In Canada, many different types of caterpillars are indigenous to our areas and can often be found in either the winter or summer seasons.
Some caterpillars are easy to identify, while others may require an entomologist’s or knowledgeable hobbyist’s expertise to identify correctly.
Here are some types of caterpillars in Canada that you might encounter if you live here, along with how to identify them.
1. Monarch Caterpillar
The monarch caterpillar, Danaus plexippus, is a butterfly species belonging to the Danaidae family.
It is native throughout North America, southwards from northern Canada and Alaska.
This species is frequently seen around gardens where milkweeds grow.
The adult monarch has black wings with orange veins, spots, and edges on its hindwings, while those on its forewings are pale yellow with darker borders.
These types of caterpillars in Canada are generally green with white longitudinal stripes.
They feed mainly on milkweed plants, although they have been known to eat other plants, such as birches, elms, and willows.
2. Cabbageworm
The cabbageworm is about 1 1/4 inches long. It has a yellowish-green body with dark spots on its wings.
The cabbage loopers feed on broccoli, Brussels sprouts, cabbage, cauliflower, kale, and collards.
Larvae may cause severe damage if populations are large. If several larvae feed aves, they will consume them entirely, leaving behind only bare stems.
Cabbage loopers also like to feed on radishes, turnips, and mustard greens.
They usually begin their life cycle in mid-May. A female moth lays eggs near broccoli or other cruciferous plants that are still small enough for her young to crawl into.
As soon as it hatches from its egg case, it begins eating leaf material at night when no one is around to see it!
3. Woolly Bear
The Woolly Bear (Pyrrharctia isabella) gets its name from its body’s fuzzy brown coat that looks like a teddy bear’s.
These caterpillars are found across Canada during all seasons except summer, when they burrow into soil or leaf litter and transform into a harmless wasp-like adult.
These types of caterpillars in Canada have several built-in defenses to avoid being eaten by birds and other predators: because they look like furry moths, most animals won’t eat them; their small size makes it difficult for predators to see them; some will bite if handled by humans or by non-prey animals such as birds.
4. Viceroy Caterpillar
Viceroy, which flits all over your parsley or cilantro, is easy to identify.
They have three pairs of prolegs on their yellowish bodies.
The larvae can grow up to one inch long. The first pair of prolegs has one spur per leg, while every other has two motivations.
The last pair of prolegs are red and usually tucked under a bud when not being used. The larva also has an orange head with black eyespots.
It is important to note that some viceroy caterpillar species may be green instead of black and white.
5. Large Maple Spanworm
The large maple spanworm is found throughout eastern North America.
It ranges from Nova Scotia west to southern Ontario, then south throughout Pennsylvania, Ohio, Indiana, Illinois, and Missouri.
It also occurs in eastern South Dakota and Nebraska.
The adult moth emerges in late May or June and lays eggs on maple trees shortly after that.
The eggs hatch just after midsummer when they become visible as small white worms less than an inch long that live gregariously within a mass of silk.
These caterpillars in Canada will feed for about three weeks when they undergo a developmental process called an instar.
Several days may elapse, during which one may see three or more iterations before winter sets upon us coldly again.
6. Variegated Fritillary Caterpillar
The Variegated Fritillary (Euptoieta Claudia) is one of several butterfly species that eat these flowers.
It lays eggs on milkweed (Asclepias spp.), which are often mistaken for its caterpillar host plants, including.
Dogbanes (Apocynum cannabinum). These caterpillars in Canada crawl onto a Dogbane leaf, where they can be found feeding on both sides.
You can find them almost any time as they resist cold weather.
If you see holes or notched leaves on your Dogbane, it might be fed upon by a Variegated Fritillary caterpillar.
7. Hornworm
One of my favorite types of caterpillars in Canada is hornworms,e also called armyworms.
They typically feed on corn and tomato plants, but they can also be pests for other gardeners, depending on where you live.
If a hornworm is walking or crawling near your home, it most likely won’t do any damage since they aren’t looking for food at that point—instead, it’s a wandering individual looking for a mate.
When identifying them, look for yellow stripes along their sides with black dots running down them.
Hornworms have large heads with tiny bodies, giving them an odd shape compared to many other caterpillars in Canada.
8. White-Marked Tussock Caterpillar
The White-Marked Tussock caterpillar is also known as a Saddleback.
This species gets its name from its distinctive black spikes, found down its back, often in clusters or rows.
These spikes are present along both sides of the body on these caterpillars, not just one side like some species.
