According to the Journey North website, monarch migration peaked last week around the Great Lakes. That means it won’t be long before the migration peaks in Kentucky. The monarch butterfly’s migration to and from Mexico each year is a familiar story. But what happens to all of our other butterflies and moths? How do they survive the winter?
A few other butterfly species that we have in Kentucky also migrate south for the winter although we don’t know as much about their migration routes and destinations as we do about the monarchs’. Species that migrate include the cloudless sulphur (Phoebis sennae), the painted lady (Vanessa cardui), the American lady (Vanessa virginiensis), the gulf fritillary (Agraulis vanillae), the red admiral (Vanessa atalanta), the common buckeye (Junonia coenia), the clouded skipper (Lerema accius), the fiery skipper (Hylephila phyleus), the sachem (Atalopedes campestris), and the ocola skipper (Panoquina ocola).
At least one of our butterfly species, the mourning cloak (Nymphalis antiopa) hibernates through the winter in tree cavities or crevices as an adult butterfly. A few other species, such as the Isabella tiger moth (Pyrrharctia isabella), aka the wooly worm caterpillar, hibernate as caterpillars. However, migrating and hibernating are relatively rare overwintering strategies for Kentucky’s butterflies and moths.
Most of Kentucky’s butterfly and moth species overwinter as a pupae. In butterflies, the pupae is the chrysalis; in moths the pupae is a cocoon. The caterpillar spends the summer and early fall eating and storing as much energy as possible. In late fall, the caterpillar crawls a few feet away from its host plants (the plants it has been eating). If it is a butterfly caterpillar, it will crawl up another plant and form a chrysalis. It’ll overwinter in the chrysalis before completing metamorphosis and emerging as a butterfly in the spring. If it is a moth caterpillar, then it may crawl up another plant and spin a silk cocoon, it may crawl into the leaf litter and spin its cocoon, or it may borrow into the soft dirt and spin its cocoon. Like the butterfly caterpillar, the moth caterpillar will overwinter as a pupae within its cocoon before completing metamorphosis in the spring.
Butterfly gardens have become increasingly popular in recent years. Most gardening books will tell you to cut back dead plant material and rake up leaves and other debris in the fall. Yet, in a butterfly garden these activities can create problems for the very animals the garden was designed to attract. Cutting back dead plant material could mean cutting back plants with chrysalises and cocoons. Raking up and disposing of fallen leaves could also result in the disposal of moth cocoons or hibernating caterpillars. If providing habitat for butterflies and moths is an important goal for your garden, then consider leaving the fall cleanup until the spring. This will give the butterflies and moths a chance to emerge and will provide year-round habitat for these insects.
This article was part of Shannon’s original Kentucky Pollinators and Backyard Wildlife blog which evolved into the blog for Backyard Ecology.
Backyard Ecology: Exploring Nature in Your Backyard
Nature isn’t just “out there.” It’s all around us, including right outside our doors. Hi, my name is Shannon Trimboli, and I am the host of Backyard Ecology. I live in southcentral Kentucky and am a wildlife biologist, educator, author, beekeeper, and owner of a nursery specializing in plants for pollinators and wildlife conservation. I invite you to join me as we ignite our curiosity and natural wonder, explore our yards and communities, and improve our local pollinator and wildlife habitat. Learn more or subscribe to my email list at www.backyardecology.net.