The saddleback, sometimes called packsaddle, is probably the most familiar “stinger.” The full-grown caterpillar is about one inch long. Its prominent “horns,” form, and markings make it easy to identify. The green midsection with large brown spot gives the appearance of a saddle and blanket, thus the common name. The full-grown caterpillar is generally a solitary feeder, but younger larvae may tend to be gregarious. The saddleback occurs on a wide variety of trees, shrubs, and other plants, including corn. Common tree hosts are apple, basswood, cherry, dogwood, maple, and oak. Larvae are most often found in late summer and fall. The sting of the saddleback is painful, but the reaction is usually less severe than that of the puss caterpillar.

The full-grown buck moth caterpillar is 2 to 2 3/8 inches long. The head is reddish brown to black; the body brown to grayish black with numerous small yellowish dots. Young larvae are solid black. A double row of short, tan-nish tufts of spines is present down its back; longer, bristled spines occur along the sides. In Alabama, the caterpillar has been found only on oak; post oak seems to be preferred. Larvae are generally present during May and the first half of June. Severity of sting is generally considered to be about equal to that of the saddleback.

The caterpillar of the white flannel moth is 1 to 1 1/4 inches long when fully grown. Coloration and markings are as pictured. Redbud is the primary host in Alabama, but larvae also feed on honey locust, mimosa, and hackberry. Caterpillars begin to appear in late July and August and are present into October. Larvae are sometimes abundant on ornamental redbud.

The full-grown stinging rose larva is 3/4 to 7/8 inch long. The body is armed with conspicuous horn-like, bristled spines. Coloration and markings are as pictured. Hosts include apple, cottonwood, dogwood, hickory, oak, redbud, sycamore, and rose. Caterpillars are generally present in August and early September but are not usually abundant.

The distinctive form of the hag moth caterpillar makes it easy to identify. Fully grown larvae are brown, hairy and 1/2 to 5/8 inch long. The lateral extensions of the body bear urticating setae. Tree hosts include apple, ash, birch, dogwood, hickory, oak, and willow. Larvae are generally solitary feeders, and are usually present in August and September. Knowledge that some larvae possess urticating structures should not generate undue fear of caterpillars. Only a relative few species have stinging capabilities, and these are not often abundant. Of the species reviewed, the puss caterpillar, saddleback, and buck moth are the most troublesome “stingers.” Reactions produced by these are somewhat similar and may sometimes be severe (see puss caterpillar). The remaining species are definitely “stingers,” but reactions produced are less painful and often short-lived. However, the severity of reaction depends on the species of caterpillar, degree of contact, and susceptibility of the individual. Reactions may be particularly severe for allergy sufferers or individuals with sensitive skin. In case of severe reaction, victims (often children) should promptly seek medical attention.