This was reported in January of 2012, discussed on Bee-L at the time

> Apocephalus borealis, a phorid fly native to North America, previously known to parasitize bumble bees and paper wasps [13], [14], also attacks the non-native honey bee. The genus Apocephalus is best known for the "decapitating flies" that parasitize a variety of ant species [15]. Apocephalus borealis belongs to the subgenus Mesophora, which is a group that contains species that attack hosts other than ants. Although the hosts of most species in the Mesophora group are unknown, previously discovered hosts include a variety of arthropods including bees, wasps, beetles and spiders, but not honey bees [14]. In this paper, we show that A. borealis has a profound effect on parasitized honey bees, leading them to abandon their hives at night. 

Citation: Core A, Runckel C, Ivers J, Quock C, Siapno T, et al. (2012) A New Threat to Honey Bees, the Parasitic Phorid Fly Apocephalus borealis. PLoS ONE 7(1): e29639. January 3, 2012

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