By Brandon Keim (Wired Science) 3/29/12
A controversial type of pesticide linked to declining global bee populations appears to scramble bees’ sense of direction, making it hard for them to find home. Starved of foragers and the pollen they carry, colonies produce fewer queens, and eventually collapse.
The phenomenon is described in two new studies published March 29 in Science. While they don’t conclusively explain global bee declines, which almost certainly involve a combination of factors, they establish neonicotinoids as a prime suspect.
“It’s pretty damning,” said David Goulson, a bee biologist at Scotland’s University of Stirling. “It’s clear evidence that they’re likely to be having an effect on both honeybees and bumblebees.”
Neonicotinoids emerged in the mid-1990s as a relatively less-toxic alternative to human-damaging pesticides. They soon became wildly popular, and were the fastest-growing class of pesticides in modern history. Their effects on non-pest insects, however, were unknown.
In the mid-2000s, beekeepers in the United States and elsewhere started to report sharp and inexplicable declines in honeybee populations. Researchers called the phenomenon colony collapse disorder. It was also found in bumblebees, and in some regions now threatens to extirpate bees altogether.
Image: Jack Wolf/Flickr