How fireflies use their electric bulbs to attract females?



Who would ever think that the lowly beetle would provide the model for a lighting engineer’s dream?

Yes, certain beetles called fireflies are living lamps, their light being without heat.

The light of the firefly is not even slightly warm to the touch.

Human’s electric light bulbs lose much of their power in heat, but this living lamps turn 100 percent of their energy into light.

But why does the firefly turn on it's glowing lights?


Why fireflies glow?



True, the glowing insects intrigue humans, but the real purpose is to find the opposite sex of their own species in the dark, enabling them to mate.

The male firefly of a common species in North America flies about during the warmer part of the night, flashing its light, usually as it is about to take an up-and-down course.

The color of the firefly light is mostly yellowish; but with some species it is rather greenish, bluish or of an orange hue.

The firefly’s lamp is fueled by a compound called luciferin.

When this comes in contact with oxygen, a catalyst known as luciferase sparks the process that produces light without heat.

Each species of firefly—there are about 2,000—has its own distinctive flashing pattern.

This is as characteristic as the songs of various birds.

When the female firefly sees the gleam she is looking for, she sends out an answering blink.

A female firefly rarely responds to the light of a species different from her own.

 At times, however, a female may respond once to a male’s flash that is similar to her own, but if the length of the next flash is not just right, she is not “turned on” and no longer lights up.

When the female firefly sees the flash she is looking for, she keeps her lamp turned on at the proper intervals, until the male reaches her and mating takes place.

Not always, however, does the firefly’s beacon result in the propagation of the species.

There is a female of one species that is a carnivorous seductress.

She is able to mimic the flash responses of many females of other species and lure the males to her, whereupon they are seized and eaten.

Unlike the individually flashing firefly of North America are the glowing insects of Southeast Asia and the South Pacific.

These fireflies can alter their flash pattern so that they blink in unison.

This enables them to light up whole trees with the regularity of neon lights.

This is the way a visitor to Mindanao, in the Philippines, described what he saw:

There were two trees about the size of apple trees and perhaps 100 feet apart, and every evening these were filled with fireflies which flashed in synchronism, first one tree lighting up, and then the other. There must have been several thousand insects in each tree, yet, the synchronism was so perfect that rarely or never did a single firefly flash at the wrong time. . . . It seemed so strange and produced so beautiful an effect that I thought it one of the most remarkable things in the Philippines.”

It is believed that the male fireflies pool their luminosity to give females spectacular notice of their whereabouts.

It is not known how each firefly is able to harmonize his flash with that of the neighboring males, but most of them blink together, as if turned on by a single switch.