Based on the measurements of the distinctive woolly bear caterpillar, you can figure out your weather forecast! Photo Credit University of Missouri
Caterpillars come in a dazzling array of colors and patterns, but some of the most eye-catching are those with vibrant orange and black markings. These tiny crawlers with their colorful coats play a crucial role in the ecosystem, and make for a fascinating study. In this article, we’ll take a close look at some of the most common orange and black caterpillars found across North America.
Caterpillars in the orange and black color family belong to a range of moth and butterfly species. The striking color combination serves as a warning to potential predators that these crawling larvae may be toxic or unpalatable.
Some of the most well-known orange and black caterpillars include
- The woolly bear caterpillar, which becomes the Isabella tiger moth
- The cinnabar moth caterpillar, with its alternating orange and black stripes
- The orange-tufted oleander caterpillar, which transforms into a bright blue moth
- The red-humped caterpillar that feeds on the leaves of fruit trees
Orange and black caterpillars go through several molts, shedding their exoskeleton as they grow. This means their appearance may vary significantly across different instars or stages. Identifying them requires a close examination of features like the head shape, presence of horns or spikes, proleg patterns, and host plants.
Are Orange and Black Caterpillars Dangerous?
The good news is orange and black caterpillars are generally not venomous or dangerous to humans. Some species may have irritating hairs or spines that could cause minor skin reactions. But they don’t sting or pose any serious health risks.
A small number of orange and black caterpillars sequester toxins from their host plants, making them unpalatable or even poisonous to some animals. However, the toxins don’t affect humans significantly.
As a rule orange and black caterpillars should be handled gently and avoided by people with skin sensitivities. Simple precautions like gloves can prevent rashes or skin irritation in most cases.
A Guide to Common Orange and Black Species
Now, let’s look at some of the most frequently encountered orange and black caterpillars across the United States and Canada:
1. Woolly Bear Caterpillar
The woolly bear caterpillar is one of the most recognizable orange and black caterpillars. It has a rusty orange band in the middle and black at both ends, giving it a ‘bear-like’ appearance. Thick hairs cover its body.
Woolly bears feed on a variety of plants before transforming into Isabella tiger moths. They are common across North America and have even inspired folklore about their coats predicting winter severity!
2. Red-humped Caterpillar
As the name suggests, these caterpillars have a characteristic red head and hump. Their early instars are orange, darkening to reddish-brown with age. Black and orange vertical stripes run along the body.
Red-humped caterpillars often feed together in clusters, quickly defoliating trees. They are most frequently found on cherry, apple, oak, and other fruit trees.
3. Oleander Caterpillar
This large orange caterpillar has long black tufts of hair arising from shiny black bumps on its body, resembling a ‘bottle brush.’ As larvae of the polka-dot wasp moth, they primarily feed on oleanders, damaging entire leaves.
4. Cinnabar Moth Caterpillar
Alternating black and orange bands ring the body of this striking caterpillar. A native ragwort feeder, the cinnabar moth caterpillar helps control these invasive weeds. Its warning colors signal toxicity from sequestered ragwort poisons.
5. Spiny Elm Caterpillar
This spiky black caterpillar has red dots running along its back. It feeds on elm, willow, and other tree leaves before becoming the aptly named mourning cloak butterfly. The menacing appearance helps deter predators.
6. Gulf Fritillary Caterpillar
With its orange body and black spikes, this passionflower-loving caterpillar transforms into the vibrant orange and black Gulf fritillary butterfly. It’s found across the southern United States and is relatively mild-mannered.
7. Milkweed Tussock Moth Caterpillar
These fascinating caterpillars are black with orange tufts, white spots, and gray hairs. As the name implies, they feed on milkweed before becoming strikingly colored adult moths. Handle with care as the hairs may irritate skin.
8. Buck Moth Caterpillar
Buck moth caterpillars are black and gray with orange longitudinal lines. They have venomous spines linked to toxin glands that help deter predators but may cause severe skin reactions in humans. Use extreme caution if handling.
9. Rusty Tussock Moth Caterpillar
This hairy black caterpillar has four distinctive ‘toothbrush’ looking yellow tufts on its back along with orange and white markings. The irritating hairs help protect it from predators as it feeds on fruit trees and other plants.
10. Unexpected Cycnia Caterpillar
This orange and black caterpillar with its fuzzy coat feeds primarily on milkweed plants across the eastern United States. It turns into a mostly white adult moth that blends into its background effectively.
In Closing
Do Woolly Bear Caterpillars Really Forecast Winter Weather?
