Salisbury, MD. Last fall, the Gardening Grannies put their collective and somewhat gray heads together and forecast the weather for this winter: a cold start, a milder than usual January and February and a colder than average March. They mentioned the coloring of the woolly bears as one of the things they took into consideration. Now, mind you, the Grannies haven't changed their forecast, nor are they even hedging on it, but they did look into the Legend of the Woolly Bear Caterpillars (hereafter referred to as "W.B.") and learned some very interesting "facts".
First of all, not all of the "experts" agree. Once you get over that, it helps you (and the Grannies) to understand why the Legend continues to exist.
Take for example, the width of the amber colored band:
* Sources confirm that it is East Coast/Canadian folklore that fosters the idea that the W.B. can predict winter
* It was generally agreed that the folklore originated in the 1600's and was fueled by a very small data sample of research which began in the fall of 1948 by Dr. C. H. Curran, curator of insects at The American Museum of Natural History in New York City. Dr. and Mrs. Curran headed up into Bear Mountain State Park that year to observe woolly bears and collected as many as they could in a day. The good doctor counted the number of reddish brown segments and forecast the weather based on the width of the W.B.'s brown and black segments. He continued this study over a period of eight years and the resulting publicity made the W.B. the most recognizable caterpillar in the country. The theory Dr. Curran sought to prove….and the legend of which lives on….was that the black segments represent harsh winter weather and the reddish brown segment represents the comparatively milder winter weather.
* A fairly prevalent theory is that, while the woolly bear cannot predict weather, there is a fairly good chance that it could represent weather. Here again, there is a split in the theories. One is that the width of the brown band has to do with how heavy the winter or how early the spring….except that it would be about the previous year. Other theories are that the width of the bands has to do with when the caterpillar hatches or how wet or dry the previous conditions were.
* The most common theory is that the width of the bands is directly connected to the age of the caterpillar. The wider the reddish brown band, the closer the W.B. is to maturity.
The life cycle of the W.B. is pretty much what you would expect the life cycle of a caterpillar to be but with an unusual twist or two. The W.B., when cold weather arrives, burrows under leaves or wood piles or hides in some other protected place. Its body exudes an "antifreeze" sort of substance that helps it survive the winter. Some reports indicate that a W.B. can survive the winter frozen in an ice cube! In the spring, the W.B. wakes up, begins munching on its normal diet of grass and weeds and spins its chrysalis. A week or so later, the Isabella Tiger Moth exits the chrysalis. The Tiger moth, dull yellow with black spots, a furry body, small head and 2" wings doesn't eat but, instead, spends several weeks mating and laying eggs in a variety of places before perishing.
The W.B. is not normally considered a threat to gardens because it primarily feeds on grasses and weeds during its larva period and eats nothing during the chrysalis and moth stage.
The Gardening Grannies did run across an interesting piece of fairly recent research that indicates that the W. B. may eat alkaloid rich leaves to help ward off parasitic fly larva. If correct, this would be the first documentation of self-medication among insects.
The Grannies encourage you to take your knowledge of woolly bears and share them with a child or two. In the fall, and it's too late to do it this year, take some kids out looking for woolly bears. The W.B.'s can often be seen crossing the road and, considering the mortality rate of doing so, catching them is probably rescuing them from an obvious fate of not looking both ways before crossing the road.
Bring the W.B.'s home and, after evaluating their coloring and putting your predictions to paper, introduce them to a satisfactory habitat. This would be, perhaps, a clear plastic jar with a few holes punched in the lid for ventilation and some dirt in the bottom. Add a twig and some fresh grass. Put the jar outside in a reasonably protected area such as a covered porch or unheated garage. As the weather cools, the W.B. will curl up on the bottom of his home. Not, he isn't dead but won't need to eat any more so you can remove the grass. In the spring, when the lawns green up and the W.B. begins to stir, put in some fresh grass and he will begin to eat again. Soon the caterpillar will spin its cocoon. In about a week or a little more, the Isabella Tiger moth will emerge. This is the time you will want to set your Tiger free to continue the life cycle as nature intended.
If you are really into Woolly Bears, some events you might want to learn more about….
* The Woolly Worm Festival in Beattyville, KY. It started in 1987, has "Woolly Worm Races" where worms are "raced up vertical strings (I guess you had to be there), live music and food.
* A "Weather Prognostication Ceremony" takes place in Lewisburg, PA in early fall and the event is said to cater to kids with crafts, food and a pet parade.
* Some years after the research of Dr. Curran at Bear Mountain, the State Park resurrected the event and began the actual counts again. Now, the event is largely for a good time and an excuse to party. Nothing wrong with that, we say.
* Banner Elk, NC, holds an annual festival highlighted by a caterpillar race following which the Mayor announces the winter forecast. You can find out more about the event by googling Woolly Worm Festival.
The Gardening Grannies are a group of avid and Master Gardeners who live, love and garden on the Delmarva Peninsula. You can reach us at firstname.lastname@example.org and we look forward to hearing from you.