30 



it occurs. The period of flight begins during the last days of May 

 and extends through June, July and into August. It is during the 

 latter days of June and in early July that the insects are most 

 abundant and the males are always most active around the lights. 

 The females are heavily built and, when the eggs are developing, 

 rarely move far from the trees out of which they were born and 

 upon which they afterward oviposit. The eggs are small, salmon- 

 pink in color, and may be laid singly or in masses, a single adult de- 

 positing between five hundred and one thousand or even more. They 

 are usually placed in a bark crevice or other sheltered situation 

 and generally on one of the smaller branches. The little cater- 

 pillar, when it hatches, makes its way to the crotch of a small branch, 

 or to one of the nodes or buds and at once bores into the wood tissue. 

 It works downward, toward the base, and grows very rapidly. When 

 it is tired of its quarters, or when they become too narrow, the in- 

 sect works out; sometimes directly, sometimes by cutting all around 

 on the inside so that the twig breaks off. Then it makes its way 

 further down, selects a larger branch and again begins feeding. 

 Each individual seems to be a law unto itself as to the manner in 

 which it feeds; it may bore a straight channel through the center 

 of the branch, it may eat out a large Cavity on one side, or it may 

 deliberately work around and kill it. By the end of the first season 

 the larva is half-grown and has usually made its way to one of the 

 large branches, leaving behind it one or two that will be almost 

 certainly broken by the winter winds. 



During the second summer growth is rapid and the larvae attain 

 a length of two inches or more. On smaller treefe they sometimes 

 get into the trunk itself and may completely girdle it; or they may 

 remain in the branches, or^ in fact, work in almost any conceivable 

 way, changing their location two or three times during the summer. 

 At the end of this growing season they have reached their full size 

 and, early in the spring following, work close to the surface and 

 form pupae, M'hieh, when the adults are ready to develop, wriggle 

 their way out so that fully half projects, beyond the bark when the 

 moths emerge. The moths do not feed. The caterpillars do not 

 feed upon the surface except for a short time, when they change 

 their quarters and start in at a new place. There is no chance of 

 reaching the moths through poisonous applications and practically 

 no chance of reaching the larvae by means of insecticides. 



