INSECTICIDES AND EQUIPMENT FOB CONTROLLING ENSECTB 33 



(iii) Cole crops — other than cabbage, including broccoli, brussels sprouts, cauli- 

 flower, kohlrabi, mustard, kale, turnips, and collards — for protection against 



caterpillars and aphids. 



(iv) Sweet corn — for protection against the European corn borer. 



' 2 ) Use on cattle for the specific control of the cattle grub fox warble) or short- 

 nosed cattle louse, or the manufacture of any insecticide for such use 



(3) Any other specified use, where specifically authorized or directed by the 

 Director General for Operations. 



SOAP SPRAYS 



Sprays made from soap are very useful, especially for small plantings 

 or house plants. Dissolve- a cubic inch of ordinary soap or 2 table- 

 spoonfuls of soap flakes in 1 quart of water. If fish-oil soap is at hand, 

 a rounded tablespoonful may be used. Soap sprays are useful against 

 aphids and the younger stages of mealybugs, scale insects, whiteflies. 

 and other soft-bodied insects, but should not be used on very young or 

 tender plants. For use on hardy plants the amount of soap may be 

 increased to kill larger insects. 



The soapy water remaining in the tub after clothes have been 

 laundered may also be used for spraying or dipping foliage of infested 

 house plants. When potted plants are dipped, they should be inverted 

 and submerged only to the soil surface and then laid on their sides to 

 drain before being set in an upright position. This will avoid saturat- 

 ing the soil with the soap solution. House plants dipped or sprayed 

 with concentrated soap solutions should not be placed in full sun for 24 

 hours, after which the foliage may be syringed with clear water and 

 the plants returned to their former locations. 



Soap is used as a wetting and spreading agent with nicotine, pyre- 

 thrum, and some other sprays. The amount of soap required in a 

 spray mixture is regulated somewhat by water hardness. If used with 

 lead arsenate, some soaps may increase arsenical injury to foliage. 



Oleates of monoethanolamine, triethanolamine, and ammonia, as 

 well as several other soaps, have been used with mineral oil and lead 

 arsenate in making deposit-building mixtures to obtain the heavy 

 deposits of lead arsenate often needed for control of the codling 

 moth. 



SODIUM ABSENTEE 



Sodium arsenite (essentially NaAs0 2 ), a white crystalline solid. 

 is soluble in water and is. therefore, unsuitable for use on living plant-. 

 In fact, it is probably best known as a weed killer. It is more gen- 

 erally available in liquid form containing about 32 percent of arsenic 

 trioxide (As 2 3 ), although it can also be purchased as a powder. Its 

 chief use in direct control of insects is in poisoned baits (page 28). 

 but it is used as a spray on wild vegetation to control grasshoppers. 



Caution. — Sodium arsenite is a violent poison and must be 

 stored in clearly labeled packages. 



SODIUM CYAMDE 



Sodium cyanide (XaCX) is a white, deliquescent, very poisonous salt 

 manufactured in this country. When it is mixed witli dilute sulfuric 

 acid a reaction takes place in which the deadly hydrocyanic acid 

 gas (HCN) is liberated. For fumigation purposes sodium cyanide 



