Hickory Bark Beetle
Scolytus quadrispinosus

The hickory bark beetle is reported to be the most serious insect pest of hickory in the United States. Several states have reported instances where thousands of trees were killed. Pecan and butternut are also hosts.

Identification:

The adult is short, stout, black, almost hairless, and 1/5 inch (5 mm) long. The underside of the posterior is concave and has spines. The larvae are typically white or cream-colored, legless grubs, about the same size as the adults.

Injury:

Dying leaves and twigs and trees with red foliage are the first evidence of attack. Short, vertical egg galleries with radiating larval galleries etched in the sapwood are good indicators of damage.

Biology and History:

Adults appear in early summer and feed for a short time at the bases of leaf petioles and on twigs before attacking the trunks. Twenty to 60 eggs are deposited in egg galleries in the phloem. When nearly fullgrown, the larvae gradually angle away from the adult gallery. Before reaching maturity, they leave the phloem to pupate in the bark. Winter is spent in the larval stage and pupation occurs in the spring. There are usually two generations each year in the southern United States.