Between 1948 and 1956, Curran’s average brown-segment counts ranged from 5.3 to 5.6 out of the 13-segment total, meaning that the brown band took up more than a third of the woolly bear’s body.
The corresponding winters were milder than average, and Curran concluded that the folklore has some merit and might be true.
But Curran was under no scientific illusion: He knew his data samples were small. Although the experiments legitimized folklore to some, they were simply an excuse for having fun. Curran, his wife, and their group of friends escaped the city to see the foliage each fall, calling themselves The Original Society of the Friends of the Woolly Bear.
Thirty years after the last meeting of Curran’s society, the woolly bear brown-segment counts and winter forecasts were resurrected by the nature museum at Bear Mountain State Park. Since then, the annual counts have continued, more or less tongue-in-cheek.
For over forty years, Banner Elk, North Carolina, has held an annual Woolly Worm Festival in October, highlighted by a caterpillar race. Retired mayor Charles Von Canon inspects the champion woolly bear and announces his winter forecast. Similarly, there is a Woollybear Festival that takes place in Vermilion, Ohio, each October.
Most scientists discount the folklore of woolly bear predictions as just that—folklore. Doug Ferguson, who served as an entomologist at the National Museum of Natural History, once said, “I’ve never taken the notion very seriously. You’d have to look at an awful lot of caterpillars in one place over a great many years in order to say there’s something to it.”
Mike Peters, who spent more than 30 years teaching entomology at the University of Massachusetts, didn’t disagree, but he once said there could, in fact, be a link between winter severity and the brown band of a woolly bear caterpillar. “There’s evidence,” Peters said during his UMass tenure, “that the number of brown hairs has to do with the age of the caterpillar—in other words, how late it got going in the spring. The [band] does say something about a heavy winter or an early spring. The only thing is … it’s telling you about the previous year.”
Do Woolly Worms Really Predict Winter Weather?
Woolly bear caterpillars—also called woolly worms—have a reputation for being able to forecast the coming winter weather. If their rusty band is wide, it will be a mild winter. The more black there is, the more severe the winter. Just how true is this weather lore? Learn more about this legendary caterpillar and how to “read” the worm!
What an orange stripe on this caterpillar can tell you about winter
FAQ
Are orange and black caterpillars venomous?
The answer is that no caterpillars are dangerous to humans, although one or two do have irritating hairs which can give mild discomfort for a time. Their jaws are used to eat plant material, and not to pierce human flesh.
What do the black and orange caterpillars turn into?
Description: The woolly bear is a fuzzy, orange and black caterpillar that becomes a dull, yellow to orange moth with a fat, furry thorax and a small head. Ecology: One of our most familiar caterpillars, woolly bears are renowned wanderers.
What does the orange and black caterpillar predict for weather?
“The claim is that the width of the band, the orange band in the middle, or in some variations the width of the black at the ends, will predict the severity of the winter,” said Dombroskie. According to legend, the wider the rusty brown sections of a woolly bear caterpillar, the milder the coming winter will be.
What is the Old Wives tale about caterpillars?
While black on both ends, the midsection of the caterpillar is reddish-brown. If the reddish-brown section of the caterpillar is narrow, the winter will be harsh, whereas if it is wide, the winter will be mild.
What colors are the caterpillars?
The caterpillars in question are orange and black. They have a base orange color with black tufts and black hairs, and they remain orange throughout each instar. You can find these caterpillars feeding on host plant leaves, with milkweeds being their preferred host, and butterfly weed being the most common host species.
What does an orange caterpillar look like?
Initially, this species is mostly orange. It develops black sections as it grows, with short hairs on the orange sections and longer hairs on the black sections. Some caterpillars may also have tiny black dots across the orange section.
Are black and orange caterpillars native to North America?
All types of black and orange caterpillars are native to North America. Here is a list of orange and black caterpillars found in the U.S.A and some parts of Canada: Red-humped caterpillar is the longest moth caterpillar with longitudinal black and orange stripes. The orangey-red rounded head and hump on the back are the distinctive features.
What do fuzzy orange caterpillars with black bands look like?
Certain orange and black fuzzy caterpillars may even appear intimidating, with noticeable black spikes adorning their backs and heads. These chubby, worm-like crawling insects can feature fuzzy orange bodies with black bands.
What are some features of black and orange caterpillars?
Black and orange caterpillars can feature black and orange stripes, fuzzy orange bodies with black bands, or tufts of spiny hairs protruding from their black and orange forms. These chubby, worm-like crawling insects represent the larval stage of various moths and butterflies.
What do some black caterpillars have?
Some species of caterpillars are black and fuzzy with hair-like spines. Other common black caterpillars have vibrant orange or yellow markings.