Cactus flies fighting and feeding

Description :

A large male cactus fly (Odontoloxozus longicornis) and smaller female are stting on a rotting opuntia branch. When a second, smaller male approaches and mounts the female, the large male chases him away. The female then moves away, and the large male maintains contact with her by touching her with his foreleg. When the large male starts feeding on a small crevice oozing cactus juice, he has apparently lost interest in the female. The female and the small male try to gain access to the crevice, but the large male keeps both of them away. After a brief, violent struggle with the female, the large male flies away. Note that the female is missing one of her forelegs. Tucson, Pima County, Arizona, USA. 16 November 2008. [taxonomy:binomial=Odontoloxozus longicornis]