Bugged: Earth's insect population shrinks 27% in 30 years

The world has lost more than one-quarter of its land-dwelling insects in the past 30 years, according to researchers whose big picture study of global bug decline paints a disturbing but more nuanced problem than earlier research.

From bees and other pollinators crucial to the world's food supply to butterflies that beautify places, the bugs are disappearing at a rate of just under 1% a year, with lots of variation from place to place, according to a study on April 23's journal Science.

That's a tinier population decline than found by some smaller localized studies, which had triggered fears of a so-called insect apocalypse.

But it still adds up to something "awfully alarming,'' said entomologist Roel van Klink of the German Centre for Integrative Biology, the study's lead author.

"The decline across insect orders on land is jaw dropping,'' said Michigan State University butterfly expert Nick Haddad, who wasn't part of the study. "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 functioning of all Earth's ecosystems.''

Insect declines are worst in North America, especially the Midwestern United States, and in parts of Europe, but the drop appears to be leveling off in the U.S. in recent years, said the study that pulled together earlier research on more than 10,000 species with data from 1,676 locations.

The Midwest lost 4% of its bugs a year. The big global losses seem to be around urban and suburban areas and croplands, where bugs are losing their food and habitat, van Klink said.

University of Delaware entomologist Douglas Tallamy, who wasn't part of the study, said he...