THE HOMOPTERA 



211 



but the eggs are fewer in number and dark purple in color, as are also the 

 crawling young which usually hatch a few days later in the season than 

 the other species. Control methods are the same as for the Oyster-shell 

 scale. 



FIG. 204. Scurfy Scales (Chionaspis furfura Fitch). Male scales at right, female 

 scales at left. Left hand figure greatly enlarged ; the other two somewhat enlarged. (From 

 U. S. D. A. Farm.' Bull. 723.) 



The San Jose Scale (Aspidiotus perniciosus Comst.). This is one of 

 the most serious pests among the scale insects. Its original home was 

 probably China, but it appears to have reached California about 1870 

 and since then has spread practically all over this country. It has a 

 wide range of food plants, on many of which it thrives sufficiently to 

 quickly kill them. The plants which suffer most from its attacks are 

 the fruit trees and currants, the dog-woods, thorns, poplars, ornamental 

 cherries and plums, hardy roses, willows, lilacs and lindens; and even 

 maples and elms are sometimes attacked, the total list of plants upon 

 which it has been found numbering over a hundred. It feeds on all 

 parts of the plant above ground, even including the fruit. 



The full-grown female scale (Fig. 205) is about the size of a pin head, 

 nearly circular in outline and rather flat, sloping gradually upward from 



