13 Stinging Caterpillars

Girl holding a caterpillar.
Did you know some caterpillars sting? Learn to recognize caterpillars that require careful handling. Getty Images/Elizabethsalleebauer
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Don't Touch That Caterpillar!

Girl holding a caterpillar.
Did you know some caterpillars sting? Learn to recognize caterpillars that require careful handling. Getty Images/Elizabethsalleebauer

Caterpillars, the larvae of butterflies and moths, come in many shapes and sizes. Though most are harmless, the stinging caterpillars let you know they don't like to be touched.

Stinging caterpillars share a common defensive strategy to dissuade predators. All have urticating setae, which are barbed spines or hairs. Each hollow setae funnels poison from a special glandular cell. The spines stick in your finger, then break away from the caterpillar's body and release the toxins into your skin.

What happens if you touch a stinging caterpillar? It hurts! The reaction depends on the caterpillar, the severity of the contact, and the person's own immune system. You'll feel some stinging, itching, or burning. You might get a rash, or even some nasty pustules or lesions. In some cases, the area will swell or become numb, or you'll get nauseated and vomit.

Stinging caterpillars mean business. Here are some nice, safe pictures to view, so you know what they look like.

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Saddleback Caterpillar

Saddleback caterpillar.
Saddleback caterpillar. Getty Images/Danita Delimont

Species and Group:

Sibine stimulea. Slug Caterpillars (Family Limacodidae)

About this Caterpillar:

Though the bright green "saddle" makes you want to take a closer look at the saddleback caterpillar, don't be tempted to pick it up. The saddleback's spines protrude in nearly every direction. The caterpillar will arch its back to get as many spines into you as possible. The young caterpillars feed together in a group, but as they get larger they begin to disperse.

Where It's Found:

Fields, forests, and gardens from Texas to Florida, and north to Missouri and Massachusetts.

What It Eats:

Just about anything – grasses, shrubs, trees, and even garden plants.

 

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03
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Crowned Slug Caterpillar

Crowned slug caterpillar.
Crowned slug caterpillar. Flickr user ()

Species and Group:

Isa textula. Slug Caterpillars (Family Limacodidae)

About this Caterpillar:

Here's a beauty of a caterpillar. The crowned slug displays its spines like the feathered headpiece of a Vegas showgirl. The stinging setae line the crowned slug's perimeter, decorating its flattened, green body. Later instars may also be marked with colorful red or yellow spots along the caterpillar's back.

Where It's Found:

Woodlands, from Florida to Mississippi, north all the way to Minnesota, southern Ontario, and Massachusetts.

What It Eats:

Mostly oak, but also elm, hickory, maple, and a few other woody plants.

 

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Io Moth Caterpillar

Io moth caterpillar.
Io moth caterpillar. Getty Images/jamesbenet

Species and Group:

Automeris ioGiant Silkworm and Royal Moths (Family Saturniidae).

About this Caterpillar:

With many-branched spines full of poison, this io moth caterpillar is ready for a fight. Eggs are laid in clusters, so earliest instar caterpillars will be seen in bunches. They start larval life a dark brown, and gradually molt from brown to orange, then tan, and finally to this green color.

Where It's Found:

Fields and forests from southern Canada all the way to Florida and Texas

What It Eats:

Quite a variety – sassafras, willow, aspen, cherry, elm, hackberry, poplar, and other trees; also clover, grasses, and other herbaceous plants

 

Sources:

05
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Hag Moth Caterpillar

Hag moth caterpillar.
Hag moth caterpillar. Clemson University - USDA Cooperative Extension Slide Series, Bugwood.org

Species and Group:

Phobetron pithecium. Slug Caterpillars (Family Limacodidae).

About this Caterpillar:

The stinging hag moth caterpillar is sometimes called the monkey slug, which seems a suitable name when you see what it looks like. It's hard to believe this is even a caterpillar, quite frankly. The monkey slug can be identified instantly by its furry-looking "arms," which sometimes fall off. But beware – this cuddly caterpillar is really covered in tiny stinging setae.

Where It's Found:

Fields and forests, from Florida to Arkansas, and north to Quebec and Maine.

What It Eats:

Apple, cherry, persimmon, walnut, chestnut, hickory, oak, willow, birch, and other woody trees and shrubs.

 

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06
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Puss Caterpillar

Puss caterpillar.
Flannel moth or puss caterpillar. Getty Images/Paul Starosta

Species and Group:

Megalopyge opercularis. Flannel Moths (Family Megalopygidae).

About this Caterpillar:

This puss caterpillar looks like you could reach out and pet it, but looks can be deceiving. Underneath that long, blond hair, venomous bristles hide. Even a molted skin can cause a serious skin reaction, so don't touch anything that looks like this caterpillar. At its largest, the puss caterpillar grows to just one inch long. Puss caterpillars are larvae of the southern flannel moth.

Where It's Found:

Forests from Maryland south to Florida, and west to Texas.

What It Eats:

Leaves of many woody plants, including apple, birch, hackberry, oak, persimmon, almond, and pecan.

 

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07
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Spiny Elm Caterpillar

Spiny elm caterpillar.
Spiny elm caterpillar. Steven Katovich, USDA Forest Service, Bugwood.org

Species and Group:

Nymphalis antiopa. Brush-Footed Butterflies (Family Nymphalidae).

About this Caterpillar:

Though most stinging caterpillars become moths, this prickly larva will one day be a beautiful mourning cloak butterfly. Spiny elm caterpillars live and feed in groups.

