Cottonwood borer

Photo 1st Choice Pest Services

The cottonwood borer ranges throughout the eastern Unites States, but highest populations and greatest damage occur in the South. It attacks cottonwood and willow. Trees weakened by severe infestations may be broken off by wind. Damage is sometime serious in cottonwood nurseries, natural stands, and plantations, particularly those planted offsite. Adult beetles are 1 to 1 1/5 inches (25 to 38 mm) long and about 1/2 inch (12 mm) wide. They are black with lines of cream-colored hair forming irregular black patches. The larvae are seldom seen. Adults appear in midsummer. After feeding briefly, they descend to the bases of host trees where the female deposits her eggs in small pits gnawed in the bark. Eggs hatch in 16 to 18 days. The larvae bore downward in the inner bark, entering a large root by autumn. Pupation occurs in the gallery from April to June and lasts about 3 weeks. The new adults chew exit holes through the sides of the pupal chambers and emerge through the soil. Some larvae complete development in 1 year, while others require 2 years.

Larvae feeding in rootstock
Photographer: James Solomon, USDA Forest Service

Ornamental pests

Ask a question about Cottonwood borer on IPCO message board , quick response guaranteed

To IPCO pest and insect information central home page