Banded Woolly Bears: Their black bands may predict winter weather
If the rusty band is wide, then it will be a mild winter. The more black there is, the more severe the winter — according to banded woolly bear folklore.
Photos by DON BARTLING When the woolly bear caterpillar is in his defensive posture he curls up like a ball until the danger is over.
“I want to be a caterpillar. Eat a lot. Sleep for a while. Then wake up beautiful…”
— Anonymous
Woolly bear caterpillars seem to be everywhere these days — creeping across roads, the lawn, and when I’m walking the dog, they are hidden in the wilted grass along the path. Last week I found a woolly bear in my garage. These fuzzy, black-and-brown-banded caterpillars seem intent these days to get somewhere. Where that is — and how they know — is a mystery.
The banded woolly bear caterpillar of a tiger moth (Isia Isabella), also called woolly worm or fuzzy worm, has the reputation of being able to forecast the coming winter weather. Whether this is fact or folklore, let’s learn more about this legendary caterpillar and how to “read” the worm! The width of the black bands is purported to predict the severity of the coming winter: the narrower the bands, the milder the weather will be.
The Woolly Bear caterpillar has 13 distinct segments of either rusty brown or black. Woolly bears do not actually feel much like wool — they are covered with short, stiff bristles of hair.
As fall approaches and temperatures begin to fall, woolly bear caterpillars appear all over in great numbers. They travel in search of a safe place to settle down for the winter.
Woolly bear caterpillars look for a safe place to hibernate, in places such as leaf piles and under logs. As temperatures continue to fall, the woolly bear caterpillar’s metabolism begins to slow down. The caterpillars are now ready for hibernation. For protection from the freezing temperatures, the caterpillars dehydrate themselves and their circulatory system produces a cryoprotectant, which freezes the tissues solid and prevents any water from freezing in their body. So long as winter conditions continue, the caterpillars hibernate and stay frozen like this.
As temperatures increase in the spring, woolly bear caterpillars begin to thaw out. They awaken and begin to prepare for becoming adult Isabella tiger moths. These fuzzy caterpillars spend a few nights eating plant matter, then prepare a cocoon. Their cocoons are crafted from their own black and brown bristles. Once fully in their fuzzy cocoon, the caterpillars pupate. They do not eat in this stage. Instead, they develop adult parts such as wings and antennae.
After pupating for one month, the now-moths emerge. The moths are tan or orange in color with fuzzy heads and several small black markings on their wings. Like pupae, the adult Isabella tiger moths do not feed. They spend only a few days mating and laying eggs before they die. New eggs hatch within two weeks and the life begins again.
In some places in the United States, the banded woolly bear worm has a pretty good weather prediction rate. Scientists would prefer not to acknowledge it, but the woolly worm, according to some authors, has an 80-85 percent accuracy rate for predicting the winter weather. The worm has held its record for accuracy for more than 20 years.
However, most scientists discount the folklore of woolly bear worm predictions as just that, folklore. So, if you come across a local banded woolly bear worm, observe the colors of the bands and what they foretell about your winter weather. If you have difficulty in reading the banded woolly bear you may consult the Farmer’s Almanac or turn to your local weather station for the weather forecast.
Explore the outdoors and all of its wonderful creatures. Enjoy the beauty of Boundary County!