INSECTS OF THE APPLE 



253 



instead of laying eggs. Owing to the great rapidity with 

 which the scale multiplies very thorough treatment is 

 imperative. At the close of a growing season, all stages of 

 the scale can be found on an infested tree. The mortality 

 of the older and the younger scales is always great and the 

 half-grown insects are the individuals that usually survive 

 the winter in the best shape and carry on the reproduction 

 the following vear. 



Fig. 110. — San Jose scale on the apple. (From Illinois Circular, 

 No. 189.) 



The San Jose scale has a number of natural enemies, but 

 owing to its great ability to reproduce so rapidly it does 

 great damage in spite of its natural parasites. 



Each grower should become familiar with the appearance 



