Air Date: Week of August 16, 1996

Facts about... fireflies.

Transcript

CURWOOD: Chasing fireflies is a classic childhood summer experience. Also known as lightning bugs, there are 2,000 species of fireflies inhabiting every continent except Antarctica. Each species is characterized by the rhythm of its flashes. Some tropical species congregate in groups and flash in unison. Controlled by the nervous system, firefly light is caused by the instantaneous oxidation of a substance located on the underside of the insect's abdomen. Firefly light is described as cold light because it contains very few infrared and ultraviolet rays. All firefly larvae, and in many cases their eggs, give off light. The term glow worms refers to the larvae and flightless females of some species. During the summer the adults spend the day resting on vegetation, but from dusk until about midnight they fly around flashing. The males do it to attract mates. The flashing may also be a protective mechanism to remind predators of their bitter taste. Still, some frogs eat such a large number of fireflies that they themselves glow. And for this week, that's the Living on Earth Almanac.