Woolly Worms and Weather
Just yesterday, a woolly bear caterpillar, or woolly worm, was
crossing the road in front of me. I pulled over and picked it up, noting
the extent of black on each end of its otherwise brown body. Its head was
only slightly black and its tail end had no black at all. According to
folklore, this predicts a very mild winter.
The Woolly Bear caterpillar is the larval stage of a tiger moth.
The moth itself is about 2 inches long and yellowish in color. On its body
are three rows of six black dots.
The caterpillar is also about 2 inches long and is densely covered
with stiff hairs, which make it look as woolly as a bear. The hairs are
black on the head and tail, but brown in the middle. When the caterpillar
is picked up, it curls into a tight ball with the bristly hairs sticking
out in all directions. These prickly hairs discourage its predators, mainly
rodents like mice, from eating it.
There are several other tiger moths in the area, and their
caterpillars are similar to woolly bears. They are about the same size
and covered in stiff hairs. They even curl up into a ball like woolly bears
do. The yellow woolly bear is pale yellow and is very common. The great
leopard moth and the hickory tiger moth caterpillars are solid black.
Woolly bears are very active this time of year as they search
for a place to spend the winter. You’ll find them crossing roads, crawling
across your lawn, or cruising on paths through the forest. They seem to
race across the paths and are, in fact, pretty fast for a caterpillar.
They’ve been clocked at four feet per minute, which translates into about
0.05 miles per hour. They spend the winter hidden underneath bark or rocks,
and emerge in the spring to feed for a few days before they spin a cocoon
and turn into moths.
The caterpillars eat a variety of plants that are found in
old fields and forest edges, including grass, clover, plantain, and dandelion.
These types of plants occur along roadsides and paths, which is why the
caterpillars are often seen there.
Underneath the stiff hairs, the woolly bear’s body is divided into
13 segments. According to legend, a long brown middle predicts a mild upcoming
winter, whereas long black ends and a short brown middle predict a harsh
winter. There are several methods for determining the length of the brown
section, but The Old Farmer’s Almanac reports that most soothsayers count
the number of brown segments.
In Banner Elk, NC, home of the Woolly Worm Festival, woolly worms
are raced up a string, and the winning worm is used for the prediction.
There is a special formula used to “read” the winning worm. The 13
segments correspond to the 13 weeks of winter, and the severity of cold
during each week is predicted by the color of that segment. This year’s
festival is this upcoming weekend, October 20 and 21, in Banner Elk. Their
website is http://banner-elk.com and the phone for the chamber of commerce
There is some scientific evidence that the amount of black is determined
by the age of the caterpillar as well as by the temperature and amount
of moisture in its habitat during its early life. The woolly bears that
are active at this time of year were hatched from eggs over the summer.
So while the woolly bears might predict the weather, it’s probably the
weather of the past summer rather than the upcoming winter. Maybe that
Woolly Bear I found was reporting that August, when it probably hatched,
was warm and dry. Was it?
Copyright 2001 by Jennifer E. Frick