Three different kinds of caterpillars are invading Michigan this fall that you should keep your eyes open for. Heres what you need to know about these venomous caterpillars.
Unsurprisingly, we have a couple of venomous spiders to watch out for in Michigan. But…Caterpillars? The word poisonous is thrown around a lot when it comes to spiders, snakes, and even caterpillars. Technically, theyre venomous, not poisonous. And when we say venomous, we dont mean caterpillars can kill humans. Its usually more of an extreme irritation. However, they are very toxic to your pets. Do not let your dogs or cats near the little buggers.
Michigan is home to a diverse range of caterpillars due to its varied landscapes and vegetation. From forests to prairies, wetlands to urban areas, there are plenty of plants and trees that caterpillars feed on.
In this article, we’ll look at 37 of the most common caterpillars found in the state and some key facts about each species.
1. Monarch Caterpillar
The Monarch caterpillar (Danaus plexippus) is perhaps the most iconic and easily recognized species. Its striking black white and yellow striped appearance warns predators of its toxicity. Monarch caterpillars feed solely on milkweed plants.
2. Spongy Moth Caterpillar
Formerly known as the gypsy moth caterpillar, this species (Lymantria dispar) can feed on over 300 types of trees and shrubs. Outbreaks of these ravenous caterpillars can completely defoliate forests. The species is a major pest in Michigan.
3. Red-spotted Purple Caterpillar
Distinguished by its red-brown body and white spots along the back, the red-spotted purple caterpillar (Limenitis arthemis astyanax) feeds on leaves of cherry, poplar, willow, and other trees. It blends in well among the foliage.
4. Black Swallowtail Caterpillar
The striking black swallowtail caterpillar (Papilio polyxenes) has green stripes with black dots. Its host plants are parsley and other plants in the carrot family. It emits a foul odor when threatened.
5. Isabella Tiger Moth Caterpillar
Covered in stiff hairs the woolly bear caterpillar (Pyrrharctia isabella) can withstand freezing temperatures. It feeds on herbaceous plants and overwinters under leaf litter. The adult is the Isabella tiger moth.
6. Hickory Tussock Moth Caterpillar
Recognizable by its tufts of hair, the hickory tussock moth caterpillar (Lophocampa caryae) favors hickory and walnut leaves but also other hardwoods. Contact can cause irritation, rashes or swelling in humans.
7. Cabbage White Caterpillar
A major pest of cabbage, broccoli, cauliflower and other brassicas is the imported cabbageworm (Pieris rapae). Its velvety green body lets it blend in and ravage crops from beneath leaves.
8. Milkweed Tussock Moth Caterpillar
With its vivid orange head and fuzzy black-and-white tufts, the milkweed tussock moth caterpillar (Euchaetes egle) feeds only on milkweed plants. Its hairs can irritate human skin.
9. Mourning Cloak Caterpillar
Sporting black hair and red spots, the mourning cloak caterpillar (Nymphalis antiopa) eats leaves of willow, elm, poplar and hackberry trees. It overwinters as a chrysalis and emerges in early spring.
10. Eastern Tiger Swallowtail Caterpillar
The eastern tiger swallowtail caterpillar (Papilio glaucus) is green with two false eyespots resembling bird droppings, fooling predators. It feeds on leaves of wild cherry, tulip, ash, and other trees.
11. Silver-spotted Skipper Caterpillar
Well-camouflaged in green, the silver-spotted skipper caterpillar (Epargyreus clarus) feeds on locust, wisteria and other legumes. The adult butterfly sips nectar from flowers.
12. Painted Lady Caterpillar
Recognizable by its spiny black body with yellow stripes, the painted lady caterpillar (Vanessa cardui) feeds on over 100 host plants like thistles, mallows and legumes. The striking orange adult butterfly migrates long distances.
13. Spicebush Swallowtail Caterpillar
The spicebush swallowtail caterpillar (Papilio troilus) is green with two large, fake eye spots resembling a snake’s head. It feeds only on spicebush and sassafras leaves. The adult has iridescent blue hindwings.
14. Polyphemus Moth Caterpillar
Growing over 4 inches long, the pale green polyphemus moth caterpillar (Antheraea polyphemus) has red spots and white lines. It feeds on oak, birch, maple and other trees, eventually spinning a large, silken cocoon.
15. Io Moth Caterpillar
Covered in spines, the io moth caterpillar (Automeris io) has a highly irritating sting causing pain and swelling in humans. It feeds on leaves of bush honeysuckle, cherry and willow. The adult moth has conspicuous yellow, purple and reddish eyespots.
16. Cecropia Moth Caterpillar
One of the largest caterpillars in North America is the cecropia moth larva (Hyalophora cecropia), growing over 4 inches long. Its knobby green body has yellow and red spots. It feeds on cherry, birch and maple trees.
17. Hickory Horned Devil Caterpillar
Growing up to 6 inches long, the intimidating hickory horned devil (Citheronia regalis) has black spikes and red stripes. Despite its fearsome appearance, it does not sting or bite humans. It feeds on hickory and walnut trees.
