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Thursday, April 27, 2017
Southwest Louisiana ,
A buck moth caterpillars. (Photo courtesy of

A buck moth caterpillars. (Photo courtesy of

Spines on buck moth caterpillar hold venom

Last Modified: Wednesday, May 07, 2014 11:05 AM

By Andrew Perzo / American Press

What is the name of those black caterpillars that are all over the place right now? They’re on the trees, and they’re falling off the trees, and they have spines on them. Do they sting, and are they native to Louisiana?

You’re likely referring to buck moth caterpillars, which — like Formosan termites, June bugs, love bugs and Eastern lubber grasshoppers — cause seasonal anxiety among some residents in parts of south Louisiana each year.

The caterpillars, the larval stage of the buck moth, are black or dark purple and have yellow-white spots and a small red head. They feed on the leaves of live oaks, red oaks and water oaks; often move in groups; and drop from the branches when they’re disturbed.

The spines arrayed along the caterpillar’s body are connected to venom glands, which produce toxic proteins that cause pain and irritation in anyone who touches them — symptoms that can last more than a week.

If you get stung, gently wash the area where the spines went in and allow it to air dry. Use duct tape to remove spines that remain and then use an ice pack, along with an oral or topical antihistamine, to help alleviate the pain and itching.

The buck moth, first identified in Louisiana in 1863, is native to North America.

“The moth is called in America the Buck-fly, from an erroneous idea that its caterpillars are bred in the heads of the buck, which blow them out of their nostrils,” reads Volume II of “Illustrations of Exotic Entomology,” written by entomologist J.O. Westwood and published in London in 1837.

“This opinion originates from the fly coming out in the rutting season whilst the bucks are pursuing the does; the hunters therefore take notice of the insect in order to know the proper season for their sport.”

More on the moth, from a 2001 issue of Louisiana Conservationist:

Found throughout Louisiana, the insect is most common in the southern sector, including the urban centers of Baton Rouge and New Orleans where high concentrations of oak trees planted for shade provide perfect habitat. During some years, the insect reaches pest status. While most moths are nocturnal, bucks fly during the daylight hours, usually between 10 a.m. and 3 p.m., between Thanksgiving and Christmas. ...

After spending approximately four to five weeks gorging on low growing vegetation (sometimes even dried oak leaves), the nomadic buck moth larva seeks undisturbed leaf litter or loose soil. There, within dark secrecy, the caterpillar sheds its skin, revealing a dark brown encasement known as a pupa. Here again the buck moth illustrates another of its interesting traits: no cocoon. ...

Throughout the long summer months, all internal tissues are reorganized to form what will eventually be an adult moth. By autumn the magic is complete. The pupal skin splits and a new creation emerges from its darkened lair to become an exquisite creature of the heavens that we recognize as the buck moth.


The Informer answers questions from readers each Sunday, Monday and Wednesday. It is researched and written by Andrew Perzo, an American Press staff writer. To ask a question, call 494-4098 and leave voice mail, or email

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