100 ARTHROPODA 



the microscope, and during the latter part of the month 

 in the latitude of Pittsburgh they give birth to living 

 young which crawl out from the scale, and during the next 



FIG. 108. San Jose scale on a pear. Photograph natural size. 



two days appear to the naked eye as minute yellowish 

 specks slowly wandering over the branches. After a free 

 life of about forty hours, these Iarva3 insert the beak firmly 

 into the bark from which they never remove it. The 

 exudations of the insect's body form the scale. The young 

 are ready to reproduce in one month, and bring forth during 

 the next three weeks about five hundred living young. 