18. American Dagger Moth Caterpillar
The American dagger moth caterpillar (Acronicta americana) is covered in tufts of long, fine yellow or white hairs that can cause skin reactions in humans. It feeds on oak, elm, maple and birch trees.
19. Gypsy Moth Caterpillar
Causing widespread defoliation of hardwood forests, the European gypsy moth caterpillar (Lymantria dispar dispar) feeds on over 300 species of trees and shrubs. Its long hairs can cause rashes and irritation in humans.
20. Tent Caterpillar
Building conspicuous silken tents in trees, the eastern tent caterpillar (Malacosoma americanum) feeds communally on cherry, apple, ash, oak and other trees. It has a white line along its dark bluish back.
21. Fall Webworm Caterpillar
Known for making messy web nests on branches, the fall webworm (Hyphantria cunea) is covered in long hairs. It feeds on over 600 species of trees but favors persimmon, pecan and ash.
22. Buck Moth Caterpillar
Clad with thick black spines, the buck moth caterpillar (Hemileuca maia) feeds on oak, willow, aspen and other trees. Contact with its spines can cause irritation, rashes, nausea and headaches in humans.
23. White-marked Tussock Moth Caterpillar
Recognizable by four white bumps on its back, the white-marked tussock moth caterpillar (Orgyia leucostigma) has black and yellow hairs that irritate human skin. It feeds on many trees like oak, birch, elm and apple.
24. Virginia Ctenucha Moth Caterpillar
Growing over 2 inches long, the Virginia ctenucha moth caterpillar (Ctenucha virginica) is black with yellow stripes and long, branched spines. It feeds on grasses and low-growing plants. The fluffy orange and brown adult is a day-flying moth.
25. Cross-Striped Cabbageworm
A common pest of cabbage, kale, broccoli and other brassicas is the cross-striped cabbageworm (Evergestis rimosalis). Its velvety green body has faint white stripes. It can completely defoliate plants.
26. Hemlock Looper Moth Caterpillar
The hemlock looper moth caterpillar (Lambdina fiscellaria) has looping movements like inchworms. Its green body has white lines and feeds communally on hemlock, spruce, fir, pine and other conifers.
27. Spotted Apatelodes Caterpillar
Growing to 2 inches long, the spotted apatelodes caterpillar (Apatelodes torrefacta) varies from bright yellow to white with black spikes. It feeds on ash, maple, oak and other hardwood trees.
28. Hag Moth Caterpillar
Also called the monkey slug, the hag moth caterpillar (Phobetron pithecium) is flattened and brown with seven pairs of stubby leg-like projections. It feeds on oak, willow, apple and cherry trees.
29. Pandorus Sphinx Caterpillar
Growing up to 4 inches long, the Pandorus sphinx moth caterpillar (Eumorpha pandorus) is light green with white, diagonal slashes along its sides. It feeds on grapevine, Virginia creeper and other vines.
30. Variable Oakleaf Caterpillar Moth
Feeding on the leaves of oak, cherry, hazelnut and apple trees is the green variable oakleaf caterpillar (Lochmaeus manteo). It has a brown head with white and yellow lines along its back.
31. Saddleback Caterpillar
Covered in brown and green, the saddleback caterpillar (Acharia stimulea) has a distinct brown patch on its back resembling a saddle. Its bristly spines contain toxins that can severely sting and irritate human skin. It feeds on garden plants and trees.
32. Imperial Moth Caterpillar
Growing up to 4 inches long, the imperial moth caterpillar (Eacles imperialis) is bright green with yellow lines along its sides. It feeds communally on pine, maple, sweetgum, and other trees, spinning a cocoon to overwinter.
33. Rosy Maple Moth Caterpillar
The rosy maple moth caterpillar (Dryocampa rubicunda) is yellow and green with red spots. It feeds on maples and other trees, eventually spinning a cocoon attached to a leaf or twig before transforming into the fuzzy, pink adult moth.
34. Blinded Sphinx Caterpillar
Growing to over 3 inches long, the blinded sphinx caterpillar (Paonias excaecata) is green with purple, diagonal slashes on its sides. It feeds on grapes, Virginia creeper and other vines before spinning an underground cocoon to pupate.
35. Waved Sphinx Caterpillar
The waved sphinx caterpillar (Ceratomia undulosa) feeds on ash, hawthorn, cherry, plum, and other Rosaceae trees. It has a green body with brown, white and purple lines along its back and sides.
36. Tuliptree Silkmoth Caterpillar
With its vibrant yellow head, the tuliptree silkmoth caterpillar (Callosamia angulifera) feeds solely on the leaves of tuliptree. It spins an oval, paper-like cocoon which remains attached to the tree over the winter.
37. Virginian Tiger Moth Caterpillar
The bright yellow virginian tiger moth caterpillar (Spilosoma virginica) has black tufts of hair along its back. Despite its fuzzy appearance, it has stinging spines and feeds on low-growing plants like dandelion and clover.
