262 



THE MONTHLY BULLETIN. 



of its life, at which time the worm has reached a length of two and one 

 half inches and a diameter of something more than a half inch. The 

 burrow is cleared of all debris and the broad galleries and halls are 

 lined with a thin coating of silk before the worm goes into the quiescent 

 or pupal state. At this time the external opening of the burrow is 

 capped with a delicate silken web. The worm then moves to the end of 

 the cavity and spins a loose cocoon about itself. 



The Pupa. A few days after entering this cell the worm casts the 

 skin, passing into the pupal stage (Fig 76). The color of the pupa is 

 dark brown, with a shining luster. It is about two inches in lengthy 

 broad at the cephalic end, and tapering to a blunt point at the posterior 



Fig. 76. — Larva and pupa case of the carpenter worm. Note the 

 ridges of spines on the segments of the case ; the use of these enables the 

 pupa to work its way from the end of the burrow to the mouth at which 

 point the adult emerges. (Original.) 



extremity. On the dorsal surface each abdominal segment possesses a 

 pair of toothed bands (Fig. 76), of which the posterior one is the more 

 prominent. Comstock reports that these are used at the time the pupa 

 makes its way to the opening of the burrow. The oval spiracle openings 

 are very prominent ; each abdominal segment, with the exception of the 

 caudal one, possesses a pair. The insect passes about two weeks in this 

 quiescent state, when it wriggles to the mouth of the burrow, continuing 

 until the head and thoracic parts are showing. A split occurs in the 

 pupal covering along the median line on the dorsal and ventral surfaces 

 of this part of the body and the adult insect emerges. Examination of 

 infested trees during the latter part of May and during the summer 

 will reveal these old cases still sticking in the mouths of the burrows. 



The adult. The males (Fig. 77) and female (Fig. 78) are quite 

 distinctive in their coloration and size, the female insect being much 

 the larger, with a wing expanse that often reaches three and one half 

 inches. She possesses a uniformly mottled gray color pattern on both 



