DDT (dichloro-diphenyl-trichlorethane). A chlorinated hydrocarbon, the
first organic insecticide to sweep the country. As both stomach and
contact poison it gives excellent control of boxwood and holly leaf miners,
iris, lilac, peachtree, and other borers, bark beetle vectors of Dutch elm
disease, sawflies, cankerworms, gypsy moth and many other caterpillars,
codling moth, gladiolus thrips, Japanese beetles as adults or grubs in soil,
and leafhoppers. It does not control Mexican bean beetles and bagworms.
vAs a spray it is usually used at 2 tablespoons 50% wettable powder to
1 gallon of water. It is also available as a 3, 5, and 10% dust.
On the debit side DDT vastly increases the incidence of mites-red
spiders, spruce mite, red mites, etc.-through killing their parasites and
to a lesser extent encourages many aphids, some scale insects. It injures
most cucurbits rather severely, sometimes tomatoes, and some varieties of
camellias. It has a long residual effect and if used continuously may
build up in the soil to injurious proportions. Used in the garden near
pools it may kill fish. In large-scale operations it has reduced bird pop
ulations, but when used at minimum dosage for control and outside the
nesting season it is not very dangerous.
DERRIS. A tropical plant, source of rotenone.
DIELDRIN (a derivative of aldrin). First released for control of cotton
pests but coming into much wider usage for wireworms and many
other soil insects, thrips, Argentine and harvester ants, etc. Used as a
foliage spray for leaf miners it has chematherapeutic value, killing the
young miners inside the leaves. It is a strong poison; wear gloves when
handling plant parts that have been recently sprayed or dusted.
Dilan (nitroparaffins, Commercial Solvents Corp., 17 E. 42nd St., New
York 17, N.Y.). Particularly effective for Mexican bean beetle,
promising for armyworms, plum curculio, oriental fruit moth.
Dimite, IMC (Di (p-chlorophenyl) methyl carbonol, Sherwin-Williams,
101 Prospect Ave., N.W., Cleveland 1, Ohio). A miticide especially
recommended for cyclamen mite. Use 1 teaspoon per gallon of water.
DINITRO COMPOUNDS. Derivatives of cresol and phenol used in some dor
mant sprays, chiefly to kill aphid eggs, sometimes in dilute dust
form for mites in growing season. Sold as DN dusts or sprays or Elgetol.
Dithane D-14 (disodium ethylene bisdithiocarbamate, Rohm & Haas Co.,
222 W. Washington Square, Philadelphia 5, Pa.). Outstanding in
control of tomato and potato blights, onion blast and mildew, azalea
flower blight, Botrytis blight and Stemphylium leaf spot of gladiolus. For
tomatoes it is used at rate of 2 quarts D-14, 1 pound 36% zinc sulfate,
and 1/2 pound lime to 100 gallons of water; on flowers, 1 quart D-14, 1
pound 25% zinc sulfate, 1/2 pound lime, and I ounce B 1956 spreader.
In small quantities the latter is 2% teaspoons D-14, 1 teaspoon each of
zinc and lime, 5 drops B 1956 or 1/3 teaspoon Dreft per gallon. The zinc
sulfate is vitally necessary in the mixture to prevent injury; lime may
possibly be omitted.