Not all caterpillars are as harmless as the ones that turn into beautiful butterflies or moths.
Some can be harmful to your garden, and some can even cause damage to your home.
It is best to know how to identify them to keep them out of your yard.
Here are 20 types of caterpillars in New Jersey, along with their characteristics and ways they can harm your garden.
1. Monarch Caterpillar
Monarch caterpillars are typically green with a yellow and black stripe. They can grow about three inches long and are mostly seen in summer. These caterpillars in New Jersey feed on milkweed found throughout.
Monarch caterpillars have no sting, but they release a milky substance called Hemolymph, which can give people an allergic reaction.
Humans should not handle these caterpillars because their skin breaks easily and removes irritating fluid.
2. Cabbageworm
The cabbageworm is a moth that lays its eggs on plants and will hatch into these white, green-striped caterpillars.
These caterpillars in New Jersey are mainly found in broccoli and cauliflower, but they also eat other vegetables.
It can be hard to tell the difference between these caterpillars and the diamondback moth larvae, which appear similarly.
However, the most significant way to identify these cabbage worms is by size. They grow much larger than those found on cabbage plants.
3. Woolly Bear
Woolly Bears are types of caterpillars in New Jersey. They are also mostly found on the Eastern Seaboard and can be seen from Maine down through Florida.
The Woolly Bear gets its name from the white, fuzzy hairs that cover its body and resemble a bear’s fur coat.
Adult females have brown heads, and males have yellow chairs. The woolly bears feed on many plants, including lilacs, apples, cabbage, lettuce, and tomatoes.
They will damage your plants by chewing off chunks of leaves or by eating flowers or fruits before they ripen.
4. Viceroy Caterpillar
The Viceroy Caterpillar is a non-native species found in North America and Europe. These caterpillars in New Jersey are mainly found feeding on the Red Maple tree leaves. They also feed on Purple Loosestrife, Rosebay Willowherb, and other plants.
Their black head can identify the Viceroy caterpillar with two white stripes running down its back. They are about 1 1⁄2 inches long and have gray or brownish lines running along their body.
These pests reproduce quickly, making them difficult to control once established in an area. The best way to keep them out of your garden is to plant other low-maintenance plants that don’t produce much food.
5. Large Maple Spanworm
The Large Maple Spanworm is one of the most common types of caterpillars in New Jersey that you’ll find around.
This type is usually found on elm and maple trees during spring. They can strip the leaves off a tree and then crawl onto other plants before laying eggs.
The eggs hatch into larvae, which eat the plant. If you see these caterpillars, taking action as soon as possible is essential. They keep moving from plant to plant until they’ve eaten all they can find.
6. Variegated Fritillary Caterpillar
The Variegated Fritillary Caterpillar is a giant, green caterpillar with pink and yellow stripes along the side. The Variegated Fritillary feeds on foliage from many trees, including oak, hickory, and walnut.
Unlike other types of caterpillars in New Jersey living in clusters or groups, the Variegated Fritillary lives independently.
However, females will lay eggs near leaves so that they can be eaten by hungry larvae when they hatch.
If you see one Variegated Fritillary Caterpillar, you’ll likely soon see many more. The caterpillar pupates close to where it hatched, emerging as an orange-brown moth in July.
7. Curve-Lined Owlet Moth Caterpillar
This caterpillar is a tiny brown type of caterpillar in New Jersey that feeds on carrots and parsley. They are typically found on plants during the summer months. The larvae develop into moths that they do not provide as adults.
The eggs overwinter and hatch into larvae when the temperatures start warming up again. As they continue feeding, they will pupate (turn into pupae) before turning into adult moths.
These insects can damage certain crops, such as carrots, cabbages, parsley, and other carrot family members.
8. Tobacco Hornworm
The tobacco hornworm is also known as the tomato hornworm. It is a green caterpillar in New Jersey with yellow and black stripes. The head of this caterpillar is pointed and curved like a tobacco pipe.
Tobacco hornworms primarily feed on tomatoes and related plants like potatoes and peppers. They can be identified by their size, ranging from two to four inches long.
Their large size makes them easy to spot among other garden plants. Their habit of feeding can identify this caterpillar.
They eat leaves from the top or sides rather than on the underside, as other caterpillars provide. This can make them more visible to those looking for pests that could harm their vegetable gardens.
9. White-Marked Tussock Caterpillar
The white-marked tussock caterpillars are moths, not types of caterpillars in New Jersey. This pest is found in the Eastern United States and Canada.
The adult moth lays eggs on the leaves or needles of conifers, including spruce, pine, fir, and cedar. Three types of larvae hatch from these eggs:
- A brownish larva with long hair.
- A green or yellow larva with short hair.
- A brownish larva that has no hair at all.
The first two types feed on conifer foliage while green but eventually move onto other plants once they turn brown. The third type remains on conifer foliage as it grows and moves onto other plants as it matures.
10. Parsley Caterpillar
The parsley caterpillar is common throughout the Northeast. They are types of caterpillars in New Jersey that can cause severe damage to garden parsley plants. It’s common for the caterpillars and their frass (fecal matter) to completely defoliate a parsley plant.
While they’re mostly found on parsley, they have been found on other members of the Apiaceae family, such as celery. This caterpillar feeds mainly at night when leaves are wet from dew or raindrops.
Do not water your plants too close to bedtime so the leaves dry off before nighttime feeding begins.
