LOGAN — Today I saw a beautiful white caterpillar inching his way across the pipe gate that leads into our pasture. I took a moment to get down to his level and admire his unique beauty remembering the first time I made the acquaintance of one of his kin.
You see white caterpillars are beautiful, but within their beauty they hide a venom that can give you a nasty rash. I know this because years ago I made the mistake of handling one like I would a Wooly Bear Caterpillar — not a good idea.
White caterpillar’s like White-Marked Tussock Moth Caterpillar Orgyia leucostigma) have what can best be described as toxic pincushion hairs on their backs. And even worse, contact with the hairs of this caterpillar don’t just cause you to recoil, the hairs actually are embedded in your skin. You just can’t get way from the stinging hairs once you’ve made contact. The result, will be at best a very irritating rash, especially on the inner arms, neck, and stomach areas.
The insect’s fuzzy black spines contain venom that does an excellent job of warding off predators. What actually happens is that these hollow, quill-like hairs connected to poison sacs, become embed into the skin causing a dermal reaction. Depending on the type of skin you have, this response could be anything from a minor rash to an oozing pustule.
While most individuals know that bees, wasps, hornets and some ants can sting to defend themselves or their nests, few realize that handling some caterpillars can produce similar painful results. Recognizing the stinging caterpillar species in our area may prevent irritating encounters.
The best thing to remember is if it is white, or really unusual or ugly it will probably sting. Those little stinging fellows include, of course, the White Marked Tussock Moth Caterpillar (pictured with this story), as well as the Hickory Tussock Moth Caterpillar; the Crowned Club Moth Caterpillar; and the Saddle Back Moth Caterpillar (The online article “What is the Threat from Stinging Caterpillars?” by Boggs, https://bygl.osu.edu/node/518, includes detailed images of Ohio’s stinging caterpillars).
Caterpillars, of course, are the larval stage of moths and butterflies. Many of these little fellows have spines and barbed hooks, however in most species, these are harmless, and strictly for show. However, as mentioned above, there are a few stinging caterpillars out there. Fortunately only the caterpillar stage of these species sting.
Where do they come from?
“Look no further than trees and brush, as these caterpillars feed on a large variety of leaves including oak, pecan, hickory, walnut, willow, rose, maple, pear, and many others, including conifers,” advises George Giltner of the Leesville Leader in his article “Learning more about the White-Marked Tussock Moth Caterpillar.”
“The population densities cycle from year to year with very high numbers one year, then possibly no reports the next year.
“They can cause economic loses of newly planted trees (one to three years old) when complete defoliation occurs.
•”Healthy developed trees usually recover even when they are completely defoliated,” he reported.
According to Giltner, the white-marked tussock moth is related to the gypsy moth, family Lymantriidae, which also has the tussock stinging hairs on the larvae.
Encounters with these stinging caterpillars frequently result from accidentally brushing against foliage on which they are feeding. Chances of running into these insects are pretty low. Plus, most of these caterpillars are white, distinctly marked or brightly colored with warning coloration.
The key to avoid being stung is if you find one on yourself, don’t be tempted to brush it off or slap it with your bare hand. Pick up a stick to remove it carefully. Note that the caterpillar’s hollow spines can also break off in clothing or gloves saving a little surprise for later!
According to by Ric Bessin, Extension Entomologist, University of Kentucky College of Agriculture, no really effective home first aid treatments for caterpillar stings are available.
“Adhesive tape or transparent tape may be used to pull out some of the broken spines in the sting area. Washing the area thoroughly with soap and water may help remove some of the irritating venom. Prompt application of an ice pack or baking soda may help to reduce pain and prevent swelling,” he explained, adding, “Antihistaminic drugs, often administered for bee and wasp stings, are reportedly ineffective.
Bessin recommends that if you have a severe reaction you should consult a physician.