Insect illumination

Fireflies have returned to Chipmunk Ridge, the name we have lately given to our little ranch in the burbs. Chasing fireflies was one of the joys of my long-ago youth, so having them around is a vital part of the summer experience for me. The flashy little insects have frequented my yard for the last twenty years or so (basically as long as I've been paying attention in my adult life), but I learned recently that not everyone is so lucky and that firefly populations are declining in the United States, depriving large numbers of our children (and adults, of course) of one of summer's free delights.

Fireflies are vanishing because of our excessive tidiness and fear of the dark. Fireflies communicate with light, and the amount of outdoor nightlighting these days seems to confuse them. Since these little insects live only a few weeks in their luminescent stage, they have very little time to shine their light and find a mate. No mate=no baby fireflies.

As if finding Mr. or Ms. Right weren't enough of a challenge (whatever one's species, if poets and novelists are to be believed), fireflies these days have difficulty finding habitat. They need rotting wood or leaf litter on which to lay their eggs as firefly larvae are carnivorous and feed on the small invertebrates such things attract. Unfortunately for the fireflies-to-be, most American yards have a shortage of fallen leaves and decaying twigs, leading to a shortage of delicacies like baby slugs. Most neighborhoods are starving their fireflies. Worse yet, fireflies are beetles, not flies, so the chemicals we dump on our yards to kill the grubs of Japanese beetles kill firefly larvae--but beetle-damaged turfgrass is un-American, isn't it?

The larvae that survive to adult fireflyhood need daytime shelter. They like hiding under poison ivy vines on trees (and I certainly wouldn't go looking under an enormous hairy poison ivy stem for fireflies or anything else) and, fortunately for those of us sensitive to uroshiol, in tallish grass. But--of course--the grass so carefully protected from beetles is then cut short, forcing our poor fireflies to waste their limited time looking for someplace to spend the day.

It's a miracle that we have any fireflies at all. Luckily, we humans have the option of helping these tiny miracles to become more common. We just need to back off a little and leave a few patches of wildness in our neighborhoods. And turn off the lights sometimes, at least during breeding season. We can see the firefly show better then, anyway.