If you’ve been searching for them, you may wonder what types of caterpillars live in the state.
The good news is that there are many different types of caterpillars in Maine, depending on where in the state you’re located.
So if you want to know more about caterpillars in Maine, read on! Maine has many types of caterpillars, and some are easier to identify than others.
1. Monarch Caterpillar
One of Maine’s most well-known types of caterpillars in Maine is the orange Monarch butterfly. The Monarch is one of our largest butterflies, reaching up to four inches across as a fully grown adult.
They are also incredibly recognizable due to their distinctive wing shape and bright orange/black coloring.
Many people are surprised that these butterflies begin life as a caterpillar! If you’re looking for some more information on how to identify a monarch caterpillar or what they eat in its early life stages, check out a few more fun facts below!
The cabbageworm is green with yellow stripes down its back. It’s easy to spot because it looks like a large silkworm.
These types of caterpillars in Maine are usually found in cabbage, kale, collard greens, broccoli, cauliflower, Brussels sprouts, and other plants.
These types of caterpillars in Maine cause damage to your plants when they feed on them. Unfortunately, there isn’t much you can do about these pests unless you have a significant amount of them in one place.
This pest goes through five molts before reaching maturity and becomes pupae after four days as an adult — which is when it’s ready to emerge from its cocoon as a moth.
Adult moths don’t eat; instead, their only purpose is reproduction. They mate for life and lay their eggs on plants where their young will be able to find food. One female cabbageworm can lay up to 400 eggs during her lifetime.
3. Woolly Bear
The woolly bear (also known as a polar bear or common bear) is perhaps one of Maine’s most famous caterpillar species.
These fuzzy little guys are commonly found on thistles but have also been spotted on clover, dandelions, grasses, plantains, willow trees, and even white pine needles.
The hairs covering their bodies are hollow; they’ve been known to use them as nesting materials during winter. Their fur has a few downsides—unsurprisingly, it makes them incredibly difficult to handle.
However, the hair also insulates them against cold weather; many woolly bears have been found frozen solid in late fall or early spring temperatures below zero degrees F.
Here is a fun fact about these types of caterpillars in Maine. They’re not bears at all! They were named for their resemblance to real-life bears, though you’d be hard-pressed to find any mammal with such soft and furry coats.
4. Viceroy Caterpillar
The Viceroy is one of many mimics butterflies, meaning they share similarities with another animal or plant to protect themselves from predators.
For example, the ruler resembles a poisonous monarch butterfly with a yellow band across its hindwings instead of an orange.
It’s a mimic rather than an imitator, meaning these caterpillars in Maine use mimicry as part of their natural defense system instead of manipulating others through deception.
These types of caterpillars in Maine lay eggs on milkweed plants, which are also poisonous to birds. That helps explain why monarchs often fly milkweed patches, which are also distasteful.
While not rare, they aren’t very common either; you can find them throughout New England during summer.
5. Large Maple Spanworm
The Large Maple Spanworm is among one of Maine’s most interesting types of caterpillars in Maine because it can be confused with another species, the White Lined Sphinx.
The easiest way to tell them apart is by looking at where they have a blue band on their bodies. The Large Maple Spanworm has a blue band from segments 4-8 (the head is 1,2 and 3).
The White Lined Sphinx caterpillar has its blue band from frosegmentsnt 1-8. Another trick to telling them apart is by size; if you see a spanworm that’s two inches long or more, there’s a good chance it will be a large maple spanworm. On the other hand, it will probably be a white-lined sphinx if it’s closer to one inch.
These types of caterpillars in Maine take about three years to go through all five instar stages before they pupate and become adult moths.
Then, they overwinter as pupae so that you won’t see adults until next year. These moths are nocturnal, but I haven’t been able to find out what color they are during daylight hours.
6. White-Marked Tussock Caterpillar
The white-marked tussock caterpillar feeds voraciously on the green leaves of various plants, including legumes, aspen, hickory, birch, elm, and oak trees.
The large caterpillar has black hairs with white markings behind each hair. The mature larvae build small tent-like webs between branches to protect themselves while eating leaves at night.
During winter, these types of caterpillars in Maine burrow into tree bark to hibernate until spring. The adult is a moth that lays its eggs on leaves during the summer.
White-marked tussocks are common throughout most of North America but are not usually found in areas with heavy snowfall or freezing temperatures.
7. Milkweed Tussock Caterpillar
The milkweed tussock caterpillar is a striking yellow-and-black caterpillar that gets its common name from its resemblance to fresh milkweed floss.
These types of caterpillars in Maine, also known as esculenta, have long been confused with words like edible, but it means plump or food. Therefore, the plant is sometimes called by its Latin name, Asclepias esculenta.
Interestingly, ingesting milkweed alone won’t result in death; these toxic plants are often so bitter that birds will only peck at them if they’re hungry.
It’s not until milkweed floss mixes with other plant food (like apple or cherry) that digestion issues arise for smaller mammals like mice or voles.
