INSECT PESTS FORMULAS FOR THEIR DESTRUCTION. 



266 



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

 recommended by the Riverside Count}- Board of Horticultural 

 Commissioners: 



Height of Tree. iDiameterof Tree. 



Cyanide C. P. ,98: Sulphuric Acid, 

 per cent. | 66 per cent. 



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

 chemical action will be less violent. The gas is a,l80 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 per cent) 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 half a gallon of the stock solution and add to 

 the forty 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. 



