The mating behavior ofHomeopronematus (Pronematus) anconai (Baker) is described. This is the first report of direct sperm transfer in the family Tydeidae (Acari: Actinedida). Male guarding of pharate females and male agonistic behavior was observed. Successful mating occurred only during the first day of active female life. Specialized male structures, a hook on femur IV and a modified seta on genu IV, were examined by scanning electron microscope. These structures appear to be involved in holding the female during copulation.