Tom Turpin
Professor of
Purdue University







Butterfly Or Moth?

Scientifically, butterflies and moths are close relatives. They are classified as Lepidoptera. If the order name Lepidoptera sounds a bit like Greek to you, that's because it is. Like many scientific names, Lepidoptera is based on Greek terms. The first part, lepidos, means scale. It is the basis for the word leprosy, a human disease that results in scaling skin. Combine lepidos with the Greek word for wing, ptera, and we get the word Lepidoptera.

Literally, then, butterflies and moths are the scale-wing insects. It is an appropriate scientific name for these insects since one of their most recognizable characteristics is their wings — their scaled wings. Almost anyone who has ever caught, or attempted to catch, a butterfly or moth has found that the wing scales rub off rather easily.

In addition to the basis for their name, butterflies and moths also share other characteristics. For instance, adults of both have coiled tubes for mouths. These tubes are used for imbibing liquids, most often the nectar from flowers or water. As immatures, the Lepidoptera are known as caterpillars, and all have chewing mouths that are used to chow down on their favorite food — which is most often the foliage of plants.

There are, however, major differences between butterflies and moths. First, they fly at different times. Butterflies are out and about during the daylight hours. Moths, on the other hand, fly at night. These activity patterns relate to the fact that butterflies tend to be bright colored while moths are dull colored. After all, it doesn't seem appropriate to dress in showy clothing if you are not going to be seen, as is the case for most moths.

Moths also have fuzzy antennae. Butterflies have hairless antennae, many times with a knob at the end. Moths tend to rest with their wings held horizontally over their backs. Butterflies rest with their wings held vertically. In flight, butterflies tend to glide or float. Moths seem to be in a hurry and keep flapping their wings.

As for body shape, butterflies and moths could serve as the before-and-after examples for a weight-loss advertisement. The moth, with its rather stout build, would serve as the "before;" the slender butterfly could be the "after."

But those aren't the only differences. Even the caterpillars look different. Generally the caterpillars of moths are hairy, and the caterpillars of butterflies are clean shaven. The same is true of these insects when the larvae turn into pupae. Moth pupae tend to be covered, many times with silk. The silkworm is a prime example. The butterfly, on the other hand, has a naked pupa.

Of course, there are exceptions to all of these rules. A few moths fly during the daytime and even have bright-colored wings. And to make matters worse, some butterflies fly more like moths than butterflies. None-the-less they are all still Lepidoptera!


Writer: Tom Turpin
Editor: Andrea McCann