PROJECT 1 PROJECT SUMMARY Vector Biology of Invasive Anopheles stephensi in Rural to Urban Landscapes in Ethiopia Anopheles stephensi is a major malaria vector species in urban and peri-urban environments of South Asia. Since its first detection in Djibouti in 2012, the distribution of this vector species has expanded to Ethiopia, Sudan, Somalia, Kenya and Nigeria. The emergence and spread of An. stephensi in Africa pose serious challenges for malaria control and elimination in fast-growing urban areas of Africa. The World Health Organization recently launched an initiative to make a concerted effort to stop An. stephensi spread by improving An. stephensi surveillance and control in Africa. The biology of An. stephensi has been well characterized in its native range in South Asia. However, the ecology, behavior and population genetics of newly invasive An. stephensi and its role in malaria transmission in Africa are not well understood. Knowledge gaps related to An. stephensi ecology and behavior and the effectiveness of intervention methods have impeded the development of a data- driven and evidence-based An. stephensi control program. Lack of sensitive surveillance methods for An. stephensi has hindered efforts to effectively track An. stephensi population spread over time. The overarching objectives of this project are to address these knowledge gaps in invasive An. stephensi vector biology and spread in Ethiopia, identify surveillance tools and methods needed to track vector spread and develop control tools that can be adapted to settings of varying malaria endemicity. The central hypothesis is that An. stephensi invasion into new African environments has dynamically shifted the malaria vectorial system and altered local transmission dynamics. We will test this hypothesis by filling in knowledge gaps related to An. stephensi ecology, behavior and genetics; examining transmission dynamics along the rural to urban continuum; and evaluating new control tools. The four specific aims are to: 1) Examine the entomological drivers of malaria transmission in rural-urban landscapes; 2) Determine An. stephensi spread and influential anthropogenic, biological and environmental factors contributing to its spread; 3) Optimize larviciding methods for An. stephensi and native malaria vector control, and 4) Identify serological biomarkers that can distinguish exposure to invasive An. stephensi from other native malaria vector mosquitoes. Because many African urban settings are predicted to be conducive to An. stephensi invasion and An. stephensi is highly susceptible to local malaria parasites in Africa, better understanding of An. stephensi biology and distribution and optimizing vector control tools will be of paramount importance to malaria control in Africa.