What is declining?
Abundance, biomass, species richness and geographical range are different measures. A site can retain many insects while losing sensitive species, or gain a few tolerant species while its ecological community becomes poorer.
The broadest abundance synthesis
A 2020 meta-analysis of 166 long-term surveys across 1,676 sites found an average terrestrial insect decline of about 9% per decade and an average freshwater increase of about 11% per decade. Trends varied strongly even between nearby sites and were geographically biased toward Europe and North America.
Why the freshwater result is not simple good news
Increasing total abundance can reflect recovery from pollution, but it can also reflect replacement of sensitive species by tolerant ones. Global coverage and standardisation remain inadequate.
The main pressures
Habitat loss, intensive agriculture, pesticides, altered nutrient cycles, climate change, drought, invasive species and light pollution can act together. A 2025 review of 75 meta-analyses found most studied global-change pressures were associated with more negative than positive insect responses.
The largest blind spot
Long-term data are sparse in tropical regions, where most insect diversity exists. Global headlines therefore rest heavily on a comparatively small and uneven monitoring network.
What recovery looks like
Habitat restoration, less pesticide exposure, connected landscapes, cleaner freshwater, varied farming systems and reduced night lighting can produce measurable local recovery.
Research record
van Klink et al. (2020), global abundance meta-analysisVidal et al. (2025), review of global-change meta-analysesWagner et al. (2021), death by a thousand cutsA widespread crisis without one universal curve
Direct answer: Serious declines are documented in many terrestrial insect populations and regions, but there is no single global rate that applies to every species or habitat. Some populations are stable or increasing, and freshwater trends are especially complex.
It is wrong to say every insect is disappearing everywhere. It is equally wrong to dismiss the crisis because some populations rise. Multiple independent datasets show major losses, while the scale and drivers remain poorly measured across much of the planet.