Most caterpillars are safe to handle, like these Black Swallowtails.
Last weekend’s post on southern caterpillars was pretty popular, and I’m glad I could share pictures with you of what’s in my yard (and maybe yours) right now. Caterpillar hunts can be lots of fun for children and adults alike, and all the species I featured are generally safe to handle and fun to watch.
I realized, though, that I’d be remiss in urging you to go out and hunt for caterpillars without warning you about a few species that are actually fairly dangerous. There are several caterpillar species in the Southeast with stinging spines that can cause pretty severe pain and even harsher reactions. I’ve highlighted three of the worst below. Take a close look at these pictures and remember this important rule of thumb: if you don’t know what it is, don’t pick it up. If you have contact with any of these caterpillars, it’s best to seek medical attention immediately.
Flannel Moth Caterpillar (Megalopyge opercularis): Sometimes called the puss caterpillar, this harmless looking little fuzzball is known to cause incredible pain on contact. Affected limbs may swell, skin may blister and burn, and victims can even experience chest pain and breathlessness. The venom comes from spines beneath the caterpillar’s fur, and even brief contact can cause reactions. These caterpillars are generally found on oaks.

Io Moth Caterpillar (Automeris io): The bright green coloration of this caterpillar seems like an invitation to pick it up, but the little spines all over the body should give you pause. Indeed, stings from this caterpillar are painful in much the same way as those from the Flannel Moth caterpillar. They are found on a variety of foodplants.

Saddleback Caterpillar Moth (Sibine stimulea): Once again, the fascinating colors of this species makes people want to reach out and touch, and once again, it’s those stinging spines that will get you with swelling, nausea, and a lingering rash. They have a variety of host plants, but are often found on ornamental palms.

There are other stinging caterpillars in the southeastern U.S. Many extension offices offer detailed info on what to look for in your area – this article from the University of Florida is very helpful. Still, it’s also important to remember that these stinging caterpillars are generally rare. Most caterpillars are safe to handle, so don’t let these few bad guys scare you away. Just learn to recognize the risks and don’t touch unless it’s safe!
Are there other stinging caterpillars in the southeast you think our readers should watch for in their gardens? Let us know in the comments below.
Garden Hazards is a new feature on the Southeastern Blog. Is there a garden danger you’d like to know more about, or think we should feature? Drop me a line in the comments!














{ 5 comments… read them below or add one }
I was recently stung by the Beautiful Io Moth Caterpillar .But not before he had a nice feast. I pulled one off of a coopertina bush after noticing an empty branch and WOW did my fingers swell up. Thanks for letting me know what it was.
I accidentally bumped into a tiny saddleback in a tender spot- the inside of my thigh! What can I say, I was lost in photographing bees, and straddling several plants and leaning out with the camera… the sting itched and hurt for days! Isn’t it hard to watch out for things like that when there’s a great photo just… right… there!?
I have a unusual caterpillar in my flower beds this year, have pics of them on my facebook page under Kathy leamon Photography could you look and tell me what kind it is or let me email a picture to you to identify, thank you
Kathy – Couldn’t seem to find your Facebook page. You can email me your photos at florida33girl@gmail.com and I’ll see if I can help out!
I have been accidentally stung by a saddleback twice and I don’t want to be stung by it again. The pain was horrible and lasted for quite some time. I believe I’ve seen the IO caterpillar and now I know not to get near his spiny stinging little self.
FlowerLady