THE MONTHLY BULLETIN. 



261 



The egg. The ogg of the earpenter worm is a greenish, elongated 

 body, sliglitly larger than the head of a pin. The surface as seen under 

 the lens is decidedly rough, being covered with numerous interlacing 

 lines and ridges. The eggs are deposited by the large gray moths in 

 the cracks and crevices of the bark or in any other position offering 

 natural protection by the tree. A scar, the result of careless pruning, 

 is often admirably adapted to the likings of the egg-laying female, for 

 in such places the tender larva% upon hatching, can make their way 

 with litth^ difficulty into the cambium. Eggs are often placed, also, 

 near the openings of the old burrows in trees where there already occurs 



Fig. 75. — Exit holes of adult carpenter worms through the 

 bark of an oak tree which has been killed by this pernicious 

 borer. (Original.) 



an infestation (Fig. 75). When so placed the young worms enter with 

 very little trouble. Prof. Doten reports the egg-laying capacity of the 

 moths as being quite large, as many as 200 or 300 having been counted 

 in various individuals. 



The larva. Upon hatching, the young larva feeds in the cambium, 

 just beneath the bark, for some time, and as its mandibles increase in 

 hardness and power it gradually works its way into the heart wood. 

 The developing larva undergoes several moults during this period. In 

 the early stages the general color is that of pinkish white with brown 

 spots at the base of the hairs, which are found in numbers about the 

 body. As the development of the insect continues it gradually estab- 

 lishes itself in the heart wood of the tree. The general coloration 

 changes somewhat as the worm reaches maturity, appearing greenish- 

 white with a shining brown head and powerful, nearly black mandibles 

 (Fig. 76). Pupation usually takes place near the end of the third year 



