59 



The adult insect is about the size of a pin head, and is covered by 

 a dark gray or brownish scale or shell nearly circular in outline. In 

 the early spring months only those from one-half to two-thirds grown 

 are living and these become adult in June, beginning to produce 

 young during the last half of this month. The young are born alive, 

 a few every two or three days during the latter part of June and the 

 month of July, and in their turn become adult in about a month at 

 this time of year, and begin to produce young. These are very small 



Fig. 7. San Jose scale ; difterent stages, enlarged five 

 times. 



and lemon yellow in color. They crawl about for a short time, then' 

 settle down, inserting their beaks in the bark, and begin to feed on 

 the sap of the tree. White waxy threads soon appear on their backs, 

 and these matting together with the molted skins of the insect added, 

 finally form the scale covering the adult. 



The extremely small size of this insect, together with its enormous 

 power of multiplication (a single insect in the spring might easily 

 have over three billion descendants before the winter if no casual- 



