Image Courtesy of Yale.edu | Illustration by Luisa Rivera for Yale E360
“The increased, widespread insect biomass decline is alarming.”
Recent results of 27 year comprehensive research study: “All traps were placed in protected areas that are meant to preserve ecosystem functions and biodiversity.”
Original Article In PLOS (Public Library of Science)
…Agricultural intensification, including the disappearance of field margins and new crop protection methods has been associated with an overall decline of biodiversity in plants, insects, birds and other species in the current landscape.
…The major and hitherto unrecognized loss of insect biomass reported for protected areas must have cascading effects across trophic levels and numerous other ecosystem effects.
…There is an urgent need to uncover the causes of this decline, its geographical extent, and to understand the ramifications of the decline for ecosystems and ecosystem services.”
Formal Scientific Analysis (Germany)
-Ongoing and rapid decline in total amount of airborne insects active in space and time.
-Seasonal decline of 76%, and mid-summer decline of 82% in flying insect biomass over 27 years of study.
-Decline is apparent regardless of habitat type.
-Changes in weather, land use, and habitat characteristics cannot explain this overall decline.
-Loss of insect diversity and abundance is expected to provoke cascading effects on food webs and to jeopardize ecosystem services.
The Scientist Magazine
“These results are not from agricultural areas but natural preserves that are well-maintained and meant to protect biodiversity. We are seeing insects slipping out of our hands.”
~Hans de Kroon, Radboud University
“The remarkable and alarming aspect of this long-term study is the magnitude of the decline. Most previous studies have reported biomass declines of less than 50 percent which is disconcerting. But the 75 percent decline reported here sends a clear call for immediate action.”
~John Losey, Entomologist at Cornell University, New York
“In September, a chief scientific adviser to the UK government warned that regulators around the world have falsely assumed that it is safe to use pesticides at industrial scales across landscapes and that the “effects of dosing whole landscapes with chemicals have been largely ignored. …The new data was gathered in nature reserves across Germany but has implications for all landscapes dominated by agriculture, the researchers said”.
"The study was performed at nature reserves across Germany, but the scientists say the findings translate across all agricultural landscapes. Insects are two-thirds of all life on Earth, the study said, and if they’re not around to pollinate and serve as food for larger animals, the entire ecosystem could fall.”
Where have all the insects gone?
"A team from the University of Regensburg in Germany reported in Scientific Reports in February that exposing the wasp Nasonia vitripennis to just 1 nanogram of one common neonicotinoid cut mating rates by more than half and decreased females’ ability to find hosts. "It’s as if the [exposed] insect is dead" from a population point of view because it can’t produce offspring, says Lars Krogmann, an entomologist at the Stuttgart Natural History Museum in Germany."
Yale Environment School of Forestry
What’s Causing the Sharp Decline in Insects, and Why It Matters
“A significant drop in insect populations could have far-reaching consequences for the natural world and for humans, who depend on bees and other invertebrates to pollinate crops.”
“Over three-quarters of wild flowering plant species in temperate regions need pollination by animals like insects to develop their fruits and seeds fully.”
“Furthermore, researchers emphasize that pollinating insects improve or stabilize the yield of three-quarters of all crop types globally — one-third of global crop production by volume.”
“Germany’s Federal Agency for Nature Conservation stresses that insects are a major food source not only for birds, but also for bats and amphibians. Another important role is played by specialized insects such as long-legged flies, dance flies, dagger flies, and balloon flies, which prey upon pest species.”