Original Source: WGEM
The recent warm weather drove many people outside and in contact with the first woolly bear caterpillars of the season. Oh, wait! Do you call them something else? They are also known as woolly worms, fuzzy bear, fuzzy worm, and banded woolly bear. It has even been called a Hedgehog Caterpillar because it curls up into a ball for protection and plays dead. They are interchangeable and could depend on your region. But one thing they have in common is the folklore that they can tell us how cold and snowy the winter ahead might be.
Have you seen them yet?
The months we transition through Fall, each cold air outbreak brings the question of what the winter ahead may bring. It can also bring out a familiar pastime of observing Woolly Bear Caterpillars. The reality is that this creature is in the early phase of the life cycle of what will become a tiger moth.
In this report, I want to share with you the folklore I’ve spent years exploring and sharing. The reality about the Woolly Bears and impostors that many think tell a dramatic story of the season ahead. I need to be completely authentic and truthful: I LOVE snow and always have Faith in the Flakes (FITF). I also need to be practical.
What determines the colors?
The bands are determined by how long the caterpillar has been feeding, age, and species.
A better growing season means it ate more. The result is a larger caterpillar and a smaller orange band. So, the color actually shows the prior growing season. However, there is some winter weather folklore that would correlate the summer season and cross over to winter snow, so there still could be a connection.
Also:
The caterpillar can molt or shed its skin up to 6 times, each one getting a little more orange. There are 260 known species of tiger moths.
But what about an all-black caterpillar?
Does that mean we are in for a Polar Vortex followed by Ice Age conditions? Faith in the Flakes! I’ve even seen a few all light brown or blonde. Would that mean a snow-free winter?
Comparing Caterpillars: DIFFERENT SPECIES
Lighter color: Yellow Bear (Spilosoma virginica). These turn into a Virginian Tiger Moth
The striped caterpillars or classic Woolly Bears (Pyrrharctia isabella) turn into a Tiger Moth
The all black caterpillars (Hypercompe scribonia) turn into a Giant Leopard Moth
If we ‘follow the science’, the relative width of the black band varies with age, and has nothing whatsoever to do with weather (Wagner 2005).
But wait! Mike Peters, an entomologist at the University of Massachusetts, says there could, in fact, be a link between winter severity and the brown band of a woolly bear caterpillar. The width of the brown band does say something about a heavy winter or an early spring. That is winter and spring, the previous year, when the caterpillar started crawling.
Note: These caterpillars can survive through the winter, producing their own antifreeze.
If we want to stick with the folklore, then here is a more elaborate breakdown of color patterns and winter.
Woolly Bear Folklore
The wider the brown (middle) band on a woolly bear caterpillar, the milder the winter?
Two ways to look at them:
- The Orange Band: This stripe in the middle will be wider when the upcoming winter is expected to be mild.
- The Black Bands: The thicker or more dominant these are means a longer and harsher winter ahead. Translation: More cold and snow!