Spraying with Bt products such as Dipel, Thuricide, and Bio-Thuricide can be effective against the parsley caterpillar.
11. Giant Leopard Moth Caterpillar
The Giant Leopard Moth caterpillar is one of the most beautiful types of caterpillars in New Jersey. However, it also has a dangerous side.
They are green with black stripes and can grow up to 2 inches long. These caterpillars are active at night when they feed on leaves and can completely defoliate plants.
The Giant Leopard Moth caterpillar’s diet is so greedy that they must eat their body weight daily. The larvae like to feed on trees, shrubs, and herbaceous plants and will die off quickly if unsatisfied.
If they damage your garden, try using Bacillus thuringiensis (Bt), which you can buy online or at your local garden center.
12. Eastern Tiger Swallowtail Caterpillar
These caterpillars are black and yellow striped types of caterpillars in New Jersey that feed on many plants.
It has been seen feeding on apple, cherry, dogwood, elm, grape, hickory, lilac, locust tree, and walnut trees. This species can be found from Maine to Florida and westward through Arkansas into Texas.
The Eastern Tiger Swallowtail is not poisonous, but it can cause some damage to the leaves by feeding off them.
If you see this type of caterpillar in your garden, try finding its eggplant to eliminate the larvae and eggs.
13. Milkweed Tussock Caterpillar
The Milkweed Tussock Caterpillar is a pest that damages plants by eating leaves and flowers. It can also suck the sap from young stems, which can cause them to wilt and die.
This caterpillar in New Jersey is yellowish with a long black head. It has three pairs of blue and black tufts on its back, which are visible as it moves.
14. Banded Tussock Caterpillar
The banded tussock caterpillar is a type of moth larva. It can be identified by the dark and light stripes that run along its body, resembling a tiger’s stripes. The banded tussock caterpillar is a pest found in gardens all over North America.
These types of caterpillars in New Jersey feed on leaves, damaging your garden and making it difficult for plants to grow.
This particular type of caterpillar will also excrete large amounts of silk on the leaves they feed. The silk causes the plant to stick together, making it impossible for sunlight to reach the plant below.
15. Spotted Apatelodes Caterpillar
The spotted Apatelodes caterpillar is a black and yellow type in New Jersey with rows of yellow spots. It can grow up to one inch long. The spotted apatelodes feed on plants’ leaves but are not considered harmful.
They can be found on various plants, including willow and aspen trees, grape vines, fruit trees, roses, and clover plants. They are most active from late May through July and sometimes into early August.
Larvae pupate for about two weeks before emerging as adults that fly away. Females lay their eggs singly or in small groups on the underside of leaves or needles during the spring.
16. Cecropia Moth Caterpillar
The cecropia moth caterpillar is also called the oak worm. These caterpillars in New Jersey feed on leaves and shoots from hardwood trees.
Cecropia moth caterpillars are green with dark stripes and have hairy tusks or projections coming out from their heads. These caterpillars usually feed at night and hide during the day.
The cecropia moth will pupate when fully grown, creating a cocoon on the ground under its host tree. The adult cecropia moth emerges from this cocoon in late summer to early fall. It usually appears as a brown, tan, or green insect with feathered antennae.
17. Spicebush Swallowtail Caterpillar
The Spicebush Swallowtail is one of the most recognizable caterpillars because it has three pairs of red tufts on its back. These tufts are made up of tiny hairs that can cause a rash if they come into contact with skin.
These caterpillars in New Jersey can be found from June to September, eating mainly leaves from the spicebush plant. This plant is toxic and should not be consumed by humans or animals!
The caterpillar eats other plants like willow and tulip trees as well. It will curl into a ball when disturbed, making it difficult for predators to eat them.
18. Monkey Slug
The monkey slug is a type of caterpillar in New Jersey that preys on snails and slugs, which can harm your garden. It also eats aphids and protects plants from being attacked by these insects.
The best way to identify one is by looking for the spiky hairs on its back. It’s easy to confuse with a small bird feather if you don’t know what you’re looking for! They are bright orange with black spots.
They like to eat pests, which may help keep your garden healthy and bug-free. You’ll find them in North America.
19. Io Caterpillar
The Io caterpillar is one of North America’s most destructive caterpillars and can cause much damage to your plants.
These caterpillars are green and measure about a quarter inch long. They tend to be found on many plants, including conifers, evergreens, fruit trees, and deciduous trees.
They feed on leaves by eating holes through them and spin webs containing frass or fecal matter. Fecal matter may contaminate your garden tools if you use them for other purposes.
One way to deter these types of caterpillars in New Jersey is to plant nectar-bearing flowers near your plants. Nectar-bearing plants will attract wasps and tachinid flies, which prey on these caterpillars.
20. Flannel Moth Caterpillar
The Flannel Moth caterpillars are types of caterpillars in New Jersey that start life as tiny eggs. The egg then hatches into a larva that can grow up to an inch long. It is dark green with yellow stripes and has hairs on its body.
The larvae feed on leaves and other parts of plants, sometimes killing the plant they are feeding on. They eat so much that they often wrap themselves around the stem of their food source, where they pupate into a moth.
There are two generations of these flannel moth caterpillars each year. In autumn, females lay eggs for the next generation.
Their color changes from dark green with yellow stripes to light brown before pupating and turning into moths.
