Twig Girdler & Twig Pruner
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
- 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
- Pick up and destroy infested twigs and branches
Chemical treatments have limited effectiveness against these pests. Please consult with your Arborist.
Additional Twig Girdler & Twig Pruner Information:
The Twig Girdler is a cerambycid beetle. As an insect, it creates v-shaped grooves in a circle all the way around a twig, effectively girdling it. Often the twig’s center is jagged and has a smooth outer edge. From August to October these beetles feed, causing the wind during those months to branches onto the ground. Once the groove is on the surface of the wood, the female lays her egg in a section of the branch that has fallen to the ground. The larvae are unable to feed on healthy wood, so the branch must be dead prior to gestation. The larvae then stay in the wood over winter. Once springtime comes, the larvae pupates inside the branch and grows to maturity to begin the process over.
Another type of cerambycid beetle is the twig pruner. Its lifecycle is nearly identical to the twig girdler. Interestingly, the twig pruner chews on smaller branches starting from the inside out. Th twig girdler, on the other hand, drills a small hole into the branches in the spring and then grows inside them during the summer. In late summer, the insect’s larvae becomes full grown and chew rings right through the branch until it makes its way through the entire branch, except for the bark. The larvae then move from the side of the branch that has fallen on the ground or one that is hanging from the tree. The pupae will stay over winter in the dead portion of the branch, emerging the following year to do it all over again.
The damage caused from these two insects is minimal to the tree, but it causes the appearance of the tree to lose its value. Fortunately, it’s very easy to control these insects and the mess they leave in their wake.