A local homeowner brought in several fuzzy-looking creatures he had captured in an old mayonnaise jar to my office. He said they were eating up his shrubs and wanted to know what they were and how to control them.
He had several puss caterpillars, a type of stinging caterpillar present in our area. These caterpillars are gray, pale yellow, or reddish-brown, about an inch long and densely covered with long, velvety hair.
Never handle puss caterpillars. The caterpillars have velvety hair that consists of hollow spines with venom. A sting on your hand may cause your entire arm to swell and become numb – after the intense pain goes away. Then you’ll probably scratch yourself to death from the itching.
So, whatever you do, make sure you don’t touch these strange worms.
I warned the homeowner about the poisonous spines and mentioned they caterpillars feed on the leaves of various hardwood trees and shrubs. The caterpillars pupate and emerge as Southern flannel moths.
Roughly 25 species of stinging caterpillars exist. Luckily, their contact with people is uncommon. Some of them have very unusual shapes and colors. The poisonous spines are a defense mechanism, and the colorful patterns and unique body shapes serve as a warning to their enemies.
The puss, saddleback and hag moth caterpillars are the most common poisonous ones around here. Control is usually not necessary since people seldom encounter them. But if you see several of them feeding on foliage in areas where children play, you might want to get rid of them.
The puss caterpillar is hairy, over an inch long, with short toxic spines hidden underneath brown or gray fur. The hairs at the posterior end form a tail-like tuft, while the head is tucked under the front. When skin brushes against the caterpillar, the spines break off, releasing irritating fluid that produces an immediate stinging sensation.
Puss caterpillars feed on oaks, pecans, persimmon, fruit trees, roses, and other trees and shrubs. They typically occur singly, although several may occur on a given tree.
The puss caterpillar causes the most painful and severe reaction of any stinging species that live in the United States. The initial burning sensation is followed by numbness and swelling, and red blotches may persist for a couple of days, accompanied by a weeping rash. Systemic reactions may include nausea and vomiting.
The saddleback is the most encountered stinging caterpillar in Georgia. The full-grown caterpillar is about one inch long, with pairs of dark brown spiny “horns” on the front and rear ends. The middle of the body is green with a white or cream margin and a large oval dark brown spot in the center, also with a white margin.
The appearance is that of a saddle and blanket, thus the common name. Small clumps of spines are visible in rows along the lower margin of the green area and at the rear of the caterpillar.
The saddleback is generally a solitary feeder; however, early-stage larvae may be somewhat gregarious. The caterpillar occurs on various trees, shrubs, and other plants, including corn but is most common on oaks, elms, dogwoods, and various fruit trees. People are most likely to bump into saddleback caterpillars in late summer and fall. The saddleback’s sting produces an immediate burning sensation, followed by inflammation, swelling, and a red rash.
People gardening, mowing lawns, picking fruit, or working in other situations where they might brush against stinging caterpillars should wear long pants, long-sleeved shirts, and gloves. If stung, several steps can reduce the pain and itching. A piece of adhesive tape can be gently stuck to the site, then pulled away to remove any spines in the skin. Application of cold compresses can lessen pain and swelling.
Over-the-counter pain medications may be indicated, along with topical hydrocortisone cream. Contact a physician if systemic reactions or other symptoms of concern develop. Symptoms typically resolve within a couple of days.
And one last precaution, don’t be tempted to touch them after they’re dead. Even dead caterpillars can still cause painful stings.