twig girdler and damage

Twig girdler (Oncideres cingulata) Image credit: Clemson University - USDA Cooperative Extension Slide Series, Bugwood.org

Updated: March 29, 2021

Key points

  • The twig girdler is a native longhorned beetle that attacks hickory, honeylocust, persimmon, elm, oak, hackberry, poplar, dogwood, linden, and flowering fruits.
  • Twig pruners are also native longhorned beetles. They attack oak, hickory, ash, maple, honeylocust, elm, linden, sweetgum, hackberry, and persimmon.

Twig girdler

  • The adult beetles are about 3⁄4 inch long, cylindrical, and gray with two dark bands across the wing covers. The antennae are longer than the body.
  • The larvae are called roundheaded borers. They are 1 inch long and white with black heads.
  • Female twig girdlers are attracted to individual shade trees.
  • They lay eggs in 1⁄4 to 1⁄2 inch diameter twigs.
  • They then chew (girdle) the twigs, which then drop to the ground (late summer-early fall).
  • The larvae overwinter in the twigs on the ground and complete their development the following summer.

 Management

  • To monitor for this insect, look for accumulations of twigs under shade trees in August and September.
  • The cut ends look as though they have been cut by a beaver.
  • To control twig girdlers, rake up and destroy twigs in the fall, or the following season before the adults emerge beginning in August.
  • There is no insecticidal control.
Twig girdler ends
Twig girdler ends. Photo: J.A. Davidson, U of MD

Twig pruners

  • Adult beetles are 3⁄4 inch long, brown, slender, elongate, with 2 posterior spines on each wing cover and have antennae longer than the body.
  • Mature larvae are 1 inch long and white with black heads.
  • Female beetles lay eggs in twigs and branches from 1⁄4 to 2 inches in diameter.
  • The larvae bore toward the trunk and girdle the twigs in late summer.
  • The twigs then drop to the ground.
  • The larvae complete their development, pupate and then overwinter in these twigs.

Management

  • To monitor for this pest look under shade trees in August and September for accumulations of twigs and small branches that have a concave cut end.
  • Cut the twigs lengthwise to check for mature larvae.
  • Rake up and destroy these twigs in the fall or winter before adults emerge the following spring.