Forest Health Protection, Southern Region

Importance. - This is one of the most destructive borers of the white oak group in the South. Its importance is compounded by the increasingly higher prices of veneerquality lumber.

Identifying the Insect. - The adult longhorned beetles are rarely seen. They are mottled brown and white, about 1 inch (25 mm) long, with a spine on each side of the thorax and antennae about as long as the body. Larvae are grub-like, pale yellow, robust, and up to 1 1/2 inches (37 mm) long.

Identifying the Injury. - Oozing of sap and frass production on trunks are the most prominent indications of infestations. The sap often attracts flies, bees, wasps, butterflies, and other insects. Internal damage consists of extensive larval mining, often accompanied by discoloration and subsequent decay of the wood.

Biology. - Adults emerge in mid-spring and deposit eggs in roughened bark or near wounds. About 3 weeks later, eggs hatch, and larvae tunnel directly into the wood. New adults develop within the tunnels and emerge through a new, circular exit hole. The life cycle requires 3 to 5 years for completion.

Control. - Removal of heavily infested brood trees, combined with measures designed to encourage tree vigor, are the most practical controls. Woodpeckers and sap ooze are the most important natural controls. Removing vines, which are good egg laying sites, may be cost effective when the wood is used for veneer. Vine removal operations should not damage bark, since this can actually encourage infestations.