26 Types of Caterpillars in North America: A Field Guide to Identification
October 26, 2026
North America is home to thousands of caterpillar species, and learning the common types of caterpillars in North America is the fastest way to tell a garden pest from a future monarch butterfly. Some species carry venomous spines that can send an unsuspecting gardener to urgent care, while others spin cocoons and emerge as silk moths with wingspans wider than a human hand. According to the Old Farmer’s Almanac, woolly bear caterpillars are said to predict winter severity through their black and brown color bands, a claim folklore has repeated for generations.
This guide covers 26 caterpillars found from the hardwood forests of the Northeast to the chile fields and high desert of New Mexico, spanning native caterpillars of the southwestern US alongside familiar backyard species. Whether it’s spotting New Mexico butterfly caterpillars along a ditch bank lined with milkweed or working through desert caterpillar identification on a backyard tomato plant, the same clues apply everywhere: host plant, coloring, hair or spine pattern, and horn shape.
Thousands of caterpillar species live across the continent, and knowing the most common and most distinctive ones makes the rest much easier to sort out. For a broader roundup beyond this list, see these additional caterpillar profiles.
1. Saddleback caterpillar
The saddleback caterpillar (Acharia stimulea) carries one of the most painful stings of any insect larva in North America, and its odd looks make it easy to remember once seen. According to LSU AgCenter, it is a sluglike caterpillar that has a bright brown spot in the middle of a green saddle-shaped area on its back, and it has four prominent horns on each end of the body that hold potent hemolytic venom.
The saddleback caterpillar is found across the eastern United States, ranging from Florida to New York, and as far westward as Texas, Indiana and Kansas. Per the U.S. Geological Survey, saddleback caterpillars feed on the leaves of basswood, chestnut, cherry, plum, oak, and other trees and shrubs. Contact with the spines triggers immediate burning pain, redness, and swelling that can last for hours.
Pro Tip: If stung, remove any broken spines with tape, wash the area with soap and water, and apply a cold compress. Seek medical attention if swelling spreads or breathing feels tight.
2. Woolly Bear caterpillar
The woolly bear caterpillar (Pyrrharctia isabella) is the fuzzy, black-and-rust-banded larva behind one of the most repeated pieces of American weather folklore. According to NC State Extension, the banded woollybear is famous for predicting the harshness of the coming winter weather, with the tale holding that the wider the black bands, the harsher the winter. Real science tells a different story: scientists largely dismiss this folklore, though brown bands may reflect caterpillar age, not future weather.
Woolly bears range across the United States and Canada, including foothill habitats in New Mexico. According to Wikipedia’s entry on the species, Pyrrharctia isabella, the Isabella tiger moth, whose larval form is called the banded woolly bear, woolly bear, or woolly worm, occurs in the United States and throughout Canada. The caterpillar overwinters in a partly frozen state, thawing out each spring to resume feeding before spinning a cocoon.
Important Note: Stripe width mainly reflects a woolly bear’s age and how wet the previous season was, not an accurate winter forecast.
3. Monarch caterpillar
The monarch caterpillar (Danaus plexippus) is easy to spot with its bold yellow, black, and white bands and two pairs of soft black tentacles. It feeds exclusively on milkweed, storing toxic compounds from the plant that make both the caterpillar and the adult butterfly distasteful to most predators.
Monarchs migrate through New Mexico each spring and fall on their way between Canada and central Mexico’s overwintering forests, so gardeners who plant native milkweed along ditch banks or xeriscaped beds often count monarchs among the more reliable New Mexico butterfly caterpillars to spot. Because the caterpillar depends entirely on milkweed, its range tracks the plant closely across open fields, roadsides, and gardens continent-wide.
4. Black Swallowtail caterpillar
The black swallowtail caterpillar (Papilio polyxenes) starts life as a small mimic of bird droppings before molting into the familiar green form banded with black and dotted with yellow spots. When threatened, it flicks out a bright orange, forked gland called an osmeterium from just behind its head, releasing a sharp smell that deters birds and other predators.
This species feeds on plants in the carrot family, including dill, fennel, parsley, and Queen Anne’s lace, making it a frequent garden visitor from the Atlantic coast to Iowa row-crop country and on into the arid Southwest. Among native caterpillars southwestern US gardeners encounter, black swallowtails also use wild desert parsley, making the species one of the more adaptable swallowtails in the region.
5. Luna Moth caterpillar
The Luna moth caterpillar (Actias luna) is a plump, lime-green larva with small reddish tubercles along its sides, feeding at night on walnut, hickory, sweetgum, and birch leaves. It passes through five instars over several weeks before spinning a papery cocoon wrapped in a leaf that often drops to the ground come autumn.
