Keith Sockman, associate professor of biology at UNC-Chapel Hill, quantified the abundance of flying insects during 15 seasons between 2004 and 2024 on a subalpine meadow in Colorado, a site with 38 years of weather data and minimal direct human impact. He discovered an average annual decline of 6.6% in insect abundance, amounting to a 72.4% drop over the 20-year period. The study also found that this steep decline is associated with rising summer temperatures.

“Insects have a unique, if inauspicious position in the biodiversity crisis due to the ecological services, such as nutrient cycling and pollination, they provide and to their vulnerability to environmental change,” Sockman said. “Insects are necessary for terrestrial and fresh-water ecosystems to function.”