A couple of years ago while mowing the lawn, I received quite a sting from a surprising source - a saddleback caterpillar. The resulting hives didn't last too long, but were a bit painful.
The technical term for hives is urticaria. And the caterpillars that cause it are referred to as urticating caterpillars.
These creepy crawlers have hollow spines that hold an irritating fluid that causes stinging and burning in a person's skin. In Georgia, urticating caterpillars show up in the late summer and fall. The two most common in Georgia are the saddleback and puss caterpillars.
The saddleback caterpillar is the one most often encountered. The full-grown caterpillar is about 1 inch long, and 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 white-bordered brown spot looks like a saddle and blanket, giving it its name.
It has pairs of dark brown, spiny "horns" on the front and rear ends. And in between are small clumps of spines along the lower margin of the green area.
Saddlebacks show up in many trees, shrubs and other plants, including corn. But they're most common on oaks, elms, dogwoods and various fruit trees. Their sting produces an immediate burning sensation, followed by inflammation, swelling and a red rash.
The puss caterpillar looks a little like something the cat might have coughed up. It is hairy and more than an inch long, with short, toxic spines hidden underneath its brown or gray fur. The hairs at the rear end form a tail-like tuft, with the head tucked under the front.
Puss caterpillars feed on oaks, pecans, persimmon, fruit trees, roses and other trees and shrubs. While they may appear harmless, they actually cause the most painful and severe reaction of any urticating species in the United States.
When your skin brushes against the puss caterpillar, the spines break off, releasing an irritating fluid that produces an immediate stinging, burning sensation. The numbness and swelling that follow may extend to your whole arm or leg in severe cases.
Red blotches may persist for a couple of days, accompanied by a weeping rash. Associated lymph nodes may swell and be tender for 12 to 24 hours. Reactions may include nausea and vomiting.
If one stings you, treat the symptoms. To remove any spines still in the skin, gently stick a piece of adhesive tape to the site and then pull it away. Applying cold compresses can lessen the pain and swelling. Pain medications and topical hydrocortisone creams may help.
Billy Skaggs is an agricultural agent and Hall County extension coordinator. Phone: 770-531-6988. Fax: 770-531-3994.