8. Banded Tussock Caterpillar
These types of caterpillars in Maine are orange with black bands running across its body.
It feeds on trees and shrubs, including oaks, pines, beeches, cherries, maples, birches, and willows. They curl into a ball when they’re not eating or looking for a new place to move on.
This defense mechanism protects them from predators who don’t have time to watch out for these wriggly insects.
Banded tussock caterpillars are often confused with woolly bear caterpillars because of their coloration and curled shape. However, banded tussock caterpillars are much more colorful than their fuzzy counterparts.
9. Giant Leopard Moth Caterpillar
The Giant Leopard Moth caterpillar is one of a few types of caterpillars in Maine that can be seen year-round. Also known as the Io Moth caterpillar, Io moth larvae feed on ash, maple, birch, and apple trees.
The giant caterpillar ranges from 2 to 3 inches long; its body coloration ranges from green to brownish, with prominent yellow lines running down it.
Unlike most types of caterpillars in Maine, which eat leaves or bark, Giant Leopard Moths are usually found on branches or twigs.
During winter months, when there is no food source for them because trees have lost their leaves, they will form cocoons until springtime, when it’s time for them to metamorphose into moths.
10. Parsley Caterpillar
The Parsley Caterpillar (Black Swallowtail) is green with long, segmented white lines on its body. These types of caterpillars in Maine have a black tail at their rear and an accumulation of shed skins.
The caterpillar feeds on parsley (hence its name) but is also known to feed on carrot tops and a variety of weeds. It lives most of its life high off the ground, so it cannot be easy to spot.
However, if you see one feeding on a plant, you will likely find more nearby as they tend to travel together. They pupate in late summer and emerge as adults in mid-summer.
11. Eastern Tiger Swallowtail Caterpillar
As you can tell from its name, it’s one of many types of caterpillars in Maine. This caterpillar, however, is not poisonous.
The Eastern Tiger Swallowtail Caterpillar, also known as Papilio glaucus to scientists, has a distinct black body with yellow and blue bands on its sides.
This type of caterpillar in Maine its head is yellow with black dots that look like eyespots. On top is a tuft of red spikes.
The Eastern Tiger Swallowtail butterfly is orange with black spots along its wings and green stripes running through them.
Interestingly enough, some other types of caterpillars in Maine mimics these tiger swallowtails, so they don’t get eaten! Like most caterpillars, Eastern Tiger Swallowtail caterpillars eat leaves and other vegetation.
These types of caterpillars in Maine’s favorite food sources include grape vines, willow, elm, oak, and ash trees.
12. Spicebush Swallowtail Caterpillar
The Spicebush Swallowtail is a large butterfly with orange, pink, and black wings. The Spicebush Swallowtail caterpillar has a unique look. The body is green with wavy yellow stripes on each side.
It has nine pairs of yellowfins on its back, giving it an almost clear look. When disturbed, they thrash around quickly to scare away predators.
They feed off spicebush leaves and rest on them after eating so as not to be eaten. If you find one of these types of caterpillars in Maine, don’t touch it!
They have been known to release a chemical that can cause severe skin irritation if touched. So if you have small children or pets, ensure they know not to touch these caterpillars.
13. Cecropia Moth Caterpillar
The Cecropia Moth is a large moth found throughout North America. The adult moth ranges in color from cream to green with brown spots on its wings.
The caterpillar is green with black dots running down its body. It feeds primarily on maple leaves but will also eat other tree leaves. It grows up to five inches long!
14. Monkey Slug
The monkey slug is one of many species that thrive in various habitats. The body length for an adult ranges from 8 to 10 centimeters (3-4 inches), and it has two small horns on its head.
These types of caterpillars in Maine species can be found throughout North America, including in places like Mexico. Its diet includes fungi, decaying plants, algae, and sometimes eggs laid by birds.
15. Io Caterpillar
Io moth caterpillars are a favorite amongst children. These types of caterpillars in Maine bright colors have made them favorites amongst kids for decades, but they’re not just interesting because they look nice – they are venomous!
The Io caterpillar is quite dangerous due to its high toxicity. Several states have declared it an endangered species due to its limited numbers. If you find it, leave it alone! It will sting if provoked or handled.
Some types of caterpillars in Maine are brightly colored, whereas others look like twigs or fallen leaves.
With so many species—and multiple variations within each species—it can be a challenge to know exactly what you’re dealing with. In general, caterpillars are harmless and typically don’t bite.
Some even feed on toxic plants; they use their bodies to break down (or sequester) poison into a digestible form. Others protect themselves by producing unpleasant chemicals or emitting foul smells.
Risks to your pets or home while identifying those you may want to encourage as biological controls for garden pests such as aphids, mealybugs, Japanese beetles, snails, and slugs!
Here is an illustrated guide to some common caterpillar varieties you might find in your backyard or when hiking through Maine’s forests.