INSECTICIDES AND EQUIPMENT FOR CONTROLLING INSECTS 23 
The flakes are mixed with soil to destroy wireworms, white grubs, 
the garden centipede, and other pests at the rate of 500 pounds per acre 
or 19 ounces distributed under 100 linear feet of 12-inch furrow slice. 
They are also scattered in places frequented by sowbugs, millipedes, 
and slugs. 
When mixed with dormant gladiolus corms in storage at the rate of 
1 handful per 100 corms or 1 pound per 2,000 corms, it destroys the 
gladiolus thrips. It should be used only in the fall, after harvest. 
Late spring treatments may injure the corms. 
Caution.—Persons breathing naphthalene vapors for several 
hours will experience irritation of the respiratory tracts and eyes. 
High concentrations can cause the same discomfort in a very 
short time. 
NICOTINE 
Nicotine (C,,H,,N.) is an alkaloid which occurs in tobacco and 
related plants. In its pure state it is an oily, colorless liquid which is 
soluble in water, alcohol, and fatty oils. For spraying purposes it is 
commonly sold in the form of solutions of nicotine sulfate. The stand- 
ard brands on the market usually contain the equivalent of 40 percent 
of nicotine. They are deep-brown, thick liquids and are very stable. 
Nicotine sulfate is a byproduct of the tobacco industry in the United 
States and normally is readily available. 
Nicotine is used as a contact insecticide, a stomach poison, or a 
fumigant. As a contact spray nicotine sulfate (40 percent nicotine) 
is used at the rate of 1 to 2 pints per 100 gallons of water or other 
sprays, to which may be added 2 to 4 pounds of soap. Nicotine sulfate 
is compatible with bordeaux mixture, lime-sulfur, or other alkaline 
materials. 
Nicotine combinations are effective against aphids, the pear psylla, 
grape leafhoppers, adult whiteflies, rose slugs, certain leaf miners, the 
young stages of plant bugs, mealybugs, and scale insects. 
The combination of nicotine sulfate and mineral oil is effective as 
a stomach poison, contact spray, and ovicide and is used against the 
codling moth. A more effective codling moth spray is the combina- 
tion of nicotine sulfate and bentonite. See Nicotine Bentonite (p. 24). 
A spray used for control of the boxwood leaf miner during the adult 
emergence period is made up as follows: 
For small For large 
quantities quantities 
Mieopiie sulfate <7 = = 5 1 teaspoonful. 114 pints. 
ESOL AS SSE eet Fra a ee Bs hs 1 pint. 12 gallons. 
SOU STS Swen SP aes a pe micron eee te 7 pints. 88 gallons. 
The material is applied to both surfaces of the leaves as a fine spray. 
It kills the adults as they emerge from the leaves and entangles others 
in the sticky deposit. 
Nicotine may also be incorporated in dusts (see p. 25). Nicotine 
fumes are used extensively as a greenhouse fumigant and for control- 
ling aphids on peas, cabbage, beans, and other crops. 
Caution.—Nicotine and its compounds are violent poisons, and 
care should be exercised in their use. Exposure to fumes or 
sprays for any length of time causes the development of acute 
nausea in some persons. Combinations other than nicotine ben- 
