Published 2026-06-09 · data 2017 · percent of 1989 insect biomass
Flying insects crashed in protected areas
German nature reserves saw roughly three-quarters fewer insects in traps over 27 years — not just farmland.
Protected areas were supposed to be refuges. Instead, German nature reserves lost roughly 75% of their flying insect biomass between 1989 and 2016 — and weather, land use, and habitat differences can't explain it. A loss this size climbs the food web: 60% of birds rely on insects as food.
1 cell = 0.1 percent of 1989 insect biomass (0.1% of insect biomass in German reserves) · 1,000 cells
Context
The figures come from Hallmann et al., published in PLOS ONE in October 2017. The Entomological Society Krefeld ran standardized Malaise traps across 63 German protected areas between 1989 and 2016, yielding 96 unique location-year combinations of total flying insect biomass.
The paper estimates a 76% seasonal decline and an 82% mid-summer decline in flying insect biomass over the 27 years. The drop was apparent regardless of habitat type, and changes in weather, land use, and habitat characteristics could not account for it.
The paper cites estimates that 80% of wild plants depend on insects for pollination. The authors warn that this 'yet unrecognized' biomass loss must be factored into evaluating declines in species that depend on insects as a food source, and in ecosystem functioning across the European landscape.
Hallmann et al. PLOS ONE 2017: ~75% decline in flying insect biomass in German protected areas.
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Credit this grid as Inagrid — https://inagrid.com/e/2026-06-09-insect-biomass-decline