While most types of caterpillars are harmless, there are some species of stinging caterpillars. Caterpillars that are toxic and sting are generally hairy or have spikes on their bodies. Handling one of these dangerous caterpillars could leave you with a nasty sting similar to a bee’s sting. Before picking up any kind of caterpillar, it is important to identify the species to know if it is harmless or not.
All caterpillars are larvae that belong to the order of moths and butterflies called Lepidoptera in the class of Insecta. After hatching from eggs, caterpillars are ravenous eaters and mainly consume plant and tree leaves. Although not all species of caterpillars are venomous, they can do tremendous damage to plant foliage.
To identify caterpillars, it is important to take note of their size, color, type of bristles or spines, and habitat. Some other insect larvae can look similar to moth or butterfly larvae. You can tell these apart because caterpillars have a maximum of 5 pairs of prolegs. Other types of crawling bugs may have more. Most stinging caterpillars are identified by spine or fine hairs covering their body.
It is important to remember that caterpillars go through many stages of growth before they become moths or butterflies. This means that immature larvae can look different from caterpillars just before the pupation stage. The descriptions of stinging toxic caterpillars in this list are of mature larvae.
How Can You Tell if a Caterpillar is Venomous?
Just because a caterpillar looks spiky, hairy, fuzzy, or furry doesn’t automatically mean it’s dangerous. How do some hairy caterpillars hurt you? Do venomous caterpillars sting?
The University of Florida says that some caterpillar species have stinging hairs called urticating hairs. These are barbed bristles or spines that can lodge in your skin and break off. This can cause irritation similar to handling fiberglass. So, stinging caterpillars don’t sting in the same way that wasps or bees sting. (1)
Also, the spikes or spines of some stinging caterpillar species contain toxins. These are slowly released when caterpillar hairs sting a person. The result in some people can be allergic reactions such as itching, nausea, blistering, or even abdominal upset. (2)
Although people refer to a ‘caterpillar bite,’ they are actually talking about the stinging sensation from urticating caterpillar hairs.
There is also a species of venomous caterpillar in South America that is so toxic that its ‘sting’ has been known to cause death. (3)
So, before picking up an exotic looking caterpillar, you should identify the species to see if it is a stinging kind.
Types of Stinging Caterpillars with Names and Pictures
Let’s look in more detail at how to identify species of caterpillars that are known to sting and cause skin irritation.
Stinging Rose Caterpillar
The Stinging Rose caterpillar has clusters of toxic spikes along its body
One of the most colorful stinging larvae is the Stinging Rose caterpillar (Parasa indetermina). Brushing against this type of caterpillar can leave you with an itchy, irritating rash.
This caterpillar is identified by clusters of bright yellow spines sticking out from its body. There are prominent spiky horns along its side, front, and rear. Some types of these larvae have red-colored bodies with rows of purple or black stripes along their back. Others are a type of yellow caterpillar that have white and blue stripes.
Stinging Rose caterpillars are found in Florida, Texas, Oklahoma and other states on the Eastern coast of the US. They love to feed on apple, hickory, oaks, and maples. It is their preference of munching rose bushes that gives them their common name.
Ranging in colors from yellow to green to red, the Stinging Rose caterpillar has clusters of spiny horns covering its soft body.
Io Moth Caterpillar
The Io moth caterpillar has green spikes that feel very unpleasant if their venom penetrates your skin
The Io moth caterpillar (Automeris io) is covered in tufts of green spikes that look like pine needles. The spines contain toxic substances that cause a lot of skin irritation
This green type of caterpillar starts life as orange worm before turning lime green. You can identify this species by the red and white stripes running the length of its side. Green spikes stick out from all parts of its body. There are even tiny spikes on the 4 pairs of prolegs on its central segments.
The urticating spines can give you a nasty “bite” if the venom gets into your skin. Even just the slightest touch of these stinging caterpillars can cause a lot of pain that lasts an hour or so.
Protruding light green spikes covering a green body are a warning sign not to handle this caterpillar.
Spiny Elm Caterpillar
The black spines of the Spiny Elm caterpillar contain toxic substance that can cause skin irritation
The Spiny Elm caterpillar (Nymphalis antiopa) is a striking type of spiny black caterpillar. These black caterpillars from the Nymphalidae order can grow up to 2” (5 cm) in length. This caterpillar turns into the beautiful Mourning Cloak butterfly.
You can identify these stinging caterpillars by the row of bright red or orange dots on their back. There is a jet-black line running up the back that seems to join the dots together. The black segments of the body are covered by clusters of white freckles. The prolegs are also red in color.
