Caterpillars That Sting

The four major stinging caterpillars occurring in Florida are the puss caterpillar, saddleback caterpillar, Io moth caterpillar and hag caterpillar. Some less common ones also occur in the state. These caterpillars do not possess stingers, but have spines (nettling hairs) that are connected to poison glands. Some people experience severe reactions to the poison released by the spines and require medical attention. Others experience only an itching or burning sensation.

Saddleback Caterpillar

Saddleback Caterpillar (UF photo)

This is a very unusual and striking insect. It is brown with a green back and flanks, on which there is a brown, oval, central area that usually is bordered with white. The brown spot looks like a saddle, and the green area looks like a saddle blanket; hence, the common name. It may exceed an inch in length and is stout-bodied. The primary nettling hairs are borne on the back of paired fleshy protuberances toward the front and hind ends of the body. There is also a row of smaller stinging organs on each side. This caterpillar feeds on many plants, including hibiscus and palms.

Puss Caterpillar

Puss Caterpillar (UF Photo)

The larva is convex and stout-bodied, almost 1 inch long when mature, and completely covered with gray to brown hairs. Under the soft hairs are stiff spines that are attached to poison glands. When touched, these poisonous spines break off in the skin and cause severe pain. Puss caterpillars feed on a variety of broadleaf trees and shrubs, and are most often found on oaks and citrus. In Florida there are two generations a year, one in spring and the other in fall. Natural enemies keep these caterpillars at low numbers during most years, but they periodically become numerous.

 

IO Moth Caterpillar (UF photo)

Io Moth Caterpillar

This is a pale green caterpillar with yellow and red stripes. It often exceeds 2 inches in length and is fairly stout-bodied. The nettling organs are borne on fleshy tubercles, and the spines are usually yellow with black tips. They feed on a wide range of plants, but ixora and rose are their favorite hosts.

Hag Caterpillar



Hag Caterpillar (UF photo)

This caterpillar is light to dark brown. It has nine pairs (sometimes fewer) of variable-length, lateral spines, which bear the stinging hairs. These spines are curved, twisted and likened by some to the disheveled hair of a hag, for which it is named. It is found on various forest trees and ornamental shrubs, but is not as common as the other stinging caterpillar species.

 

Less Well Known Venomous Caterpillars

Flannel Moth Caterpillar



Buck Moth Caterpillar

Spiny Oak-slug caterpillar (UF photo)


 




 

 

First Aid

Place clear tape over the affected area and strip off repeatedly to remove spines. Apply ice packs to reduce the stinging sensation, and follow with a paste of baking soda and water. If the victim has a history of hay fever, asthma or allergy, or if allergic reactions develop, contact a physician immediately.