Photomacrograph; color transparency film; electronic flash

Arizona Research Laboratories, Division of Neurobiology, The University of Arizona, Tucson, Arizona, United States

Male boxing flies, Rhagoletis boycei of the family Tephritidae, fight to defend oviposition sites on an Arizona Black fialnut, Juglans major. Males that successfully defend these sites are permitted to mate with females prior to their ovipositing, or egg-laying, within the tree's fruit.