Thursday, June 2, 2011

Lights Out for Lightning Bugs

Memorial Day is behind us, summer is ahead of us, and, if we're lucky, lightning bugs (or fireflies) are all around us on the long summer evenings in Atlanta. Of course, they aren't really flies, they're winged beetles of the order Coleoptera. And for many of us, they're the highlight of a summer's evening.

Thirty years ago the trees and fields of suburban Atlanta were full of fireflies in the early summer. There are many fewer now, possibly because of the drought of a couple of years past. Fireflies like to breed in dark, moist places, and those have been few and far between until last year. It is also possible that light pollution has reduced the population. The fireflies we see flying around are usually males. The flashes are to attract mates, and if there's bright artificial light, young fireflies in love may not be able to find each other.

Even with those barriers, Georgia has more species of fireflies than any other state.

Larval fireflies are predators; they feed on the larvae of other insects, on snails, and on slugs. So, having fireflies around is good for lawn and garden.

Encouraging Fireflies

One of the easiest things you can do to encourage fireflies to inhabit your yard is to reduce outdoor lighting to the minimum necessary. Keep lights out from Memorial Day to about midsummer... as long as you see fireflies blinking in the dusk.

Reducing or eliminating outdoor use of insecticides, especially in early summer, will help give the fireflies a chance.

Female fireflies like to stay on or near the ground. Mowing infrequently and setting aside some part of your property that can grow a little wild gives fireflies a place to shelter.

Fireflies like moisture. If you are lucky enough to live by a stream or pond, try to keep that area dark in the evening and mow it infrequently.

Kids, Fireflies, and Fun

About fifty-five years ago when I was a child, we'd catch fireflies in a mason jar with holes poked in the lid and pretend the jar gave enough light to let us find our way through the dark woods. That wasn't a good idea then, and it still isn't. You will end up explaining to your child why all the fireflies died over night, and that won't be a fun time. It's also possible that children might put fireflies in their mouths. They taste really nasty; it's a defense against predators like birds. Or small children!

There are plenty of things to do that don't involve catching or eating fireflies. Different species flash different colors from green through yellow to pale red. Ask your child to see whether there are different colored flashes, and if so, explain that those are different kinds of fireflies.

Have your child look for two or more fireflies that are flashing simultaneously and see how long they stay in step.

Try to count the number of fireflies in two different areas of your yard and speculate about why there's a difference.

Time the flashes of one firefly by counting one-Mississippi, two-Mississippi and see whether they are all flashing at the same rate. Differences may indicate different species.

Have your child lift the back of her hand underneath a close-by firefly. It will likely land there and continue to flash for several seconds before taking off again in search of a mate.

The sun's been down for a while. Dusk is coming on, and those sound like so much fun I think I'll go outside and try them out!

This article also appears on the Elite Property Maintenance site.  Photograph by roguewriter3 on Photobucket.