From butterflies to grasshoppers, many delicate little things that run our world are in dire trouble. Not just in regions where human activity directly affects the landscape, but even in remote, human-free zones, a new study finds.
The loss of insects in key areas around the globe has been attributed in the past to the deliberate reduction of biodiverse habitats and changes in local climate. Now it's clear these forces stretch far beyond our immediate spheres of influence.
Related: There's Growing Evidence That Insects Feel Pain, Just Like Us
In areas relatively undisturbed by direct human activity, University of North Carolina biologist Keith Sockman recorded a dramatic drop of over 70 percent of flying insects in just 20 years.
Sockman calculated insect density in summers between 2004 and 2024 in a remote Colorado meadow. He found the hotter summers, as recorded by the weather station at the sampling site, were associated with fewer insects the following year.
"It's quite remote, quite pristine, and yet still showing this substantial decline in insects," Sockman told Alana Wise at NPR.
"That doesn't leave a lot of other options other than changing climate to explain this."
Sockman's findings are far from the only recent study to suggest climate change is impacting insects.
Populations of butterflies, beetles, and other tropical insects have been ravaged by the changed El Niño cycle in the tropics. Even flies are vulnerable to Earth's now rapidly changing conditions.
While there has been some contention around the extent of insect declines, this is often due to a lack of data, and misunderstandings around complexity.
With over 5 million species of insects, some species will inevitably benefit from the same changing conditions that harm others. But these 'winners' are unlikely to neatly take on ecological roles left open by the 'losers', leading to further disruptions in the delicate webs of interactions that keep our life-supporting ecosystems stable.
Historic evidence of shrinking insect populations, which addresses some of that previously missing data, is also mounting – a recent example traces the decline of ants in Fiji since humans first arrived, 3,000 years ago.
"It can be difficult to estimate historical changes to insect populations, because with few exceptions, we haven't been directly monitoring populations over time," explains evolutionary biologist Evan Economo at the University of Maryland.
"We took a new approach to this problem by analyzing the genomes of many species in parallel from museum specimens collected recently. The genomes hold evidence of whether populations are growing or shrinking, allowing us to reconstruct community-wide changes."
"We found 79 percent of ant species native to Fiji have experienced a decline in population, while introduced species are exploding in numbers."
The domino effect of this shifting bulk of Earth's biomass is now also evident in data describing bird numbers – lizards and frogs, too.
There are now hundreds of peer-reviewed studies suggesting sustained declines in many insect populations globally, entomologists point out.
"There is consensus among experts that there is an insect biodiversity crisis," University of New England ecologist Manu Saunders and colleagues recently wrote in an article addressing denial around this issue.
And Sockman's study suggests this crisis is occurring in remote regions too.
"Without insects, everything dies: all mammals, all reptiles, all birds, and even humans," zoologist Jessica Ware from the American Museum of Natural History, told Madeline Bodin at Smithsonian Magazine. "If you want to conserve any of those other things, including us, you should want to conserve insects."
The remote insect study was published in Ecology.