Klowden 9807538 In many species of mosquitoes, the females mate only once during their lives. When the males inseminate the females shortly after they emerge, they not only receive sperm to fertilize their eggs, but also products that are transferred from the accessory gland of the male. These accessory gland products have been believed to be active in the female in various ways, switching her behavior to turn off subsequent mating behavior and activate egg-laying, but these generalizations have been based on the easily colonized Aedes mosquitoes that are usually the subjects of laboratory research. None of the previous studies for which this accessory gland mechanism has been determined have examined Anopheles mosquitoes, which are important vectors of malaria. The PIs preliminary experiments indicate that in these Anopheles mosquitoes, male accessory glands indeed have no role in the behavioral switchover, although mating itself does affect the female in several ways. The PIs research will determine how Anopheles mosquitoes are affected by mating, and what possible role male accessory gland substances do play in these mosquitoes. Because future methods of mosquito control may involve the introduction of novel genes by modified males, it is important to understand the mechanisms that regulate mating in these vectors of human disease.