Facts About Fireflies

A firefly is an interesting creature. It isn't really a fly at all! It's a beetle. Fireflies are also known as lightning bugs. And their larva as glow worms. There are close to two thousand species of fireflies around the world. In North America, there are about 200 species of fireflies.

What do fireflies look like?

A firefly is mostly black or brown. The outside of the wings are usually rimmed with colors. These colors may be shades of green or red. Fireflies have a soft underbelly that gives off it's noted glow. Two antennae are visible upon close inspection. And photographs show a strong mandible and three toothed saw plate. You can find some very detailed firefly photos at http://www.byteland.org/naturalist/firefly_faq.html . You have to scroll past some text between the pictures. There is some pretty good information in the text. About the middle of the page is a video of a firefly eating another insect!

Where do lightning bugs live?

Lightning bugs thrive in warm, humid areas. Some are found in arid regions, as well. Most firefly species are found in tropical Asia , South America, and Central America. Fireflies can be found in large numbers around bodies of fresh water, such as streams, ponds, and rivers. In arid locations, more fireflies emerge after heavy rains.

What is a lightning bug's life cycle like?

When the female lightning bug lays eggs (usually on the surface of moist rotting leaves , logs, or moss), it takes about three weeks for the eggs to hatch. The eggs do glow, as do the larvae (hence the name glow worm). Lightning bugs remain as larvae for about one year. This is the longest part of the firefly's life cycle. As larvae, fireflies feed through the Spring and Summer until the cool Fall weather appears. At this time, the baby fireflies snuggle under leaf litter and other decomposing materials for the winter. When temperatures rise again in the Spring or early Summer, the larvae pupate into an adult lightning bug. Adults will live from one to two weeks before mating and dying. Firefly photos from breeding through hatched larvae can be found at: http://www.byteland.org/naturalist/urban_jungle/ppyralis_gallery.html . Some more very detailed firefly photos of eggs and larvae can be found at:

What do fireflies eat?

Firefly larva are carnivorous. They eat earthworms, snails, and slugs. On occasion, they may even eat each other! Adult fireflies sometimes drink nectar. Most species are carnivorous. They usually attack other species of fireflies and eat them. They may also eat some other insects, too.

Mating habits of the firefly

There are so many different firefly species that it would take a book to tell the mating habits of each one. Instead, here is the mating habits of one of the most common species in North America, Photinus pyralis. In this species, the females are usually stationary. They stay on tree or shrub branches. The flashes you see flying around are most likely the males. They fly around and flash to attract females. If the females think they want to mate with a particular male, she answers his flash with a matching one. Each species has a distinctive flash. The male then flies to the female and they mate. Well, most of the time. Some species of female fireflies have learned how to mimic another species' flash. When the unsuspecting male firefly swoops in for a little romancing, she pounces on him and eats him. You can find a video of a male firefly in flight and flashing at:

How do lightning bugs flash?

Lightning bugs make their "lightning" when chemicals, enzymes, and oxygen mix together. This creates the flash of light you see. More specifically, Luciferin combines with the enzyme Luciferase. This is mixed with oxygen and ATP (adenosine triphosphate). This glow is called bioluminescence. All lightning bug larvae glow, but not all adult fireflies do. There are a few theories on how fireflies are able to turn their glows 'on' and 'off'. However, none of them have been proven. Lightning bugs are very energy efficient critters. Almost all the energy produced from the lighting process is expelled as light. For comparison, a light bulb uses about 90% of it's energy for heat and 10% for light.

Fireflies in a jar

You can spend an entertaining evening catching fireflies in a jar. As children, my sister and I spent many summer evenings chasing lightning bugs. We would catch them in a canning jar. I remember fondly how we would take the jars into the garage light to observe our "pets".

I'm sure my mother tired of having to compare fireflies to see who caught the best specimen. Nevertheless, we never tired of releasing our friends to play another round of catch the fireflies in a jar.