When disturbed, these caterpillars in Canada will move away with an undulating motion resembling a hunchbacked centipede, hence another common name: Centipede.
The White-Marked Tussock Caterpillar is most commonly found feeding on raspberry bushes in late spring and early summer.
9. Milkweed Tussock Caterpillar
This tiny black-and-white caterpillar can be found on large milkweed plants, mainly Eastern and Swamp Milkweed.
It has a white tussock (tuft) on its head that gives it its name.
Their black-and-white pattern helps them hide among their host plant’s leaves during times of danger, like when birds try to peck at them, or other predators like ants and wasps attack.
They have long orange pincers near their heads, which they can use for defense.
Still, if those fail, they are capable of secreting an unpleasant-smelling liquid that serves as an extra line of protection against potential predators.
10. Banded Tussock Caterpillar
While some types of caterpillars in Canada may not be easy to spot, as they’re often camouflaged or blend into their surroundings, Banded Tussock Caterpillars are different.
Not only are they orange-yellow with light green spots, but they are also covered with thin black stripes that run down their bodies.
So, if you see a bright yellowish-green caterpillar with thin black stripes, you’ve likely spotted a Banded Tussock.
Read on to learn more about other common caterpillars and how to identify them!
11. Giant Leopard Moth Caterpillar
This is one of North America’s most unique caterpillar species. They are so large that some people describe them as cats or leopard-sized leopard moths.
The basic body coloration is black, with white hairs all over their bodies.
However, depending on which part of their habitat they are from, Giant Leopard Moths may look slightly different.
For example, if they came from an area with abundant oak trees (like around Toronto), these caterpillars in Canada may have brown or reddish markings to blend in with their environment.
12. Parsley Caterpillar
The parsley caterpillar is about 3/4 long. It is yellowish, with two distinctive stripes on each side. The insect will often curl into a C shape when disturbed.
The adult form resembles a yellow wasp. This species feeds on parsley, dill, and fennel; it may cause significant damage to commercial crops of these plants if left untreated or uncontrolled.
Once it becomes an adult, it will lay eggs on these plants during the late fall and winter months.
They can be found anywhere in North America, Europe, and Asia.
13. Cecropia Moth Caterpillar
This species’ caterpillar is black with a yellow stripe along its back with red marks.
It can be found in Ontario, Quebec, and parts of New Brunswick.
What makes them so appealing is they are non-toxic to animals that try to eat them.
However, humans should still steer clear because they can cause allergic reactions. These caterpillars in Canada do not spin cocoons but stay inside their old skin as they develop into moths.
There are four stages for a cecropia moth’s life cycle: egg, larvae, pupae, and adult.
The process takes six weeks and two months, depending on weather conditions.
The adult moth lives between three weeks and one month when it does not eat anything.
The female lays her eggs on tree branches or leaves, where they will hatch within ten days.
14. Monkey Slug
These common caterpillars in Canada are easy to spot thanks to their bright orange head with white spots.
They can grow as large as 2 inches. Monkey slugs spend most of their time on trees where they munch on leaves, but when it’s time for a change, they find a peaceful place to turn into their next stage, a green and black butterfly.
The larval stage is native to North America and can be found from southern California to British Columbia.
You’ll also find monkey slugs on oak trees (the leaves) across Canada.
However, these unique caterpillars in Canada have also been spotted on maple and ash trees.
15. Spotted Apatelodes Caterpillar
This brightly-colored caterpillar has yellow spots on its body and head.
It’s only a few millimeters long when it emerges from its cocoon.
In one year, it will grow into a moth about 12 cm long with brown wings and white spots.
The Spotted Apatelodes Moth can be found in British Columbia, Alberta, Saskatchewan, Manitoba, Ontario, and Quebec.
It feeds on poplar trees as a caterpillar; then, as an adult, it lays eggs near those trees.
16. Io Caterpillar
The Io caterpillar is a type of Sphinx moth whose larvae are known for their voracious appetite.
They are considered pests because they eat holes in the grass, trees, bushes, and other green foliage.
The Io caterpillar prefers eating plants from tomato families, such as eggplants, peppers, potatoes, and tomatillos.
However, it will also eat other crops like carrots, peas, parsley, and apples when given the opportunity.
Cover crops with mulch to keep these caterpillars in Canada out of your garden, or lay down collars around your prized fruits or vegetable plants before adding mulch.
This will help deter them from getting close enough to attack your plants!
