Where does a firefly get it’s light?
A flock of fairy fireflies in the summer dust sparks your imagination and curiosity so this is a very popular question among Andy’s readers, If you are one of the many who asked Andy about fireflies, please do not feel sad or mad that your question was not selected for the column. Just try again. The number of questions you can ask your busy reporter is equal to all the winking fireflies in the world.
When a light bulb burns out, you find that it is too hot to handle for several minutes, This is because our lighting system produces a lot of heat, which we do not want, along with the light which we do want. It is a wasteful system because the useless heat uses up power. The little firefly is more economical, for he produces his winking light while wasting practically none of his fuel energy on unnecessary heat.
The fireflyts golden lantern has been called cold light and many teams of scientists are trying to find out exactly how he does it. The trick is called bioluminescence, which means light produced by living things. Click beetles, glow worms, certain fungi and bacteria also are able to produce glowing bioluminescence, They produce cold light which wastes almost no energy on heat.
The light organ of the firefly is in the tail end of his soft little abdomen, It is a wad of fatty tissues riddled with a network of fine air tubes. The little generator uses a very complex chemical process which, as yet, we do not fully understand. But we know some of the chemicals used and we are fairly sure of a few of the steps in the process.
One chemical present in the firefly's generator is called luciferin, another is luciferase, another is adenosine triphosphate which is written in shorthand as ATP. The ATP chemical is also present in our own muscles. So far as we know, the firefly’s luciferin changes into other chemicals in the presence of luciferase and ATP.
When this complicated chemical process is going on, energy is released. Almost all of this energy is released in the form of light. Unlike our own extravagant lighting systems, hardly any of the energy is wasted on unnecessary heat.
Fireflies are actually beetles and usually drab, peanut sized fellows who spend the day hiding under stones and fallen leaves. At dusk, they fly forth in hosts and flash on and off their fairy lanterns. The winking flashes are courtship signals. When trapped, say, in a spider web, the firefly turns his light en and keeps it on. This steady flow, we suspect, may be a firefly SOS distress signal.