Thomas Hörren, a member of the Entomological Society Krefeld, collecting beetles from a soil sample. CreditGordon Welters for The New York Times

Thanks to Sally McGrane for this important article:

KREFELD, Germany — In a nature preserve in western Germany, an elderly gentleman approached a tent-like structure that was in fact a large trap for flying insects. Peering through thick eyeglasses, the 75-year-old retired chemist checked the plastic bottle attached at the top, filled with alcohol and bugs.

Then, with a glance at the clear, late-autumn sky, the man, Heinz Schwan, recalled comparing a 2013 haul from a trap like this one to samples taken in the same place some 20 years earlier. The drop was huge: “75 percent,” Mr. Schwan, a caterpillar lover, said.

Alarmed, the group of local insect enthusiasts Mr. Schwan is co-chairman of ran similar tests in different locations the next year. And the next year. And the next. Continue reading →