by Rick Forrester
You may have noticed the recent appearance of woolly worms crossing the trail. These bristly black/ brown/black caterpillars are often associated with the length and severity of the upcoming winter.
Of the 13 segments in its body, it is said the length of the black band at the head (which end is the head?) indicates the length and severity of the beginning of winter; the middle brown band indicates the length/mildness of the middle of winter, and the tail end the length/severity of the end of winter. If the woolly worm is seen traveling in a southward direction, it means it is trying to escape a severely harsh coming winter.
There are actually eight species of woolly worms (or woolly bears) in the United States, with the two most common in Ohio being the Banded Woolly Bear (Pyrrharctia Isabella) and the Yellow Woolly Bear (Spilosoma virginica). The more commonly seen banded caterpillar becomes the Isabella Tiger Moth and the yellow woolly bear becomes the Virginia Tiger Moth. Woollies can be found as far north as the Arctic Circle and as far south as Mexico. There are actually two generations of banded woollies each year (May and August), although the August-born caterpillars are more noticeable due to their rapid movement as they hurry to find food and shelter. The caterpillar emerges from an egg and then spends a few weeks feeding on a wide variety of leaves. It then seeks out refuge under leaves, tree bark, or other protective covers where it will over-winter. In spring, the caterpillar will emerge and feed briefly before forming a cocoon around itself. It actually uses its own bristles in the structure of the cocoon. The tiger moth that emerges will have a wing span of about two inches and will only live between a few short days and two weeks – just enough time to mate and lay eggs.
One of the amazing facts about the over-wintering process is that the woolly’s heart stops beating, then its gut freezes, then its blood, then the rest of its body. It can stay frozen for several years and still revive. This amazing feat is accomplished through the use of chemical cryoprotectant anti-freeze to keep its cells from rupturing during its frozen state. The protectants, which can comprise 20 percent of the total body mass, can preserve the tissues down past 40 degrees below zero!
The first woolly I saw this season, curled up in a defensive position, was 100% pure black. So are we in for a brutal winter? Actually, their black and brown band lengths are a result of their food source, food amount, and other environmental factors during their growth phase. Woollies from the same clutch of eggs often have different patterns.
Vermilion, Ohio (near Cleveland) even has a woolly worm festival every year if you are interested. However, the festival is hibernating in 2020 due to Covid.
Woollies aren’t poisonous, but watch those spines—they can poke you and irritate your skin. When you see one of these guys scurrying across the trail, pause for a second to wonder at how marvelous he is and then move him off the trail into the woods so he can continue safely on his way!
October 2020
