The global insect population has declined by 25% within the last 30 years, according to a new study published in the journal Science on April 23.
Based on 166 long-term surveys from nearly 1,700 locations, the study revealed that land-dwelling insects are disappearing at an annual rate of just below 1%.
While the overall population decline is smaller than what other local assessments have found, the loss is still significant.
"It’s a quarter less than when I was a kid," the study’s lead author Roel van Klink from the German Centre for Integrative Biodiversity Research in Leipzig, told the Guardian. "One thing people should always remember is that we really depend on insects for our food."
The study also found that North America and Europe have experienced the largest declines in insect populations.
While the decline has begun to level off in the United States in recent years, the Midwest still loses 4% of its insects every year.
The largest overall losses, however, come from urban and suburban areas, where insects are losing access to food and habitats.
In addition to habitat destruction, the global loss of insects is partly due to light pollution and the use of pesticides.
While the study noted that dramatic changes in heat and rain could harm certain insect species, it did not make a clear connection between climate change and the decline in the world’s insect population.
"The decline across insect orders on land is jaw dropping," Michigan State University’s butterfly expert Nick Haddad, who was not involved in the study, told the Associated Press. "Ongoing decline on land at this rate will be catastrophic for ecological systems and for humans. Insects are pollinators, natural enemies of pests, decomposers, and besides that, are critical to the functioning of all Earth’s ecosystems."