By MARION BARNES
Senior County Extension Agent
Clemson University
The old adage, “looks can be deceiving” certainly holds true, especially when it comes to the world of insects. Some of nature’s most colorful creatures can pack a potent punch. A cute, fuzzy, brightly colored exterior may actually hide a painful surprise.
Caterpillars are the immature stages of butterflies and moths. Although there are many species that are harmless, there a few stinging caterpillars that should be approached with caution. Most people are aware that bees, wasps, hornets and some ants will sting to defend themselves and their nests. Only a few people may realize, until firsthand experience, that certain caterpillars can produce painful stings.
Stinging caterpillars have hollow quill-like hairs that are connected to poison sacs and are for defense against predators. These hairs produce irritation and rashes when they come in contact with or pierce your skin. Reactions can range from mild irritation and itching to intense throbbing pain, swelling and inflammation, blistering and dermatitis. Other symptoms include headaches, nausea, vomiting and sometimes respiratory stress. Some individuals who are more sensitive to insect stings may be at even greater risk and should seek immediate medical attention if stung by these pests.
Stinging caterpillars usually show up in late summer or fall. One of the most common venomous caterpillars is the puss caterpillar. According to the United States Department of Agriculture, most caterpillar stings in the South can be attributed to the puss caterpillar, Megalopyge opercularis. They are also called “toxic toupees” because they resemble a mass of hair on a leaf. The moth of the puss caterpillar is the southern flannel moth and is found from New Jersey to Florida and west to Arkansas and Texas. Adult moths are small with wing spans of one to one-and-a-half inches, with females generally larger than males. The flannel moth gets its name from the thick fur-like coating of seta (bristles or flannel-like scales) that cover their bodies.
The moths are thought to lay their eggs in batches since young larvae feed in groups on leaf surfaces. There are 1-2 generations a year, usually around the fall (July through October). Larvae go through several instars (stages of development) before maturing. The mature caterpillar, which is about one inch in length, spins a unique-shaped cocoon where it spends the winter on the trunk or branches of host plants.