APRIL
2002

 

By
Tom Turpin
 
Professor of
Entomology
Purdue University

 

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Check out these books by Tom Turpin:

Flies in the face of fashion

What's Buggin You Now?

 

 

 

4-25-02

Download the audio of On Six Legs: MP3, WMV.

Butterflies Are Favorite Insects for Most People


Most people don't care much for insects. An exception is the insect that some poets have called a flying flower. Yes, almost everyone has a soft spot in his or her heart for butterflies.

If any insect group is perceived by humans to be warm and fuzzy, it is the butterflies. Butterflies really aren't warm, though. Like all insects, they are cold-blooded. But they are fuzzy! Butterflies, and their insect cousins the moths, have fuzzy wings.

Butterflies and moths are classified in the same insect order. The order name, Lepidoptera, reflects the fuzzy nature of their wings. It means "scale wing." There are roughly 10 times as many species of moths as butterflies, but most people are more familiar with the butterflies.

That is partially because butterflies are active during the day while moths are active at night. In addition, butterflies are mostly bright-colored. Moths tend to be somewhat drab. Consequently, people are more likely to notice butterflies than moths.

The color of butterfly wings is achieved in one of two ways. Some of the color is in pigments, much as it is in most other animals. In addition, color in some of the brighter butterflies--and a few other insects--is due to light reflection. In butterflies, small parallel ridges on the wing scales break up the light into component parts. Water droplets in the air do the same thing to light when a rainbow is produced.

The color of the beautiful morpho butterflies of the Amazon is produced in this way. Because the color is the result of light reflection, the color changes when these butterflies move their wings. Many morphos are a bright, metallic blue when the wings are held out from the body. When held vertically, however, the bright color disappears and the wings appear a brownish gray.

Morpho butterflies tend to slowly open and close their wings when at rest. Because the color changes as the wings move, the behavior works to confuse a potential predator, which might be considering a butterfly meal. The butterfly is playing a now-you-see-me, now-you-don't game with the predator.

The same effect is achieved by butterflies that have bright colors on the outside of their wings but duller colors on the underside. When the wings are folded, such as when the butterfly is resting, the color pattern may allow the insect to blend into the environment. Such is the case with the angle-wing butterflies. These butterflies are medium-sized of a reddish-brown color with black spots. The undersurface of their wings is gray and brown, colors that imitate bark and dry leaves.

Butterflies are often named after the way their wings look. Most people would recognize that swallowtail butterflies are named after the a projection, which looks like the tail of a bird known as a swallow, found on the hind wings.

The angle-wings have wing margins that are scalloped and indented as if they had been cut with scissors.

The whites and sulfurs are common butterflies, with names based on the color of their wings. There is a group of butterflies called the purples, and, you guessed it--they are purple in color. There is a banded purple, a spotted purple and a great purple hairstreak.

Peacock butterflies are dusky brown in color but have eyespots on the wings, similar to those found in the feathers of peacocks. Another group of brown-colored butterflies is the tortoise shells. Of course, their wing pattern reminds folks of the shell of a tortoise.

What is it that people like about butterflies? It might be the bright colors. Maybe it is their delicate nature. It might be the fact that they visit our gardens. But I suspect that people really like butterflies because--unlike some other insects--these flying flowers can't bite or sting!

 

 

Writer: Tom Turpin
Editor: Olivia Maddox