January 28, 2022

CT Naturalist: Caterpillar’s Encore

The month of September provides an encore for butterfly, moth, and caterpillar activity. Although frequently associated with spring and summer, there are many species caterpillar that are active during the autumn, feeding on seasonal plants.

The best places to view caterpillars this autumn are in open fields with plentiful golden rod and/or milkweed. Golden rod is a common host plant to many caterpillars including Asteroids, Loopers, Flower Moths, Tussocks, and more. (See video for two examples of September caterpillars from Connecticut)

Patches of Golden rod can be found in open fields or along the roadside. These locations are easily accessible for family outings with easy hiking trails.

Milkweed is another plant that often grows in open fields. During the autumn it is recognized by its large pod-like seed casings, now bursting open with large dandelion-like seeds. A favorite food of the famous monarch butterfly caterpillar during the summer, the milkweed leaves now serve the Milkweed Tussock caterpillar. They have long hair-like structures called setae that cover their body with bright orange, white, and black colorations.

If you’re planning on taking your children out for an autumnal walk, these caterpillars are easy to find and will provide much gratification for young naturalists to encounter. All caterpillars have a degree of camouflage, but identifying their location and host plants are more than half the challenge. Once discovered, they don’t run away, making them a perfect specimen for children to observe and learn from.

If you can’t make a trip to the parks mentioned above, keep your eyes alert to any area in your community where golden rod is prevalent. You may find some of the most colorful wildlife of the year, rivaling that of the fall foliage that will soon color our landscape.