INSECTICIDES AND EQUIPMENT FOR CONTROLLING ENSEQTfi 25 



a higher percentage of nicotine may be incorporated in the dusi 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 V- 2 ounce- 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 

 foliage when the temperature is above 65 c 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 source-. 

 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 pipe.-. The pressure-can 

 method may be used to fumigate a few individual plants, a >ingle 

 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 2.0<>0 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 c 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 

 concentrated nicotine preparation (containing 80 percent of free 

 nicotine) into the exhaust pipe of a gasoline engine while the engine 

 is running at a comparatively high speed. The vaporized nicotine 

 produced is blown out through a boom at the rear of the engine and 



