Ninety-year trends reveal sharpest insect declines in the mid-twentieth century
10 affiliations
- 1Agricultural Landscapes and Biodiversity, Agroscope, Zurich, Switzerland. [email protected]
- 2Biodiversity and Conservation Biology, Swiss Federal Research Institute WSL, Birmensdorf, Switzerland
- 3info fauna, Neuchâtel, Switzerland
- 4Department of Environmental System Science, Institute of Terrestrial Ecosystems, ETH Zurich, Zurich, Switzerland
- 5Forest Health and Biotic Interactions, Swiss Federal Research Institute WSL, Birmensdorf, Switzerland
- 6Agricultural Landscapes and Biodiversity, Agroscope, Zurich, Switzerland
- 7Department of Environmental Sciences, Landscape Ecology and Ecosystems Conservation and Research Station Petite Camargue Alsacienne, University of Basel, Basel, Switzerland
- 8Swiss Ornithological Institute, Sempach, Switzerland
- 9Department of Ecology and Evolution, Estación Biológica de Doñana EBD (CSIC), Seville, Spain
- 10Department of Evolutionary Biology and Environmental Studies, University of Zurich, Zurich, Switzerland
Abstract
Most studies on insect trends have focused on the past few decades, but major changes could have occurred earlier. If so, shifted baselines can result in misleading conclusions or poor conservation decisions. Here we analyse nine decades of insect trends in Switzerland and relate them to changes in land use and climate. By reconstructing continuous trends in species richness based on 1.2 million records of 595 saproxylic beetle and 216 butterfly species, we find that both groups declined from the 1930s to the 1960s. While saproxylic beetle richness stabilized and subsequently recovered, butterfly richness continued to decline until the 1980s and has not recovered. The strong mid-century decreases were linked to increases in agricultural mechanization, while the subsequent increases were linked to climate warming. Over the entire 90-year period, declines primarily affected specialist and cold-adapted species, while warm-adapted species have increased since the 1980s. Recent gains in saproxylic beetle richness might also reflect increased deadwood availability from windthrow and 'biodiversity-friendly' forest management. Our findings suggest that reducing adverse land use is key to maintaining and promoting insect diversity, and that shifted baselines and climate-change effects should be considered when setting restoration goals and priorities.
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BibTeX
@article{neff2026ninetyyear,
title = {{Ninety-year trends reveal sharpest insect declines in the mid-twentieth century}},
author = {Felix Neff and Kurt Bollmann and Yannick Chittaro and Martin M. Goßner and Félix Herzog and Fränzi Korner‐Nievergelt and Glenn Litsios and Carlos Martínez‐Núñez and Marco Moretti and Emmanuel Rey and Andreas Sanchez and Eva Knop},
journal = {Nature Ecology \& Evolution},
year = {2026},
month = jun,
doi = {10.1038/s41559-026-03074-6},
url = {https://doi.org/10.1038/s41559-026-03074-6},
note = {CC BY},
}
RIS
TY - JOUR
TI - Ninety-year trends reveal sharpest insect declines in the mid-twentieth century
AU - Felix Neff
AU - Kurt Bollmann
AU - Yannick Chittaro
AU - Martin M. Goßner
AU - Félix Herzog
AU - Fränzi Korner‐Nievergelt
AU - Glenn Litsios
AU - Carlos Martínez‐Núñez
AU - Marco Moretti
AU - Emmanuel Rey
AU - Andreas Sanchez
AU - Eva Knop
PY - 2026
DA - 2026/06/02
JO - Nature Ecology & Evolution
DO - 10.1038/s41559-026-03074-6
UR - https://doi.org/10.1038/s41559-026-03074-6
AB - Most studies on insect trends have focused on the past few decades, but major changes could have occurred earlier. If so, shifted baselines can result in misleading conclusions or poor conservation decisions. Here we analyse nine decades of insect trends in Switzerland and relate them to changes in land use and climate. By reconstructing continuous trends in species richness based on 1.2 million records of 595 saproxylic beetle and 216 butterfly species, we find that both groups declined from the 1930s to the 1960s. While saproxylic beetle richness stabilized and subsequently recovered, butterfly richness continued to decline until the 1980s and has not recovered. The strong mid-century decreases were linked to increases in agricultural mechanization, while the subsequent increases were linked to climate warming. Over the entire 90-year period, declines primarily affected specialist and cold-adapted species, while warm-adapted species have increased since the 1980s. Recent gains in saproxylic beetle richness might also reflect increased deadwood availability from windthrow and 'biodiversity-friendly' forest management. Our findings suggest that reducing adverse land use is key to maintaining and promoting insect diversity, and that shifted baselines and climate-change effects should be considered when setting restoration goals and priorities.
SN - 2397-334X
ER -