Caterpillars in Georgia: Identification and Poisonous Species
Georgia’s mix of Blue Ridge mountain hollows, rolling Piedmont forests, and subtropical Coastal Plain supports one of the richest caterpillar rosters in the eastern United States. You’ll find zebra swallowtails on pawpaw trees along Flint River bottomlands, monarch caterpillars working through roadside milkweed from May through September, and puss caterpillars tucked into the bark folds of oaks and pecans across the Piedmont. Most are harmless. Three species in Georgia sting on contact, and one of them, the puss caterpillar, is considered the most venomous caterpillar in North America. Georgia doctors have issued public advisories on puss caterpillar stings in multiple recent seasons. This guide covers 9 caterpillars in Georgia you’re most likely to find, with the stinging species clearly marked so you know which ones to leave alone.
Common caterpillars in Georgia include the monarch on milkweed, the woolly bear crossing roads in fall, the eastern tent caterpillar building silk webs in cherry trees each spring, and the vivid zebra swallowtail on pawpaw. Three species sting on contact: the puss caterpillar, the saddleback caterpillar, and the IO moth caterpillar. Puss caterpillar stings can cause severe burning, swelling, and in some cases nausea requiring medical attention.
Common Caterpillars in Georgia to Know
Georgia’s caterpillar diversity reflects three distinct ecoregions packed into one state. The Blue Ridge Mountains in the north support Appalachian woodland species such as the spicebush swallowtail and forest tent caterpillar. The Piedmont, covering central Georgia including Atlanta and Macon, is prime habitat for monarch milkweed corridors and IO moth caterpillars on hardwoods. The Coastal Plain in the south extends the range of subtropical species including the zebra swallowtail on pawpaw. More than 159 caterpillar species have been documented in Georgia. The state’s warm climate means caterpillar activity starts as early as February in the Coastal Plain, roughly 4 to 6 weeks ahead of Midwest states. Three species sting on contact: the puss caterpillar, the saddleback caterpillar, and the IO moth caterpillar. The puss caterpillar is considered the most venomous caterpillar in North America and is documented across Georgia’s Piedmont counties on oaks, pecans, and common yard trees including boxelder and elm.
1. Monarch Caterpillar (Danaus plexippus)
Bold black, white, and yellow rings circling the whole body, with two black tentacles at each end. About 2 to 2.5 inches long at full size. Found only on milkweed plants (Asclepias species), which is the fastest way to confirm the ID. If the caterpillar is on milkweed, you’re almost certainly looking at a monarch.
Present statewide from May through September. Georgia sits along the eastern migration flyway, so milkweed corridors in the Piedmont and Coastal Plain see steady traffic through late summer. The chemicals in milkweed make monarchs toxic to most predators, which is why the bold coloring works as a warning. Common in gardens, roadsides, and old fields wherever milkweed grows.
2. Woolly Bear Caterpillar (Pyrrharctia isabella)
Fuzzy with a rusty-brown middle band and black at both ends. About 2 inches long. The hairs don’t sting, though they can irritate sensitive skin if you handle one. Best known for crossing roads and trails in September and October, searching for somewhere sheltered to overwinter under bark or leaf litter.
The folk tale linking the width of the brown band to winter severity has no scientific support. Band width varies by age and food availability, not by forecast. It turns into the Isabella tiger moth in spring. Found statewide, with peak road-crossing in October.
3. Eastern Tent Caterpillar (Malacosoma americanum)
Hairy and blackish with a white stripe down the back, blue spots along the sides, and a row of oval yellow marks. Young caterpillars build communal silken tents in the forks of wild cherry, apple, and crabapple tree branches, starting in late February or early March in Georgia’s warmer counties. They feed during the day and return to the tent at night.
By April most disperse as solitary wanderers, which is when you typically find them on sidewalks and fences. Heavy infestations can strip trees bare, but established trees push out new leaves within a few weeks. One of the most recognizable spring caterpillars in Georgia, common statewide.
