Stinging Caterpillars

By Lee Townsend, Roanoke Master Gardener, October 2010

Late season caterpillars are out in full force. Many use camouflage or secretive behavior to avoid predators, especially birds. A few are protected and advertise their presence by bright warning markings. These should be avoided.

The distinctive larva of the white flannel moth is one of the less common species. They feed on a variety of deciduous trees and shrubs. These caterpillars do not actively sting like a bee or wasp. Contact usually comes as a person accidentally brushes against a caterpillar that they did not see.

Stinging caterpillars have some brittle, hollow spines that are connected to venom glands in the body. These spines easily penetrate skin and break off. Then, the irritating venom goes to work. Reactions to the chemicals vary from slight irritation to pustules, inflammation, and sometimes intense pain.

Wide masking tape can be applied to the site to lift injury, the area should not be rubbed until they are removed. The wound area should then be washed with soap and water. Place an ice pack or cold compress on the wound intermittently (15 minutes on and 15 minutes off). See a physician if there is a severe or persistent reaction to the toxin.