Marc Magnuson, age 13, of Sioux Falls, S.D., for his question:
WHAT MAKES THE FIREFLY GLOW?
Did you know that fireflies have been used for decorations? Cuban women sometimes pin a firefly called a click beetle on their gowns, or attach one to a golden chain. The click beetles give off a strong, green light that is ornamental.
Travelers through dense, tropical forests at night sometimes attach fireflies to their boots to light the path in front of them.
Firefly is the name given to a number of different beetles that glow in the dark. Some types give out a tiny spark of fire in the darkness.
Often called lightning bugs or lightning beetles, fireflies live in warm and tropical countries. Most in the United States live east of the Rocky Mountains.
One of the most common type of fireflies is about a half inch long and is black with red and yellow spots. Found often during midsummer, it eats pollen and other foods during the day, and then spends the warmer part of the night flying around and flashing his light. The flashing usually happens at just the second the beetle starts his up and down course of flight.
In the firefly's abdomen five chemicals are bound up by a chemical controller. Some of the chemicals are tongue¬twisters: adensine triphosphate, luciferin, oxygen, magnesium and luciferase. When nerve stimulations release another chemical, this one called inorganic pyrophosphate, the bond breaks and the reaction produces the firefly's light.
The firefly's light area usually appears on the side of the abdomen. Seconds later the light goes out because another chemical destroys the pyrophospate.
The firefly is one of the few insects that uses vision to find a mate. Male fireflies actually find females by following their flashing lights.
Most fireflies have wings. Some, such. as the common glowworm of Europe, have no wings. Female glowworms give off little or no light.
The railway beetle of Paraguay is another insect that doesn't have wings but can give off light. It is about three inches long and sends forth a red light from both ends of his body. It gives out a green light from other points of his body. He's called the railway beetle because of his red and green signal lights.
People in some tropical countries actually use fireflies for light. They put the insects in bottles and then use them for lanterns. Although fireflies give off flashes of light, when many are in a bottle together, they give a continuous though wavering light.
Biochemists use fireflies to study bioluminescence, the heatless light that is given off by certain animals and plants.