Extension

David Hillock, Senior Extension Specialist in Consumer Horticulture and Statewide Master Gardener Coordinator

This time of year, we can find many small branches from the tips of trees lying on the ground. These small branches accumulating on the ground are a good indicator of an insect called a twig girdler.

The twig girdler is a small beetle that has one generation in Oklahoma per growing season. Some indicators that these branches lying on the ground are due to twig girdlers include: the presence of clean-cut twigs, and/or dangling (flagged) branch tips within a tree. The Twig girdler female chews a V-shaped groove around a small twig, girdling it. She then will lay an egg underneath the bark on the girdled limb. This portion of the limb dies quickly and will fall to the ground or sometimes hang in the tree with the larva inside. The small larva will overwinter in the fallen twig. During the following spring, the larva resumes feeding, consuming most of the wood. As the larva grows it bores further down into the twig and fills the tunnel with wood shavings and waste. Pupation occurs in a cavity within the twig. Adults emerge in late summer and early fall.

Twig girdlers are a pest that can be managed easily with good sanitation practices. Homeowners should collect and destroy infested twigs and branches they find on the ground, beginning in the fall or early spring. This will eliminate the overwintering larvae. Infested limbs should also be pruned out and burned, if feasible. Sanitation is a cheap environmentally friendly way to manage these pests, especially for small plantings.

Figure 1. Twig girdlers chew around stems, causing fallen branches around trees. (Credit:  Clemson University - USDA Cooperative, Bugwood)