In conclusion, Michigan’s diverse range of plants and trees supports a wide variety of caterpillar species. While some are strikingly colored or oddly shaped, others blend in among the foliage as camouflage. Knowing how to identify these fascinating insects can make any nature walk more interesting!
The Deadly 7: Michigan’s Most Venomous and Poisonous ThreatsIn Michigan, we may not have hurricanes or gators, but we have bugs that carry fatal diseases, blister-causing plant life, and 3 deadly native Michigan species.
Gallery Credit: Scott Clow
3 Venomous Caterpillars In Michigan
American Dagger Caterpillar
The American Dagger Caterpillar is mostly yellow and white with a few black hairs. Back in 2019 Click on Detroit reported on the dangers these little critters pose to humans,
These caterpillars grow to about 2 inches long and can be found on the ground and in many different types of trees in Michigan between July and October.
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Hickory Tussock Moth Caterpillar
This caterpillar is most common along East Coast states from Maine down to the Carolinas. The Hickory Tussock Moth caterpillars peak from July to September each year according to MSU. These little furry guys are relatively harmless. You might get a rash if you get stung by them. However, some people are allergic to them.
Spongy Moth Caterpillar
These invasive caterpillars can cause a rash and a stinging sensation if they have contact with your skin according to CottageLife.com.
READ MORE: Michigan Homes Could Experience a Rodent Invasion This Winter
Michigan Caterpillars
FAQ
What do woolly bear caterpillars turn into?
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Caterpillar Stage:Woolly bear caterpillars, the larval stage of the Isabella tiger moth, are known for their fuzzy, banded appearance (often black on the ends and rusty brown in the middle).
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They overwinter as caterpillars, seeking shelter under leaves, logs, or other debris to protect themselves from the cold.
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Cocoon Formation:In the spring, they emerge from hibernation, continue to feed, and then form a cocoon.
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Moth Emergence:After a period of transformation within the cocoon, the Isabella tiger moth emerges, a moth with a muted orange, salmon, or yellow coloration and black spots on its body and wings.
How can you tell if a caterpillar is poisonous?
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Certain caterpillars, like the Io Moth caterpillar, have bright colors as a warning to predators, indicating they may be poisonous.
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Caterpillars with spines, especially those that break off and embed in the skin, can be dangerous. The puss caterpillar, for example, has spines under its soft hairs.
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Caterpillars with bristly or hairy exteriors, like the American dagger moth, may have venomous bristles that can cause irritation or pain.
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Some caterpillars have hairs or spines connected to poisonous glands, which can cause pain, itching, burning, swelling, and blistering upon contact.
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- Puss Caterpillar: Has a hairy, light-brown coat with small spines underneath that break off and cause irritation.
- American Dagger Moth: Bright yellow-green with black bristles that resemble eyebrows, a warning sign for predators.
- Io Moth Caterpillar: Pale green bodies with yellow and red stripes.
- Saddleback Caterpillar: Has spines that break off and can cause a rash.
- Puss Caterpillar: Has a hairy, light-brown coat with small spines underneath that break off and cause irritation.
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Contact with poisonous caterpillar hairs or spines can cause intense burning, nettling, severe pain, reddening, inflammation, pustules, lesions, numbness, swelling, and nausea.
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If you encounter a caterpillar that looks potentially dangerous, avoid touching it and relocate it if necessary. If you get stung or have contact with a caterpillar, remove the hairs or spines, wash the area thoroughly with soap and water, and apply an ice pack to reduce swelling and pain. You may also consider using a paste of baking soda and water to reduce itching. Seek medical attention if symptoms worsen or if you experience a severe allergic reaction.
How do you get rid of moth caterpillars?
- Inspect plants regularly: Check for caterpillars and their egg masses.
- Remove caterpillars: Carefully pluck them off plants and drop them into a bucket of soapy water to kill them.
- Soapy water solution: Mix a small amount of mild dish soap with water.
- Drown caterpillars: Ensure the caterpillars are submerged in the soapy water to kill them.
- Caution: Some caterpillars have irritating hairs, so wear gloves.
What are the yellow caterpillars with black spikes?
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Appearance:American dagger moth caterpillars are easily recognizable by their bright yellow to white fuzzy hairs and the presence of five long black “seta” or hair-like structures. These tufts are located along the caterpillar’s back.
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Habitat:They are commonly found in forests and backyards, particularly on hardwood trees like maple, oak, ash, and willow.
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Potential for Irritation:While not known to be poisonous, the hairs can cause skin irritation in some people, leading to rashes or allergic reactions.
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Other Similar Caterpillars:Other caterpillars with similar appearances include the Io moth caterpillar and the Tussock moth caterpillar. However, the Io moth is known to be more venomous, and the Tussock moth caterpillar has stinging hairs that can cause irritation.
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What to do if you handle one:If you do handle an American dagger moth caterpillar and experience skin irritation, wash the area with soap and water, remove any remaining spines with tape, and apply rubbing alcohol followed by ice.