Prairie Ridge Ecostation

Caterpillar Wanderings

Caterpillar Wanderings

It’s that time of year again, a time when many caterpillars notice the change in the season and begin to prepare for winter.  Many species of caterpillars overwinter as pupae (also known as the cocoon or chrysalis stage, depending on the species) and are moving from their summer feeding areas to the areas where they are going to pupate and transform into butterflies or moths over the winter.  These wandering caterpillars can be found all over the Prairie Ridge grounds as they look for the perfect place to pupate.

We still have Monarch caterpillars (they were late this year), and you may see them wandering about as they move from the Common Milkweed where they feed to other areas to form their pupae.  The pupae are a brilliant, beautiful green, though they blend in very well with their environment:

monarch chrysalis

Monarch pupae develop quickly so that the adult butterfly can emerge and migrate to Mexico for the winter.  The Monarchs we have on the grounds now will make their way to Mexico as adults soon if the weather holds out.

Another caterpillar preparing to pupate is the Pipevine Swallowtail.  They munch on the Woolly Pipevine plant in our Nature Neighborhood Garden, then climb down the fence and onto the ground before searching for a safe, protected place to pupate.  Many of them climbed up our garden entrance and pupated on the ceiling:

Pipevine swallowtail pupa

If you look up when you enter the garden, you might see many pupae.  Most will remain in place throughout the winter and will emerge as adults in the spring.

There are several species of moth caterpillars wandering too.  One great moth on the go is the Fall Webworm:

Fall webworm

Fall Webworms are typically considered tree pests because when they are young they form dense aggregations inside a silken web at the tips of trees and eat the leaves.  At this time of year, they are looking for a place to pupate for the winter and are wandering the Prairie Ridge grounds in search of good hiding places.  You’ll see a lot of Fall Webworms in the Nature PlaySpace, and they’ll eventually settle into spaces in the leaf litter at the base of trees to overwinter.

Another great moth caterpillar is the Sycamore Tussock Moth:

Sycamore tussock moth

Sycamore Tussock Moths feed on Sycamores, as their name suggests.  At this time of year, you might find them out on the tops of Sycamore leaves as they hurry to eat enough to finish their larval development in time for winter.  You might also find them crawling around on the ground under the trees.

Unlike the other species featured here, Wooly Bear caterpillars overwinter as caterpillars, sometimes freezing solid during cold snaps or in the northern part of their range.  They are fuzzy caterpillars, typically brown in the middle and black at both ends.  We’ve seen hundreds of them crossing the road to the Outdoor Classroom recently:

Wooly bear

There are great old wives’ tales about Wooly Bear caterpillars!  As the tales have it, the wider the brown band in the middle, the milder the winter will be.  However, some Wooly Bears are all black or all brown, so you might want to use a more accurate measurement to predict the weather.

While many caterpillars are safe to handle, such as the Wooly Bear caterpillars, others have “stinging” hairs (called urticating hairs) that can cause itchy or painful hives in some people.  For example, the Sycamore Tussock Moth caterpillar fluff might make it look cute and cuddly, but it hides urticating hairs.  Handling the caterpillars can cause an unpleasant reaction in many people.  If you don’t know enough about a caterpillar to know whether it can sting or not, it’s generally a good idea to look but not touch.

There are many caterpillars roaming about Prairie Ridge now!  On your next visit, look for Wooly Bear caterpillars on the road to the Outdoor Classroom and Fall Webworm caterpillars in the Nature PlaySpace.  There are so many great caterpillars, you never know exactly what you’ll find!

Find out more about the natural happenings at Prairie Ridge at our What Time is it in Nature Archive.

Images by Chris Goforth.