Our whole insect population is declining

Where have all the insects gone? That question may be a touchy one to ask gardeners, who would much rather do without some of those bugs! But it began to worry me this summer when I realized that, despite our increasingly soggy weather, I’d seen strangely few mosquitoes in the past few years.

I could recall all the slapping we had to do when I was a child to avoid itchy bites. But that ominous droning mosquitoes make as they circle for landing virtually has disappeared from our summers here.

I suspect those bloodsuckers’ spreading of certain diseases may have caused local governments to implement a spraying program—on the quiet, to avoid complaints! So that might explain the mosquito mystery.

But a couple other incidents alerted me to the fact that it wasn’t only the mosquitoes which had gone missing. When I drove to my job one evening this summer, I winced over all the unfortunate fireflies splatting against my windshield on the way. When I commented on that to another employee, she mentioned that there actually weren’t nearly as many insects in car grilles anymore as there used to be. My abrupt realization that she was right left me feeling unsettled and vaguely uneasy.

So, do I really want the mosquitoes back? No, but I understand that insects are a fact of life. Not always a pleasant fact, but part of the balance of nature. And what happens when that balance gets skewed?

katydid in daylily

More than pest insects are on the decline

Coming, yawning, into the kitchen one morning this summer, I heard a chirring noise which made me run to the refrigerator, as that appliance makes a similar sound when the door is left ajar. Then I realized it must just be a cricket, which I hadn’t recognized at first because I’d heard so few of them lately.

Grasshoppers such as the one in the banner and katydids such as the one in the daylily above also have become so rare here that I try to take their pictures when I see them. The strident buzzing that occurred during summer evenings in years past has declined to a much lower and later level. Now, I suspect, most of it comes from cicadas calling in trees rather than from the more down-to-earth hoppers.

Granted, much of the decline in our part of the country could be due simply to insect eggs drowning in our increasingly moisture-logged soil. (Because cicadas tend to stick to the drier ground near trees, they may be less affected.) I doubt the problem could be pesticides here, since our local farmers don’t need those to grow corn, wheat, and soybeans. And a site I consulted on the sprays usually used to kill mosquitoes stressed that the effects of those pesticides didn't remain long in the environment. However, the writer passed rather hastily over the fact that such sprays also can kill other invertebrates. That, of course, includes other bugs.

The decline of insects will also mean a decline in insect-eaters

Such indiscriminate bug-killing can be a problem, since recent studies have shown that about 40 percent of the earth’s insects are experiencing drastic drops in their populations. According to an article by Jason Daley on the Smithsonian web site, both the order of butterflies and the order which includes crickets, grasshoppers, and katydids have declined by about half, while bees are down by about 40 percent.

bee on milkweed flowersMost of the attention has been paid to the pollinators, since so much of our food supply depends on them. But we may need to start being concerned about bug-eating birds and bats as well. As the populations of the insects they eat decline, so will the populations of the eaters. We may be closer to Rachel Carson’s Silent Spring than we thought—not to mention silent summers without many of our “singing” insects.

Helping all insects survive is important

What can we gardeners do? Well, our sowing of flowers—especially native varieties—may help make up for the fewer wildflowers on developed land. I’ve already noticed that the Monarch butterflies seem to be making something of a comeback, perhaps in response to so many of us planting milkweeds.

We’ve also been advised that we should limit the pesticides we use as much as possible and avoid polluting the soil with excessive amounts of fertilizer. Finally, we must do what we can to avoid the climate change which is making my section of country wetter while it makes others drier.

Unlike the folk song “Where Have All the Flowers Gone?,” the lyrics to “Where Have All the Insects Gone?” would have to continue with “Short time passing.” But that tune, too, might have to conclude with a plaintive question about humans: “When will they ever learn?”

Photos: The photos included in the article are my own.