This is Scientific American's 60 Second Science.

I'm Christopher Intagiyata.

Over the last year, beekeepers in the US lost nearly half their honeybee hives.

And there are a lot of suspected culprits for this so-called beepocalyps, from parasitic

mites to viruses to simple land use changes. But a study out earlier this year pointed

to another possibility. poor sperm quality among the drone bees, leading to colony crashes.

And now another group of researchers may have found a reason for the subpar sperm, neonicotinoid pesticides.

These substances contain chemicals similar to nicotine and affect insect nervous systems.

The drones that were exposed to the pesticides in their development, it appears that there were just more dead sperm in their reproductive tracts.

Jeff Williams, an entomologist at the University of Byrne in Switzerland and Agroscope, a Swiss Federal Research Facility.

Williams and his colleagues studied the effects of two neonicotinoid pesticides on honeybee drones,

genetically assigned to mate with Queens.

They're a bit bigger and they have really big eyes just so they can really identify these

queens that are flying through the air.

They eat and have sex, or try to have sex at least.

But in 20 honeybee hives, Williams and his collaborators found that those drones exposed

to standard environmental levels of the pesticides were shorter lived, thus having fewer opportunities to mate.

And even if the drones did survive, they had nearly 40% fewer living sperm than did control bees, meaning the pesticides were acting like honey bee

contraceptives. The study appears in the proceedings of the Royal Society bee.

Williams says pesticides are just one of many factors assaulting bees, but it looks like the way farmers treat some crops could adversely affect the pollinators those crops also rely on.

Thanks for listening.

For Scientific American 60 Second Science,

...