Saturday, October 15, 2011

Woolly Bears -- © Dave Spier

Woolly-bear caterpillar at Blue Cut Nature Center between Newark and Lyons in Wayne County, NY - © Dave Spier

When was the last time you remarked, “Oh, there goes an Isabella Tiger Moth”?  Probably never (unless you’re an entomologist).  The wings are yellow-brown with some small black dots and a few faint lines for camouflage.  When opened, the wings span two inches or less.  During the summer, these moths can be found in meadows and fields and along road edges, but I don’t remember ever seeing one.  Frankly, it never occurred to me to even look for them.  Part of the problem is that these moths are nocturnal; look for them around porch lights.  I think I’ll put it on my calendar of things-to-do for next summer.  I guarantee they’re here, whether or not I can actually find one.  How do I know?  Read on…
When was the last time you remarked, “Oh, there goes a Woolly Bear”?  Probably within recent memory, and some days, several times – depending on the weather.  These are the familiar bristly caterpillars with black on each end and orange in the middle.  I see them crossing roads and open hiking trails, wiggling through the grass, or trying to hide in my garage.
It’s said that the amount of black portends the severity of the coming winter, but actually it only indicates how close to full grown it is.  It will find a snug shelter and spend the winter in the larval (caterpillar) stage, and by producing a type of antifreeze [technically a cryo-protectant chemical] they can survive freezing to temperatures of -90 degrees Fahrenheit.  This is why we see them again in early spring on a warm day.  They complete their metamorphosis (change) and emerge as adult Isabella Tiger Moths starting in June.  Other members of the Tiger Moth family are more strikingly marked and attractive.  Some have black and beige wings and rouge accents on the body and these are the species that give the clan its family name.
Tiger Moths are capable of producing ultrasonic sounds above our hearing range.  These are used to attract mates and also to interfere with bats’ echo location and thereby avoid capture and consumption by the flying mammals.  Most moths are nocturnal and this could help explain why most of us have never seen the adult Woolly Bear, a.k.a. the Isabella Moth (Pyrrharctia isabella).

Questions, comments and suggestions may be sent to  For more information on New York's butterflies and moths, please visit the D.E.C. website for a PDF copy of their flyer.

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