Can Woolly Worms Really Predict the Winter Weather

Legend has it that the woolly worm, a tiger moth caterpillar, can portend what weather winter will bring. In the fall, people look for wandering woolly worms to determine whether winter will be mild or harsh. How much truth is there in this old adage? Can woolly worms really predict the winter weather? What Is a Woolly Worm? The woolly worm is actually the larval stage of the Isabella tiger moth, Pyrrharctia Isabella. Also known as woolly bears or banded woolly bears, these caterpillars have black bands at each end, and a band of reddish-brown in the middle. The Isabella tiger moth overwinters in the larval stage. In the fall, caterpillars seek shelter under leaf litter or other protected places. The Legend of the Woolly Worm According to folk wisdom, when the brown bands on fall woolly bears are narrow, it means a harsh winter is coming. The wider the brown band, the milder the winter will be. Some towns hold annual woolly worm festivals in the fall, complete with caterpillar races and an official declaration of the woolly worms prediction for that winter. Are the woolly worms bands really an accurate way to predict the winter weather? Dr. C.H. Curran, former curator of insects at the American Museum of Natural History in New York City, tested the woolly worms accuracy in the 1950s. His surveys found an 80% accuracy rate for the woolly worms weather predictions. Other researchers have not been able to replicate the success rate of Currans caterpillars, though. Today, entomologists agree that woolly worms are not accurate predictors of winter weather. Many variables may contribute to changes in the caterpillars coloration, including larval stage, food availability, temperature or moisture during development, age, and even species. Woolly Worm Festivals Although the woolly worms ability to predict the winter weather is a myth, the woolly bear is revered by many. In the fall, many communities in the U.S. celebrate this cuddly caterpillar by hosting Woolly Worm Festivals, complete with caterpillar races.   Where to go to race a woolly worm: Woolly Worm Festival - Held the 3rd weekend of October in Banner Elk, NCWoolly Worm Festival - Held in mid-October in  Lewisburg, PAWoolly Worm Festival - Held in October in Beattyville, KYWoolly Worm Festival - Held in early October in Vermilion, OHApple Festival - Held in late September in Central Square, NY (Woolly worm races are held as a fundraiser for the local search and rescue team.)