Twig Girdler & Twig Pruner

Scientific Name: Oncideres cingulata & Elaphidionoides villosus

Twig pruners and Twig girdlers are beetles that lay their eggs in twigs at the ends of branches and then cut (chew) the branch ends off. The larvae feed on the decapitated twigs and pupate inside the twigs to overwinter. Pruners and girdlers primarily affect oak trees in Minnesota.

Attacks: Basswood, dogwood, elm, hackberry, pecan, honeylocust, oak, hickory, poplar, persimmon, redbud, and fruit trees

What you will see:

• Twigs are girdled or “chewed”
  • Twig girdlers sever the twig from the outside
  • Twig pruners sever the twig from the inside
• Twigs die and eventually snap off
• The outside of the twig is smoothly cut but the center of the twig has a broken appearance
• Landscape trees can become badly misshapen

Life cycle:

• In late summer the female lays her eggs, singly, beneath the bark in a twig
• A notch is chewed around the twig, girdling it
  • The notch is cut below the site of egg laying
• The twigs soon die, snap off and fall to the ground
• The larvae feed on the fallen twig until the middle of the following summer
• Adults emerge late summer and feed on fresh twig tips or stem bark

Cultural Management of Twig Girdlers and Twig Pruners

Cultural practices:

• Pick up and destroy infested twigs and branches

Chemical treatments have limited effectiveness against these pests. Please consult with your Arborist.

An integrated approach

When caring for urban trees it is important to make a complete evaluation of all environmental conditions to accurately diagnose all stress factors and prescribe care based on specific circumstances. This prescriptive care will help your tree meet its full potential.