4. Zebra Swallowtail Caterpillar (Eurytides marcellus)
Bright green with yellow and black cross-bands and two small false eyespots near the head. About 1.5 to 2 inches long at full size. Found exclusively on pawpaw trees (Asimina triloba), which are native to Georgia’s river bottomlands and moist woodland edges. If you spot this caterpillar, you’re standing near pawpaw.
The zebra swallowtail is one of the most visually striking butterflies in the Southeast, and Georgia’s bottomland forests along the Flint, Oconee, and Ocmulgee rivers offer prime pawpaw habitat. Early instars are dark brown with false eyespots, mimicking bird droppings. Doesn’t sting. Common from April through August in areas where pawpaw grows.
5. Spicebush Swallowtail Caterpillar (Papilio troilus)
Plump and green with two large false eyespots on the thorax: yellow with a blue center and a dark pupil. The eyespots make it look like a small snake peering back at you, which is exactly the point. Early instars are dark brown with a white saddle mark, mimicking bird droppings.
The caterpillar rolls a leaf over itself and rests inside during the day, so you find it by looking for curled leaves rather than exposed caterpillars. Found almost exclusively on spicebush and sassafras in woodland edges and creek-side thickets throughout Georgia’s Piedmont and mountain counties. Doesn’t sting.
6. Black Swallowtail Caterpillar (Papilio polyxenes)
Bright green with black bands, each band dotted with yellow spots. Disturb one and it extends an orange forked organ (the osmeterium) from behind the head and releases a sharp, pungent smell. Very effective at convincing you to back off.
Found on plants in the carrot family: parsley, fennel, dill, Queen Anne’s lace, and wild carrot. If you found it in a herb garden or along a weedy roadside with carrot-family plants nearby, this is almost certainly what you have. Common across Georgia from April through October. Doesn’t sting.
Stinging Caterpillars in Georgia
Three caterpillars in Georgia deliver a venomous sting on contact. None are life-threatening to healthy adults, but all three cause significant burning, swelling, and hives that can last several hours. The puss caterpillar is in a category of its own for intensity. The identifying rule for the other two: branching, tree-like spines on a caterpillar almost always mean it stings.
For a broader look at spiny species across North America, see Spiky Caterpillars: How to Identify and Avoid Stings.
7. Puss Caterpillar (Megalopyge opercularis)
Looks like a small tuft of soft, silky fur in shades of tan, gray, or brown, about 1 inch long. That “fur” is hair-like setae covering hollow venomous spines underneath. Touch it anywhere and the spines break off into skin. Immediate burning, a raised grid-pattern welt that follows the spine contact pattern, and in some cases nausea, headache, and difficulty breathing.
Found on oaks, pecans, elms, and boxelder trees across Georgia’s Piedmont. Also common in landscaping shrubs and yard trees in Atlanta suburbs and central Georgia communities. Present from late summer through fall, peaking in August and September. Georgia physicians and UGA Cooperative Extension have both issued public advisories on puss caterpillar stings in recent seasons. If stung, use tape to lift out the embedded spines, wash with soap and water, apply ice, and see a doctor if symptoms extend beyond the sting site.
8. Saddleback Caterpillar (Acharia stimulea)
One of the most distinctive caterpillars anywhere: dark brown at both ends with a bright green midsection, and a brown oval “saddle” outlined in white sitting squarely in the center. Four knob-like protrusions at the corners of the green section carry the stinging spines. The saddle marking works as a warning, and it’s reliable.
Touching the spines causes immediate burning, a raised welt, and a rash lasting several hours. The University of Georgia Forest Health guide lists the saddleback as the most commonly encountered stinging caterpillar in Georgia. Found on oaks, maples, cherries, elms, and many garden plants. Present throughout Georgia from July through September.
9. IO Moth Caterpillar (Automeris io)
Lime green with a white stripe outlined in reddish-brown along each side. The venomous spines are the same lime green as the body, which makes them easy to miss against foliage. Touching the spines causes immediate burning, swelling, and hives lasting several hours.
