5g6 Bulletin 283. 



II. INSECTICIDES. 



M. V. SLINGERLAND, GLENN W. HERRICK AND C. R. CROSBY. 



This can be applied in a stronger mixture than other arsenical 



Arsenate poisons without injuring the foliage. It is, therefore, much 



of lead. used against beetles and other insects that are hard to poison. 



It comes in the form of a paste or powder. The paste should 



be mixed thoroughly with a small amount of water before placing in the sprayer, 



else the nozzles will clog. The powder may be applied dry or mixed in water. 



Arsenate of lead may be safely used with Bordeaux or lime-sulfur. It is used in 



strengths varying from 4 to 10 lbs. per 100 gals., depending on the kind of insect 



to be killed. 



This is used in varying strengths, depending on the insect to be 



Paris green, controlled and the kind of plant treated. Mix the Paris green 



into a paste and then add to the water. Keep the mixture 



thoroughly agitated while spraying. If for use on fruit trees, add i lb. of quick 



lime for every pound of Paris green to prevent burning the foliage. For potatoes 



it is frequently used alone, but it is much safer to use the lime. Paris green and 



Bordeaux mixture may be combined without lessening the value of either and the 



caustic action of the arsenic is prevented, but it is unsafe to use with lime-sulfur. 



(For use with Bordeaux mixture only.) Sal soda 2 lbs., water 



Arsenite i gal., arsenic i lb. Mix the white arsenic into a paste and then 



of soda. add the sal soda and water and boil until dissolved. Add water 



to replace any that has boiled away so that i gallon of stock 



solution is the result. Use i quart of this stock solution to 50 gallons of Bordeaux 



mixture for fruit trees. Make sure there is enough lime in the Bordeaux mixture 



to prevent the caustic action of the arsenic. 



(For use without Bordeaux mixture.) Sal soda 1 lb., water 



Arsenite r gal., white arsenic i lb., quick lime 2 lbs. Dissolve the 



of lime. white arsenic with the water and sal soda as above and use 



this solution while hot to slake the 2 lbs. of lime. Add enough 



water to make 2 gallons. Use 2 quarts of this stock solution in 50 gallons of 



water. 



For wet application use fresh white hellebore 4 oz., water 2 or 

 Hellebore. 3 gals. For dry application use hellebore i lb., flour or air- 

 slaked lime 5 lbs. This is a yellowish white powder made from 

 the roots of the white hellebore plant. It loses its strength after a time and should 

 be used fresh. It is used as a substitute for the arsenical poisons on plants or 

 fruits soon to be eaten. 



Hard, soft or whale-oil soap J lb., water i gal., kerosene 



Kerosene 2 gals. Dissolve the soap in hot water; remove from the fire 



emulsion. and while still hot add the kerosene. Pump the liquid back 



into itself for five or ten minutes or until it becomes a creamy 



mass. If properly made the oil will not separate on cooling. 



For use on dormant trees, dilute with 5 to 7 parts of water. For killing plant- 

 lice on foliage, dilute with 10 to 15 parts of water. Crude oil emulsion is made 

 in the same way by substituting crude oil in place of kerosene. The strength 

 of oil emulsions is frequently indicated by the percentage of oil in the diluted 

 liquid : 



