The moth and the milkweed

By Jane Bielecki, Master Gardener

I have to start this article on a personal note, as I planted common milkweed this summer. I dug up some smaller plants that had escaped the borders of my mother’s garden.

I knew milkweed, as well as other native flowers, was in decline in Wisconsin, because of habitat loss. Since I had a new area of garden to fill up, I thought planting it with milkweed would be a great idea and I could help Mother Nature along.

I planted about eight small plants in a sunny location. I didn’t think much would come if it this season, as the plants were so small. I watered them well, and like every good gardener, waited for them to grow. I looked forward to the day when they would attract the lovely monarch butterfly, give it a place to lay eggs and provide food for its caterpillars.

In the end, I didn’t have to wait long at all for my little milkweed plants to attract attention. Within a couple weeks, I had monarch butterfly caterpillars snacking all over the place. Two of the caterpillars were full-grown and perched on the mini-milkweed. I wondered how the plants remained standing at all.

Then one day, I noticed a fury, black mass on the back of a leaf. When I investigated further, I discovered the fury, black mass was a group of tiny caterpillars. The caterpillars were all covered in tufts of hair, mostly black, but had tufts of white and bright orange along their back.

I wondered what they were and did some research.I discovered they were the larvae of the milkweed tussock moth. These caterpillars feed on various types of milkweed and dogbane. After they hatch, they feed together as a group. As they grow, individuals move to different areas of the plant to continue feeding.

The milkweed tussock moth is found throughout eastern North America. The adult moth will lay its eggs on the underside of the leaves of the milkweed plant and produces two generations, annually.

The adult tussock moth is not as colorful as its larval form. In fact, it is a simple, light gray moth, with no distinctive markings on its wings. Its body is orange and black striped.

So, little did I know, that in the end, I was also helping to provide habitat for the tussock moth. The tussock moth caterpillars stayed quite awhile, grew rapidly and ate all the leaves off my little milkweed plants. I wished I had more for them – it is certainly needed.

Growing milkweed is not difficult to do and it is vital to supporting selective feeders like the monarch butterfly, and the milkweed tussock moth. Milkweed is a native plant to this area, and readily grows in average soil. It prefers full sun and is drought resistant.

Milkweed can be purchased at nurseries that carry native plants. Make sure to plant some, and watch the moths and butterflies flock to it.

Happy Gardening!