Most studies have been conducted in Canada and Europe, but the data holds true for all of North America. The numbers of flying insects has virtually crashed.
When Jeff Skevington’s parents used to take the family camping in Algonquin Park, they needed to stop the car halfway and buy windshield washer fluid because of all the squished bugs. But we are actually running out of bugs
Skevington is now 52, and his windshield rarely hits bugs today. He is also an Agriculture Canada scientist who studies insects — and why there’s a shortage of them.
“Insect numbers are way down,” he says. “It’s a little under the radar from the public perspective, but it’s really high on the radar in terms of research.”
Bug scientists agree: There just aren’t as many insects across Europe and North America as there were a generation ago. And the cause (or group of causes) remains a mystery, though many suspect the modern spread of pesticides has a leading role.
So who cares about bugs?
When the flying insects disappear, so do the birds that eat them.
Insects pollinate the plants to produce much of your food, from apples to corn that livestock eat. Agriculture Canada estimates that while bees are the main pollinators, other insects such as hoverflies pollinate about 39 percent of agricultural plants.
And birders have watched in alarm as populations of many insect-eaters have crashed in recent decades: Swifts, swallows, nighthawks, martins and, of course, flycatchers are all a tiny fraction of their former populations.
Bird Studies Canada, a major conservation group, says annual bird counts have shown declines of 50 to 70 percent in many of these species, and it says a loss of insects is one likely cause.
The disappearance of insects could cause other problems that we haven’t even thought of yet.
The trouble lies in measuring the change since it’s hard to find a bug census from the mid-1900s to compare with numbers today.
“It’s, unfortunately, a little bit informal in terms of measurements,” said Jeremy Kerr, an ecologist and insect scientist at the University of Ottawa. “Like, ‘How pasted did your windshield get?’ is not a normal scientific measurement. But it is something that I think many people have noticed.
“The general trend is something I myself have noticed and thought about on many occasions.
“It’s a big deal, right? When you think about this it sounds kind of nuts, but the number of insects splattering on your windshield is a really good indication of just how abundant life is in the environment,” Kerr said.
“It’s anecdotal, but if it’s true there seems to be a lot less life out there than there used to be. And that is not something we should be ignoring.”
Still, solid evidence is building.
• Beginning in 2013, Axel Ssymank, a German biologist, updated results from a 1989 insect count in a nature preserve in Germany. Ssymank did new counts in the same place with the same trapping method — and found 80 percent fewer insects, even though it is a protected reserve.
Maybe he just hit a bad summer, he thought. So he went back a year later — and got the same result. There’s no indication it has improved since.
Skevington was at a conference last week where Ssymank presented his results.
“He got audible gasps from the scientists,” he recalls. “I don’t think anyone knew just how bad it was.”
• Some of the data came through good luck and ingenuity.
Queen’s University biologists found a two-metre-deep pile of guano left by chimney swifts in a campus building, and were able to date the droppings layer by layer. They found that as DDT use became common in the 1950s the birds switched from feeding mainly on beetles, which were killed by DDT, to eating lower quality but hardier insects like stink bugs.
Since then the number of chimney swifts has fallen by more than 90 percent.
• The British might win the prize for the oddest research.
In 2004, the Royal Society for the Protection of Birds invented the Splatometer — a square of flypaper that drivers put on the front of their cars. Tens of thousands of volunteers drove around for a couple of weeks and then counted the bugs. It was an attempt to find a “baseline” number to compare with future years.
• A long-term study at the Long Point Bird Observatory beside Lake Erie is also showing “an overall decrease in quantity” of flying insects.
Skevington says most of the studies have been on flying insects, and it is mostly in Europe so far. But his colleague Henri Goulet has spent 50 years studying insects for Agriculture Canada and he says non-flying insects are disappearing just like the flying ones. Entire species of beetles that he used to study no longer exist at the Central Experiment Farm, he says, and he believes the change came as Ontario farmers shifted to growing more corn. Goulet blames the herbicides sprayed on cornfields in spring before the seed is planted.
Mosquitoes seem to have escaped the decline, perhaps because they lay eggs in little spring pools that are remote from pesticide use, Skevington speculates.
And some places seem protected. Pinery Provincial Park west of London, Ont., is beside Lake Huron, and it seems to resist the disappearing-insect trend. One theory is that the prevailing west winds come a long way across the lake and are cleansed of pesticides.
Skevington believes the public no longer sees all bugs as pests and enemies, partly because of the spread of websites and field guides similar to all the books on birds and wildflowers.
He also pointed out the “Bug Day” event at Central Experimental Farm has steadily grown in popularity.
Meanwhile, birder Bruce Di Labio, while agreeing there’s been a decline in insect-eating birds, cautions against writing off bugs, and bug-eating birds, just yet.
On Aug. 30 he counted more than 300 common nighthawks gobbling up newly-hatched flying ants between Carp and Ottawa. It’s the largest number he has ever seen.