Insect populations are collapsing even in ecosystems with minimal direct human disturbance, says a new study from the University of North Carolina at Chapel Hill. Over 20 years, flying insect abundance in a subalpine meadow in Colorado fell by more than 70 percent, raising alarms about the future of biodiversity.
The research, led by UNC associate professor of biology Keith Sockman, tracked insect numbers over 15 seasons between 2004 and 2024, supported by nearly four decades of weather records. Results showed an average annual decline of 6.6 percent, amounting to a 72.4 percent drop during the study period.
Climate Change, Not Just Human Activity, Drives Decline
Unlike many insect decline studies that focus on heavily altered landscapes, this research examined a relatively pristine site. Sockman found that the steep losses were closely associated with rising summer temperatures, pointing to climate change as a major driver.
“Insects have a unique position in the biodiversity crisis due to the ecological services they provide—such as pollination and nutrient cycling—and to their vulnerability to environmental change,” Sockman said. “They are necessary for terrestrial and freshwater ecosystems to function.”
Biodiversity Hotspots at Risk
Mountains host large numbers of locally adapted endemic species, many of which are insects. Sockman warns that the declines observed in Colorado could signal broader risks: “The status of mountains as biodiversity hotspots may be in jeopardy if the declines shown here reflect trends broadly.”
The findings underscore the global scale of the biodiversity crisis, demonstrating that even remote and relatively undisturbed ecosystems are not immune. The study calls for more comprehensive insect monitoring across diverse landscapes and highlights the urgency of addressing climate change.
