78 



sects to reach maturity and begin reproduction in their turn, 

 and as their parent may only be ceasing the production of 

 young by this time, there is, in consequence, an almost con- 

 stant appearance of young from about the middle of June 

 until cold weather puts an end to the process, at which time 

 there will probably be all stages of the insect present at once. 

 There are usually only three generations a year in Massa- 

 chusetts, though, with 

 the longer seasons, four 

 or even more may 

 occur in the South. 



Increase from the 

 scales coming to ma- 

 turity in the spring is 

 usually about 100 per 

 female. In the later 

 generations it is nearer 

 500, so that a tree 

 having only a few 

 scales on it in the 

 spring can easily have 

 millions on it by the 

 following winter, and 

 be in very bad con- 

 dition or even dying 

 from the lack of the 

 sap these insects have 

 abstracted from it. 

 Control of this pest cannot be like that for the oyster-shell 

 and scurfy scales, which was based upon the appearance of all 

 the delicate, unprotected, crawling young at about _the same 

 time. Here a treatment aimed at the destruction of these 

 young would have to be repeated every ten days or two weeks 

 from the end of June until into October, — evidently a costly 

 and impracticable method. Accordingly, the plan adopted is 

 to treat this scale, during the winter months or in spring be- 

 fore the buds open, with a material strong enough to get at 

 the insect under its protecting scale and kill it there. At this 

 time there are no leaves to interfere with the thorough appli- 



Different stages of the San Josfi scale, enlarged five 

 times. (From Virginia State Crop Pest Commis- 

 sion Bulletin, 1904.) 



