Venomous caterpillars have poisonous bristles, spines, and barbs on their bodies that can cause a severe sting. Some venomous caterpillars appear soft and cute, but their hairy bodies conceal toxin-filled spines that can lodge in the skin. Because they have bright coloring, sharp-looking spines, and a menacing appearance, other caterpillars with poisonous spines appear to be dangerous.
A venomous caterpillar sting can cause skin swelling, redness, itchiness, and a burning sensation. It’s important to keep in mind that “toxic” caterpillars don’t harm people or bite. Only when you touch a venomous caterpillar’s sting do you experience adverse skin reactions.
Knowing which venomous caterpillars to avoid depends on being able to identify them. Nonetheless, many hairy caterpillar species are completely harmless and do not contain poisonous sacs or spines. Of course, it’s best to avoid handling a spiky caterpillar if you’re not sure about its identification.
This is a list of venomous caterpillars that can be used to identify species. You’ll learn about 14 Caterpillar species that have poisonous spines and toxic barbs, as well as their features and characteristics.
What Makes a Caterpillar Venomous?
Urticating setae, which are hollow thorny barbs connected to poisonous glands, are found on stinging, venomous caterpillars. These are used by hairy and spiky caterpillars as a defensive mechanism to ward off predators. However, when the caterpillars touch the quill-like hairs on their bodies, they release poison, causing mild to adverse skin reactions.
According to scientists, the symptoms of touching a venomous caterpillar are wide and varied. Blistering, mild to severe burning pain, swelling, hives, dermatitis, and tissue damage are, however, the most common skin reactions. Furthermore, certain caterpillar kinds contain poisons that may trigger rheumatoid arthritis-like symptoms.
Some caterpillars contain poisonous chemicals that are harmful to birds and tiny animals. The patterns on poisonous caterpillars are usually bright and appealing to predators. Birds, on the other hand, will find the stinging caterpillars unpleasant and will quickly avoid them.
Types of Venomous Caterpillars (With Pictures) – Identification Guide
Venomous caterpillars range in size from that of a small butterfly or moth larva to that of a large snake. As a result, being able to recognize poisonous caterpillars may help you avoid becoming bitten. Continue reading to learn more about the most prevalent caterpillars’ venomous setae, as well as identifying characteristics.
Southern Flannel Moth Caterpillar (Megalopyge opercularis)
The Southern flannel moth caterpillar’s hairs conceal sharp venomous spines, and the southern flannel moth caterpillar can be distinguished by its covering of long, wavy brown hairs. Golden brown or dark gray is the most common color of the hairy caterpillar, although it can be grayish white. Since they hide painful spines capable of causing a horrible sting, the delicate-looking hairs are deceptive.
The 1″ (25 mm) long poisonous hairy brown southern flannel caterpillar has an oval body that tapers at the tail. It has long, thin setae on its body that gives it a bright yellow color. It develops into a mass of hair with many instars (growth phases), which some people characterize as having a terrible hair day.
The southern flannel caterpillar is considered a dangerous caterpillar, and it is also known as the puss caterpill, the Italian asp, the fire caterpillar, the woolly slug, or the Texas asp. The southern flannel caterpillar stings result in severe “white hot” pain that can be compared to being hit by a blunt force. Burning, blisters, nausea, headaches, and breathing difficulties are just a few of the symptoms of the caterpillar sting.
Venomous Caterpillar Identification
The golden brown or gray hairy coat of the southern flannel caterpillar distinguishes it.
Black-Wave Flannel Moth Caterpillar (Megalopyge crispata)
The black-wave flannel moth’s spiky, toxic spines are disguised beneath its long, thin white hairs. Sharp spines attached to poisonous glands are hidden by the non-stinging hairs. A painful sting can be caused by even brushing against the caterpillar’s wispy hairs. It’s best to leave it alone if you see a bushy-shaped white caterpillar.
The caterpillar of the black-wave flannel moth varies in size from 0.7 to 1.5 inches (20 to 40 mm). The moth caterpillar’s early stages are distinguished from its latter stages by a change in appearance. A frilly tangle of hair looks like the long wispy white setae. The caterpillar, on the other hand, develops a velvety look as it grows older.
The hairy larva is very frequent on the southern coast of North America, and it’s also known as the white flannel moth or crinkled flannel moth. The venomous caterpillars of Florida are afflicted with this bug.
Venomous Caterpillar Identification
The mass of frilly, creamy-white hairs that become soft and furry as the larva matures is known as the black-waved flannel moth caterpillar.
Saddleback Caterpillar (Acharia stimulea)
Because of its large spike-covered fleshy horns at both ends, the saddleback caterpillar is easily recognizable as a venomous caterpillar with spiny venomous horns that cause painful sting. Tufts of urticating hairs, a vivid lime-green body with a saddle pattern, and eye-like creamy-yellow dots at the front of the head are some of the distinguishing features of this fearsome caterpillar.
