Observations of adult blueberry maggot, Rhagoletis mendax Curran, and cherry fruit fly, R. cingulata (Loew), were conducted in Michigan fruit crops during the summer of 2004. To determine whether the addition of an attractant to the baited insecticide GF-120 increases fly interaction with the insecticide, host plant foliage was treated with GF-120, GF-120 + ammonium acetate, or GF-120 + ammonium carbonate. Fly behaviors observed included the duration of time spent in contact with bait, duration of close proximity to bait, and frequency of contact with and feeding on bait. Fly mortality was also compared among treatments. In a concurrent laboratory study, ammonium acetate was added to the fruit fly bait NuLure at three rates then applied to foliage and presented to cherry fruit flies in cage bioassays to determine whether the attractant affected the frequency or duration of fly contact with the bait.