The different types of caterpillars in North America in our backyard are among the most fascinating organisms we can encounter.
These insects vary in size and shape, some being vividly colored and others being drab brown or green.
They can be long, short, stout, or thin and can even resemble bird excrement and dried leaves.
In North America, there are over 100 distinct species of caterpillars. It may be difficult to keep track of all of them.
Therefore, we will compile a list of the most common types of caterpillars in North America in our post to help you learn more about them.
Let’s get started!
1. Variegated Fritillary Moth
The Variegated Fritillary (Euptoieta claudia) is first on our list of types of caterpillars in North America with multiple colors, including brown.
Long brown stripes are visible on its body. This species is distinguished by its black-and-white patterns and its long, sharp black hairs.
These types of caterpillars in North America turn white and black during their metamorphosis.
Brown coloring is also unique to the species’ adult butterflies. The dorsal wings retain the brown and black hues of the caterpillar.
Light brown and white sections distinguish the Variegated Fritillary’s ventral wings.
The species’ caterpillar is known to feed on plantain. On at least 20 additional plants, this caterpillar has been observed.
Other host plants for the caterpillar include passion flowers, flax, and swallow-wort.
In the southern states of the United States, violets and passion flowers are prevalent hosts for the Variegated Fritillary caterpillar.
2. Ailanthus Webworm Caterpillar
The Ailanthus Webworm caterpillar is also one of the types of caterpillars in North America.
It is distinguished by its brown or dark brown body, with the final instar being black. This caterpillar is covered in small whitish or gray dots.
As the species jumped host species throughout North America, it has a fascinating history.
Its hosts are Simarouba trees in Central and South America. This tree species is not native to North America.
This species is believed to have exploited the introduced tree-of-heaven species, which is much more prevalent in North America.
As a nuisance, the caterpillar is considered a minor to moderate threat to these introduced trees.
These types of caterpillars in North America invade trees in large numbers and construct silk netting to keep wasps and other predators at bay.
3. Salt Marsh Caterpillar
This caterpillar (Estigmene acrea) undergoes color changes from one instar to the next.
It is predominantly brown at first. As a mature caterpillar, it reverts to its original dark brown hue.
Salt Caterpillars in March are a bad omen for gardens and crops. These tiny types of caterpillars in North America are renowned defoliators.
They skeletonize legume leaves to the point that the entire plant ceases to thrive.
They are found in beans, asparagus, cabbages, and maize in North America. This implies that the species affects some of the continent’s most common crops.
Without appropriate precautions, this species can defoliate a significant proportion of garden legumes.
The majority of these larvae are affected by Tachinidae. In North America, lady beetles are also common predators of these species, though to a lesser extent than Tachinidae.
4. Pipevine Swallowtail Caterpillar
The late instars of Pipevine Swallowtail caterpillars (Battus philenor) are dark brown in color.
This caterpillar can reach a maximum measure of 2 inches. Occasionally, this species has a dark brown-red coloring with brown or red patches.
Additionally, these types of caterpillars in North America have lengthy filaments along the sides of its body.
The species name is derived from the carriers of the caterpillar. Its primary hosts are tobacco-shaped plants in the Aristolochia family.
This caterpillar also fed on ginger and additional vegetation. It absorbs toxins from these plants to impart an unpleasant flavor to its prey.
The Pipevine Swallowtail caterpillar is also able to feed on morning blossoms. The brown caterpillar either transforms into a green pupa or remains brown as a pupa.
5. Monarch Caterpillar
The monarch butterfly caterpillar is one of North America’s most prevalent types of caterpillars.
Its body is black with patterns of white and yellow. This species’ larvae consume milkweed plants as part of their life cycle.
They can reach a length of 2 inches, but their colorful bands make them simple to spot in their natural habitat.
They inhabit areas where milkweed plants flourish naturally or have been planted by humans. This can include wetlands, pastures, and desolate roadside areas.
6. Viceroy Caterpillar
From eastern Canada to Mexico, one of North America’s admiral types of caterpillars is the Viceroy.
It inhabits meadows, marshes, wetlands, and other wet areas, where it feeds on trees such as willow, aspen, and poplar.
When lying on leaves or stems, the larvae have the appearance of bird droppings and are white, brown, black, or olive green in color.
This mimicry protects them from predators such as birds, who would rather consume something resembling feces than a tasty caterpillar.
7. Woolly Bear
The woolly bear caterpillar is an arthropod belonging to the family of tiger moths.
The native range of this caterpillar includes Canada, the United States, and Mexico.
Its shaggy appearance and orange-to-brown coloring characterize the woolly bear.
Additionally, it is clothed in hair, which deters predators. The wooly bear’s head and tail are black, while its body is rusty brown to orange.
During their larval stage, these types of caterpillars in North America can be found in areas with an abundance of their host plants, feeding on elm trees, sunflowers, asters, and clovers.
8. Monkey Slug
The “monkey slug” caterpillar is a hag moth larva with a distinct appearance. The larvae are brown in color and resemble an arachnid with hairs.
They also have poisonous hairs that induce a burning sensation when contacted. This allows caterpillars to avoid predators and mature into moths.
