Agricultural Research Service (ARS) scientists are tracking a honey bee killer, and their investigations have taken them from hives in Tucson, Arizona, to Bismarck, North Dakota. Led by ARS entomologist Gloria DeGrandi-Hoffman, the team is staking out hive entrances and monitoring the comings and goings of foraging honey bees, which may be the killer's unwitting accomplices. None of the busy little winged bearers of pollen and nectar will get by without inspection: The prime suspect—an eight-legged, pinhead-sized parasite called the Varroa mite—seems to be sneaking into the hives on the bees' bodies. The Varroa mite, Varroa destructor, is considered public enemy number one to honey bees nationwide. The parasite feeds on the blood of adult bees and their brood, weakening them and endangering the entire hive when infestations become severe. But the mite also poses an indirect threat to more than 90 flowering crops that depend on bee pollination, including almonds, apples, blueberries, cherries, and cantaloupes.