64 College of Forestry 
palpus barbatus, the wood is in a condition more than usually 
favorable for its uses due to the burrows already present 
and to the introduction of decay by their presence. 
Phymatodes dimidiatus Kirby. 
Hamilton (1894, p. 381) records the distribution of 
Phymatodes dimidiatus as Unalaska, Vancouver, Washing- 
ton, Idaho, through the Rocky Mountains to Mexico, thence 
across the northern part of the continent to Maine and Mas- 
sachusetts. Hopkins (18938a, p. 192) reports it from Wash- 
ington and Felt (1906, p. 669) from various points in New 
York and New Jersey. Evidently spruce has been practi- 
cally the only host recorded for this cerambycid (Hopkins, 
1899, p. 458), although it undoubtedly breeds in other 
species, especially in the Rocky Mountains. Davis (1891, 
pp- 81) states that he has taken it “from oak posts of a 
summer house.” The senior author has taken the adults 
from beneath the bark of spruce in the Adirondacks. 
P. dimidiatus lives during the greater part of its larval 
existence directly under the bark, excavating its winding 
galleries for the most part in the same direction as the grain 
of the wood. The eggs are laid during June under the small 
flakes of bark or injured places and even occasionally in the 
deserted or still occupied burrows of P. rufipennis in trees 
that have been killed the previous year. The larva, from 
the first grooves the sapwood, the burrow becoming deeper 
and wider as the larva becomes larger (Figs. 14, 15). How- 
ever, during its larval existence the burrow is always directly 
under the bark, and it is not until the insect is ready for 
pupation that it extends its burrows into the sapwood. Just 
before it transforms into the pupal stage, which may occur 
either before or after hibernation, the larva burrows for about 
a quarter of an inch below the surface of the sapwood and 
here enlarges its mine to form a pupation chamber. Before 
pupation, however, the larva burrows up to the bark and 
packs the end of the gallery with coarse frass so that the 
adult when it is ready to emerge may work its way out with 
a minimum amount of labor. The rest of the larval mine is 