Adult Luna moths, with their pale green wings and long trailing tails, are common across the eastern half of the continent, including hardwood forests in Georgia, but the species thins out west of the Great Plains. Because the adults have no functional mouthparts and never feed, the caterpillar stage is the only time in a Luna moth’s life when it eats at all.
6. Cecropia Moth caterpillar
The Cecropia moth caterpillar (Hyalophora cecropia) is North America’s bulkiest native moth caterpillar, growing into a blue-green giant studded with colorful tubercles: red and yellow near the head, blue along the sides. It feeds on a wide range of trees and shrubs, including maple, cherry, birch, and box elder.
Populations stretch from the Atlantic coast west through Wisconsin and into the northern Great Plains, though the species has declined in parts of its range due to introduced parasitic flies. Like other giant silk moths, the adult Cecropia does not feed and survives only about two weeks, existing solely to mate and lay eggs.
7. Milkweed Tussock caterpillar
The milkweed tussock caterpillar (Euchaetes egle) is a fuzzy, gray-and-orange larva that often shares milkweed plants with monarch caterpillars, though the two rarely compete for long since tussock caterpillars tend to feed in groups on older, tougher leaves. Dense tufts of black, white, and orange hair cover the body, offering some visual protection from predators.
Unlike true stinging caterpillars, milkweed tussock hairs are not urticating, though sensitive skin can still react to contact. The species ranges across most of the eastern and central United States wherever milkweed grows, and like the monarch, it sequesters toxic compounds from its host plant that make it unpalatable to birds.
8. Viceroy caterpillar
The viceroy caterpillar (Limenitis archippus) looks nothing like the butterfly it becomes, resembling a lumpy bird dropping with a mottled brown-and-white body and a pair of knobby horns on its thorax. It feeds on willow, poplar, and cottonwood rather than milkweed, rolling a leaf edge into a shelter it retreats to between meals.
The adult viceroy butterfly is famous for its close resemblance to the monarch, a similarity that holds across much of the continent, from the southern United States north into Canada. Both species carry a degree of unpalatability to predators, making their shared warning coloration mutually reinforcing.
Key Insight: Monarchs and viceroys were long cited as a classic case of one-sided mimicry, but research shows viceroys are also distasteful to birds, making this closer to mutual mimicry between two protected species.
9. Eastern Tent caterpillar
The Eastern tent caterpillar (Malacosoma americanum) is a black caterpillar with a white stripe down its back, blue spots along its sides, and a coat of fine hair, best known for the silky communal tents it spins in the forks of cherry and apple trees each spring.
Colonies can strip small trees of leaves within days, especially in orchard country from New England south through Tennessee. Despite the visible damage, established trees usually recover and refoliate within weeks, making the tents themselves more of an eyesore than a real threat in most home landscapes.
10. Forest Tent caterpillar
The forest tent caterpillar (Malacosoma disstria) is often confused with its tent-building cousin, but despite the name, this species does not build a true tent at all. Instead, it spins a silk mat on tree trunks or branches where the colony rests between feedings, identifiable by a row of keyhole-shaped white spots down its back instead of a solid stripe.
Outbreaks can defoliate large stands of oak, aspen, and sugar maple across the northern United States and Canada, sometimes persisting for several years before natural predators and disease bring populations back down.
| Feature | Eastern Tent Caterpillar | Forest Tent Caterpillar |
|---|---|---|
| Back Marking | Solid white stripe | Row of keyhole-shaped white spots |
| Shelter | Silk tent in branch forks | Silk mat on trunk, no true tent |
| Preferred Hosts | Cherry, apple, crabapple | Oak, aspen, sugar maple |
| Typical Range | Eastern and central US | Northern US and Canada |
11. American Dagger Moth caterpillar
The American dagger moth caterpillar (Acronicta americana) is covered in dense, pale yellow to cream-colored hair with several longer black hair “pencils” projecting from its front, middle, and rear. Those long black hairs can cause mild skin irritation in sensitive people, even though the species is not considered dangerously venomous.
It feeds on the foliage of maple, oak, birch, elm, and willow across most of the eastern and central United States, dropping to the ground in fall to pupate in leaf litter rather than spinning an exposed cocoon.
12. Eclipsed Oak Dagger caterpillar
The eclipsed oak dagger caterpillar (Acronicta increta) belongs to the same dagger moth genus as the American dagger and shares a similarly hairy build, though its coloring runs more toward gray and brown mottling that blends into oak bark. As its name suggests, it feeds almost exclusively on oak leaves.
