Terrie Humphreys, age 10, of Charleston, W. Virginia, for her question:
What do lightning bugs turn into?
These fairy flashers are just as beautiful whether we call them lightning bugs, fireflies or glowworms. But they are not true flies or true worms. And the word bug may mean almost any bitsy type of insect creature. The lightning bugs are insects and not related to such bugs as spiders or centipedes.
The world has a multitude of different bugs and each type has its own life story. Most of the creatures that we call bugs belong to the vast insect clan. And insects are famous for their amazing changes. You would expect a wormy grub to remain a wormy grub all his life. But if he happens to be an insect, he may change from a wormy caterpillar into a crusty chrysalis and later emerge as a glamorous butterfly with gorgeous wings. A wormy grub may hide his true identity until he reaches the final, grown up stage of his life. Then, if he has a body in three sections a head, a thorax and an abdomen, we can suspect that he is an insect. If he has three pairs of jointed legs attached to his middle thorax section then we know for sure that he is an insect.
The class of insects is a huge one and is divided into small groups called orders. And the biggest order is filled with insects we call beetles. Scientists do not use the word "bug" because it can mean too many things. But they understand when we ordinary folk refer to the beetles as bugs. So we may talk about lightning bugs. People who call them fireflies are not correct, for the fairy flashers do not belong in the insect order of true flies. They are beetles. And all the many beetles grow through four stages of life.
Like all the other beetles, our lightning bugs begin life as eggs. The eggs hatch into wormy grubs and spend this hungry stage of their lives grubbing for food, in soil or rotting logs. In North America, we have 50 different types of lightning bugs and there are many other varieties in different parts of the world. Some types glow with soft glimmers even during the egg stage of life. Some glow softly during the grubby larva stage of their lives. Sooner or later, the grubs change into pupae and sleep soundly inside their smooth, tough skins.
As a lightning bug sleeps through his pupa stage, miraculous changes happen to his little body. When the job is done, his skin cracks open and out he comes to greet the world as a different creature or so it seems. He has six long twiggy legs attached to his middle section and a pair of long twiggy feelers on his chunky head. Most amazing, he has two pairs of gauzy wings, also attached to his midsec¬tion. His head and mid section are small compared to his long, soft abdomen. His dainty little flashlight is built into the tail end of his large tummy section. Through this adult stage of life, he may dine on a little pollen or eat nothing at all. His main interest is dating a lady lightning bug after dark. Later, she will lay a batch of eggs in the loamy ground and leave them to carry on the same life cycle through the next generation.
In America, the little grubs we call glowworms are at the larva stage of their life cycles. In Europe, a glowworm may be an adult lightning bug. She is a female beetle with six long, twiggy legs and no wings. The male, however, does have wings and takes to the air. But his glow may be very dira or he may have no flashlight at all. In order to find a date, he must watch for ground signals. And the female glowworms do all they can to attract his attention by flashing on and off the little fairy lights in their tails.