Call them fireflies, lightning bugs, glowworms or whatever, one thing you can’t call them in recent years, is plentiful. You can still find the flashy bugs in many areas of the country, but in Texas you might have to do some serious searching, say two Texas A&M University researchers. Entomologists Ed Riley and Bart Drees say the past few years have dimmed the lights of the flashy insects dramatically.
“Why are fireflies disappearing?” It is a good question and the truth is that nobody really knows for sure. Oh, there are many speculations, and in most cases the problem comes down to we humans.
“There’s no doubt the severe drought we had a few years back affected them, too,” adds Drees, who is a Texas AgriLife Extension Service entomologist. “The lack of water had to be one big reason why you don’t see as many as in years past, but there are probably other reasons, too.” You bet there are; urban sprawl, light pollution and the over use of pesticides are at the top of my list!
Both experts agree that there has been very little research over the past decade to determine why there appears to be fewer fireflies, which are technically beetles and not actually flies at all.
“As to whether pesticides are to blame,” says Drees, “it is very probable, but there is no definite research. There are just not that many scientific studies to look at to come to any single or group of definitive answers.”
Their environment of choice is warm, humid and near standing water of some kind and in tall grass. They're nocturnal, and during the day they spend most of their time on the ground. At night, they crawl to the tops of blades of grass and fly into tree branches to signal for mates. Long grass conceals the fireflies better and allows them a better vantage point for signaling at night, and over-mowing your lawn may disturb your firefly population.
The problem is that throughout the world, our open fields and forests are being paved over, and our waterways are seeing more development and noisy boat traffic. As their habitat disappears, firefly numbers dwindle. Logging, pollution and increased use of pesticides also contribute to destroying firefly habitat and their natural food sources.
Human traffic is believed to disrupt firefly habitat as well. While scientific studies have only been done for the past few years, there's plenty of anecdotal evidence in areas that were once full of fireflies, and much of it goes back generations. Some areas once had so many fireflies that they profited from running firefly tours in marshes and forests, but since human traffic has increased, firefly populations have gone down.
Scientists aren't completely sure what most species of fireflies eat. It's probable that firefly larvae feed on different prey from that of adult fireflies, this is not uncommon with insects. The larvae are believed to be carnivorous, living off smaller insects, snails and slugs. Adult fireflies may also live on other insects, as well as pollen and plants, but it's possible that some species don't eat anything, after all, their lifespan is only a few weeks long. But scientists believe fireflies thrive in wet areas because their prey does as well.
Fireflies love humid, warm environments. In the US, almost no species of light producing fireflies are found west of the Rocky Mountains. The western US does have fireflies, but just not the flashing kind. They have some glow worms, where the female will give off a constant glow while on the ground, but most of these females can't fly, and some daytime fireflies where the adults do not produce light at all. No one knows why the flashing fireflies never made it past the Rockies, although there are warm and humid areas to the west.
Ecological damages are not easily reversed because they cannot be undone, and only remedied to some extent. But that shouldn’t discourage us from trying. A few of the measures we can take to welcome the fireflies back are:
- Preserve wild hubs – A bit of wilderness left undisturbed in the farthest corners of the garden will welcome these insects.
- Increase tree cover – The female fireflies park themselves on the cracks of tree barks awaiting their dates. They need some privacy.
- Avoid chemical use – Turn to natural pesticides and composting to make your gardens healthier for you as well as the fireflies.
- Reduce mowing frequency – The taller grass will provide the much-needed cover for the adults as well as the larvae.
- Install water features in the garden – They encourage the growth of slugs and worms that the larvae feed on.
- Reduce exterior lighting – Let them have a better chance at increasing their numbers. Businesses have to flash their signboards to attract customers, but do we really need our outdoors to be lighted up so brightly? If people are educated about how light pollution is driving fireflies away, a collective effort could be made to keep residential hubs dark enough to welcome them back, while still being lighted enough to be safe for us.
Awareness of the plight of butterflies and the sudden die-off of bees has brought much scientific research and grass roots efforts which are helping these beneficial insects, isn't it time we all put a little effort into the plight of the firefly?
I don't know about you but if we sit ideally by and allow fireflies to disappear from the Earth, then our summer nights will become a little darker and will forever be a lot less magical!