The small green and brown saddleback caterpillar can grow to be 0.78″ (20 mm) long and 0.27″ (7 mm) wide. This striking caterpillar can be found in warmer parts of North America, where it eats oak, maple, holly, elm, and dogwood trees. The tubercles and spines of the saddleback caterpillar release toxins when they are broken. Burning sensations, redness, blistering, migraines, and gastrointestinal symptoms are all signs of a poisonous saddleback caterpillar.
Venomous Caterpillar Identification
The lime-green blanket-like marking with an oval brown patch in the center is used to identify the saddleback caterpillar. The venomous caterpillar has fleshy spines that protrude from it, giving it a threatening appearance.
Io Moth Caterpillar (Automeris io)
When the larva of the io moth touches your skin, it causes a distinct irritation due to its serrated venomous spines. The io moth caterpillar is easily identified by its huge size, green color, and crimson and creamy-white stripes down its abdomen. The io moth caterpillar can grow to be 2.7 inches (70 mm).
The io moth caterpillar grows from orange to green as it ages. Bands of spiky tufts with poisons cover its green body. A prominent dark red and white band can be seen along the sides of their final instar.
Venomous Caterpillar Identification
The green body of the io moth caterpillar, as well as its lateral abdominal red and white stripe, reddish prolegs, and venomous spiky tufts, are all identifying features.
Hag Moth Caterpillar (Phobetron pithecium)
The hag moth caterpillar’s venomous hairs can cause skin irritation, and the haga moth larva is one of the most terrifying venomous caterpillars you’ll ever come across. The unusual furry brown caterpillar has 18 spine-covered projections on its flattened, hair-covered body.
Rather than a caterpillar, the hag moth resembles a brown spider’s skin. Hag moth caterpillars are also known as monkey slugs and measure 0.6 inch to 1 inch (15 to 25 mm). Apple, birch, oak, chestnut, willow, and hickory trees are all home to the weird-looking larvae. In the eastern United States, the brown bug is ubiquitous.
Venomous Caterpillar Identification
The hag moth is an easily recognizable brown caterpillar because of its distinctive curly projections covered in urticating hairs.
White Cedar Moth Caterpillar (Leptocneria reducta)
The white cedar moth caterpillar is a cylindrical dark brown caterpillar covered in irritating bristles. It is covered in venomous urticating hairs all over its body. Because of the long pencil setae that cover its body, the dark caterpillars have a distinct spiny appearance. Its orange feet and faint yellow line down its back are other features that may help you identify it.
The length of white cedar moth caterpillars is around 1.57″ (40 mm). These stinging caterpillars move in groups to defoliate chinaberry or white cedar trees, which is a distinctive habit. In certain individuals, the urticating hairs may sting, producing dermatitis, reddness, and itching.
Venomous Caterpillar Identification
The dark brown cigar-shaped body, orange prolegs, and sometimes a dim yellow line along its back are all used to identify the venomous white cedar moth caterpillar.
Spiny Oak Slug (Euclea delphinii)
The venomous spiny oak slug caterpillar, which is green and orange in color, has poisonous spines that can cause an adverse reaction. It is an unusual caterpillar with fleshy, spine-covered protections along its back and sides. The larvae’s back is striped with two orange stripes, which are the larva’s most prominent feature. The caterpillar’s greenish ringed patterns also provide a distinct pattern. The spiny oak slug is up to 20 mm in length.
The caterpillars’ hollow spines bind to toxin glands on the spiny oak. These may simply penetrate the skin, releasing harmful toxin that causes a bad skin reaction. Locally redness, stinging sensation, and skin inflammation are just a few of the symptoms of a spiny oak slug sting.
Venomous Caterpillar Identification
The spiny oak caterpillar has two orange bands and tufts of toxin-filled spines on its sides, and is a strange green caterpillar with big fleshy orange projections on its back.
Buck Moth Caterpillar (Hemileuca maia)
The buck moth caterpillar is a large stinging caterpillar that is one of the most venomous of all moths. Its larvae are a large, dark brown spiky caterpillar covered in tiny white dots. The dark caterpillar’s spine-covered, brownish multi-branched projections are attached to venomous glands in its body. The larva’s feet are likewise crimson-brown, black or dark brown. Brown striped caterpillars belong to the Hemileuca maia genus.
Before entering its pupal stage, the buck moth caterpillar can grow to 2.5 inches (65 mm). The spiny black caterpillar is frequently found feeding on various species of oak trees. Hollow quill-like hairs attached to poison sacs make up this venomous caterpillar. The caterpillar’s sting can cause skin itching, burning, and severe irritation. The caterpillar’s sting can cause nausea in some cases.
Venomous Caterpillar Identification
The black body of the buck moth caterpillar is covered in rows of multi-branched spines, with white markings, and it is a venom-carrier larva.
White Flannel Moth Caterpillar (Norape ovina)
The white flannel moth larva has venomous spines on its back that can sting painfully. The venomous caterpillar’s tufts of yellow hairs, wispy black setae, short stinging needle-like hairs, and white spots on its back are some of its other identifying features.
