Lightning bugs strike this summer

Published 1:59 pm Saturday, June 9, 2018

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Susan and Biff Andrews

We were recently visited by an insect swarm. No, it wasn’t termites. The bugs were the size and roughly the same shape as lady bugs — but dark all over. It was clear they were not fully formed. And then a few days later we saw them again in more developed form. They were lightning bugs.

We older folks have fond memories of soft summer evenings collecting lightning bugs in a glass jar with grass and sticks in there — holes poked in the top for air…. until bedtime when all specimens were released. Our grandkids have had the same experience once or twice. But lightning bugs are going the way of the dinosaur.

First the facts. Lightning bugs, or fireflies, are beetles. Eggs are laid about a hundred per female in midsummer. They are deposited in moist leaf litter or moist rotting logs. In three weeks they become larvae, looking like worms… glowworms. They stay in larval form for 50 to 102 weeks. In late spring the larva constructs a mud chamber and goes through a pupal form to become an adult. But the adult has only one purpose in life: to flash enough to find a mate and consummate the relationship.

Each species has its own flash pattern. The males fly low and the females resting on the vegetation respond to flashers flying by. Bingo. They live only three to four weeks.

They may or may not eat. If the predate, it’s on other bugs — even other lightning bugs.

The most amazing thing about their light is that it is 100 percent efficient. An incandescent light bulb emits 10 percent light, 90 percent heat. More modern bulbs may be up to 90 percent efficient.

But nothing can challenge to cold light of the firefly.

So why are they dying off? Several factors, most predictable. Habitat loss or development. If a field or wooded area is paved over, they won’t move… just die.

Light pollution is another problem. Since they communicate and court by light, ambient light from housing interferes. And then there are pesticides on lawns and marshes trying to limit mosquitoes or grubs or… .

So leave some of your leaf litter in a hidden corner of your yard. Turn off outdoor lights at night. And spray sparingly. If you’re lucky, maybe you, too, will experience a swarm

of juvenile fireflies. Maybe you, too, can look forward to grandkids collecting and releasing adults. Ahhhh, summer!

SUSAN and BRADFORD “BIFF” ANDREWS are retired teachers and master naturalists who have been outdoor people all their lives, exploring and enjoying the woods, swamps, rivers and beaches throughout the region for many years. Email them at