruits. Enclosing fruit clusters in
paper bags will offer some protec-
tion. Dusting the plants with cryo-

14

lite when fruit begins to form also
will help. Repeat applications every
10 days, or after each rain, as long
as injury persists. Dusted tomato
fruits should be washed thorough-
ly before they are eaten or mar-
keted. Corn earworms once inside
the ear Cannot be controlled. Stop
them with a medicinal mineral oil,
or, preferably, a commercially pre-
pared oil with another insecticide
added to make it more effective.
Place the oil in the silk about one-
half inch inside the tip of the ear.
About one-fourth of a teaspoonful,
or 20 drops, to each ear can be
applied with an eyedropper or an
oilcan. Wait at least 3 days after
the silks first appear at the tip of the
ear before applying the oil. By that
time the silks should be wilted and
the tips beginning to turn brown.
Earlier treatment will damage the
ear, and later treatment may not
give good control.

INSECTICIDES are the chemicals used to
control insects. However, the home gardener
cannot afford to stock all kinds. Only those
necessary to give practical control of the
most common insects are recommended in
this guide. When in doubt about the mixture
to use, follow directions on the package.
Rotenone and pyrethrum are _ excellent
garden insecticides, but the supply, espe-
cially of pyrethrum, is limited. These ma-
terials, if available, should be restricted to
use on vegetables, at the time the edible
paris are forming, for insects that cannot be
controlled by other measures.

The following insecticides are poison-
ous to human beings as well as to
insects. Caution should be taken in
storing and handling them.

Cryolite gives good control for many
chewing insects, and the national supply is
expected to be adequate. Local supplies
will depend on local dealers. Do not use
cryolite on leafy vegetables, or on the
exposed parts of vegetables such as tomato
fruits, cabbage, cauliflower or broccoli
heads, or on string (snap) beans.

Nicotine sulfate, used to control a number
of insects, especially plant lice, is expected
to be available in quantity sufficient to
meet the demand by Victory gardeners.
Nicotine dusts and sprays mixed for use
must be kept sealed tightly, because they
lose their strength rapidly. To give best
results, nicotine dusts or sprays must be
directed to hit the insecis and used when the
air is calm and warm.

Arsenicals, such as calcium: arsenate
and paris green, are sometimes used to
protect garden vegetables, but in some
areas they cause injury to more tender
plants. Such insecticides should not be
used on the edible part of the plant.

Naphthalene has a limited use for con-
trolling pests. Its principal use is against
wireworms.

All mercuric compounds are poison-
ous, and mixtures containing copper
sulfate, which is the principal element
in bordeaux mixtures, are more or less
poisonous to men and animals. In
handling and mixing these. also be care-
ful not to breathe them or get them into
the mouth.

15

Dusters and sprayers are the equipment used to apply
insecticides. The Victory gardener will have to depend on
the kind of duster or sprayer available. Many of the metals
formerly used to make such equipment have gone to war.
Commercially prepared applicators will give best results.
However, use of home-made devices such as shaker cans
or sack dusters will offer some protection to garden plants.

For more detailed -informa-
tion on the control of insects
affecting your Victory Garden,
see your county agricultural
agent, consult your State agri-
cultural college, or write to the
United States Department of
Agriculture for Miscellaneous
Publication 525, A Victory
Gardener’s Handbook on In-
sects and Diseases.

Extension Service and et ;
Bureau of Entomology |
and Plant Quarantine

16 U.S. GOVERNMENT PRINTING OFFICE: 1944