©Marlene Condon
July 3, 2020
Now is a special time of year to sit outside as evening falls. If you’ve provided good firefly habitat, you may get to see several species of fireflies, one of which creates a wondrous display reminiscent of fireworks!
Numerous male fireflies — all making their tiny flashes of light — rise from plants at the same time, just like fireworks ascending into the night sky. It’s an enchanting experience for adults and children alike to watch these critters make light, especially because most animals are unable to replicate this feat. Even firefly eggs emit the curious glow.
Some folks know these insects as “lightning bugs,” while others call them “fireflies.” But these animals are not classified as either “true bugs” or “flies,” but rather as “beetles.” They are distantly related to ladybeetles/ladybugs.
All those little flashes of light are a sort of Morse code that males use to find females. Signals range from a simple single flash of light repeated at regular intervals to more complicated groups of flashes that vary in brightness and speed.
Male fireflies start looking for mates shortly after sunset. The females wait on leaves or grass stems and watch the show. When a female sees a familiar flashing that identifies a potential mate, she waits a few seconds before shining her own light.
The length of this pause seems to be the distinguishing factor between species. A male can determine whether he has found an appropriate mate by whether her “answer” comes too soon, too late, or at just the right moment!
When a male firefly does find a female of the same species, he flies towards her while repeating his light signals over and over. The female repeats her light signals until the male reaches her side, and they mate quickly. The male then flies off to find another partner.
The fertilized female lays her eggs five or six days later when they have fully developed. After darkness falls, she finds vegetation, such as moss, that tends to stay moist, not wet. The eggs will be concealed, and the right amount of dampness will keep them from either drying out or rotting.
TIP: If you enjoy seeing fireflies, don’t get rid of the moss in your yard. It serves as your firefly incubation area.
After about a month, the immature fireflies bite their way out of their tough eggshells. They spend their time among leaf litter and soil, hunting for soft-bodied animals, such as worms, slugs, and snails, to eat.
A firefly larva can seize a snail’s soft body with its sharp jaws and hold on even as the snail withdraws into its shell. It injects the snail with digestive juices that dissolve its body so the larva can suck out the softened tissue.
Firefly larvae hibernate for winter, changing into the adult form underground.
They emerge the following spring to reward us with many nights of light shows, especially if we’ve kept moss in the yard. Be sure to make time to enjoy the show!