Impressive Insects

All, Nature Notes
A banded woolly bear caterpillar (Isia isabella) travels across a fallen leaf at Sharon Woods.
Though small, woolly bear caterpillars can travel fast when they’re hungry.

Are you wondering how cold this winter will be? Some people believe that banded woolly bear caterpillars can give us that answer. It is thought that if a woolly bear has longer black stripes than red, the winter will be colder and thus, if it has a wider red stripe, the winter will be mild. I won’t guarantee these furry little guys will be right but, they can’t be any more off-course than some other weather predictions!

Woolly bear is the general name for many tiger moth caterpillars. Banded woolly bears (Isia isabella) are the larvae of the Isabella moth (one type of tiger moth). You can easily identify a banded woolly bear by its striped bristles. The insect is about 1 1/2-inches in length and have dense bristles all over their bodies. The bristle color forms 3 bands: black on both ends and reddish brown in the middle.

Woolly bear caterpillars (Isia isabella) are about 1 and 1/2-inches in length and have dense bristles all over their bodies.
Is this woolly bear predicting a mild or harsh winter?

September and October are a good time to find these caterpillars. They will be eating the leaves of asters, sunflowers, clover and other various wildflowers. Wasting no time, after filling up on food, they quickly (traveling 4 feet per minute!) search the ground for a good place to spend the winter months. Usually, this will be under a log or in leaf debris. When the warmer months approach, woolly bears come back out, gorge themselves again and build a cocoon made mostly of their bristles and silk. Two weeks later, they emerge as a beautiful Isabella moth. There are 2 broods every year: one in spring and another in summer (these are the ones we can see now).

I suggest checking your driveways and backyards for these impressive insects. Once spotted, go ahead and gently pick it up. This will not harm you or the woolly bears. Most likely, they will curl up into a ball in the attempt to defend themselves. Once you get a good look, gently place the caterpillar back where you found it. Then, simply enjoy and remember the experience! Keeping nature the way you found it is the best way to enjoy the outdoors.


Julie Robinson
Regional Education Manager, Sharon Woods

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