INSECTICIDES AND EQUIPMENT FOR CONTROLLING INSECTS 25 
NICOTINE DUSTS 
Nicotine dust is the name commonly used to designate a dust made 
by combining nicotine with a powdered carrier (see Diluents or Car- 
riers, p. 11). Ground tobacco, which also contains nicotine, is usually 
called tobacco dust; see page 37. The former has the advantage that 
a higher percentage of nicotine may be incorporated in the dust and 
the nicotine is more volatile and effective. Also, the nicotine dust 
is composed of finer particles, unless the tobacco dust is very finely 
ground. 
For small plantings, nicotine dust may be prepared with an ordinary 
flour sifter, using 1 pound of hydrated lime and 1 to 114 ounces of 
40-percent nicotine sulfate solution. Or, place a quart of fresh 
hydrated lime in a container which can be tightly closed. Then add 
a handful of small stones or marbles, pour in 1 fluid ounce of nicotine 
sulfate, close the lid, and shake well for several minutes. To prepare 
larger quantities, roll the ingredients together in a drum or keg for 
at least 20 minutes with a peck of stones the size of goose eggs. Until 
used, the nicotine dust must be preserved in tight metal or glass con- 
tainers, as it loses its strength very rapidly when exposed to the air. 
Nicotine dust is used against aphids, such as occur on pea, cabbage, 
melon, turnip, and other plants, as well as against the striped cucum- 
ber beetle, adults of the greenhouse leaf tier, adults of the boxwood 
leaf miner, and the orchid fly. 
For greater effectiveness, nicotine dusts should be applied to dry 
folage when the temperature is above 65° F. and the air is still. 
Apply thoroughly to reach all insects present and repeat the treat- 
ment if control is not complete. For the boxwood leaf miner, make 
applications daily throughout the period of adult emergence. 
NICOTINE FOR FUMIGATION 
Nicotine for fumigating purposes is derived from several sources. 
The burning of tobacco stems is one of the oldest methods, but is now 
being discarded because of the difficulties surrounding their use. At 
present fumigating with nicotine is done almost entirely by the burn- 
ing of commercially prepared nicotine powders: available in espe- 
cially devised pressure cans, or by vaporizing liquids containing free 
or volatile nicotine from the heating pipes. The pressure-can method 
may be used to fumigate a few individual plants, a single bench, or 
an entire greenhouse. 
When free nicotine is to be evaporated on the steam pipes, it should 
be painted on the pipes while they are cool, after which the steam 
is turned into the pipes to drive off the nicotine vapors or fumes. 
The usual dosage ranges from 1 fluid ounce to 2,000 cubic feet of 
space in older houses to 1 fluid ounce to 4,000 cubic feet in newer or 
tight houses. The exposure is usually for overnight. 
Fumigation of plants with nicotine should be done on still nights 
and after sunset, and under dry conditions at temperatures between 
50° and 70° F. Violets and certain ferns are often injured by nico- 
tine fumigation. 
Detailed directions on the dosage and procedure to be followed are 
usually given on the labels of the containers in which these materials 
are purchased. 
Vaporized nicotine is also used to a limited extent for the control of 
aphids on peas and cole crops. The method consists of injecting a 
605160°—45——4 
