Light pollution can foil plant-insect hookups, and not just at night

For flowers, too much light at night could lead to a pollination hangover by day.

Far from any urban street, researchers erected street lights in remote Swiss meadows to mimic the effects of artificial light pollution. In fields lit during the night, flowers had 62 percent fewer nocturnal visitors than flowers in dark meadows, researchers report August 2 in Nature.

For one of the most common flowers, daytime pollination didn’t make up for nightly losses, says ecologist Eva Knop of the University of Bern in Switzerland. In a detailed accounting of the pollination life of cabbage thistles (Cirsium oleraceum), Knop and colleagues found that night-lit plants produced 13 percent fewer seeds overall than counterparts in naturally dark places.

Night lights could affect the entire network of plants and pollinators, the team suggests. In the test fields, nighttime pollination wasn’t