The exotic emerald ash borer (EAB), Agrilus planipennis, is a lethal pest that attacks and invariably destroys unprotected Fraxinus spp. in its current southeast Michigan range. In 2003 trials, trunk injection of imidaclprid provided variable levels of control. Follow-up experiments in 2004 sought to understand the effects of injection on EAB by measuring imidacloprid distribution over time and between tissues (phloem, xylem sap, foliage); mortality and feeding inhibition on adult EAB; and larval density. These measures were used to compare injection methods (mauget and arborjet), application timing, and pesticide formulation.