Nature Nearby: Fireflies light up our nights
By FRED SEITZ — On a warm evening a few weeks ago, my wife and I walked down to Magruder Park in hopes of seeing the Lyrid meteor shower, which occurs every year in April. Unfortunately, it was a bit cloudy, plus local light pollution prevented us from seeing the meteors. (The Lyrids were fortunately visible the following night.)
We were, however, pleasantly surprised to see some sort of flying flickering nearby. While it was mild out, it still seemed a bit early in the season to witness the phenomena of well over a dozen fireflies gracing our evening. In recent years, firefly sightings have been reported earlier in the year, and experts have suggested that the emergences are sooner because of climate change, including increased rainfall.
Fireflies (aka lightning bugs or glowworms) are one of Mom Nature’s gifts to night walkers and campers. Lightning bugs are on every continent except Antarctica. Their chemically produced “cool light,” which doesn’t produce any heat, has intrigued and inspired people for centuries. Japanese legend suggests that fireflies are the souls of dead warriors, whereas an Apache legend tells that a fox once tried to steal the firefly’s light but set his tail on fire, then was forbidden from ever using their light again. Victorians feared that if a firefly got in your house, someone would die.
Whatever interpretation you prefer, the magic of these small beetles (they belong to the Lampyridae family and are not really flies) is in part attributable to the luciferin in their tails, which allows for the wonderful glow. This glow entertains us and, if we temporarily harness these nightlights in a jar, may help us find our way home.
From the fireflies’ perspective, males use their glow to entice females for mating and females may glow their approval in return. Some more dangerous femme fatales use their light to attract males and devour them. Interestingly, the male mostly does his courtship lighting in flight, while the female is usually perched in the grass when she either consents to courtship or invites him to be her dinner.
Females lay their eggs in the ground. The eggs hatch in about three weeks, and the larvae burrow in for the remainder of the year; for some species the larvae may remain underground for several years. Interestingly, not all fireflies can illuminate, but some species’ larvae can produce a glow while maturing underground.
While lightning bugs may not be the magical critters of folklore, some species offer one more surprise: In some places, including areas of Pennsylvania and along the Great Smoky Mountains of the southeastern U.S., synchronous fireflies illuminate collectively and simultaneously. Their spectacular shows attract thousands of spectators, and festivals are held in their honor.
When walking in the evening, look high into the trees and low in the grass to see if you can share in their magic.