150 [NJDRIOUS IlND BENEFICIAL [NSECTS OF CALIFORNIA. 



long and | as wide. They average, however, about -^ inch in length 

 and are quite convex, while the immature forms are very flat. The 

 surface is slightly rough and covered with a fine, white powder, from 

 which the common name is derived. The eggs are oblong and pearly 

 white in color. 88 



Fig. 12S. — The frosted scale. Lecanium pruinosuvt 

 Coij. Mature females on English walnut. Natural 

 size. Collected in Contra Costa County by Geo. P. 

 Weldon. < Original) 



Life History. — The females reach maturity and begin egg-laying in 

 March and April, the eggs hatching from the middle of April to the 

 middle of May. The species is exceedingly prolific and a single female 

 may lay several thousand eggs. The young usually first settle upon 

 the leaves: however, a large number remain upon the new growth of 

 (he branches. In the fall those on the leaves also move to the branches 

 where all mature and begin egg-laying the next spring. There is but 

 one brood a year. Though very prolific, this scale seldom becomes 

 abundant enough to be a serious pest and only occasionally may control 

 measures be necessary. 



Nature of Work. — The young attack the leaves and the adults the 

 branches, and. if abundant, secrete enough honey-dew to smut the fruit 

 and foliage. 



\ closelj allied species, the oak Lecanium, Lecanium quercitronis Fitch, greatly 

 resembles the above in size and color, but is found only on the oak. It is slightly 

 pruinose and sometimes lias a light, longitudinal stripe on the dorsum. Fig. 129. 



