INSECT PESTS FORMULAS FOR THEIR DESTRUCTION. 257 



The chemicals are to be used in the following proportions, as 

 recommended by the Riverside County Board of Horticultural 

 Commissioners: 



The cyanide should be used as coarse as possible, so that 

 the chemical action will be less violent. The gas is also 

 generated more evenly, and there is not so much danger of 

 the chemicals boiling over or spattering the tent. As soon as 

 the tent is removed the vessel is rinsed with clean water and 

 prepared for another charge. 



(5) For Mites (Tetranychus) on Citrus Trees. 



(To be applied in summer.) 



Caustic soda (70 percent) 10 pounds. 



Sulphur 20 pounds. 



Dissolve in water 20 gallons. 



Take the sulphur, mix to a paste not sloppy with cold 

 water in a barrel; then add to this wet sulphur 10 pounds of 

 caustic soda (98 per cent) and it will boil the sulphur just like 

 lime slacking; have 20 gallons of water to add to it as it boils, 

 to prevent burning. This is the stock solution. When ready 

 to spray the mites or spiders, put 40 gallons of water in another 

 barrel, and take a half gallon of the stock solution and add to 

 the 40 gallons of water, straining it to take out any sediment 

 there may have been in the sulphur. Apply with a spray 

 pump under one hundred pounds pressure. 



I7c 



