Be careful with our Woolly Worms
The Woolly Worm is very wildly distributed throughout the US and Canada, and festivals held to celebrate its appearance may be found in many towns. The Woolly Worm Festival in Banner Elk is looked forward to every October by both children and adults. Kids from across the region bring their favorite caterpillar(s) to race and see which is the fastest (and thus predict the winter), while local artists and food vendors provide a very festive atmosphere. This festival is one of the highlights of Northwest North Carolina's fall season, so making sure it continues is important. One aspect of this is ensuring that the main insect attraction continues to thrive in nature so that it can be the star of the show for years to come. This article briefly describes the life history of the Woolly Worm to aid in understanding a few things to keep in mind to make sure one of our most familiar High Country insects continues to thrive.
A member of the Tiger Moth Family of insects, the caterpillar of the Woolly Worm is much more familiar and seen more than the adult. A relatively small, yet handsome orange with black dots, the adult moth is found in our area primarily in the spring, and unless you really look hard for it at night it’s not easily found. After hatching from eggs laid by the female moth caterpillars eat a variety of plants and grow into the familiar black and brown banded "fuzzy" caterpillar. When reaching their largest size, the caterpillars are seen moving across our roadways beginning in September and lasting into the fall. This type of behavior, called wandering by insect biologists, is not uncommon for many insects and is necessary for their survival. Its purpose is for a caterpillar to locate a suitable place to hibernate over the winter before resuming an activity like eating in the spring before forming the pupa from which the adult will emerge. A secluded place of the caterpillar’s choosing under a structure or piles of leaves affords them protection. Interestingly, to survive a potentially cold winter the Woolly Worm caterpillar actually makes its own antifreeze and can survive very cold temperatures!
Photo Credit: Rebekah D. Wallace, University of Georgia, Bugwood.org
Here are three things to keep in mind if you collect caterpillars for races at the local festival (or perhaps just to observe them). Carefully considering these will go a long way to making sure the Woolly Worm remains a natural wonder in our area.
First, avoid collecting too many Woolly Worms. Even though observing our roadways it appears there may be lots of caterpillars in our area, it’s hard to know the actual number. There is currently great concern about many insect numbers declining across the globe for reasons that are poorly understood, and no one wants this to happen to one of the favorite insects. If attending the Woolly Worm festival with your race favorite, or just spending some time watching these fascinating insects at your home, limiting your collection to one caterpillar or a very small number, will help maintain a healthy local population of Woolly Worms.
Second, you really want to keep any Woolly Worm caterpillars out of their natural environment for as little time as possible. It’s not always clear what conditions they need to survive, so even if you place a caterpillar in a nice box with leaves to provide them shelter, this may not be what the caterpillar really needs. Keep in mind that the wandering caterpillars are no longer interested in eating, so feeding them does not affect their survival. Although there are some sources out there for raising Woolly Worms, all in all they do not make good pets and you should not try to keep one over the winter to watch them develop into an adult moth next spring. Natural conditions for them to survive are very hard to copy and it’s very possible that your caterpillar will not survive overwinter in a setting you create.
Finally, keep track of where you collected your caterpillar(s) and return it to this same place (though not to the road surface!). Even though the Woolly Worm caterpillars wander seemingly far and wide, the distance they cover does not have to be that great. Compared to us insects are small, so what seems a short distance to you can be substantial for them. The place you find your Woolly Worm is what it “considers home” and its survival will be increased by staying in that area.
It's hard not to be fascinated by the Woolly Worm, and whether you believe they can forecast the winter, or be the champion at the local Festival, doing what is needed to make sure we can look forward to them each fall seems something everyone wants. A few simple considerations will help assure this so please be mindful of them as you enjoy our fuzzy friends.
References:
Gretchen Voyle. Wooly worms and winter weather predictions. Michigan State University Extension. 2011.
https://www.canr.msu.edu/news/wooly_worms_and_winter_weather_predictions
James Baker. Banded woollybear/Isabella moth. NC State Extension Publications. 2017.
https://content.ces.ncsu.edu/banded-woollybear
Tiffany Means. Woolly worms: the original winter weather outlooks. ThoughtCo. 2019.
https://www.thoughtco.com/woolly-bears-and-winter-outlook-3444522
Portions of this article appeared in the Watauga Democrat (Boone, NC) on September 14, 2022.