Outside is the summer night is getting dark. What are those twinkles in the yard?
They are fireflies. With their twinkles, they communicate to one another. The males zigzag in their flight. The females wait on the grass or a plant and watch for a male’s twinkling light. If a female likes him, she will twinkle once to him. These bugs flash at one another for about twenty minutes, not all night. Some kinds flash for hours.
Fireflies are not flies. They are beetles with three main body parts: a head, a thorax, and an abdomen.
Its head has two large eyes. The eyes have many flat surfaces. The scientists believe these make the firefly see objects as if it were looking through a cracked mirror. On its head are two antennas. These are used to touch and smell and to check out its surroundings. The head also has two sharp jaws called mandibles that it uses to catch its food.
The firefly has no teeth. It uses maxillas to chew its food. These are found behind the mandibles.
The thorax comes behind the head. The firefly’s six legs are attached to the thorax. Each leg includes a foot with two claws. These serve the beetle in climbing.
The firefly’s two sets of wings are attached to the thorax. The front pair is stiff and protects the lightweight wings underneath. When the firefly wants to take off, it opens its front wings and uses the other wings to fly like a ladybug does.
The abdomen is behind the firefly’s thorax. On the bottom of the abdomen lie its light organs. These make the firefly glow yellow or yellow-green.
The light organs contain chemicals to mix and make light energy. The firefly’s light is called bioluminescence (by-oh-loo-muh-NEH-sunts).
A firefly hatches from an egg. The mother firefly (female) lays from 40 to 1,000 eggs at one time during the summer. She deposits them in loose, damp soil to keep them safe from the sun’s heat and light.
The tiny egg is round and soft and smooth, and it glows! But it doesn’t twinkle. The egg hatches in less than a month.
Then the firefly is called a larva (LAR-va). It still doesn’t look like an adult. It resembles a worm with ridges.
In the day the larva hides and sleeps and hunts for food at night. It eats earthworms and soft insects. It’s like a human baby and must eat liquids. The larva grabs the insect by its mandibles. Then it squirts a liquid into the insect through its mandibles to soften the insect into a thick liquid. This is the firefly’s meal.
Soon the larva grows too big for its skin and molts. When it molts, the larva splits its skin open and wiggles out, and then grows a new skin. Molting occurs several times through the winter.
Some species of firefly larvae are adults in the spring; other kinds take another summer and winter to become an adult.
The firefly larva builds a shelter out of mud. The larva chews the soil until it is mud, and then spits the mud out in strips. Over and over, the larva piles strips of mud on top of each other to make its shelter.
The larva crawls in and curls up in its new home. There it stays for about five weeks.
Once more it molts. This time it forms a stiff, white cover. Now it is called a pupa (PYOO-puh). The pupa grows all its adult firefly organs, which takes 10 days. Then it is an adult firefly.
The new adult stays in its shelter for a few more days. It is white or tan, but turns to brown or gray within only a few hours. When its wings and legs are strong, the firefly chews its way out.
Most adult fireflies don’t eat or drink. Some species drink flowers’ liquids; some drink water. Adults live from five days to a month.
