Past studies suggest that sugar feeding is rare for Anopheles gambiae, the primary vector of malaria in Africa, as sugar sources are infrequent in space and time. To determine the importance of sugar availability on their ability to inseminate receptive, virgin females, male mating capacity was evaluated within a screen house. Given sugar, males under semi-natural conditions in open space were able to inseminate 5% of females by night two after emergence, and up to 40% by night four. With rare exceptions, males without a sugar source were unable to inseminate females under semi-natural conditions. We conclude that male performance is closely tied to sugar availability, and therefore, tied to the plant communities found in their habitat.