The caterpillar of the white flannel moth grows to be 1 to 1.25 inches (25 to 31 mm) long. In Florida, Texas, Washington, D.C., and southern Mexico, the yellow and black caterpillar is prevalent. According to doctors, urticarial dermatitis is caused by venom-filled hairs piercing the skin and causing symptoms of a white flannel moth caterpillar sting.
Venomous Caterpillar Identification
The dark brown or black band on the abdomen of the white flannel moth caterpillar, as well as the contrasting bright yellow tufts of stinging hairs, make it easy to identify. Its tail and head are orangey-red, with a black silky covering over its body.
Stinging Rose Caterpillar (Parasa indetermina)
The stinging rose caterpillar is a brightly colored caterpillar with yellow or orange spine-covered spikey toxin-filled projections. It has clusters of toxic spikes along its body. The black, white, orange, and red line running along its back are easily recognizable by the venomous stinging caterpillar.
The caterpillar is 1.5 inches long (25 mm) and colorful but dangerous. Toxins in each of the seven pairs of spiny horns are severe irritants. A nasty sting results from brushing against the caterpillar, with skin swelling and rashes that can last for days.
Venomous Caterpillar Identification
The flattened, oval form, seven pairs of fleshy conical projections, and yellow, red, orange, and black colors make the stinging rose caterpillar a colorful venomous caterpillar easy to identify.
Pine Processionary Moth Caterpillar (Thaumetopoea pityocampa)
The larva of the pine processionary moth is a black caterpillar with yellowish-white toxin-filled hairs, amber dots, and a rounded head that may be found in coniferous woodlands. The processionary actions of hundreds of hairy caterpillars moving in a line to discover new pine trees is what makes this stinging caterpillar’s behavior unique.
Mature pine processionary caterpillars may grow to be 1.57″ (40 mm) long and are best seen on the tree. URTICATING chemicals cause severe and persistent itching on the irritable hairs covering the black worm-like creature. Hives, contact dermatitis, pain, and tiny red irritations may all develop as a result of the caterpillar’s sting.
In coniferous woods, pine processionary caterpillars do the most harm. This destructive caterpillar, according to some reports, damages trees in southern Europe, Asia, and North Africa.
Venomous Caterpillar Identification
The caterpillars of the venomous stinging pine processionary moth move in a line, making them easily identifiable. Caterpillars with white urticating hairs may be found in dark gray to black coloration.
Giant Silkworm Moth Caterpillar (Lonomia obliqua)
The larva of the giant silkworm moth is a hairy brown caterpillar with poisonous bristles that may be hazardous. The back of the cylindrical worm-like brown caterpillar is dotted with white and tan lines. Multi-branched greenish spines cover the caterpillar, which contains a potentially deadly poison.
Caterpillars of the Giant Silkworm Moth grow to be about 1.77″ to 2.1″ (45 to 55 mm). The caterpillars may be green in color, despite their normal brown appearance. A poison with anticoagulant properties is found in the venomous spines of Lonomia obliqua. Swelling, redness, discomfort, and internal bleeding are all possible side effects.
Venomous Caterpillar Identification
Soft, light green poisonous spines surround the brown body of the giant silkworm moth caterpillar, which distinguishes it. Moreover, these caterpillars’ backs are frequently adorned with white, black, or rusty-brown stripes.
American Dagger Moth Caterpillar (Acronicta americana)
The American dagger moth’s larvae are a venomous hairy yellow-whitish caterpillar with several pairs of long black pencil bristle hairs that can be distinguished by its distinct yellow-white hairy look. Stinging hairs cover the slender caterpillars, which contain toxic venom that can cause severe skin irritation.
The furry pale yellow caterpillar can grow to be 2″ (50 mm) long. Oak, maple, elm, ash, and other hardwood trees are infested with the American dagger moth caterpillar. From July to October, the caterpillars are the most active. When the toxic bristles of the venomous yellowish caterpillar break off and embed in the skin, it causes damage.
Venomous Caterpillar Identification
The hairy white-yellowish hairs with numerous long black pencil hairs protruding from its body distinguish the American dagger moth caterpillar.
Hickory Tussock Caterpillar (Lophocampa caryae)
The larva of the hickory tussock moth has black designs on its white back, which causes rash-causing irritation. Long white pencil hairs at each end, bands of black dots across a white body, and bothersome black tufts on its back are all identifying characteristics of the worm-like caterpillar.
The caterpillars of the hickory tussock reach a length of 1.77 inches (45 mm). Willow, pecan, hickory, and walnut trees may be completely defoliated by caterpillars that feed in large groups. The gorging white and black caterpillars, on the other hand, seldom eat through an entire tree.
Because of the microscopic, barbed spines that can lodge in the skin, urticating tufts may cause skin irritation. The caterpillar isn’t poisonous, according to some reports, although its stinging spines may cause skin reactions that are similar to those of poisonous barbs.