Puss Caterpillar (Megalopyge opercularis) (Photo 7)
The puss caterpillar (the adult is called southern flannel moth) is our most "dangerous" stinging caterpillar. Contact may produce severe reactions including: intense burning and nettling of the skin; severe pain; reddening and inflammation; development of pustules and other lesions; numbness; swelling, which may sometimes be extensive; and nausea. Pain may persist from one to twelve or more hours. In some instances, victims have required medical attention. The larva is urticating in all stages, but severity of the reaction is generally proportional to size. Also, newly molted skins retain stinging capabilities.
The caterpillar is thickly covered with fine, long, tan, grayish to brown hairs, among which are hidden venomous setae. Hairs peak roof-like over the back and taper rearward to form a "tail". Hairs along the "ridge" of the back occur in small tufts; on each side are small patches of white. The full-grown larva is about 1 inch long, but with its hairy coat, appears to be much larger. The overall length of the specimen shown at left in Photo 7 is 1 5/8 inches.
Puss caterpillars feed on foliage of a variety of broadleaf trees and shrubs. Some common tree hosts are apple, elm, hackberry, maple, oak, pecan, and sycamore. Two larval broods likely occur each season in Alabama, one in spring and early summer and one in late summer and fall. It is the caterpillars of the second brood that are most often encountered. Specimens pictured here were collected in Lee County during September.