Can You Predict the Weather by Woolly Bear Caterpillars?

With our first hard freeze and snowfall having borne down upon us this week, many folks are starting to “guess” the weather by the colors of the woolly bear caterpillar. I say guess, because that is all it is, guessing. There is no scientific research to back up claims that you can predict the weather by the colors of the woolly bear caterpillar, anymore than you can predict it by cutting persimmon seeds in half! I once cut 3 seeds from the same persimmon fruit and had all 3 results that are supposed to predict the different kinds of winter weather!

The woolly bear caterpillar is the larval stage of the Isabella tiger moth. Woolly bear caterpillars feed on a variety of plants in summer and fall. There are usually 2 broods of Isabella tiger moths per year in Kansas, Nebraska, and Missouri. The reason we see so many woolly bear caterpillars in the fall, crossing the road, and curling up in the leaves is because they spend the winter in the larval stage. Woolly bears tend to curl up under boards, leaf piles, and garden debris, before awakening next year. 


While the woolly bear caterpillar does not have venomous bristles, it is not advisable to handle them or any other “hairy” caterpillar. My kids know not to touch any caterpillar until I have identified it for them on this point. 

The folklore states that the more black is on the ends of the woolly bear, the harsher the winter will be. The more orange or rust color-the milder the winter will be. However, I came across a number of woolly bears this week and found many variations in the same area, as well as a nearly all-orange caterpillar. If you could truly predict the weather with this caterpillar, all found in a given area would have identical markings. 


All this being said, you can still enjoy looking for the woolly bears crossing the road as a sign that winter is coming. And, there are many festivals across the United States dedicated to the woolly bear. 


Happy Planting!

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