03/29/01 Twig Girdler Damage and Control

John L. Foltz (retired)
University of Florida
Department of Entomology & Nematology
Gainesville, FL 32611-0620

At this time of the year I would expect the twig girdler to be half-grown larvae inside the fallen branches. A collection and destruction of these branches would reduce the number of adults and, hence, the amount of twig girdling this fall. Burning, burying in a moist location, and exposing the twigs in a hot, dry area are some of the options for destroying the larvae.

Here are two possible press releases for September when the twig girdler is laying its eggs.

Alternative #1 (Three sentences for quick info).

Watch for twig girdlers. Beetles are now laying eggs and the girdled branches are falling to the ground. Pick up and destroy these branches to control the insect and reduce twig pruning next fall.

Alternative #2 (Two paragraphs for life cycle education).

Watch for twig girdlers. Longhorned beetles known as twig girdlers are now laying eggs in the small branches of many hardwood trees. The female beetles chew a deep notch around pencil-sized branches and typically lay three to six eggs under the bark of the dying tip. Most girdled branches fall to the ground within a few weeks. Beetle larvae hatch in three to four weeks and will feed and grow within the branch until late next summer. These insects pupate in late August and early September after which the new adults emerge.

Homeowners concerned about twig girdler damage to their trees should gather and destroy the fallen branches. Kids (and grownups) interested in entomology may wish to collect many branches and place them in a shaded area. Then, at about monthly intervals, a few branches can be cut open to observe the number and size of the developing insects.

If you would like more information about Oncideres cingulata, the twig girdler, I recommend the web page created by Lacy Hyche at Auburn. The URL is:

http://www.ag.auburn.edu/dept/ent/bulletins/twiggirdler/twiggirdler.htm


The UF/IFAS Pest Alert WWW site is at: http://entomology.ifas.ufl.edu/pestalert/