Mosquitoes transmit disease-causing pathogens. Plasmodium parasites alone, the causative agents of malaria, kill millions of people each year. For natural transmission of Plasmodium to the vertebrate host, the parasite undergoes a series of obligatory developmental and propagative processes in a mosquito vector. Of interest in the current application is the biology of the sporogonic stages of Plasmodium in the mosquito hemocoel. Preliminary experiments have identified a family of proteins in the mosquito Anopheles gambiae with homology to an Aedes aegypti putative salivary gland sporozite receptor. Here, we will characterize the temporal and spatial expression of these An. gambiae proteins, and determine their involvement in salivary gland invasion by sporozoites. Furthermore, salivary gland invasion is a very inefficient process. Many sporozoites are unable to invade and rapidly die in the hemocoel. Here, we will also attempt to characterize the endogenous mechanisms used by mosquitoes to kill sporozoites. Understanding the mechanisms used by parasites to complete their life cycle inside the vector, and the mechanisms used by the vector to kill parasites, may lead to novel transmission control strategies. [unreadable] [unreadable]