Apocephalus borealis is a species of North American parasitoid phorid fly that parasitizes bumblebees, honey bees, and paper wasps. These flies are colloquially known as zombie flies and the bees they infect are colloquially known as zombees. The association with honey bees has so far only been documented from California, South Dakota, Oregon, Washington, and British Columbia (Vancouver Island); elsewhere, they are primarily associated with bumblebees and paper wasps, but most recently this species has changed host and has begun to attack the European honey bee. A case was confirmed in October 2013 of an infestation of honeybees in Vermont.