Insect Gallery

Name: Twig Prunner

Latin Name: Elaphidionoides villosus

Description: The adult beetle is about one-half of an inch long, slender, grayish-yellow, with long antennae. It has spines on the first few joints of the antennae.

Insects Life Cycle: During the spring, about the time of budding and new growth, adult beetles start to emerge. The adult female will chew a hole in the bark at a leaf axil near a twig tip and lay an egg. The larva bores into the twig and feeds on the wood as it tunnels toward the base of the twig. The larva will continue to feed for a time but will overwinter as a pupa in the fallen twig or branch. Twig pruners produce one generation a year.

Insects Symptons: When full-grown (late summer), the larva begins to make concentric cuts through the wood outward from the center and usually stops chewing at the thin bark layer. The larva moves back into the severed portion of the twig. Infested branches, which can range in diameter from 1/2 inch to 2 inches, usually break and fall to the ground. During the fall, small branches with smooth, concave cuts accumulate under infested trees.