The common moth
Pyrrharctia isabella is known by different common names at its two main life stages. The adult is the
Isabella tiger moth and the larva is called the
banded woolly bear. The larvae of many species of
ArctiidArctiidae is a large and diverse family of moths with around 11,000 species found all over the world, including 6,000 neotropical species. This family includes the groups commonly known as tiger moths , which usually have bright colours, footmen , lichen moths and wasp moths...
moths are called "woolly bears" because of their long, thick, furlike
setaSeta is a biological term derived from the Latin word for "bristle". It refers to a number of different bristle- or hair-like structures on living organisms.-Animal setae:In zoology, most "setae" occur in invertebrates....
e. This species is black at both ends with a band of coppery red in the middle. The adult moth is dull yellow to orange with a robust, furry thorax and small head.
The common moth
Pyrrharctia isabella is known by different common names at its two main life stages. The adult is the
Isabella tiger moth and the larva is called the
banded woolly bear. The larvae of many species of
ArctiidArctiidae is a large and diverse family of moths with around 11,000 species found all over the world, including 6,000 neotropical species. This family includes the groups commonly known as tiger moths , which usually have bright colours, footmen , lichen moths and wasp moths...
moths are called "woolly bears" because of their long, thick, furlike
setaSeta is a biological term derived from the Latin word for "bristle". It refers to a number of different bristle- or hair-like structures on living organisms.-Animal setae:In zoology, most "setae" occur in invertebrates....
e. This species is black at both ends with a band of coppery red in the middle. The adult moth is dull yellow to orange with a robust, furry thorax and small head. Its wings have sparse black spotting and the proximal segments on its first pair of legs are bright reddish-orange.
The banded woolly bear larva emerges from the egg in the fall and overwinters in its caterpillar form. It survives winter freezes by producing a
cryoprotectantA cryoprotectant is a substance that is used to protect biological tissue from freezing damage . Arctic and Antarctic insects, fish, amphibians and reptiles create cryoprotectants in their bodies to minimize freezing damage during cold winter periods. Insects most often use sugars or polyols as...
in its tissues. Once the weather warms, the larva devours all the grass and weeds it can, pupates, and becomes an adult, which then lives through the summer. It is the larvae of this species which are the subject of common folklore, which has it that the forthcoming severity of a winter can be predicted by the amount of black on the caterpillar; this is the most familiar woolly bear in
North AmericaNorth America is the northern continent of the Americas, situated in the Earth's northern hemisphere and in the western hemisphere. It is bordered on the north by the Arctic Ocean, on the east by the North Atlantic Ocean, on the southeast by the Caribbean Sea, and on the west by the North Pacific...
. But in fact, larvae produced in the same clutch of eggs can vary from mostly red to mostly black, even when reared under the same conditions, and this variability invalidates any actual temperature-related trends that may otherwise be evident. In fact, the orange band will grow towards the ends of the body, with the black bands decreasing in size, as the larva matures.
The setae of the woolly bear caterpillar do not inject venom and are not
urticantUrticating hairs are one of the primary defense mechanisms used by some New World tarantulas and lepidopteran caterpillars. This term refers to the barbed hairs that cover the dorsal and posterior surface of the tarantula's or caterpillar's abdomen. Many tarantula species will frequently kick...
—they do not cause irritation, injury, inflammation, or swelling. However, they will play dead if picked up or disturbed. Handling them is discouraged, however, as the bristles may cause
dermatitisDermatitis is a blanket term meaning any "inflammation of the skin" . There are several different types of dermatitis. The different kinds usually have in common an allergic reaction to specific allergens. The term may be used to refer to eczema, which is also known as dermatitis eczema or...
in people with sensitive skin.
This species is a
generalistA generalist species is able to thrive in a wide variety of environmental conditions and can make use of a variety of different resources . A specialist species can only thrive in a narrow range of environmental conditions or has a limited diet. Most organisms do not all fit neatly into either...
feeder—it feeds on many different species of plants, especially
herbA herb is a plant that is valued for flavor, scent, or other qualities. Herbs are used in cooking, as medicines, and for spiritual purposes....
s and
forbForbs are herbaceous flowering plants that are not graminoids . The term is frequently used in vegetation ecology, especially in relation to grasslands...
s.
Self-Medicating Insect
Recent research has shown that the Woolly Bear caterpillar may eat
alkaloidAlkaloids are naturally occurring chemical compounds containing basic nitrogen atoms. The name derives from the word alkaline and was used to describe any nitrogen-containing base. Alkaloids are produced by a large variety of organisms, including bacteria, fungi, plants, and animals and are part of...
-laden leaves to help fight off parasitic fly larva that can be laid inside their abdomens. This research showed what is called "the first clear demonstration of self-medication among insects".
Weather Predictions
Folklore of the eastern United States and Canada holds that the relative amounts of brown and black on the skin of a woolly bear caterpillar (commonly abundant in the fall) are an indication of the severity of the coming winter. It is believed that if a woolly bear caterpillar's brown stripe is thick, the winter weather will be mild and if the brown stripes are narrow, the winter will be severe. In reality, hatchlings from the same clutch of eggs can display considerable variation in their color distribution, and the brown band tends to grow with age; if there is any truth to the aphorism, it is minimal.
Societal Influence
The annual
Woollybear FestivalThe annual Woollybear Festival is held every Fall in downtown Vermilion, Ohio, on Lake Erie. The one-day, family event, which began in 1973, features a woolly bear costume contest in which children, even pets, are dressed up as various renditions of the woolly bear caterpillar.The festival,...
occurs each October in
Vermilion, OhioVermilion is a city in Erie and Lorain counties in Ohio, U.S. The population was 10,927 at the 2000 census. The current mayor is Jean Anderson...
. The family event, started in 1973, features a woolly bear costume contest in which kids, even pets, are dressed up as various renditions of the woolly bear caterpillar.
There also is an annual Woolly Worm Festival that occurs in
Beattyville, KentuckyBeattyville is a city in Lee County, Kentucky, United States. The population was 1,193 at the 2000 census. It is the county seat of Lee County.- Geography :Beattyville is located at ....
. It started in 1987, and features many food booths, live music, a "Woolly Worm Race" in which people race the Woolly Bear caterpillar up vertical strings.
There is also an annual Woolly Worm Festival that occurs in Banner Elk, NC. It began in 1977 and celebrated its 30th anniversary in 2007. The festival includes booths with crafts, food, and races. The winning Woolly Worm predicts the winter weather for the following winter.
Oil City, PennsylvaniaOil City is a city in Venango County, Pennsylvania noted especially in the instrumental exploration and development of the petroleum industry. After the first oil wells were drilled nearby in the 1850s, Oil City became central in the petroleum industry while hosting headquarters for the Pennzoil,...
is producing a new character "Oil Valley Vick" who will predict the winter weather. It is hoped they can someday draw a crowd similar to
Punxsutawney Phil'Punxsutawney Phil is a groundhog resident of Punxsutawney, Pennsylvania, USA. On February 2, of each year, the town of Punxsutawney celebrates the beloved groundhog with a festive atmosphere of music and food...
. http://www.thederrick.com/stories/09152008-1004.shtml.