The caterpillar stings from sharp-looking black spines poking out from its body. These are surrounded by smaller white bristles
A long black and white caterpillar with red dots and a spiky fuzzy appearance.
White Flannel Moth Caterpillar
The venomous spines on the White Flannel caterpillar can cause a painful sting
Another fuzzy stinging caterpillar is the White Flannel caterpillar (Norape ovina). These multi-colored caterpillar has long wispy hairs and tufts of stinging spines.
The caterpillar looks black, yellow, and brown. There is a wide black stripe on its central segments and with brown-colored tips. Rows of yellow dots around each segment give the caterpillar a spotted appearance.
The venomous spines on White Flannel moths can cause a nasty sting. On some people, the inflammation and pain can last for many days and cause allergic reactions.
These caterpillars are found anywhere from Washington DC to Texas, Arizona, and Florida to Mexico and South America.
Look out for a black-looking caterpillar with yellow dots covering its back.
Southern Flannel Moth (Asp) Caterpillar
The hairs of the Southern Flannel Moth (Asp) Caterpillar conceal sharp toxic spines
One of the most toxic stinging caterpillar species is the Southern Flannel caterpillar (Megalopyge opercularis). This caterpillar gives a nasty bite and is also called a puss moth, woolly slug, or Italian asp.
The name of ‘puss caterpillar’ comes from the fact that they look like tiny Persian cats. Due to their painful bite, this species is also called ‘asp’ caterpillars as their bite can be as painful as a snake’s one.
They can range in color from gray-white to dark brown and almost black.
Mostly found in states in the Southern US, these furry caterpillars may look soft but their looks are deceiving. The soft fluffy hairs conceal sharp stinging toxic spines than can cause pain if they sting you. These furry caterpillars are considered dangerous insects due to their nasty sting.
A fluffy mound of fur measuring up to an inch (2.5 cm) long with a distinct tail.
White-Marked Tussock Caterpillar
The fuzzy hairs of White-Marked Tussock caterpillar can cause skin irritation or rash
One of the most unusual hairy stinging caterpillars you will come across is the White-Marked Tussock moth caterpillar (Orgyia leucostygma).
These are brightly-colored black, yellow, red, and white caterpillars. The segmented caterpillar body has black and yellow stripes running its length. There are red dots on its body along with 4 white tufts of hair.
One feature of the White-Marked Tussock caterpillar are the long hair pencils on each end. At the rear end are prominent red defensive glands with black long tails on either side. At the other end is a dark brown hair pencil pointing at 45 degrees upward.
Although this caterpillar doesn’t sting, the fine hairs (called setae) can cause irritation or allergic reactions.
They feed on tree leaves such as apple, cherry, elm, spruce, rose, and chestnut.
Growing to about 1.3” (3.5 cm) long, these ‘tussock’ caterpillars have an exotic appearance due to their bright colors and unusual tufts of hairs.
The Saddleback caterpillar has spiny venomous horns that cause painful sting
The Saddleback caterpillar (Acharia stimulea) has an angry look that is able to ward off many predators and humans alike. In the Limacodidae family of slug-type caterpillars, the Saddleback has spiny horns that sting.
The identifying feature of the Saddleback is a saddle-like marking on its back. This is a square green patch with a large brown dot in the middle. The end of the caterpillar also has 2 white dots that look like menacing eyes.
The sting from Saddlebacks come from the urticating spines on the horns and rest of its body. These venom-filled hairs can cause a painful sting resulting in a rash and possible nausea. You may come across these strange-looking caterpillars when gardening, so handle them with care.
Spiky horns on either end, a saddle marking on its back, and tufts of spines along its side make this an easy caterpillar to identify.
Crowned Slug Caterpillar
The Crowned slug caterpillar has stinging spines around its sides
In the same family as the Saddleback, the Crowned slug caterpillar (Isa textula) looks like a flattened leaf.
Crowned slug caterpillars have an almost spherical green shape. Stinging spines stick out from around the peripheral of the larvae. These spines are more colorful at the head end and can be a deep red rusty color. They gradually fade to white or beige at the tail end.
Although the caterpillar has a flattened shape, a raised ridge in the middle means it is not completely flat. This ridge has 2 yellow lines running up the green body. Yellow and red dots cover this ‘flat-looking’ caterpillar.
A pale green caterpillar with a flattened shape and venomous spines sticking out around its edge.
Spiny Oak Slug Caterpillar
The Spiny Oak slug caterpillar has venomous spikes all over its body
Another type of green stinging caterpillar is the Spiny Oak slug caterpillar (Euclea delphinii). This is a bright colorful hairless caterpillar that has venomous spikes all over it.
