In open-field patches of five potted host trees containing varying amounts of proteinaceous food and host hawthorn fruit, we investigated the comparative influence of varying fly physiological and experiential states on the location and duration of residence of 18-d-old released apple maggot,Rhagoletis pomonella(Walsh), females. Several patterns of fly response were consistent with our preexperimental expectation. Thus, duration of residence was greater in patches where proteinaceous food and host fruit were present on all trees than in patches where either or both resources were absent from one or more trees, largely irrespective of fly physiological or experiential state. Flies that had no access to protein up to day of release (low egg load flies) were sighted in greater numbers on proteinaceous food than were flies that had continuous access to protein up to day of release (high egg load flies), whereas the reverse was true for flies sighted on host fruit. Flies that had partial access to protein up to day of release (intermediate egg load flies) were sighted in intermediate numbers on proteinaceous food and fruit. Flies that had continuous access to protein up to day of release were observed in greatest numbers on fruit if they received brief experience with fruit (as opposed to water or proteinaceous food) just before release. Presence on fruit of flies that had partial access to protein up to day of release was unaffected by type of brief experience just before release. Some patterns of fly response were not consistent with our preexperimental expectation. Thus, flies that had no or partial access to protein up to day of release were observed in fewer numbers (not greater or equal numbers, respectively) on proteinaceous food if they had brief experience with proteinaceous food just before release compared with brief experience with water or fruit. Flies that had no access to protein up to day of release and received brief experience with proteinaceous food just before release were found on tree foliage and in total in greater numbers (not equal numbers) than flies that had continuous access to protein up to day of release and received brief experience with fruit just before release. These and other findings are discussed in relation to previous knowledge of the resource foraging behavior of tephritid flies and in relation to improvement of behavioral methods of managingR. pomonellaflies in commercial apple orchards.