Posts Tagged ‘Pyrrharctia isabella’

Legend of the Woolly Bear caterpillar

January 29, 2018

A “Woolly Bear caterpillar” was spotted during a photowalk at Occoquan Bay National Wildlife Refuge, Prince William County, Virginia USA.

Wooly Bear caterpillar is the larval form of the Isabella Tiger Moth (Pyrrharctia isabella).

According to legend, …

The Woolly Bear caterpillar has 13 distinct segments of either rusty brown or black. The wider the rusty brown sections (or the more brown segments there are), the milder the coming winter will be. The more black there is, the more severe the winter. Source Credit: WOOLLY BEAR CATERPILLARS AND WEATHER PREDICTION – USING WOOLLY WORMS FOR A WINTER FORECAST, The Old Farmer’s Almanac.

Is the legend scientifically valid?

…this myth has been around since, you know, the colonial times. But in 1948, this curator of entomology from the American Museum of Natural History, Dr. Howard Curran, he did a little study. He went out to Bear Mountain, New York, and he counted the woolly bears, the bands – the brown bands of the woolly bear there. And he counted about 15 different specimens, and he made a prediction. Source Credit: The Myth of the Woolly Bear, National Public Radio.

Problem is, a sample size of 15 is insufficient for making meaningful conclusions. So looking at one caterpillar, as I did, is completely meaningless. Nonetheless, I always think of the legend whenever I see a Woolly Bear and wonder what it tells me about the upcoming winter.

Related Rescources

Copyright © 2018 Walter Sanford. All rights reserved.

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