54 



THE SCOLYTID BEETLES. 



from overwintered larvae may emerge during the period from August 

 to October, but apparently the majority go over the second winter, 

 together with a few larvae. Full-grown larvae observed by Mr. Webb 

 on June 28 had not all transformed to adults on October 10, and 

 only a few adults had emerged. The broods developing from the eggs 

 deposited by the overwintered parent adults may develop to adults 



Fig. 16. — The roundheaded pine beetle: Egg galleries and larval mines. Reduced. (Author's 



illustration.) 



before activity ceases in the fall, but the majority evidently pass the 

 winter as medium to matured larvae. 



GENERATION. 



The overwintered broods of young adults begin to emerge and 

 deposit eggs in June and continue to do so until September, or 

 later. Some of the larvae from these eggs may transform to pupae 



