42 ENTOMOLOGICAL NEWS. [Feb., 'l8 



28 pupae and 17 larvae were taken. Of the adults Si were 

 males and 52 females. When the log was discovered, one 

 adult had made its exit, as was shown by the freshly bored 

 exit hole. The colony therefore totaled 179. 



Many other logs in these three canyons had exit holes in 

 them, but with the exception of the one above noted all were 

 black with years of weathering. The average number of exit 

 holes, making a count of 20 trunks, was 14, the highest num- 

 ber being 21 and the lowest 2. A great many must perish and 

 decay in their pupal cells if the colonies average anywhere 

 nearly as many as the one which I found. 



A few of the adults were yet soft from their change from 

 the pupae, but the majority were hard and would undoubtedly 

 have emerged in 7-14 days. Thus, if there are any survivors 

 of this species, the time of emergence must be the latter part 

 of June or the first part of July. 



The galleries of the fully grown larvae averaged 18 mm. in 

 diameter. This diameter was exceptionally constant for larvae 

 of the curled type. The galleries crossed and recrossed each 

 other in a confused manner, practically destroying all fibre 

 in the region attacked, the powdered material being packed ex- 

 tremely compactly. The galleries never approached closer 

 than an inch to the hard outer layer of the trunk and the very 

 centre of the log for six inches in diameter was untouched. 

 All the wood in between was completely riddled by the bor- 

 ings. The larvae were working usually at a depth of about 

 3 to 7 inches beneath the surface. Although the position of 

 the log may have had something to do with it, almost all of 

 the pupal chambers were either parallel to the surface of the 

 log or nearly so. The exit holes were being bored almost 

 perpendicularly from the pupal chamber to the outside. 



Two of the larvae were of a much smaller size than the 

 rest, thus tending to show that the life cycle is at least of two 

 years' duration. 



The weakening of the trunk bv the galleries often causes 



o - 



the trees to fall, 19 logs occurring in Palm Canyon alone. A 

 great many of the standing trees have exits visible on them, 

 but usually only two or three per tree, most of them situated 