The Spiny Oak slug has flattened look and a number of interesting marking patterns on its back. Colors on these stinging insects are yellow, brown, green, and orange. The back has 2 orange stripes running up it. On either side of these are lime-green markings in circular patterns.
The tufts of toxic spines sticking out around the sides are the stinging part of this caterpillar. There are also venomous horns at either end as well as on the back. Its spiky look and bright colors are signs to humans and predators to stay away.
Bright green and orange colors, a slightly spherical shape, and spiny yellow horns are identification features of this caterpillar.
Smeared Dagger Moth Caterpillar
The Smeared Dagger caterpillar has venomous spine tufts around its body
A long black caterpillar with yellow stripes could be the Smeared Dagger caterpillar (Acronicta oblinita). These long caterpillars with bright colors have spine tufts sticking out all over the body.
The Smeared Dagger moth caterpillar can be described as a black and yellow caterpillar variety. These caterpillars are identified by tufts of grayish-white or sometimes brown spines sticking out from black and white bands that wrap around its body. A light brush against these stinging caterpillars can leave your skin with itchy hives.
These are found as far north as Canada and as far south as Indiana, Texas, and Florida.
Buck Moth Caterpillars
The Buck moth caterpillar is a large stinging caterpillar and one of the most venomous ones
Some of the spikiest species of caterpillars you will find are the larvae of the Buck moth caterpillar (Hemileuca maia). Although this isn’t a colorful caterpillar, there are jaggy dark spines sticking out all over the place. These are some of the largest stinging caterpillars and can measure up to 2.5” (6.5 cm).
Buck moth caterpillars tend to feed mostly on oak trees. If they feed in large numbers, they can quickly decimate vegetation.
All of the hollow spines contain irritating venom that can cause a painful “bite.” If the spines break off in your skin, poison is slowly released. Although this isn’t enough to kill a person, they can cause severe burning sensations under the skin.
These caterpillars are most prevalent in areas where there are a number of oak trees. States most commonly affected are Louisiana and Virginia.
Predominately black or dark brown in color, most species have faint white markings, tufts of spines, and jaggy venomous horns that identify them.
Monkey Slug Caterpillar
The hairs on the Monkey slug caterpillar can cause skin irritation
One of the strangest-looking hairy caterpillars is the Monkey slug caterpillar (Phobetron pithecium). This brown-colored caterpillar looks as if it has hairy arms and resembles a squashed hairy spider.
This stinging hairs of this caterpillar can cause skin irritation. In some people, an allergic skin reaction may happen from handling a Monkey slug caterpillar.
Giant Leopard Moth Caterpillar
The stiff spines on the Giant Leopard caterpillar are not venomous but can prickle the skin
The Giant Leopard caterpillar (Hypercompe scribonia) is a fuzzy black type of caterpillar with red markings. These larvae belong to the ‘woolly bear’ caterpillars due to their thick-looking coat.
One of the features to help identify a Giant Leopard caterpillar are red bands between its segments. These are often seen when the large caterpillar rolls up into a ball or when it’s moving.
Unlike most varieties of stinging caterpillars, these giant moth caterpillars don’t have urticating spines. The pain from the sting comes from the stiff spines than can prick the skin.
Variable Oak Leaf Caterpillar
The Variable Oak Leaf caterpillar can be dangerous as it spits out acid when under threat
The name Variable Oak Leaf caterpillar (Lochmaeus manteo) is very appropriate as its colors and markings can change from species to species.
Generally, these are long yellowish-beige caterpillars with brown, white, and yellow patterns along their body. Some brown patterns can resemble an oak leaf. White lines run up the back and along the side. The unusually-shaped head also has white and black stripes on it.
There are very few short spines on this species and it is not a stinging caterpillar. However, care needs to be taken as the crawling caterpillar can spit out acid when under threat. This can cause a burning skin sensation similar to being stung or bitten.
These nasty spitting caterpillars love to gorge on deciduous trees, with oak being their favorite.
South American Caterpillar
The South American Caterpillar (Lonomia obliqua) can be deadly and dangerous
One of the most toxic and deadliest caterpillars is the Giant Silkworm moth or South American Caterpillar (Lonomia obliqua).
These extremely toxic larvae can grow up to 2” (5.5 cm) long and be shades of green or brown. Their bodies are covered with urticating spines that contain potentially deadly poison. Deaths due to coming in to contact with these deadly caterpillars have been reported in Brazil.
Although many caterpillars in the Lonomia genus are stinging caterpillars, it is only the Lonomia obliqua and Lonomia achelous species that are dangerous enough to cause death.
These caterpillars only inhabit countries in Central and South America.
The most dangerous caterpillar on the planet due to its highly toxic venom contained in the spines. It is about 2” (around 4.5 – 5.5 cm) long, with rows of tubercles with spines of different sizes.
