Feature

Where have all the insects gone?

+ See all authors and affiliations

Science  12 May 2017:
Vol. 356, Issue 6338, pp. 576-579
DOI: 10.1126/science.356.6338.576

You are currently viewing the summary.

View Full Text

Summary

Entomologists call it the windshield phenomenon: Car windshields used to be covered in the spring and summer months with the remains of insects. Today, cars remain clean. Observations about splattered bugs don't count as scientific, of course, but remarkably few reliable data exist on the fate of these important species. Scientists have tracked alarming declines in domesticated honey bees, monarch butterflies, and lightning bugs. But few have paid attention to the moths, hover flies, beetles, and countless other insects that buzz and flitter through the warm months. Of the scant records that do exist, many come from amateur naturalists, whether butterfly collectors or bird watchers. Now, a new set of long-term data is coming to light, this time from a dedicated group of mostly amateur entomologists who have tracked insect abundance at hundreds of nature reserves across western Europe for more than 30 years. Over that time, the group, the Krefeld Entomological Society, has seen the expected ups and downs in the yearly insect catches. But in 2013 they spotted something alarming. When they returned to one of their earliest trapping sites from 1989, they found that the total mass of their catch had fallen by nearly 80%. Perhaps it was a particularly bad year, they thought, so they set up the traps again in 2014. The numbers were just as low. The group, which had carefully saved thousands of samples over 3 decades, did more direct comparisons. They found dramatic declines across more than a dozen other sites. Their observations raise questions about how widespread such losses are, and what might be the cause.