WINTER PREDICTIONS OF THE "WOOLLY BEAR"

Insect Meteorologist?

Old-time folklore and superstitions are usually laughed at in today’s modern, scientific world.  But can your technology predict the severity of the coming winter?  Undoubtedly, we think it can.  Weather satellites, historic weather trend analysis, computer modelling and the heavily degreed men and women of meteorology would indicate that technology can do a decent job predicting the weather, I think.  But in simpler times, before the advent of space travel and computers, our ancestors would use a number of naturally occurring indicators to help them predict the weather.  The times of bird migrations and insect activity were among them.  In the case of winter weather one of the insects used to predict the severity of the coming season was the coloring of the “Woolly Bear” or “Woolly Worm”, a common caterpillar native to North America, so called because of its woolly appearance. It is the caterpillar of the Isabella Tiger Moth (Pyrrharctia Isabella), a rather understated moth of yellow, orange or pink with small black spots.  The moth lays her eggs during the warm summer and they grow into brown and black fuzzy caterpillars that are evident in October.  Normally, the front and rear sections of the caterpillar are black and the mid sections are rust brown. 

Isabella Tiger Moth

According to tradition, the coloring of the 13 segments of the Woolly Bear’s body indicated the severity of the coming winter.  More brown segments indicate a milder winter and more black segments indicate a harsher winter.  “How does the caterpillar know?”, I ask?  Well, according to the University of Virginia’s Mountain Lake Biological Station, the caterpillar doesn’t “know”, per se.  The caterpillar has black end segments and as it ages the black segments shrink as it molts.  So it seems to follow that if the fall is milder and longer that you will find more Woolly Bears with more brown than black.  To add to the confusion, there are variants of the same caterpillar that are all brown have no black at all.    

All brown Isabella caterpillar

There are even all white “Woolly Bears” caterpillars that are the larva of the Spotted Tiger Moth.  I didn’t see any the day I was exploring but if I find one I will update this article.  So, the brown and black segments of the Isabella caterpillar seem to be a better indicator of how long it’s growing season was as opposed to how severe the coming winter will be.  As the weather cools the caterpillars find a safe place to hide and hibernate through the winter, emerging in spring and cocooning until emerging as the moth.  Tiger Moths have two generations every year, one in spring after emerging and one in summer, which will hibernate through the winter.

Woolly Bears do not sting!

The great thing about Woolly Bears is that they do not sting!  Many other woolly or hairy caterpillars have stinging spines or hairs.  Not so with the Woolly Bear.  All of its color variations are safe to handle, making it an excellent and fun little insect to introduce children to insects.  When handled they tend to curl up in a protective little ball, but they will soon crawl around on your hand at surprising speed!  Some people keep Woolly Bears as pets and they seem to do well, of course you should expect them to hibernate over winter, which is probably not very exciting for the kids.  

So unless a long, warm fall indicates a mild winter, which it may or may not, it is hard to say that our Woolly Bear weather predictor is any more accurate than a heavily degreed meteorologist, but they are probably more entertaining.  

In the Southern States the caterpillar is mostly referred to as the Woolly Worm.  The tradition of observing the Woolly Worm is still strong in North Carolina, where every year there is a Woolly Worm Festival and a properly trained Woolly Worm is selected as the year's winner and winter weather forecaster.  The 2016 festival is 15-16 October in Banner Elk, North Carolina.  If you go to festival let us know how it was!