Who’s Counting?
Oliver said that up until recently, no one was counting insects. Even scientists didn’t see the point in it because insects are everywhere. It is far more interesting to scientists to describe new species and look at behaviors and changes to habitats. Counting insects also seems like a monumental and tedious task, and was seen as rather pointless.
“Some of the studies that have come out in the last few years are really kind of instructive because they, for the first time, shine a light on what’s actually happening to insect populations,” Oliver says. “And some of those population drops are just astonishing.”
Oliver spoke to entomologist Brad Lister of Rensselaer Polytechnic Institute in Troy, New York. Brad visited the El Yunque rainforest in Puerto Rico in the 1970s to investigate insect populations. It is the only rainforest in U.S. territory and quite pristine.
Brad put plates with sticky substances on the forest floor and in the canopy and returned the next morning to see how many insects were stuck there.
“In the ’70s, they were kind of matted. These plates were kind of black with the insects,” Oliver says. “He went back a couple of years ago to repeat this experiment just to see if things had changed, and the contrast was astonishing. He said he was absolutely blown away by the change. It was just a couple of insects on these sticky plates in the morning.”
Brad discovered an 80% decline in insects in the canopy and a 98% decline on the forest floor, by biomass. A similar study in Germany in nature reserves in the height of summer found an 82% insect decline between 1989 and 1997.
Some scientists believe we are entering a sixth great extinction, and Oliver says insect decline is happening quickly in terms of evolutionary time scales. Many people have experienced this in their own lifetimes. They can recall road trips with their families when they would have to pull over to clean all the bugs off the windshield, but today, splattered bugs are no longer an issue because there are fewer bugs out there.