Tom Turpin
Professor of
Purdue University







Flies of the Butter Season

Springtime has been called the butter season. It's an appropriate name. Butter is a milk product. Agriculturally, the greening of the grass and the birth of calves means milk production. Cream from the milk was used to make butter. So springtime was associated with butter.

Thus the season is the reason butterflies have their name. These insects, along with some birds, are the true harbingers of spring. Robins may get most of the press as predictors of spring, but many of us have noted ol' robin red breast, looking rather embarrassed, sitting on a snow-covered limb. No such mistake from butterflies; you know for certain spring is here when they begin to flit over the greening countryside.

Some people say butterflies are so-named because they are the flying insects of the butter season, in other words, butter flies. Others suggest the term might have originated because some of the earliest seen of the butterflies are those known, because of their yellow color, as sulfurs. They are the color of butter and were, therefore, called butter-colored flies.

Where do the butterflies of spring come from? The earliest butterflies are most often the mourningcloak, a name befitting the brownish-black color of the wings. These are one of the few butterflies that overwinter in the adult stage. They hide under the bark of trees or other sheltered places during the winter and appear early in the spring.

Most of the butterflies of Midwestern states spend the winter in the pupal stage. They are programmed to remain in that stage until the warm weather of late spring and summer is upon us. Thus many butterflies are most numerous during the summer.

Such is the case with the well-known yellow and white butterflies that, as caterpillars, damage alfalfa and cole crops and are hated by gardeners and farmers alike. The largest and most brightly colored of the butterflies, the swallowtails, also overwinter in the chrysalis stage. The swallowtails, for the most part, are not pests since they mostly feed on the foliage of trees. One exception might be the black swallowtail that, in the larval stage, feeds on parsley, carrots and related species of plants.

A few butterflies don't even attempt to deal with winter temperatures in the frozen north. The monarch migrates to the mountains of Mexico to spend the winter. Each spring these butterflies begin to move northward with the advance of the season. When the Monarch arrives, you know warm weather is here to stay. Maybe this butterfly should be called a summerfly!


Writer: Tom Turpin
Editor: Andrea McCann