35 Common Caterpillar Names with Free Picture ID Guide

Caterpillars represent one of nature’s most fascinating transformations. These voracious eating machines spend their brief lives consuming enormous amounts of plant material before undergoing metamorphosis into the butterflies and moths we admire in gardens and wild spaces. Understanding caterpillar names and identification is essential for gardeners, naturalists, and anyone interested in observing the complete life cycle of Lepidoptera.

This comprehensive guide covers 35 common caterpillar names found throughout the United States, providing detailed identification characteristics to help you identify these remarkable insects in your own backyard.

Understanding Caterpillar Anatomy and Identification

Before exploring specific caterpillar names, it is important to understand the key anatomical features used for identification. Caterpillars possess three distinct body regions: the head, thorax, and abdomen. The head contains chewing mouthparts and typically features six small eyes called stemmata on each side. The thorax comprises three segments, each bearing a pair of true legs with jointed claws. The abdomen consists of ten segments, with the first eight typically featuring pairs of fleshy prolegs that lack joints.

Identification specialists look for several critical characteristics when distinguishing between caterpillar names. Body coloration and pattern serve as primary identifiers, with many species displaying distinctive stripes, spots, or bands. The presence or absence of hairs, spines, or tubercles provides another distinguishing feature. Host plant preference offers additional confirmation, as most caterpillars feed exclusively on specific plant species. Body length and shape complete the identification profile.

Swallowtail Caterpillar Names

Swallowtail butterflies produce some of the most recognizable caterpillar names in North America. These robust larvae often display vibrant coloration and distinctive OSMETERIA, a foul-smelling organ they evert when threatened.

Black Swallowtail Caterpillar

The black swallowtail caterpillar (Papilio polyxenes) reaches 2 inches in length and displays a striking appearance. Young caterpillars resemble bird droppings with their mottled black and white coloration. Mature specimens develop vibrant green bodies adorned with yellow spots and black bands across each segment. TheOSMETERIA, an orange organ behind the head, emits a disagreeable odor when the caterpillar feels threatened. These caterpillars commonly feed on parsley, dill, fennel, and carrot family plants.

Tiger Swallowtail Caterpillar

Tiger swallowtail caterpillars (Papilio glaucus) exhibit a unique appearance among common caterpillar names. Early instars appear brown with white saddle markings, closely resembling bird droppings. Mature caterpillars turn bright green with large eye spots on the thorax. A distinctive yellow band bordered by black marks appears before pupation. Host plants include wild cherry, tulip tree, birch, and ash.

Spicebush Swallowtail Caterpillar

The spicebush swallowtail caterpillar (Papilio troilus) represents one of the more distinctive caterpillar names for identification. These elegant larvae display an orange ground color when young, transitioning to bright green with two rows of bright blue spots along the sides in their final instar. Large eye markings on the thorax create a snake-like appearance that deters predators. They feed exclusively on spicebush and sassafras leaves.

Pipevine Swallowtail Caterpillar

Pipevine swallowtail caterpillars (Battus philenor) feature a dark brown to black body covered in orange tubercles. These distinctive appendages along the body segments make this one of the most recognizable caterpillar names. The striking appearance warns potential predators of the toxic compounds derived from their host plant, pipevine. Unlike some swallowtail species, they lack a functional OSMETERIA.

Monarch and Milkweed Caterpillar Names

Monarch caterpillars represent perhaps the most famous names among all caterpillars due to their remarkable migration story and conservation significance.

Monarch Caterpillar

The monarch caterpillar (Danaus plexippus) displays iconic warning coloration that makes it instantly recognizable. Alternating yellow, white, and black bands extend the full length of its cylindrical body. Black tentacles project from both ends of the body, with three pairs of true legs near the head and five pairs of prolegs along the abdomen. Mature specimens reach approximately 2 inches. These caterpillars feed exclusively on milkweed species, sequestering cardiac glycosides that make them toxic to predators.

Queen Caterpillar

The queen caterpillar (Danaus gilippus) closely resembles the monarch but displays more extensive orange coloration across its body. Like its famous relative, this species sequesters toxins from milkweed host plants. Black tentacles and characteristic banding patterns distinguish it from monarch caterpillars. They occur primarily in the southern United States where milkweed plants remain available throughout the year.

