ESSEX JUNCTION (AP) -- Vermont beekeepers say they face mite infestations, extreme temperature swings and the possibility of colony collapse. But a San Francisco State University professor says a new threat has arrived in Vermont: zombie bees.

John Hafernik told a meeting of Vermont beekeepers on Tuesday that a fly attaches itself to the bee and injects its eggs, which grow inside the bee. Hafernik says this is presumed to cause neurological damage resulting in erratic, jerky movement and night activity, "like a zombie."

Beekeeper Anthony Cantrell says he discovered zombie bees in his hive in October. Hafernik says they’re the first zombie bees identified on the East coast as well as in Vermont.

Vermont Agricultural Production Specialist Stephen Parise says they are not sure if Cantrell’s zombie bees are an "isolated" occurrence.