Woolly bears are not true predictor of snowfall

Q: Is it true that the more black a woolly bear caterpillar is, the more snow we will get this winter?

• Robin from Berlin Center

A: While predicting our snowfall and the coldness of our winter is a fun discussion, the caterpillars are not a true predictor of our winters. In fact, this old wives’ tale was probably made up by an old husband.

As the tall tale goes — the black band on the woolly bear caterpillar will expand to predict bad winters with heavy snows and be almost nonexistent on the caterpillars in the fall before a mild winter.

But, this is just a tall tale.

It never fails that I get into an in-depth conversation each fall — answering questions and explaining how this is good fun, but it really means nothing.

In most years, caterpillars with varying widths of that black band are found throughout much of the Midwest. Then there is the giant leopard moth caterpillar that is completely black. This caterpillar is the one that stirs the most emotion out of some because they may have never seen it before and it could mean the “worst winter, ever.”

It does look all black, but when it curls up and then you can see red stripes on its sides.

The one most commonly mistaken for foretelling our winters is the banded woolly bear, of which the adult is the Isabella moth. These brownish-orange caterpillars have a black band at the front and a smaller black band on the back. As happens often in nature, there are exceptions. These black bands can in fact vary in width on both the front and back of the caterpillars.

Research has debunked the winter prediction legend by showing the amount of black varies with the age of the caterpillar and the moisture levels in the area where it developed.

The woolly bears are the caterpillar stage of medium-sized moths known as tiger moths. There are eight or more species of woolly bear caterpillars. The most common in Ohio are the banded woolly bear, the yellow woolly bear, the salt marsh caterpillar and the giant leopard moth.

So why do we suddenly see these caterpillars this time of year? October and November are the months when these woolly bear caterpillars search for a location to over winter. They usually hide under plant debris for some time. Their annual search is why you see them crawling over everything this time of year.

On another note, be sure to check your boots before putting them on if they were left outside or in the garage. While these are not stinging hair caterpillars, some people do have severe localized reactions when the hairs penetrate their skin.

Be sure to take a moment and enjoy these beauties this fall season. And have a good time shooting the breeze about their apparent ability to predict the winter weather.

To read more: http://go.osu.edu/woollybear.

Barrett is the Ohio State University Extension educator for agriculture and natural resources in Mahoning County. Visit the Plant and Pest Clinic or call the hotline at 330-533-5538 from 9 a.m. to noon Mondays and Thursdays for help with plant issues, soil testing and insect identification. For details, visit go.osu.edu/mahoningclinic.


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