Complex integrated behavior is primarily the result of processes in the central nervous system of an organism. However, the peripheral sensory system plays a decisive role in that it provides a basis on which the CNS can operate. The peripheral sensory organs of the mosquito detect and discriminate between many different chemical signals in its environment that are important in modulating the various behavior patterns of the mosquito. To understand the mechanisms controlling these behaviors, we must determine the relationships between the information provided by the peripheral sensory system and the behavior of the mosquito. The research proposed herein will provide fundamental information on the physiological processes underlying the selection and modulation of host-seeking behavior. Through the correlation of electrophysiologic responsiveness of single antennal chemosensory neurons with the host-seeking behavior of the female mosquito, we will provide a clearer understanding of the role of the peripheral sensory system in mediating host-seeking behavior. We hope that this information may be useful in preventing the transmission of mosquito-borne diseases.