The hickory bark beetle is one of the most important insect pests of hardwoods in 
the Eastern United States (76). During drought periods. outbreaks in the Southeast 
have killed large tracts of hickory timber. At other times, damage is generally 
confined to the killing of single trees or to portions of their tops. The foliage of 
infested trees or tree limbs turns red within a few weeks of attack. Control practices 
include felling infested trees and destroying the bark during the winter months. 
treating infested bark with insecticides, or storing infested logs in ponds. To be 
effective. this type of control should be conducted over large. natural units. 
The shothole borer, S. rugulosus (Muller), an introduced species known to have 
been in the United States since 1878. now occurs throughout temperate North 
America. It breeds in most fruit trees, and uncommonly in mountain-ash, 
hawthorn, and elm. The adult is grayish black, and from 1.7 to 2.9 mm long. The 
elytra are covered with short hairs and are reddish brown at the apex. The venter is 
unarmed and more gradually ascending than in other Sco/ytus that occur in North 
America. Because of its preference for broken, cut, or dying material, this species 
is of minor economic importance in forestry. However, the shothole borer is an 
important horticultural pest because populations that build up in pruned limbs and 
culled trees kill buds, limbs, and sometimes entire trees. Twig and bud damage 
results from adults feeding: branches are killed when they are mass attacked and 
colonized. Egg galleries are somewhat irregular but generally are parallel with the 
grain. Larvae mine the cambial region and pupate there during summer months. 
Larvae that mature in the fall generally bore cells into the sapwood where they 
overwinter and then pupate in the spring. There are one to four generations per year, 
depending on locality. A parthenogenic race occurs in Israel (508). 
Scolytus fagi Walsh breeds in beech and hackberry from Illinois to Texas. Adults 
are 4.5 to 5 mm long. The elytral striae are distinctly impressed, and the strial 
punctures are much coarser than those of the interstrial rows. The species is of slight 
economic importance. 
The hackberry engraver. S. muticus Say. occurs from North Dakota and 
Pennsylvania to Texas and Florida, and breeds in dying and dead limbs of hack- 
berry. 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 galleries are similar 
to those of the hickory bark beetle. The larvae feed first between the bark and wood: 
later they burrow into the wood where they pupate. 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 Alaska and Nova 
Scotia to California and New York approximately coincident with the range of 
white and Englemann spruces. It breeds in all spruce species within its range: 
reports of spruce scolytus in larch and balsam fir represent aberrant occurrences or 
errors. Adults are readily distinguished from other eastern members of the genus by 
a ventral spine that arises from the center rather than the anterior margins of the 
second abdominal sternite. The unique burrows of this species typically consist of 
two and sometimes three egg galleries extending across the grain from a central 
nuptial chamber. Broken limbs and tops are preferred breeding material. 
Members of the genus Pseudothysanoes are closely related to those of the genus 
Thysanoes. They differ. however. by breeding in the bark instead of the wood of 
their hosts. P. lecontei Blackman attacks various oaks, hackberry. hophornbeam., 
chestnut, and walnut from New York to North Carolina. The adult is dark brown. 
shiny, and about 1.2 mm long. P. rigidus (LeConte) breeds in basswood from 
Canada to Michigan, Ohio, and West Virginia. 
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