Woolly Bear and Hairy Caterpillar Names

Several common caterpillar names feature prominent hairs or spines that serve as defense mechanisms against predators.

Woolly Bear Caterpillar

The woolly bear caterpillar (Pyrrharctia isabella) ranks among the most recognizable caterpillar names in North America. This species displays dense, medium-length hairs covering its body in bands of rusty red and black. The distinctive pattern creates the appearance of a tiny bear, hence the name. Woolly bear caterpillars freeze when disturbed, coiling into a tight ball that protects their soft underparts. They feed on various low-growing plants including clover, dandelion, and plantain. These caterpillars are famous for their supposed weather-predicting abilities based on the width of their rust-colored bands.

Yellow Bear Caterpillar

The yellow bear caterpillar (Estigmene congrua) appears similar to the woolly bear but displays more yellow than rust coloration. Dense hairs cover the body, providing protection from predators. These caterpillars feed on a wide variety of herbaceous plants and often occur in agricultural settings. They are commonly found throughout the United States.

Salt Marsh Caterpillar

Salt marsh caterpillars (Estigmene acrea) display distinctive yellow to orange coloration marked with black spots. Unlike the woolly bear, their hairs appear more uniformly distributed across the body. These caterpillars feed on numerous garden plants and crops, occasionally reaching pest status. They occur most commonly in coastal areas and the southern United States.

Hornworm Caterpillar Names

Hornworms represent some of the largest caterpillar names in North America, with several species reaching impressive sizes.

Tomato Hornworm

The tomato hornworm (Manduca quinquemaculata) stands as one of the largest and most recognizable caterpillar names in gardens. These massive larvae reach 4 inches in length when mature, displaying bright green bodies with eight V-shaped white markings along the sides. A characteristic black horn projects from the rear of the body. Despite their large size, their green coloration provides excellent camouflage against tomato leaves and stems. They feed voraciously on tomato, pepper, eggplant, and related plants.

Tobacco Hornworm

The tobacco hornworm (Manduca sexta) closely resembles the tomato hornworm but displays straight-edged white markings rather than V-shaped marks. A red horn replaces the black horn found on tomato hornworms. These caterpillars also reach impressive sizes and feed on the same host plants. The two species often occur together in gardens, making careful observation necessary for accurate identification.

Catalpa Sphinx Caterpillar

The catalpa sphinx caterpillar (Ceratomia catalpae) represents a distinctive member of the hornworm family. These caterpillars display a yellow-green to white body with distinctive black spots along the sides. Unlike typical hornworms, they lack the prominent horn, instead featuring a reduced tail spike. They feed exclusively on catalpa trees, sometimes defoliating entire branches.

Tent Caterpillar Names

Tent caterpillars build distinctive communal shelters that make their caterpillar names well-known to homeowners and naturalists.

Eastern Tent Caterpillar

The eastern tent caterpillar (Malacosoma americanum) builds prominent silken tents in the forks of tree branches, making this one of the most recognizable caterpillar names in eastern North America. These social caterpillars live communally within the tent, emerging to feed on surrounding leaves. They display black bodies with blue and white markings along the sides, reaching approximately 2 inches. Host trees include cherry, apple, crabapple, and hawthorn.

Forest Tent Caterpillar

The forest tent caterpillar (Malacosoma disstria) differs from its eastern cousin by not building communal tents. Instead, these caterpillars construct silken mats on tree trunks where they aggregate during molting. They display a similar dark base coloration but feature a distinctive row of white keyhole-shaped marks along the back. They feed on various hardwood trees including oak, maple, birch, and aspen.

Fall Webworm

The fall webworm (Hyphantria cunea) creates extensive webbed enclosures at branch tips, encompassing leaves and caterpillars within a single protective structure. These caterpillars display considerable color variation, ranging from pale yellow to dark brown, often within the same population. White or yellow hairs cover their bodies. They feed on over 100 tree species and represent one of the most widely distributed caterpillar names in North America.

