Insects Bred from American Larch 43 
/ excavates a gallery from one edge of the nuptial chamber 
through the inner bark to the wood, thence through the inner 
layer of bark, usually at right angles to the bark fibers, for 
a distance of one or two inches. Along the sides of this 
so-called brood or egg-gallery, she deposits her minute, pearly 
white eggs in a succession of small notches. By the time the 
first female has her egg-gallery fairly started, one to three 
other females are admitted, and each excavates a similar egg- 
gallery in different directions from the nuptial chamber. 
Before all of the galleries are finished, the first eggs com- 
mence to hatch into minute white grubs, which burrow 
through the inner bark, on which they feed. By the time all 
the eggs have hatched, the surrounding bark is filled with 
these grubs of various ages and sizes, and soon, all of the 
bark from the inner to the outer layer, for a radius of two 
to four inches, is completely perforated with their irregular 
burrows. In the meantime, the male guards the entrance 
and the females either rest in the nuptial chamber or egg- 
galleries or emerge to enter the bark in another place to start 
a new brood. When the grubs and larve have attained their 
full growth, they excavate a broader cavity at the end of their 
burrow or mine, in which they change to the pupze stage, 
thence to the adult and either emerge from the bark and 
start a second brood, or remain until the following spring. 
Probably two or three broods may occur in one season, com- 
mencing with the first eggs deposited in the spring, but my 
observations lead me to believe that owing to the shortness 
of the season at the high elevations occupied by ‘the spruce 
of this State [West Virginia] there is generally but one 
brood.” 
But little can be added to the observations upon the phases 
of the activity of P. rufipennis covered in the above account. 
However, observations upon the behavior both of this species 
and of other species of polygamous beetles leads us to doubt 
very much if the female ever normally starts the excavation 
of a brood burrow. In all cases, observed by the senior 
author where the burrow was started by a female the excava- 
tion was continued as a simple gallery with no sign of a 
