Mayfly

A lucky mayfly just misses hitting a car windshield. Fewer bugs hitting windshields is one of many signs signaling a decline around the world of important insects eaten by birds and other animals that may be impacting our food supply, animal populations, and environmental health.

I don’t like to drive with dirty car windows, especially those covered with splattered bugs! This is such a big deal for me that I carry a bucket of glass cleaner and squeegee with me in the car to keep my windows clean during trips.

Sometimes I keep my car windows so clean it seems to some people like the windows are open when they are not. This came as a surprise to my brother one time when he was sorting out collected rocks in the back seat of my car from one of our hikes. As I was driving, he came upon a duplicate rock and decided to throw it out the backseat window. Suddenly, I heard a big ‘clunk’ as a rock hit the window, fortunately not breaking it but leaving a nice divot in the window. He thought the window was open!

On another occasion I was driving across North Dakota when I hit a swarm of mayflies that had hatched from a lake. My windshield was covered with a greasy mat of the bugs resulting from my attempt to clean the windshield with my wipers making it even worse. I retreated to a rest stop and got out my handy glass cleaner bucket and proceeded to successfully clean my windshield. While doing so, a guy with the same problem called to me and asked whether I would clean his windshield too which I gladly did.

Then there was the time when I stopped at a 7/11 type store when I noticed the car parked next to me had a window so full of bugs, I just had to clean his window too while the driver was in the store.

So now you get the idea, I like clean windows which brings me to an interesting observation I have made in recent years. There seems to be fewer and fewer bugs hitting my windshield lessening the need to clean the glass despite about the same amount of driving. Being a scientist, I began to ponder why, and this is what I found out.

Curt Stager, a professor of natural sciences, noted that automobile windscreens in Britain are no longer heavily caked with splattered insects. He found in his own travels in northern New York where he lives there is barely an insect blemish on his car. Last July, he examined parked vehicles in Saranac Lake and found little or no bug debris, even on license plates or the blunt fronts of vans.

A May 2018 article in the New York Times reported on a study published last fall that documented a 76 percent decline in the total seasonal biomass of flying insects netted at 63 locations in Germany over the last three decades. Losses in midsummer, when these insects are most numerous, exceeded 80 percent.

There is study after study documenting steeply declining insect populations, too many to report on here, but they all raise two important questions, what is behind the insect decline and why is it important?

By scientific elimination of possible factors, the most likely suspect causing major insect declines is thought to be pesticides. Do you remember Rachel Carlson who correctly warned us about pesticides over half a century ago? Do you hear alarm bells ringing — again? No matter the cause, insect decline is important because trillions of bugs flitting from flower to flower pollinate some three-quarters of our food crops, a service worth as much as $500 billion every year. This doesn’t count the 80 percent of wild flowering plants, the foundation blocks of life everywhere, that rely on insects for pollination.

An across-the-board decline in flying insects that seems to be happening would put an entire sector of the animal kingdom in trouble along with all its cascading negative impacts on other plants and animals including the human species.

Writer Jim Williams recently made a profound statement, “Insects, according to researchers, are disappearing in a way similar to the disappearance of birds, only more so. The decline is constant, but so slow as to be unrecognizable until, suddenly, with one focused look it’s all too apparent.”

That is why noticing fewer bugs on windshields is so important, kind of like a canary in a coal mine.

Those of us who have done research on migratory birds over the decades have noticed the same subtle, alarming, decline in some bird species mainly blamed on habitat loss. But now, an alarming decline in insects may also be contributing to bird decline in species who depend upon insects for food! Think about that the next time a juicy insect hits your windshield.

Nature notes

A mayfly’s life cycle starts with the males forming a swarm above the water and the females flying into the swarm to mate. After mating, the female descends to the surface of the water where she lays her eggs. After that, she will fall, spent, onto the water surface to lie motionless, with her wings flat on the surface, where fish pick them off at their leisure. The male fly rarely returns to the water but instead he goes off to die on the nearby land.

The eggs fall to the bottom of the water where they stick to plants and debris. The nymphs take a few days to weeks to hatch, depending on water conditions and the species. The resultant nymphs will spend various lengths of time, up to two years, foraging on the bottom before emerging as an adult fly and the process starts all over again to mess up our windshields and feed the fish.

(Copyright © 2019 APG Media)

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