Emerald ash borer (EAB), Agrilus planipennis Fairmaire (Buprestidae), a newly introduced wood-boring insect, has been identified as the cause of extensive ash (Fraxinus spp.) mortality throughout southeastern Michigan, northern Ohio, and southwestern Ontario since its first discovery in 2002. Successful containment and eventual eradication of this pest from North America relies on aggressive quarantine enforcement as well as effective management strategies. We studied the potential of the entomopathogenic fungus, Beauveria bassiana GHA (BotaniGard® ES) in the management of EAB under field conditions through foliar and trunk applications. The impact of the fungus on EAB population dynamics and the conditions of infested ash trees will be discussed.