Hickory Spiral Borer

Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Coleopteran
Family: Buprestidae (flat headed borers or metallic wood borers)

Hickory Spiral Borer General Information Hickory Spiral Borer Pictures

The Hickory Spiral Borer is found from southern Canada throughout the eastern United States. They are a primary pest of hickory trees, but will also attack pecan trees. They have been found in hickory and pecan nurseries and in nut tree orchards. It gets its name from the spiral or winding burrow in makes within the bark of the tree. It often mines in twigs, stems, roots and beneath the bark of trunks and branches.

Its family name refers to the broad flattened front segment of the larvae and the metallic body colors on the adult beetles. Eggs are laid on the bark of twigs and after they hatch the larvae burrows under the bark in a downward spiral. It then branches off and burrows from the inner bark to the heart of the branch. Eggs are flat, disk-like and are attached firmly to the bark of twigs. They resemble the shield of a scale insect. They are pale yellowish green and turn almost black before hatching. Pupas are white and curved with a flat back and antennae, wings and legs. They have eyes and a dark body that changes to a purplish black during the last twenty days. During the pupa state they rest in a vertical position in the pupa chamber. Adults are dark and slender. Males are smaller than females and have a head and thorax that are greenish bronze. They also have brassy under parts. Females are mainly bronze in color. Adult beetles emerge from the pupa chamber from May to July and live about two months. Two to fifty-five eggs are deposited from July to August.

A primary pest to the hickory and pecan tree, the hickory spiral borer can cause serious damage and reduce nut production, produce a ragged appearance and stunt the growth of the tree. Infested branches are usually severed in winter and the spring. Infestations can be seed by the single or small groups of holes on the bark of the tree. Each borer leaves two holes. From those holes sap is produced that darkens the bark and eventually leaves a stain that becomes yellowish brown.

Credits:
Our thanks to Lani Powell for research and writing which made this hickory spiral borer information page possible.