In experiments comparing biodegradable, plastic and wooden imidacloprid-treated spheres for control of Rhagoletis mendax Curran, the mean number of flies caught on plexiglas panes below each sphere type was not significantly different for the entire season. However, the mean time spent by R. mendax flies alighting on biodegradable imidacloprid-treated spheres was significantly greater (2.6×) than plastic imidacloprid-treated spheres. During 2001, significantly fewer larvae were found in blueberries harvested from bushes that had wooden imidacloprid-treated spheres hung within the canopy compared with bushes where biodegradable and plastic imidacloprid-treated spheres were deployed. There was no significant difference between the number of larvae found in berries picked from bushes where biodegradable or plastic spheres were deployed. All imidacloprid-treated sphere treatments were found to significantly reduce blueberry maggot larval infestation in fruit compared with the control.