distinctly impressed, and the strial punctures are much coarser 
than those of the interspaces. The species is of slight economic 
importance. 
The hackberry engraver, Scolytus muticus Say, occurs from 
New Jersey to Florida, Texas, Kansas, and Minnesota, and breeds 
in dying and dead limbs of hackberry. The adult is reddish- 
brown to black, and from 4.5 to 7.5 mm. long. There are long, 
ashen hairs on the elytra and sides of the pronotum. Egg gal- 
leries are similar to those of the hickory bark beetle. The larvae 
feed first between the bark and wood; later they burrow into the 
wood. Pupation occurs just beneath the surface of the wood. 
There are two generations per year in the Deep South and one 
per year in the Lake States. 
Scolytus piceae (Swaine), the spruce scolytus, occurs from Que- 
bec to Manitoba, and from Maine to Colorado and Montana: Its 
hosts are recorded as white, red, and Engelman spruces and 
larch, and balsam fir. Adults are readily distinguished from other 
eastern members of the genus by the presence of a tubercle or 
spine extending backward from the center of the second ventral 
abdominal segment. The burrows of the species also differ from 
those of other eastern species in consisting typically of two and 
sometimes three egg galleries extending longitudinally from a 
central nuptial chamber. Broken limbs and tops are preferred 
for breeding purposes. : 
The genus Crypturgus Erichson is represented in eastern for- 
ests by three common species. The adults are very small, brown 
or black, about 1 mm. long, and are found in the inner bark of 
dead or dying conifers. Their burrows usually originate from the 
burrows of larger bark beetles, but sometimes from ventilation 
holes made by Monochamus spp., and are very short. C. alutaceus 
Schw., the smallest of all North American bark beetles, occurs 
from New Jersey to Florida. It breeds in species of pine, and in 
black and Norway spruces. C. borealis Swaine breeds in various 
conifers from Maine to Pennsylvania. C. atomus LeC. attacks 
pine, spruce, balsam fir, and larch in eastern Canada and from 
Maine and New York to West Virginia and the Lake States. 
The genus Carphoborus Eichoff is represented in eastern for- 
ests by at least two species. The adults are dark-brown to black, 
more or less covered with short scalelike hairs, and are less than 
2 mm. in length. C. bifwreus Kichhoff is a fairly common species 
in the South. It breeds in dying, broken, and cut limbs of pines. 
The genus Chramesus LeC. is represented in the East by two 
species of stout, strongly convex, ‘humpbacked’ beetles, less than 
2 mm. long. They are further distinguished by their large, long- 
oval, unsegmented antennal clubs and the five-segmented anten- 
nal funicle attached to the side of the club. Both species breed 
in broken or dying twigs and small limbs. The adults construct 
longitudinal, unbranched egg galleries, partly in the bark and 
partly in the sapwood. C. hicoriae LeC. attacks various species of 
hickory throughout the Eastern States and in eastern Canada. 
C. chapuisi LeC. attacks hackberry from Pennsylvania to Florida 
and Texas (75). 
The genus Phloeotribus (—Phthorophloeus) is represented by 
a number of eastern species, all but one of which breed in decidu- 
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