Hickory Tussock Caterpillar (Lophocampa caryae)
The hairy hickory tussock caterpillar has black patterns along its white back
The larva of the hickory tussock moth is a black and white caterpillar covered in rash-causing tuffs of irritating hairs. Identifying features of the worm-like caterpillar are long white pencil hairs at either end, bands of black dots traversing a white body, and irritating black tufts on its back.
Hickory tussock caterpillars grow up to 1.77” (45 mm). The caterpillars tend to feed in large groups and can completely defoliate willow, pecan, hickory, and walnut trees. However, the gorging white and black caterpillars rarely damage trees entirely.
The urticating tufts can cause skin irritation because the microscopic, barbed spines can lodge in the skin. According to some reports, the caterpillar isn’t venomous, but its stinging spines cause skin reactions like venomous barbs would cause.
The hickory tussock moth is identified by its white body covered in black dots, black tufts of hairs, and soft-looking setae.
FAQ about Stinging Caterpillars
How long do caterpillar stings last?
The pain, swelling, and burning sensation from a caterpillar sting can last for any time from an hour up to a few days. If allergic reactions occur, you should seek medical attention. It is also important to take a good description of the type of caterpillar that stung you.
What do stinging caterpillars turn into?
Like all caterpillars, species of stinging caterpillars turn into beautiful butterflies and moths.
What happens if you touch a fuzzy caterpillar?
It depends on the species of caterpillar. Some furry caterpillars or ones with horns are completely harmless. Other types of hairy caterpillars have urticating spines that can irritate the skin and may release poison.
What should you do if you are stung by a caterpillar?
You can use some sticky tape to carefully remove the barbed spines or hairs. You are also advised to seek medical attention if any severe reaction or allergic reaction occurs.
Do hairy caterpillars bite?
Although caterpillars have jaws to feed on leaves and other insects, they don’t bite people. Usually, when someone refers to a caterpillar bite, they are talking about a caterpillar sting.
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The caterpillar has been responsible for many human deaths, especially in southern Brazil. Its venom has been the subject of numerous medical studies. The species was first described by Francis Walker in 1855. Guinness World Records classified the Lonomia obliqua as the most venomous caterpillar in the world.
Experts say the caterpillar that causes the most painful reaction is the Southern Flannel, also known as the asp or puss caterpillar. Experts say the caterpillar that causes the most painful reaction is the Southern Flannel, also known as the asp or puss caterpillar.
Caterpillars that are brightly colored, have spines or hairs are probably venomous and should not be touched. "If it is in a place where it can cause problems, clip off the leaf or use a stick to relocate it," Ric Bessin, an entomologist at the University of Kentucky College of Agriculture, tells USA TODAY.
The puss caterpillar, which is the larva of the southern flannel moth, is the most venomous caterpillar in the U.S. and even a simple brush with the insect can cause excruciating pain. The caterpillars' fur hides toxic spines that stick to your skin.
One of the most toxic and deadliest caterpillars is the Giant Silkworm moth or South American Caterpillar (Lonomia obliqua). These extremely toxic larvae can grow up to 2” (5.5 cm) long and be shades of green or brown. Their bodies are covered with urticating spines that contain potentially deadly poison.
In the US, several types of caterpillars can cause misery to humans who touch them. Among them are the saddleback, io moth, puss, gypsy moth, flannel moth, and buck moth caterpillars.
This caterpillar not only eats leaves on trees and shrubs, but it is a member of a small group of caterpillars whose skin is covered with stinging spines attached to venom glands, which if they touch your skin can cause a nasty rash and deliver a terrible sting inducing immediate pain, severe itching, swelling, and ...
The blue-ringed octopodes (Hapalochlaena spp.) produce tetrodotoxin, which is extremely toxic to even the healthiest adult humans, though the number of actual fatalities they have caused is far lower than the number caused by spiders and snakes, with which human contact is more common.
The white hickory tussock moth caterpillar has a white, fuzzy body with black spots. Those spots are filled with venom, used as a defense mechanism against predators. "Little black like almost little spines that stick up, and if you touch those they will cause a stinging reaction to your skin," Ivy said.
Monarch butterfly caterpillars eat milkweed, which contains a substance that can poison dogs and harm their hearts. Other caterpillars like the Slug, Asp and Gypsy moth varieties appear hairy or spiny and can also be toxic to pets, causing intestinal problems and painful internal reactions.
In contact with human skin, they can cause pain, rashes, itching, burning, swelling, and blistering. Avoiding caterpillars is best. Remove spines by applying and removing tape to strip the irritating hairs and spines out of the skin.