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Summer evening light-bearers

Backyard Safari

Tuesday, June 01, 2010

Media contact: Jessica Basham

Humidity hangs thick in the night air.  The sun has disappeared from the horizon, but the evening is still warm.  Suddenly there is a tiny twinkle - a gentle glow that flashes on and off every few seconds. A firefly!

A firefly's glow and flashing is how this member of the beetle family mates, defends itself and communicates it is in trouble.  These small insects live in marshes or wet, wooded areas and open fields by water. Many of the firefly's food sources live near water.  Would you believe a firefly can eat snails? Fireflies also enjoy munching on slugs, caterpillars and other soft insects. Nectar is another food they enjoy.

How does the firefly produce its flickering light in the night sky, and why does it flash?

The light produced by fireflies is a chemical reaction in its abdomen. The cells it carries to make light are called photocytes.  These cells contain two chemicals: luciferin and luciferase. When fireflies breathe in oxygen, the chemicals create the light we see, which is why its family scientific name, Lampyridae, meaning "torch bearer," is so appropriate.

To attract a mate, male fireflies flash a series of lights.  The female sits low to the ground on a leaf or branch. If she likes what she sees, she signals back.  This can be a dangerous game of love.  Certain female fireflies imitate blinks of other, smaller species and will lure a male of that species so she can eat him.  The firefly also can become a meal when it flashes distress signals.

But the firefly's flashes also may protect it.  The yellow light it produces warns predators that it doesn't taste good.  The chemicals that make the firefly glow are bitter to birds and insects that are looking for a meal.

Adult fireflies live only long enough to mate and lay eggs.  The larvae usually live for a year before becoming adults.  Firefly larvae also glow, which is why people call them glowworms.  There also are other beetles known as glowworms.

Fireflies are important to scientific discoveries.  One of the neatest things a firefly has helped scientists invent is the glow stick. Also, scientists reproduced the glowing chemical it creates to help with many medical procedures.  The chemical helps scientists detect harmful bacteria in blood or urine and milk, juices and other foods.

Join the Get Outdoors Florida! movement and the Museum of Science in Boston to track fireflies.  Scientists want to learn as much as they can about these insects.  So, while you are outside looking for nature's flashing beetles, you can help researchers learn where fireflies live and information about their activity during the summer. Visit to learn more about the program and how to participate.

FWC Facts:
The North Atlantic right whale is one of the most endangered marine mammals in U.S. waters.

Learn More at AskFWC