Ruth Bass: Woolly bears get credit as forecasters


RICHMOND -- We never see the Isabella tiger moth, an orangey-yellow creature whose range extends into the Arctic. But she's here, two inches small. She apparently had an astounding egg production this year because her offspring are everywhere. We know them well. They are the woolly bear caterpillars, which for some reason have become a beloved crawling creature rather than one that makes everyone cry, "Eek," and run.

Woolly bears abound this fall. We find them in pots of flowers, under a fallen leaf, in the bottom of a basket of apples, inching their way across warm, stone steps and -- most of all -- crossing the road.

It's hard to know whether these little ones have an exact destination in mind, but they know what they need: A safe, nestling spot in leaves where they can curl up and wait for spring. The evidence on our road indicates that they would be smarter to look both ways before crossing, but even with the obvious casualties, they are legion.

When they find their safe spot, they freeze. Solid. Frogs lower their metabolism and subsist on whatever they've stored up in the winter. When spring comes, they emerge from what's called their hybernaculum -- now there's a word for Bananagrams.

But the little woolly bear doesn't just slow down. Its heart stops beating entirely and its blood freezes. It thaws in spring and moves into its next phase. Perhaps it's the way this fuzzy caterpillar copes with winter that makes people think its stripe is a weather forecaster. The creature is jet black on both ends of its body, cinnamon in the middle. Supposedly, if the cinnamon stripe is smaller than the black ones, winter will be mild.

An American Museum of Natural History scientist studied this phenomenon in the 1950s and decided the worm was right 80 percent of the time. (Some of us would feel that's quite a success in the seemingly uncertain world of meteorology.) But other researchers have not been so sure.

For the record, most of the woolly bears we've seen this year have had three stripes of equal length, black fore and aft, cinnamon in the middle. So the black would outweigh the brown if the two halves were combined, foreseeing wicked winter. But since the brown is equal to each of the blacks, perhaps winter will be mild. It's a conundrum, sort of like predicting what Congress will do next.

One of the charms of the woolly bear is that when you pick him up, he curls into a tight little ball. He's been to ‘possum school. And he's non-toxic to humans.

For the first time last year, we noticed a jet-black caterpillar. Was it going to snow from Nov. 1 to Memorial Day? No, it seems this caterpillar descends from the giant leopard moth. The moth is bright white with black markings in a leopard-like pattern. No fears with this guy: He's non-toxic, too, and is easily recognized when he curls up and you can see the tiny red bands that circle his body between the jet bristles.

But we've also met this year the white hickory tussock caterpillar. Rumors have run through social media about this handsome creature, soft white with two sets of spikes at the front and rear of his body. He's been labeled poisonous, and the grapevine or whatever passes for gossiping in these tweeting days has labeled him lethal.

Not so, says the Cornell Cooperative Extension. But he isn't cuddly and will create rashes that last a long time on human skin. This one is not to be played with. Interestingly, it seems to love golf. That's where we keep seeing them. If one is curled around your ball, you get a free lift. New rule.

Ruth Bass watches caterpillars and butterflies in Richmond. Her website is


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