The genus Hylurgopinus is distinguished by its seven-segmented antennal funi- 
cle, the strongly chitinized first two sutures of the antennal club, and the widely 
separated forecoxae. One species occurs in North America. 
The native elm bark beetle, H. rufipes (Eichhoff), breeds in various species of 
elm in southern Canada and throughout the Eastern United States north of Alabama 
and Mississippi. The adult is brownish black, thinly clothed with short, stiff, yellow 
hairs, and from 2 to 3.5 mm long (fig. 158A). The head is convex, thickly 
punctured, and nearly invisible from above; the antennal club is almost twice as 
long as wide; the pronotum is narrow in the front, densely punctured, and reddish at 
the rear; the elytral striae are composed of deep punctures; and the legs and 
abdominal sternites are red. 
A, F-532844 
B, courtesy G. N. Lanier, SUNY Coll. Environ. 
Sci. & For. photo by E. M. Gallagher 
Figure 158.—The native elm bark beetle, Hy/urgopinus 
rufipes: A, adult; B, gallery pattern. 
Beetles overwinter as larvae or adults. Adults that mature during the late summer 
or fall fly to healthy elms in which they bore overwintering tunnels in the bark at the 
root collar or lower bole. In April and May overwintering adults emerge from 
hibernation chambers, crawl up the tree and burrow into the bark of small (1 to 5 cm 
in diameter) branches (/20/). Later they fly to dead and dying trees, broken limbs, 
or recently cut logs or limbs to breed. Usually, dying or fairly moist recently dead 
limbs at least 5 cm in diameter are selected. Entrance holes are made in bark 
crevices or under overhanging bark flakes and they penetrate directly to the surface 
of the wood. A biramous egg gallery is constructed with the arms extending away 
from the entrance hole at various angles (fig. 158B). The gallery may be con- 
structed horizontally, but is most often inclined from the horizontal. Galleries may 
be constructed entirely in the bark, or they may scar the wood slightly. Eggs are laid 
on both sides of the gallery, sometimes very close together. Young larvae feed away 
from the gallery, usually following the grain. Pupation occurs in cells at the end of 
the larval tunnels in the bark. There appears to be two generations per year in the 
southern portions of the insect’s range and one and one-half in the northern portions 
(O51; 1207). 
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