282 Report of tub Department of Entomology of the 



The results witb the plum buds wore practically the same as 

 with the apples. The gas at a strength of .3 gram of cyanide 

 had practically no more effect than at .18 gram. There was also 

 but little difference in the percentage of treated buds that set 

 and the percentage of the checks that set. The total number 

 of treated buds was 1505, of which 81.1 per ct. set, and the total 

 number of checks 1673, of which 84.7 per ct. set, making a differ- 

 ence of only 3.6 per ct. in favor of the checks. As with the other 

 varieties the growth was nearly equal to the checks. 



SERIES II. EFFECT OF THE GAS UPON THE SAN JOSE SCALE. 



The experiments were conducted in four different orchards in 

 the vicinity of Geneva. Some of the trees were fumigated in 

 December and the remainder in June. But one treatment was 

 made. The results are shown in the following tables. 



ORCHARD II : PEARS. ORCHARD IV: PEACHES. 



Weather during tests in Table XVII. — Winter treatment. Trees 

 treated Dec. 13 to 24, average temperature 27°, cloudy with light 

 rains or snow. Weather during the week following cloudy with 

 average temperature of 29°. 



Table XVII. — Fumigation Tests on Infested Peak and Peach Trees. 



TreoB. 



