California beekeper Gene Brandi got suspicious when he sent half of his hives to a farmer who irrigated with the pesticide imidacloprid, and half of them died. The hives he didn't send continued to thrive.

"Stories like Brandi's have become so common that the National Honeybee Advisory Board, which represents the two biggest beekeeper associations in the U.S., recently asked the U.S. Environmental Protection Agency to ban the product. 'We believe imidacloprid kills bees -- specifically, that it causes bee colonies to collapse,' says Clint Walker, co-chairman of the board.

Beekeepers have singled out imidacloprid and its chemical cousin clothianidin, also produced by Bayer CropScience, as a cause of bee die-offs around the world for over a decade. More recently, the same products have been blamed by American beekeepers, who claim the product is a cause of colony collapse disorder, which has cost many commercial U.S. beekeepers at least a third of their bees since 2006, and threatens the reliability of the world's food supply."

Julia Scott reports for Salon May 18, 2009. [2]