Apr 25, 2020 - Science

Delaying the insect apocalypse

Map showing where land-dwelling insects may increase or decrease

Credit: van Klink et al., Science [2020]

A comprehensive new assessment of insect diversity finds that while the overall population of land-dwelling insects has fallen by more than a quarter over the past 30 years, some species are increasing in numbers.

Why it matters: A raft of studies in recent years have raised alarms about an "insect apocalypse." The new assessment offers some room for hope, while making it clear that insects and arachnid populations are still under tremendous pressure.

The new meta-analysis, published in this week's Science, examined 166 long-term surveys of land-dwelling and freshwater insect populations across the globe.

  • Insects that live on land are struggling, declining by an average of 9% a decade, likely due in part to the spread of human populations. That's still a smaller decline than many earlier studies had found.
  • Freshwater insect populations appear to be increasing by an average of 11% per decade, which may be due to successful efforts to clean up rivers and lakes.
  • Insect declines are worse in North America, and especially the Midwest, but appear to be leveling off.
"Insect populations are like logs of wood that are pushed under water. They want to come up, while we keep pushing them farther down. But we can reduce the pressure so they can rise again."
— Roel van Klink, lead researcher on the Science study, to CNN

The bottom line: Insects are an invaluable part of the Earth's ecosystem and food web. Their future is tied into ours — and vice versa.

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