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Publication #SP107

 

Stinging and Venomous Caterpillars1

D.E. Short, D.H. Habeck and J.L. Castner2

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 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.

First aid: Place Scotch 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.

  • Saddleback caterpillar, Sabine stimulea (Clemus) (Plate 1). This is a very unusual and striking insect. It is brown with a green back and flanks, on which there is a conspicuous 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, but appears to show little host preference.

  • Puss caterpillar, Megalopyge opercularis (J.E. Smith) (Plate 2 and Plate 3). It is a convex, stout-bodied larva, almost 1" 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, Automeris io (Fabricius) (Plate 4). This is a pale green caterpillar with yellow and red stripes. It often exceeds 2" 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, Phobetron pithecium (J.E. Smith) (Plate 5 and Plate 6). This caterpillar is light-to dark-brown. It has nine pairs (sometimes fewer) of variable-length, lateral processes, which bear the stinging hairs. These processes are curved and twisted and likened by some to the disheveled hair of a hag, for which it is aptly named. It is found on various forest trees and ornamental shrubs, but is not as common as the other stinging caterpillar species.

  • Buck moth caterpillar, Hemileuca maia (Dury) (Plate 7). This is a large caterpillar, 1-3/4" to 2-1/4" long when mature. It is yellow-brown to purplish-black with many small white spots and a reddish head. It feeds on oak, willow and other deciduous plants.

  • Spiny oak-slug caterpillar, Euclea delphinii (Plate 8). It is a pale-green caterpillar about 3/4" long when mature. Favorite food plants include oak, willow and other deciduous plants.

  • Flannel moth caterpillar. This caterpillar is about 1" long when mature. Stinging hairs are intermixed with soft hairs in diffuse tufts. Larvae are creamy white (Plate 9), turning dark as they mature (Plate 10). They feed on oak and various other shrubs and trees.

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Footnotes

1.

This document is SP 107, one of a series of the Department of Entomology and Nematology, Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida. This document is available for sale as a high-quality, color publication. For ordering information or to order using VISA or MasterCard, call 1-800-226-1764. Date first printed: January 1992. Reprinted: February 1997. Reviewed: June 2005. Please visit the EDIS Website at http://edis.ifas.ufl.edu.

2.

D.E. Short, professor; D.H. Habeck, professor; J.L. Castner, scientific photographer; Department of Entomology and Nematology, Cooperative Extension Service, Institute of Food and Agricultural Sciences (IFAS), University of Florida, Gainesville, 32611. The term plates, where used in this document, refers to color photographs that can be displayed on screen from EDIS. These photographs are not included in the printed document.

The Institute of Food and Agricultural Sciences (IFAS) is an Equal Opportunity Institution authorized to provide research, educational information and other services only to individuals and institutions that function with non-discrimination with respect to race, creed, color, religion, age, disability, sex, sexual orientation, marital status, national origin, political opinions or affiliations. For more information on obtaining other extension publications, contact your county Cooperative Extension service.

U.S. Department of Agriculture, Cooperative Extension Service, University of Florida, IFAS, Florida A. & M. University Cooperative Extension Program, and Boards of County Commissioners Cooperating. Millie Ferrer-Chancy, Interim Dean.