INSECTICIDES A2sD EQUIPMENT FOR CONTROLLING INSECTS o< 



UMBO 



See Rotenone-Containing Roots (pp. 30-32). • 



TOBACCO DUST 



Tobacco dust is finely ground tobacco refuse and is a native product. 



Fresh tobacco dust containing at least 1 percent of nicotine is applied 

 as a mulch on the soil surface about rose plants to destroy larvae of the 

 rose midge as they drop to the ground to pupate in the soil. This 

 material, as a surface mulch or worked into the top inch layer of soil, 

 is also a remedy for the larvae of fungus gnats and for root aphids. It 

 is used undiluted as a dust to control the chrysanthemum midge and 

 thrips and aphids on various plants. Tobacco dust is also used as a 

 diluent for pyrethrum powder, rotenone root powder, and other 

 insecticidal dusts. 



VEGETABLE OILS 



Vegetable oils are used as insecticides or with them in a number of 

 ways. Emul-ifiers for mineral oil have been made from olive oil, 

 castor oil. and corn oil. Cottonseed oil is used with paradichloro- 

 benzene for the control of the lesser peach borer. Linseed oil and 

 crude soybean oil have been used as adhesives for lead arsenate or 

 nicotine "bentonite sprays applied to fruit trees. These oils are also 

 partially effective against the eggs of the codling moth and certain 

 other insects. 



Peanut oil or soybean oil (1 or 2 percent) is used in the preparation 

 of dusts containing derris or cube for the control of the pea weevil and 

 pea aphid. 



Sulfonated castor oil. commercially known as Turkey-red oil, is a 

 viscous, transparent light-yellow liquid. It is one of the wetting and 

 emulsifying agents used in the preparation of various sprays. In a 

 derris-pyrethrum spray used for the control of red spiders and thrips 

 on greenhouse and garden plants, it is added at the rate of 1 part to 

 300 or 400 parts of the spray. 



WETTING OR SPREADING AGENTS 



In addition to soap, which is discussed on page 33. many other mate- 

 rials are used as wetting and emulsifying agents. Sold under various 

 trade names, some of them are chemically known as — sodium mono- 

 sulfate of monobutyl diphenyl, sodium oleyl sulfate, sodium lauryl 

 sulfate, sulfonated vegetable oils (see Vegetable Oils. p. S7), sodium 

 salt of an alkyl naphthalene sulfonic acid, and sodium lauryl sulfate 

 paste. 



Sodium monosulfate of monobutyl diphenyl is a fine tan-colored 

 powder readily soluble in water. It takes up moisture from the air. 

 hence must be stored in a tight container in a dry place. A 40-percent 

 aqueous solution is also available and is convenient to use. 



Sodium oleyl sulfate is a brown liquid, readily soluble in water. 