Giant Silkworm Caterpillar Names

Giant silkworm caterpillars produce some of the most spectacular Lepidoptera larvae found in North America.

Cecropia Caterpillar

The cecropia caterpillar (Hyalophora cecropia) represents North America’s largest native moth larva. These impressive caterpillars reach 4 inches in length, displaying green bodies covered in distinctive orange, yellow, and blue tubercles. The bristle-like structures along the body segments create an otherworldly appearance. They feed on various trees including maple, birch, cherry, and willow.

Luna Moth Caterpillar

Luna moth caterpillars (Actias luna) display a striking appearance among common caterpillar names. These green caterpillars feature distinctive red-orange spots along their sides and numerous small tubercles covering the body. They feed on various trees including sweetgum, walnut, hickory, and birch. The distinctive appearance helps identify this remarkable species.

Polyphemus Moth Caterpillar

The polyphemus moth caterpillar (Antheraea polyphemus) ranks among the largest North American caterpillars, reaching 3.5 to 4 inches. These robust larvae display green bodies with yellow lines along the sides and distinctive red-orange spots on each segment. They feed on numerous trees including oak, maple, birch, willow, and elm.

Common Garden Caterpillar Names

Several caterpillar names commonly appear in gardens and suburban environments throughout the United States.

Cabbage White Caterpillar

The cabbage white caterpillar (Pieris rapae) represents one of the most widespread caterpillar names in gardens worldwide. These green caterpillars blend remarkably well with their host plants, displaying subtle green coloration marked with a thin yellow line along the sides. They feed on cabbage, broccoli, cauliflower, and related cruciferous vegetables. The caterpillars reach approximately 1 inch before pupating.

Painted Lady Caterpillar

The painted lady caterpillar (Vanessa cardui) displays a distinctive appearance among garden caterpillar names. These spiny caterpillars feature a dark brown to black body covered in short spines. A yellowish line runs along each side, visible when the caterpillar moves across its host plants. They feed on over 100 plant species, including thistles, mallows, and various garden plants.

Red Admiral Caterpillar

Red admiral caterpillars (Vanessa atalanta) display black bodies covered in conspicuous white spots and branched spines. These distinctive features make them relatively easy to identify despite their cryptic behavior. They feed primarily on nettles, often hiding within rolled leaves during the day.

Buckeye Caterpillar

The buckeye caterpillar (Junonia coenia) displays one of the most distinctive appearances among butterfly caterpillars. These spiny black caterpillars feature bright orange to reddish spots along their sides and distinctive orange spots on the head. They feed on plantain, snapdragon, and related plants.

Inchworm and Measuring Worm Caterpillar Names

Inchworms represent a unique group of caterpillars that move with a distinctive looping motion.

Common Inchworm

Inchworms, also called measuring worms, belong to the family Geometridae and display a distinctive body structure. Lacking prolegs in the middle of the body, they move by drawing their rear legs forward to form a loop, then extending forward again. These caterpillars vary considerably in coloration and pattern depending on species. They feed on various trees and shrubs.

Canopy Inchworm

Canopy inchworms represent numerous species that feed in tree canopies throughout North America. Their cryptic coloration provides excellent camouflage against leaves and bark. Many species overwinter as pupae in the soil, emerging as adults the following spring.

Additional Common Caterpillar Names

Saddleback Caterpillar

The saddleback caterpillar (Sibine stimulea) displays one of the most distinctive appearances among North American caterpillars. A brown body features a prominent purple to brown saddle marking on the back, bordered by white lines. More importantly, these caterpillars possess urticating spines capable of delivering painful stings. They feed on various trees and shrubs including oak, cherry, and corn.

Yellow-Necked Caterpillar

The yellow-necked caterpillar (Datanaministra) displays a distinctive yellow “neck” region behind the black head. The body displays alternating orange and black lines along its length. These caterpillars often feed in groups, moving in unison across branches. They feed on oak, apple, birch, and other hardwood trees.

Imperial Moth Caterpillar

The imperial moth caterpillar (Eacles imperialis) ranks among North America’s largest caterpillars, reaching 4 inches or more. These robust larvae display green bodies with numerous yellow to white tubercles along each segment. They feed on various trees including oak, pine, maple, and elm.