They consume trees, vegetation, and nonwoody plants in deciduous forests, orchards, and other habitats.
The cabbageworm is next on our list of types of caterpillars in North America that feed on numerous plant species, including cabbage, broccoli, and Brussels sprouts.
It is among the most prevalent horticultural caterpillars.
It has a yellowish-green body covered in short filaments. This species is common throughout the continental United States and southern Canada.
As it matures, it transforms into a cabbage-white butterfly with a wing span of approximately 1.3 to 1.9 inches.
10. Pansy Worm
The larvae of the variegated fritillary butterfly are pansy worms. It is also one of North America’s most prevalent spiny caterpillars.
This species has an orange body with black patterns and white spots.
This species’ patterns are also lined with spines. The plant’s spiny appearance helps it avoid predators, but is not poisonous.
It prefers open areas with passion flowers and violets as host plants, such as pastures and meadows.
11. Pearl Crescent Caterpillar
The pearl crescent caterpillar inhabits pastures, road edges, vacant lots, fields, and open pine forests throughout North America, from Florida to Canada and westward into Mexico.
This larva’s body is brownish-black with yellowish patterns and is covered with black and yellow spines.
The majority of their larval stage is spent feeding on aster plants before emerging from their cocoons to reproduce and produce the next generation.
12. Western Tiger Swallowtail Caterpillar
The color of caterpillars of the western tiger swallowtail ranges from green to brilliant scarlet, with blue and yellow eyespots.
You can locate these caterpillars in gardens, parks, canyons, meadows, and near rivers, lakes, and streams.
They consume numerous plants, including aspens, wild cherries, and cottonwoods.
The adult butterfly has yellow and black wings and is also quite colorful.
These types of caterpillars in North America have a wing span of 3 to 4 inches and have been observed drinking minerals from the soil.
13. Curve-lined Owlet Moth Caterpillar
Caterpillars of the owlet moth have a distinctive appearance.
As a form of self-defense, these caterpillars disguise themselves as dried leaves dangling from a plant.
Their structures are unlike those of other types of caterpillars in North America.
They have brown or green bodies that are fractured and deformed. The presence of white markings on their bodies makes them desiccated leaves.
This species can be found feeding on greenbriers from New Hampshire to Florida and Texas.
They are typically found in fields, forests, and gardens, but their remarkable camouflage may make them difficult to spot.
14. Grey Hairstreak Caterpillar
The gray hairstreak larva is widespread throughout the United States and Canada. Typically, its body is green, with a dark green line and brief setae.
This caterpillar inhabits fields, gardens, croplands, and open habitats, with various pea and mallow family plants serving as caterpillar hosts.
15. Spring Azure Caterpillar
The larva of the spring azure is a tiny green, whitish, or brown caterpillar with slender, white, star-shaped setae. As larvae, they can reach 1.5 cm in length.
Azures inhabit trees and shrubs in woodlands, forest margins, and stream banks throughout North America.
Between the months of May and September, you can locate these mature types of caterpillars in North America feeding on blueberries and dogwoods.
16. Spicebush Swallowtail Caterpillar
The spicebush swallowtail caterpillar has two pairs of golden eyespots on its green body.
A black dot resembling a pupil is visible on one pair of eyespots on the cranium. This caterpillar can grow up to 5.5 inches in length.
Additionally, there are 15 yellow butterflies in Texas. Adults can be observed in gardens, fields, forests, and wetlands.
From June to July and August through October, these types of caterpillars in North America reach maturity.
17. Banded Tussock Caterpillar
The larva of the banded tussock is a medium-sized insect with yellow-brown to gray-black setae.
Additionally, it has long black and white eyelashes at both extremities of its body. When these hairs are stroked, an itchy rash may result.
These types of caterpillars in North America feed on a variety of trees and vegetation, such as birch, blueberry, chestnut, willow, and hazel.
They are primarily found in North American forests and woodlands.
18. Mourning Cloak Caterpillar
Mourning cloak caterpillars are also on our list of types of caterpillars in North America.
The larva of the mourning cloak is a thorny caterpillar found across North America, including in Florida and Texas. Its body is black with white patches and black spines.
They also have crimson spots on their back. Mourning cloaks can be found in wetlands, forest margins, yards, and urban parks.
The caterpillar spends the majority of its time feeding on the foliage of trees such as willows and poplars and is most frequently spotted in June and July.
19. Milkweed Tussock Caterpillar
The milkweed tussock caterpillar is a furry insect that inhabits North American fields and open areas.
This hairy caterpillar is white, yellow, orange, and black, among other colors. It has a sizable tuft of black and white hairs on its back.
This species is able to persist in the wild because its bright colors and hairy exterior make it appear unappealing and dangerous to predators.
They can grow up to 3.5 centimeters in length and feed on milkweed plants.
20. Question Mark Caterpillar
Question mark caterpillars are ending our list of types of caterpillars in North America.
The larva of the question mark butterfly is a spiny, orange-branched caterpillar with black ends.
The majority of their bodies are black, but they are covered with white and orange patches.
This species favors habitats like floodplains, watercourse margins, parks, and yards.
They are commonly observed in early and late summer when they feed on elms, hops, and hackberries.