Where It's Found:

Wetlands, forest edges, and even city parks from northern Florida over to Texas, and north well into Canada.

What It Eats:

Elm (surprise!), birch, hackberry, willow, and poplar.

 

Sources:

08
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White Flannel Moth Caterpillar

White flannel moth caterpillar.
White flannel moth caterpillar. Lacy L. Hyche, Auburn University, Bugwood.org

Species and Group:

Norape ovina. Flannel Moths (Family Megalopygidae).

About this Caterpillar:

The white flannel moth caterpillar feels like anything but flannel – it's prickly. Look closely, and you'll see long hairs extending from its sides. Clumps of shorter, stinging spines line its back and sides. The adult moth is white, as the name suggests, but this larva wears a color scheme of black, yellow, and orange.

Where It's Found:

Fields and forests from Virginia to Missouri, and south to Florida and Texas.

What It Eats:

Redbud, hackberry, elm, black locust, oak, and some other woody plants. Also greenbrier.

 

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09
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Stinging Rose Caterpillar

Stinging rose caterpillar.
Stinging rose caterpillar. Getty Images/John Macgregor

Species and Group:

Parasa indetermina. Slug Caterpillars (Family Limacodidae).

About this Caterpillar:

The stinging rose caterpillar does just that – it stings. The color may vary from yellow to red with this caterpillar. Look for the unique pinstripes to identify it – four dark stripes along the back, with cream-colored stripes between them.

Where It's Found:

In barrens and scrubby coastland areas, stretching from Illinois to New York, and south to Texas and Florida.

What It Eats:

A good variety of woody plants. Including dogwood, maple, oak, cherry, apple, poplar, and hickory.

 

Sources:

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Nason's Slug Caterpillar

Nason's slug caterpillar.
Nason's slug caterpillar. Lacy L. Hyche, Auburn University, Bugwood.org

Species and Group:

Natada nasoni. Slug Caterpillars (Family Limacodidae).

About this Caterpillar:

Nason's slugs don't sport the biggest spines in the stinging caterpillar world, but it can still pack a mild punch. These small spines retract, but if the Nason's slug feels threatened, it can quickly extend the poisonous barbs. If you look at the caterpillar head-on, you'll notice its body is a trapezoidal shape (not obvious in this photo).

Where It's Found:

Forests from Florida to Mississippi, north to Missouri and New York.

What It Eats:

Hornbeam, oak, chestnut, beech, hickory, and some other trees.

 

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Smeared Dagger Moth Caterpillar

Smeared dagger moth caterpillar.
Smeared dagger moth caterpillar. Flickr user Katja Schulz (CC by SA)

Species and Group:

Acronicta oblinita. Owlets, Cutworms, and Underwings (Family Noctuidae).

About this Caterpillar:

Here's another stinging caterpillar that varies in color. Look for the yellow patches along each side, and raised red spots on its back. The smeared dagger moth caterpillar also goes by the name smartweed caterpillar, for one of its preferred host plants.

Where It's Found:

Beaches, marshes, and barrens, with a range stretching from Florida and Texas all the way to southern Canada.

What It Eats:

Broad-leaved herbaceous plants, as well as some woody trees and shrubs.

 

Sources:

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Buck Moth Caterpillar

Buck moth caterpillar.
Buck moth caterpillar. Susan Ellis, Bugwood.org

Species and Group:

Hemileuca maia. Giant Silkworm and Royal Moths (Family Saturniidae).

About this Caterpillar:

These black and white caterpillars use branching spines to fend off predators. Like the io moth caterpillars, these buck moth caterpillars live gregariously in their early instars. David L. Wagner, author of Caterpillars of Eastern North America notes that a sting he received from a buck moth caterpillar was still visible 10 days later, with hemorrhages at the sites where spines had penetrated his skin.

Where It's Found:

Oak forests from Florida to Louisiana, north through Missouri and all the way to Maine.

What It Eats:

Oak in early instars; older caterpillars will chew on most any woody plant

 

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Spiny Oak Slug Caterpillar

Spiny oak slug caterpillar.
Spiny oak slug caterpillar. Wikimedia Commons/GothMoths (CC by SA)

Species and Group:

Euclea delphinii. Slug Caterpillars (Family Limacodidae).

About this Caterpillar:

The spiny oak slug comes in a rainbow of colors; this one happens to be green. Even if you find a pink one, you can recognize it by the four clusters of darker spines near the hind end.

Where It's Found:

Woodlands from southern Quebec to Maine, and south through Missouri to Texas and Florida.

What It Eats:

Sycamore, willow, ash, oak, hackberry, chestnut, as well as many other trees and smaller woody plants.

 

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White Marked Tussock Moth Caterpillar

White marked tussock moth caterpillar.
White marked tussock moth caterpillar. Getty Images/Kitchin and Hurst

Species and Group:

Orgyia leucostigma. Tussock Caterpillars (Family Lymantriidae).

About this Caterpillar:

The white-marked tussock moth caterpillar is easy to identify. Note the red head, black back, and yellow stripes down the sides, and you'll be able to recognize this stinging caterpillar. Many tussock moth caterpillars, including this one, are considered tree pests due to their ravenous and undiscriminating taste for woody plants.

Where It's Found:

Forests from southern Canada to Florida and Texas.

What It Eats:

Just about any tree, both deciduous and evergreen.

 

Sources: