342 Report of the Entomologists of the 



water clear, while the green arsenite remained in suspension for 

 over two honrs. 



It is because the green arsenite stays suspended in water so 

 much longer than Paris green, that it is more valuable as an in- 

 secticide. Without doubt much of the failure to get good results 

 from Paris green is because of the difficulty of keeping it evenly 

 distributed through the tank. Unless the mixture is almost con- 

 stantly agitated, the Paris green sinks to the bottom and is quickly 

 drawn out by the pump, so that before the tank is half empty 

 most of the poison is gone and the remainder of the water contains 

 so little Paris green as to be hardly worth applying. 



HOW TO USE GREEN ARSENITE. 



Green arsenite should be used the same as Paris green. For 

 ordinary purposes use 1 pound to from 100 to 150 gallons of 

 water with the addition of enough freshly-slaked lime to make the 

 mixture slightly " milky " in appearance. Lime should always be 

 added, for, in addition to other uses, it prevents injury to the 

 foliage. It may be used with Bordeaux mixture in the same man- 

 ner as Paris green. 



PRICE PER POUND AND WHERE OBTAINED. 



Green arsenite can be obtained from the Adler Color and Chem- 

 ical Works, New York, and probably from other leading dealers 

 in similar products for 15 cents per pound. 



EXPERIMENTS WITH GREEN ARSENITE. 



No strictly comparative experiments with this insecticide have 

 been made here at the Station. Comparative tests 11 by C. L. 

 Marlatt, however, indicate that green arsenite and Paris green are 

 equally effective as insecticides. 



Experiments with green arsenite made by the writer are re- 

 corded on pages 600-601 of Bulletin 136 of this Station and on 



" U. S. Dept. Agr., Div. Ent., Bui. G, n. ser.: 30-35. 



