  The Firefly is sometimes called a Lightning Bug or Glowworm, but is actually a small beetle. North American fireflies are usually tiny, and can be mistaken for mosquitoes as they float around or sit on a leaf, until you see them up close, ... or until they flash a tiny light at you!Fireflies are beetles in the family Lampyridae, and have two sets of wings (like all other insects except true flies, which have just one pair). Most firefly species are bioluminescent as adults. This means that they 'light up' by mixing chemicals in their bodies. Fireflies are often found around water, near ponds, streams, or marshes. 
Almost 100% of the energy in firefly's light is given off as light. By comparison, a normal lightbulb gives off just 10% light and 90% heat. The chemical reaction that does this is very efficient. Learn more about the bioluminescence reaction here. The chemicals that produce this light, particularly a chemical called luciferin, can now be synthesized in a laboratory, and are used in common glow sticks, which mix chemicals to give off a bright but cool light. They also have medical applications. Because luciferin reacts to a substance in living organisms (ATP), scientists use it to detect bacteria. By using luciferin in blood or urine samples, or in foods such as milk or orange juice, scientist can determine how many bacteria are in the sample by the amount of light that it gives off. NASA may use it to detect living organisms on other planets.
 Classroom Activities:  Demonstration: Use light sticks, which you can find in sporting good shops, to demonstrate how chemicals can mix together to create light without giving off any heat. These light sticks are often used by campers and hikers as a simple source of light. The light from green ones is very similar in colour to the light from a firefly. A Firefly Game: All students will need a small flashlight. Prepare three sets of cards, one for each of three firefly species. Each set of cards will all contain the same instruction for how to signal with the flashlight. For example, the species 1 cards might say 'one short, two long'. Distribute the cards to the students randomly. Have all the girls sit in the center, while the boys move around the room. Dim the lights, and have everyone begin flashing their species 'code'. When a girl recognizes a flashing sequence from a boy as being the same as her own, she gets up and joins the boy, and sits down with him at the side of the room. Continue until all possible pairs have been 'linked up' by the flashing messages. |