478 



JOURNAL OF ECONOMIC ENTOMOLOGY 



[Vol. 8 



Wenatchee 



In previous years sprays used at Wenatchee have shown their final 

 value within two w^eeks' time. This year the first counts, twenty 

 days after the application, showed about 40 per cent of the individ- 

 uals still in living condition whenever sulphur sprays were used. Oil 

 . prayed insects after the same interval were completely killed. The 

 second count, however, thirty-seven days after spraying, uniformly 

 showed practical extermination, only 1 to 3 per cent of the scales being 

 rated as alive. This was also the condition recorded at the final count, 

 twenty-four days later. The following tabulation briefly gives the 

 proportion of living insects at the successive counts: 



20 days 17 days 24 days 



Sulphur-Hme, 5° 45% 2.3% 1.4% 



Sulphur-lime, 3° 34 0.8 1.6 



Sulphur-lime, 2° 48 3. 2.2 



Sulphur-soda, 2° 50 1.1 1.8 



Oil, 5% 0 0 0 



Check 53 67 45 



North Yakima 



Tests of 1914 carried on by M. A. Yothers indicated that the San 

 Jose scale at North Yakima died about as slowly from the effects of 

 sulphur-lime spraying as at any of the other places of the circuit. This 

 year the first counts, twenty-one days after the application, showed 

 about 50 per cent of the insects still ahve. The second count hovered 

 around 20 per cent, and the third around 10 per cent. The several 

 proprietary oil sprays used gave much more rapid and effective results, 

 practically exterminating the insects by the twentieth day. 



21 days 19 days 12 days 30 da^s 



Sulphur-lime, 5° 36% 19% 4% 10% 



Sulphur-lime, 3° 49 17 2 3 



Sulphur-Hme, 2° 35 31 3 8 



Sulphur-soda, 3° 45 26 9 25 



Sulphur-soda, 2° 58 24 8 24 



Oil, 5% 1 1 0.2 0 



Check 88 83 67 74 



There is some uncertainty ^s to the best time to apply sulphur- 

 lime. The general custom in Washington does not call for fall spray- 

 ing, but formerly applications in early February or late January were 

 in vogue. The tendency is to postpone this spraying, possibly due 

 to the influence of the introduced budmoth and twig-borer which 

 require later spraying, until now the winter application is not begun 