Young IO moth caterpillars are bright orange and cluster in groups: those clusters are easier to spot. By the final instar they’ve shifted to the lime-green form that delivers the sting. Found on oaks, maples, willows, and other hardwoods throughout Georgia. Active from July through September. A plump lime-green caterpillar with bristly tufts on hardwood leaves in summer deserves caution until you’ve confirmed the ID.
How to Identify Caterpillars in Georgia by Photo
For most caterpillars in Georgia, four clues narrow it down fast:
- Color and pattern: solid, striped, banded, or spotted
- Texture: smooth skin, hairy or fuzzy, or spiny
- Host plant: what plant was it on? Monarch on milkweed. Black swallowtail on parsley or fennel. Zebra swallowtail on pawpaw. Host plant alone closes most IDs.
- Season: spring tent caterpillars (February through April), summer stingers (July through September), fall woolly bears (September through October)
If those four clues leave you with multiple options, a photo does the rest. Animal Identifier lets you photograph the caterpillar and returns the species name in seconds. After the ID you can ask follow-up questions in the same session, whether you want to know if it stings or what it’ll turn into, without leaving the app. It covers insects including caterpillars statewide across all three of Georgia’s ecoregions.
For more on the state caterpillar series, see Caterpillar Identification in Michigan and white fuzzy caterpillar identification for the tussock and flannel moth species that also appear across Georgia. For the black-and-yellow species common in Southeast gardens, black and yellow caterpillars covers the full roster.
Frequently Asked Questions
Are there poisonous caterpillars in Georgia?
Three Georgia caterpillars sting on contact: the puss caterpillar, the saddleback caterpillar, and the IO moth caterpillar. The puss caterpillar is considered the most venomous caterpillar in North America and causes immediate burning, a grid-pattern welt, and sometimes nausea or breathing difficulty. The saddleback and IO moth caterpillar deliver a painful sting causing burning and hives lasting several hours. If stung, use tape to remove spines, wash with soap and water, apply ice, and seek medical attention if symptoms spread beyond the sting site.
What is the fuzzy caterpillar I keep seeing in fall in Georgia?
Either a woolly bear or a puss caterpillar, both of which are fuzzy. Woolly bears (Pyrrharctia isabella) have a rusty-brown middle band and black at both ends, about 2 inches long, and cross roads in October heading for a winter shelter. Their hairs don’t sting. The puss caterpillar looks like a small tuft of tan or gray fur and does sting severely: leave it alone and resist the urge to touch it.
What builds those silken tents in Georgia trees each spring?
Eastern tent caterpillars (Malacosoma americanum) build communal silk tents in the branch forks of wild cherry, apple, and crabapple trees. In Georgia’s warmer counties they appear as early as late February, several weeks ahead of northern states. The caterpillars leave the tent to feed during the day and return at night. Heavy infestations strip branches bare, but established trees typically recover by pushing out new foliage within a few weeks.
When are caterpillars most active in Georgia?
Georgia has two main windows. The first runs late February through May, when spring-hatching broods feed on fresh foliage. The second runs July through October, when late-season broods fatten before winter. Georgia’s Coastal Plain sees activity start 4 to 6 weeks earlier than states in the Upper Midwest. Stinging caterpillars (puss, saddleback, IO moth) peak in August and September. Woolly bears cross roads in October.
What is the green caterpillar with eyespots I found on a pawpaw tree in Georgia?
The zebra swallowtail caterpillar (Eurytides marcellus): bright green with yellow and black cross-bands and small false eyespots near the head. It feeds exclusively on pawpaw (Asimina triloba), so the host plant confirms the ID. Common in Georgia’s river bottomlands and moist woodland edges from April through August. It doesn’t sting and will turn into one of the most striking swallowtail butterflies in the Southeast.
If you find a caterpillar in Georgia you can’t place, photograph it and open Animal Identifier. Point the camera, snap the picture, and you’ll have the species and details in seconds. You can ask follow-up questions in the same session, whether you want to know if it stings or what butterfly or moth it becomes. Download it free on iOS or Android and start with 2 identifications a day at no charge.
