Pseudothysanoes dislocatus (Blackman) is brown and about 1.3 mm long. The 
head is slightly concave at the middle, with a row of long hairs at the lower margin 
of the concavity. The antennal funicle is six-segmented, the club unsegmented, and 
the scape armed with long hairs. It constructs its galleries just beneath the bark of 
twigs of its hosts. It has been recorded from hickory from West Virginia to Florida. 
The genus Pityogenes contains a number of species, all of which breed in the 
twigs, limbs, and thin-barked portions of the boles of pines. Some species prefer to 
breed in slash, whereas others most commonly attack decadent lower limbs of living 
trees. Vigorous trees are usually not attacked except in heavily infested areas. Trees 
weakened by drought or transplanting, or by ground fires or mechanical means, are 
frequently attacked and killed. Adults are usually stout and sparsely pubescent. The 
antennal funicle is five-segmented, and the antennal club is flat and sutured on both 
sides. The elytra are marked with rows of punctures, excavated, and ornamented 
with teeth at the posterior end. Females of all species except P. meridianus 
Blackman have conspicuous cavities in the front of their heads. Males have three 
slightly enlarged to very enlarged spines on each side of the elytral declivity. 
Attacks are initiated by the males which are joined by two to seven females. The 
gallery system is usually engraved on the surface of the wood and consists of 
several egg tunnels radiating from a central nuptial chamber. 
Pityogenes hopkinsi Swaine is a common species wherever its host, eastern white 
pine, occurs in eastern North America. Rarely other pines and spruces serve as 
hosts. In early spring, overwintering adults infest winter-pruned limbs and other 
white pine slash. A summer generation attacks trees weakened by basal canker or 
blister rust or joins the pine engraver or the red turpentine beetle in attacking 
stressed trees. Logging slash may be infested any time when adults are active. P. 
hopkinsi concentrates its attacks in the smooth-barked portions of the tree, thereby 
limiting competition with the pine engraver, which infests areas with fissured bark. 
The insects are 1.8 to 2.1 mm long. The male has three similar teeth on the elytral 
declivity; the female has large frontal fossa. 
Pityogenes meridianus Blackman is known to occur in North Carolina and 
Mississippi. It breeds in slash and the dead and dying lower branches of pines 
weakened by shading or injured by ground fires. The adult is dark reddish-brown 
and from 2.7 to 3 mm long. Males have a large, blunt, downward curving spine at 
the upper margins of the elytral declivity and two smaller, upward curved spines at 
the lower margin of the declivity. Females have no frontal fossa. Burrows consist of 
two to five galleries originating at and radiating away from a central nuptial 
chamber. The related species, P. plagiatus (LeConte), breeds in pines in the 
Atlantic States. The elytral declivity is similar to that of P. meridianus but the 
species are easily distinguished by the female’s large frontal fossa that is divided by 
a vertical partition. 
The genus Pityokteines is represented in the United States by several species, 
only one of which occurs in eastern forests. The beetles breed primarily in dying or 
felled trees, particularly firs and spruces. The eastern species, P. sparsus (Le- 
Conte), the balsam fir bark beetle, is frequently injurious to balsam fir, killing 
large groups of trees. Pine, spruce, and larch are also attacked. Infestations are 
found in logging slash in the limbs and tops of trees dying suddenly, in windthrows, 
and in weakened and perfectly healthy trees. The adult is about 2 to 3 mm long and 
is distinguished by long yellow hairs arising from the front of the head and from the 
apical margin of the pronotum. Eggs are deposited in large niches along the sides of 
several galleries that radiate away from a central nuptial chamber and scar the wood 
deeply. Larval tunnels are longitudinal and follow the grain of the wood. 
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