Hackberry Emperor Caterpillar

The hackberry emperor caterpillar (Asterocampa celtis) displays a distinctive appearance with multiple branching spines over the body. Brown to gray coloration provides camouflage against hackberry bark and leaves. These caterpillars feed exclusively on hackberry trees.

Mourning Cloak Caterpillar

The mourning cloak caterpillar (Nymphalis antiopa) displays spiny black bodies with white spots along the back. These social caterpillars often feed in groups when young, dispersing as they mature. They feed on willow, birch, elm, and poplar trees.

Red-Spotted Purple Caterpillar

The red-spotted purple caterpillar (Limenitis arthemis) displays a distinctive appearance with a brown body covered in white to cream marks and paired spines. These caterpillars roll leaves for protection while feeding on willow, poplar, cherry, and birch.

Question Mark Caterpillar

The question mark caterpillar (Polygonia interrogationis) displays spiny orange to brown bodies with white spots. The distinctive appearance helps identify this species among the many anglewing butterflies. They feed on elm, nettle, and hops.

Pearl Crescent Caterpillar

The pearl crescent caterpillar (Phyciodes tharos) displays a dark brown to black body covered in branched spines. These small caterpillars feed on various aster species throughout their range.

Common Wood Nymph Caterpillar

The common wood nymph caterpillar (Cercyon pegala) displays a brown body with lighter stripes along the back. These caterpillars feed on various grasses and may overwinter in ground-level litter.

Conclusion

Understanding caterpillar names and identification opens a window into the remarkable diversity of Lepidoptera in North America. From the iconic stripes of the monarch caterpillar to the impressive size of the hornworm species, these larval forms display incredible variation in color, pattern, and behavior. Learning to identify these 35 common caterpillar names provides a foundation for observing the complete life cycle of butterflies and moths in your local environment.

Remember that many caterpillars require specific host plants for survival, making habitat preservation essential for supporting Lepidoptera populations. Whether you encounter a fuzzy woolly bear crossing a autumn path or discover a tent caterpillar fortress in your cherry tree, take time to observe and appreciate these remarkable immature insects that transform into such beautiful winged creatures.

Frequently Asked Questions

What is the most common caterpillar name in North America?

The cabbage white caterpillar (Pieris rapae) is among the most frequently encountered caterpillar names across North America. Originally introduced from Europe, this species has spread throughout the continent and commonly appears in gardens, particularly on cruciferous vegetables. Their green coloration provides excellent camouflage, making them sometimes difficult to spot despite their abundance.

How do I identify a caterpillar by its name?

Caterpillar identification relies on several key characteristics: body coloration and patterns, presence of hairs or spines, stripe or spot arrangements, body shape and size, and most importantly, the host plant where you found it. Many caterpillars feed exclusively on specific plants, making host plant identification nearly as important as physical characteristics. Field guides and online resources from entomological societies provide detailed photographs and descriptions for comparison.

Are all hairy caterpillars dangerous to touch?

Not all hairy caterpillars are dangerous, but many possess urticating hairs that can cause skin irritation or more severe reactions. The saddleback caterpillar, for example, possesses spines connected to toxin glands that can deliver painful stings. The woolly bear caterpillar, conversely, has dense but non-stinging hairs. When in doubt, observe caterpillars without handling them, and always wash hands thoroughly after touching any caterpillar.

What do most caterpillars eat?

Most caterpillars are herbivores, feeding primarily on leaves, flowers, or fruits of specific host plants. Some species like the monarch caterpillar feed exclusively on milkweed, while others like the cabbage white caterpillar accept numerous plants in the mustard family. A few species have unusual diets—the harvester caterpillar feeds on aphids, making it the only predatory caterpillar in North America.

How long do caterpillars live before becoming butterflies?

The caterpillar stage typically lasts 2 to 8 weeks depending on species and environmental conditions. Some species overwinter as caterpillars, while others complete their development in just a few weeks. During this period, caterpillars undergo multiple molts called instars, growing larger with each stage until they pupate and begin their metamorphosis into adult butterflies or moths.