In 2012, BVT began pitching its biopesticide to farmers. The white dust comes in small foil-covered trays that slot into commercial hives. (Competitors in Europe sell similar products: BeeTreat in Finland and Flying Doctors in Belgium.) To exit her hive en route to the field, a bumblebee has to walk through the dust. It clings to her furry body, long evolved to pick up microscopic particles of pollen. When the bee alights on a bloom, she shimmies her wing muscles in rapid-fire contractions, knocking out pollen—a move, called "buzz pollination," made by bumblebees, but not honeybees. The shimmy drops some of the white dust onto the bloom, too, inoculating it against Botrytis. By BVT's calculations, each tray holds, at a minimum, more than 2 billion Clonostachys spores, and individual bees can carry around 300,000. To protect a plant from gray mold, it only takes a few.