342 Report of the Horticultural Department of the 



the sulpliiiric acid. After having placed the receptacle in proper 

 position add the cyanide. This amount is sufficient for 150 cubic 

 feet of space. The operator should take great care not to inhale 

 any of the fumes. The treatment is efficient. It is especially adapted 

 for greenhouse and nursery fumigation. For further details see 

 Bulletin 202 of this Station. 



TOBACCO. 



Tobacco stems i pound. 



Water 2 gallons. 



Boil the stems and strain the liquid. Add water to make the 

 decoction up to 2 gallons. The efficiency of tobacco water may be 

 increased by stirring in i pound of whale-oil soap to each 50 gallons. 

 Tobacco is valuable against plant lice and woolly aphis. 



PYRETHRUM. 

 For use as spray: 



Pyrethrum I ounce. 



Water 3 gallons. 



For use in dry form : 



Pyrethrum I part. 



Flour 2 to 3 parts. 



This is a powerful contact poison, especially adapted for fighting 

 lice and many small insects. It is not poisonous to the higher 

 animals or to man. 



CARBON BISULPHIDE. 



This is used against root-inhabiting insects, such as plant lice, 

 woolly aphis and ants, and against wire-worms, beetles, weevils, etc., 

 affecting stored grains. The fumes destroy the insects, and should 

 be confined to secure best results. For bin pests use i pound of 

 carbon bisulphide for each 1,000 cubic feet of space. Remember 

 that the fumes are explosive. Do not bring fire near them. 



