Butterflies are a beneficial pollinator. People love to watch them in their gardens because of their delicate beauty. Once you experience them coming into your garden, you may also begin to wonder what happens to them in the wintertime.
Most butterflies are "residents" which means they winter over right in your garden. Some, like the famous monarchs, migrate to warmer climates. The Monarchs go all the way to Mexico, but many migrating species go only as far as the Carolinas. A few of our very common butterflies that migrate are the Cloudless Sulphur, Painted Lady, Red Admiral, and the Common Buckeye. There are more than one hundred species of butterflies that have been reported in Pennsylvania, but exactly which ones you may see depends on the habitat needs of that species, and what your property has to offer.
Almost everyone is familiar with the monarch butterfly. Its beauty is unsurpassed in the butterfly world. In recent years they have attracted a lot of attention because they are endangered. Their single host plant, Milkweed, is systematically being destroyed by the "progress" of modern civilization. Since the monarch caterpillar can survive on nothing but milkweed, and most people don't want Common Milkweed growing in their lawn, the monarch numbers have been diminishing at an alarming rate. Today, savvy gardeners are providing a section of Asclepius (milkweed) in their ornamental gardens, and also discovering Butterfly Weed, a very attractive member of the Asclepias family.
Almost every school child can relate the story of how the monarch lays her eggs on the leaf of the milkweed plant. The egg hatches and the caterpillar (larva) eats the leaves of the milkweed. It then forms it's chrysalis (pupa) which hangs by a thread until the adult butterfly emerges.
Every butterfly species will go through the same life cycle. What changes is the host plants that enable them to survive, and the form in which they survive the winter.
Our beautiful and very common Eastern Swallowtail butterfly is a resident. It goes through the same stages of metamorphosis - egg - caterpillar - chrysalis - butterfly, but it does not migrate. Shortly after it emerges from its chrysalis, it will mate, lay its eggs, and the cycle will begin again.