474 INSECT PESTS OF FARM, GARDEN AND ORCHARD 



winter treatment has been neglected or has proven inefficient. 

 10 or 15 per cent kerosene emulsion, dilute miscible oils, dilute 

 lime-sulfur mixture, or whale-oil soap, 1 pound to 4 or 5 gallons, 

 may be used for summer spraying. 



On the Pacific Coast trees are very generally fumigated with 

 hydrocyanic acid gas * for this and other scale insects, but the 



FIG. 398. Young larva and developing San Jos6 scale (Aspidiotus perniciosus 

 Comst ) : a, ventral view of larva, showing sucking beak and setae sepa- 

 rated, with enlarged tarsal claw at right; b, dorsal view of same, still 

 more contracted and with the first waxy filaments appearing; c, dorsal 

 and lateral views of same, somewhat contracted, illustrating further 

 development of wax secretion; d, later stage of the same dorsal and lateral 

 views, showing matting of wax secretions and first form of young scale 

 all greatly enlarged. (After Howard and Marlatt, U. S. Dept. Agr.) 



treatment has never come into favor in the East, principally, 

 perhaps, because of the larger trees and the more scattered nature 

 of the fruit industry. 



Practically the only methods now used in the East consist in 

 spraying the dormant trees with washes which penetrate the 

 scales and destroy the insects. This may be done more effec- 



*See C. W. Woodworth, Bulletins 122 and 152, Cal. Agr. Exp. Sta.; 

 R. S. Woglum, Bulletins 79 and 90, Bureau of Entomology, U. S. Dept. Agr. 



