It’s hard enough to grab an insect during the day, so try doing it in the dark, while wearing night-vision goggles. These eyepieces offer little in the way of depth perception, and “catching insects without that is not easy,” says Eva Knop from the University of Bern. Nevertheless, she and her colleagues persisted, and became better with practice.
Over several summer nights, they would head out into 14 Swiss meadows, half of which were illuminated by artificial lights, and half of which were kept in darkness. For several hours, the team would wander slowly through the fields, peering into local flowers, and catching every insect that they found. And their census, conducted over two consecutive summers, provides the first clear evidence that night-lighting deters or distracts pollinating insects. That, in turn, harms the plants they would typically visit.
Insects help to keep the world green, by spreading the pollen of 88 percent of flowering plants. Those species account for 30 percent of crop production, with a total value of $361 billion—so a world full of buzzing insect wings is also one of full human stomachs. But pollinators are in trouble. Despite the recent good news that honeybee populations have bounced back slightly in the last year, the general trend is still a downward one in Europe and North America. A third of bee and butterfly species are in decline, beset by parasitic mites, destructive diseases, toxic pesticides, and changing climate. And recently, scientists have started considering another culprit—light pollution.