The wonder of fireflies

Published 4:58 pm Friday, April 21, 2023

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Watching fireflies glow in the backyard makes my heart sing. Fond memories of catching them in jars and watching them blink until we carefully released them back into the wild before we had to go to bed are conjured up every time I see them.

First, what exactly is a firefly or what’s commonly known as a lightning bug? The simplest definition is they are glow-in-the-dark beetles, and there are over 170 species in just the US. So what are the ones in my backyard called? Believe it or not, they are called big dippers, just like the constellation.

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Their light is called bioluminescence, with the yellow-green glow coming from their abdomen. Chemical reactions inside the firefly’s body create light. While there are numerous bioluminescent animals in the ocean, fireflies are among the few animals living on land that glow. 

Each species has its own light pattern, and by flashing each other, males and females can find mates. Research has shown females respond to male flashes that last the longest. 

Fireflies are beneficial to your garden, feeding on snails and slugs which eat your plants. Plus, they are pollinators, helping your plants make baby plants. These are really cool bugs!

In North Carolina, we have a very special species that are not found in other parts of the world, the blue ghost firefly. It is unique for holding a steady, bluish glow rather than flashing. They can stay lit for a minute as they look for a mate while flying a few feet above the forest floor. The females don’t fly but wait patiently on the ground for the right male to find them. I have yet to see one, but I am hoping to see them next month when they fly for a short 2-week period near Asheville.

One other well-known but rare species is the synchronous firefly. We have them in N.C., especially in the Great Smoky Mountains National Park. All the fireflies blink at exactly the same time, which is, again, a mating call. The females want to be sure the male is one of her species and not a predator firefly looking for a meal. Nature is so clever!

You may notice there aren’t as many fireflies as when we were kids. This is true of so many insects. Why are there fewer?

Fireflies face many threats, including habitat loss, light pollution and pesticide use. Even firefly tourism, which is becoming big business, can cause problems with trampling habitats and too much light at night.

So how can we help? Turn off your outside lights at dusk to help the fireflies find mates. And did you know when you rake your leaves, you are destroying their habitat since dead leaves are where a number of fireflies overwinter? Leave some tall grasses around your property, as this is where fireflies hang out during the day. And please limit or stop using pesticides. They kill all the good bugs, including fireflies, butterflies, and bees, in addition to the ones you are trying to eliminate.

I hope you will stop tonight, at dusk, and look outside for fireflies. Feel the wonder of one of Mother Nature’s many miracles.