by James B. “Jim” Kea
Area Extension Forestry Agent – now retired
Thursday, February 9th, 2006
Most caterpillars are not poisonous; however, there are several kinds of so called “stinging caterpillars” in North Carolina that have stiff poisonous hairs or spines on their bodies. These spines are connected to poison glands. When a person comes in contact with the spines, they break and a venom is released. Reactions to the venom vary from mild to severe, depending upon the kind of caterpillar, the area stung, and the sensitivity of the victim. Some people, especially young children and people with sensitive skin, may have severe reactions that require a doctor’s care or, in rare cases, hospitalization. Most reactions are little more than itching and burning pain.
The puss caterpillar is up to one inch long and is covered with long grayish or tan hairs. A sting from this caterpillar is usually the worst with burning pain and numbness with an aching pain and nausea that may last for hours. Hospitalization may be required.
The saddleback caterpillar is also up to one inch long. It is brown on each end and green in the middle with a brown or purple center resembling a saddle. Its sting is probably the most common and normally less severe than that of the puss.
The crinkled flannel moth caterpillar resembles the puss, but is sting is usually found further north.
The hag moth caterpillar is light brown in color with nine pairs of lateral pegs. Its sting is also usually mild.
The io moth caterpillar is pale green with yellowish to reddish to maroon stripes. It is often over two inches in length. It is covered with sandspur-like barbs with black tips. Stings are usually mild.
The sixth is called Nonape cretata. It has a spotted body that is sparsely covered with tufts of hair. Stings are usually mild.
Stings usually occur in the fall, but can occur in early June.
It is often difficult to locate the caterpillar since several seconds elapse before the sting is noticed and the caterpillar is often well camouflaged or hidden under leaves. They can be found on any type of plant from the yard or garden to the woods.
Stings should be washed thoroughly with a solution of household ammonia or bicarbonate of soda. Menthol salves such as mentholatum usually help reduce stinging. If pain and symptoms are severe, contact your physician as soon as possible.
Caterpillars are often found alone, so control with insecticides can be limited to the offender. Dead caterpillars should be disposed of since the barbs remain armed.