The hickory bark beetle is reported to be the most serious insect pest
of hickory in the United States. Population explosions where thousands
of trees were killed have been reported from New York, Pennsylvania,
Maryland, Virginia, and recently from Georgia. Hickory bark beetles are
distributed throughout the range of their host in eastern United States.
All species of hickory are subject to attack, as well as pecan and
possibly butternut. Adult beetles emerge in May and June in the southern
portion of their range. They feed for a short time by boring into the
petioles of leaves and into small twigs of the host. Dying leaves and
twigs are the first evidence of attack. After feeding, the beetles fly
to the trunk and larger branches of the host and bore into the inner
bark to lay their eggs. Short, longitudinal egg galleries are etched
into the sapwood and from 20 to 60 eggs deposited in small niches cut on
either side of the gallery. As the larvae develop, their galleries
radiate out from the egg gallery. Two generations per year have been
reported from northern Mississippi. The beetle overwinters in the larval
stage. With the coming of warm weather in the early spring, it changes
into the pupal stage, and finally, in May, to an adult.
[Illustration: Hickory bark beetle adult.]
Outbreaks of this insect begin in periods of hot, dry weather and
subside when rains commence.
[Illustration: Larval galleries of the hickory bark beetle.]