This species draws far less attention than its showier dagger moth relatives, in part because its muted coloring provides excellent camouflage against tree trunks during the day, when the caterpillar tends to rest motionless.
13. Brown-hooded Owlet caterpillar
The brown-hooded owlet caterpillar (Cucullia convexipennis) is one of the most strikingly patterned caterpillars in North America, banded in black, white, yellow, and orange stripes running the length of its body. Despite the bold warning colors, it is not venomous or stinging.
It feeds on asters and goldenrod, often resting in plain sight on the flower heads it eats rather than hiding. The species ranges across most of the eastern and central United States wherever its host plants bloom in late summer and fall.
14. Yellowstriped Armyworm caterpillar
The yellowstriped armyworm caterpillar (Spodoptera ornithogalli) is a dark, velvety caterpillar marked with a pair of bright yellow stripes down its back and a row of black triangular spots along each side. It is a generalist feeder capable of damaging vegetables, ornamentals, and field crops alike.
This species is a significant agricultural pest across the southern and central United States, including gardens and farm fields in New Mexico, where warm-season crops like chile and alfalfa can suffer noticeable feeding damage during outbreak years. Populations move in waves, stripping one planting before dispersing to fresh host plants nearby.
15. Dimorphic Pinion caterpillar
The dimorphic pinion caterpillar is the larval stage of a mottled gray, night-flying moth in the genus Lithophane, part of the owlet moth family Noctuidae. The caterpillar itself is a smooth, pale green larva that blends easily into fresh spring leaf growth on its host trees.
Like other Lithophane species, it feeds on deciduous trees in spring, and the adult moth overwinters as one of the earliest fliers of late winter, taking to the air on unseasonably mild nights well before most other moths emerge.
16. Polyphemus Moth caterpillar
The Polyphemus moth caterpillar (Antheraea polyphemus) is a large, bright green larva with silver-touched diagonal lines along its sides, capable of growing to roughly three inches before pupating. It feeds on a wide variety of hardwoods, including oak, maple, birch, and willow.
As a heavy-bodied night feeder, both the caterpillar and the adult moth it becomes are prey for nocturnal hunters, including the bats that pick off adult moths in flight. The species ranges across nearly all of the continental United States and southern Canada, making it one of the most widely distributed giant silk moths.
17. Funerary Dagger Moth caterpillar
The funerary dagger moth caterpillar (Acronicta funeralis) stands out among dagger moths for its striking black-and-white pattern, broken by patches of yellow-orange and tufts of long black hair along its back. The bold coloring makes it one of the more photogenic members of the genus.
It feeds on a variety of trees and shrubs, including maple, willow, and blueberry, and is found across much of the eastern and central United States and adjacent Canada. Despite its long hairs, it is not considered a stinging species, though the hairs can still irritate sensitive skin.
18. Tiger Swallowtail caterpillar
The tiger swallowtail caterpillar (Papilio glaucus) starts out looking like a bird dropping, then turns bright green with a swollen thorax marked by two large eyespots that make it resemble a tiny snake when viewed head-on. That bluff is usually enough to make a bird think twice before attacking.
It feeds on the leaves of tulip tree, wild cherry, and ash, folding a leaf over itself with silk to create a daytime shelter. Eastern tiger swallowtails range from the Atlantic coast west into the Great Plains and south through Virginia and the Gulf states, with closely related tiger swallowtail species taking over identification duties in the Rockies and Southwest.
19. Hickory Horned Devil caterpillar
The hickory horned devil (Citheronia regalis) is the caterpillar of the regal moth and one of the largest caterpillars in North America, capable of reaching more than five inches long. Its turquoise-green body is studded with black-tipped orange spines, including long curved “horns” near the head that look far more dangerous than they actually are.
Despite its intimidating appearance, the hickory horned devil does not sting and is harmless to handle. It feeds on hickory, walnut, sweetgum, and sumac, mainly in the southeastern United States, and its size alone makes it a target for opportunistic hunters, including owls that hunt after dark.
20. Stinging Rose caterpillar
The stinging rose caterpillar (Parasa indetermina) is a small, colorful slug-type caterpillar with rows of spine-tipped tubercles in shades of yellow, orange, and purple running down its back. Like its saddleback relatives in the Limacodidae family, those spines deliver a genuinely painful sting on contact.
According to the University of Florida IFAS Extension, many stinging caterpillars also release a toxin on contact with the spines, which may be a health concern for some people. The stinging rose caterpillar feeds on roses, oaks, maples, and other woody plants across the southeastern and eastern United States.
