The efficiency of DDT is due to the fact that it is long lasting in it's effectiveness 
against insects, and because it is not necessary that the insects be present at the time 
of application. Any of the insects controlled by it will be killed simply by walking 
across sprayed surfaces as much as two weeks after applied. Rain does not greatly 
reduce the effectiveness of the material on the plants. Application may be made at 
any time of the day. DDT is compatible with most insecticides, except those containing 
lime, and may be applied at the same time in one application. 
If a dust is preferred, a 3% dust can be purchased ready to use, which will do 
the job as well as dusts of higher concentrations, and with less possibility of ill effects 
to plants. If a 39% dust can not be purchased in your locality, a dust of higher per- 
centage of DDT may be reduced to 3% by adding the proper amount of tale or sulphur. 
Never use lime with DDT. 
The spray which we use is made up to contain 34 pound of actual DDT crystals 
to 100 gallons of water. To make up the spray, a wettable powder should be used. 
Most of the powders on the market for this purpose also contain spreaders so that 
it is not necessary to add anything to the powder. We use Deenate 25W manufac- 
tured by duPont, which contains 25°94 DDT, or one fourth of each pound. Thus it 
will require three pounds of the 25% material to supply the 34 pound of actual DDT 
needed for 100 gallons of water. This is approximately !/> ounce per gallon. 
DDT is not soluble in water but mixes readily to form a suspension (materials sus- 
pended in water). Since it is a suspension, it is necessary to keep the material well 
agitated after mixing until used. In this form (suspension), DDT is not injurious to the 
user and can easily be washed off the hands. However, it is well to avoid contact of 
the material with the skin as much as possible. 
CAUTION: Be sure the material you purchase is made specifically for application 
to plants. 
APHIDS cause a lessening of vitality by sucking plant juices. Easily detected as 
they usually are found in clusters on the stems and around buds. Soft bodied insects 
which remain quite stationary on the plant. They may be black, red or green. Control 
by dusting or spraying with contact insecticides such as nicotine sulfate (Black Leaf 40), 
pyrethrum extracts or rotenone according to manufacturer's directions. DDT is partly 
effective on aphids but can not be relied upon to control them completely at all times. 
However, the suggested materials for aphid control can be combined with DDT. 
CORN BORES drill holes into the stalk, usually at a leaf or branch. They live 
and grow inside the stalk, eventually enlarging their bores until a portion of the plant 
is so weakened that it breaks down. The adult moth of the corn borer lays it’s eggs 
on a leaf. As the eggs hatch the larva starts moving toward the stalk eating tiny 
trails in the leaf surface. It is at this time, only, that control measures are effective. 
DDT is a very effective control. The material must be present on the plant surfaces 
as the eggs hatch and the larva start for the stalk. For best results it may be advisable 
to apply the DDT at shorter intervals during the short hatching period. Your County 
Agricultural Agent may be able to tell you when that period will be. 
CUCUMBER BEETLES are sometimes quite serious pests of dahlias. They eat holes 
in the petals of the flowers, disfiguring the blooms. There are two common types of 
the cucumber beetle. One is the Twelve Spotted Beetle, characterized by twelve 
black spots on the greenish wings. The other is the Striped Beetle, which has alter- 
nate black and yellow stripes on the wings. Chlordane, used as a 5% dust or as a 
spray according to manufacturer's instructions, has been found highly successful in 
their control. Cryolite is also an effective control. 
CUT WORMS hide under clods or in the soil during the day and emerge at night 
to cut off young plants, usually at soil level. If these pests are not too numerous they 
may be controlled by carefully searching the top inch or two of soil within a few inches 
of the plant and destroying the grub which is often two inches long and fleshy. Heavy 
infestations may be controlled by scattering poison bran mash lightly over the garden 
area. DDT is effective for climbing cutworms and others when they must cross sprayed 
or dusted surfaces. 
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