Trap placement and density were evaluated for detecting first and early emergence of western cherry fruit fly adults in 12 commercial cherry orchards in Utah County during 2003. Pherocon AM traps with ammonium carbonate bait were placed at two trap densities (1 and 3 traps per acre) and in two placement designs (in border trees only or in both border and interior trees). Total number of adults caught per orchard for the pre-harvest period was negatively related to date of first capture. Almost six times more adults were caught in orchards with the higher trap density. Mean adult densities were greater on traps in interior trees (20.5 adults per trap) than in border trees (7.0 adults per trap). The ovaries of female fruit flies were dissected to determine egg maturity. Females with mature eggs were first present 3 or 10 days before fruit were susceptible to egg deposition (based on fruit color and penetrometer measurements) for sweet and tart cherries, respectively. Results from five years of research plot trials show that one biological and two nicotinoid insecticides can provide comparative control of western cherry fruit fly to that of the organophosphate Guthion. The nicotinoids stimulated spider mite densities following two or three applications per season.