21. Sycamore Tussock Moth caterpillar
The sycamore tussock moth caterpillar (Halysidota harrisii) is a pale, creamy-white tussock caterpillar covered in soft, dense hair tufts, closely tied to a single host tree as its name suggests. It feeds almost exclusively on American sycamore leaves.
Because it depends so heavily on sycamore, its range mirrors that tree closely, following river bottoms and floodplains across the eastern and central United States where sycamores grow tallest. The caterpillar’s hairs are not known to cause a strong sting, though they can still irritate sensitive skin.
22. Tobacco Hornworm
The tobacco hornworm (Manduca sexta) is a large green caterpillar with seven diagonal white stripes along each side and a curved red horn at its rear end. It feeds on plants in the nightshade family, with a particular fondness for tobacco, tomato, and pepper plants.
This species is common across the southern United States, including chile and tomato fields throughout New Mexico, where warm growing seasons let populations build up quickly late in summer. Left unchecked, a handful of tobacco hornworms can strip a pepper or tomato plant of leaves within days.
23. Tomato Hornworm
The tomato hornworm (Manduca quinquemaculata) looks almost identical to the tobacco hornworm at a glance, which leads to plenty of misidentification in home gardens. It carries eight V-shaped white marks along each side instead of diagonal stripes, and its rear horn is dark blue-black rather than red.
| Feature | Tobacco Hornworm | Tomato Hornworm |
|---|---|---|
| Side Markings | Seven diagonal white stripes | Eight V-shaped white marks |
| Horn Color | Red | Dark blue-black |
| Typical Range | Southern US, common in warm climates | Widespread across the US and southern Canada |
| Preferred Hosts | Tobacco, tomato, pepper | Tomato, pepper, eggplant, potato |
Both hornworms are frequent targets of parasitic braconid wasps, which lay eggs on a caterpillar’s back that hatch into larvae feeding internally before pupating in small white cocoons visible on the skin.
Common Mistake: Killing a hornworm covered in small white cocoons removes a natural pest control ally. Leave it be; the wasp larvae will finish the job and go on to parasitize more pests nearby.
24. Promethea Moth caterpillar
The promethea moth caterpillar (Callosamia promethea) is a smooth, blue-green larva with a small red tubercle behind its head and a pair of yellow ones farther back, giving it a subtly festive look compared to plainer silk moth relatives. It feeds on spicebush, sassafras, wild cherry, and tulip tree.
Before pupating, the caterpillar reinforces a curled leaf with silk and lashes the leaf stem firmly to its branch so the finished cocoon does not fall with the leaf come autumn. The species ranges across the eastern half of the United States and into southeastern Canada.
25. Pipevine Swallowtail caterpillar
The pipevine swallowtail caterpillar (Battus philenor) is a dark reddish-brown to black caterpillar covered in fleshy, tapering tubercles, feeding exclusively on toxic pipevine plants in the genus Aristolochia. The toxins it absorbs make both the caterpillar and the adult butterfly unpalatable to predators, and several other species mimic its dark coloring for protection.
Pipevine swallowtails range from the East Coast through Maryland and the Gulf states into the Southwest, where native desert pipevine supports populations in New Mexico and neighboring states. That makes it one of the more distinctive native caterpillars southwestern US gardeners can attract simply by planting the right host vine.
26. Spicebush Swallowtail caterpillar
The spicebush swallowtail caterpillar (Papilio troilus) is known for its large false eyespots, which make its swollen thorax resemble the head of a small snake, a bluff aimed squarely at birds and other visual predators. Younger caterpillars mimic bird droppings before molting into this more dramatic green form.
It feeds on spicebush and sassafras, folding a leaf into a tent-like shelter with silk and hiding inside during the day while feeding mostly at night. Despite the elaborate snake mimicry, woodpeckers and other sharp-eyed birds still account for a share of caterpillar losses in the forests where this species lives, mainly across the eastern half of the United States.
Learning these 26 types of caterpillars in North America really comes down to reading a handful of clues at once: host plant, color pattern, hair or spine type, and horn shape. Put those together and most backyard finds, from a hairy woolly bear crossing a driveway to a green hornworm working through tomato leaves, sort themselves out quickly.
- Check the host plant first; many caterpillars feed on only one or two plant families.
- Note whether the body is smooth, spiny, or covered in dense hair before touching anything.
- Look for eyespots, horns, or tubercles, which often point straight to a species or genus.
- In arid regions, desert caterpillar identification often comes down to the same handful of widespread host plants, such as milkweed, mesquite, and garden nightshades.
For gardeners across the Southwest, keeping an eye on native host plants remains the simplest way to support the caterpillar species New Mexico butterflies and moths depend on, while still catching early signs of pest species like hornworms and armyworms before they cause serious damage.