Malaria Epidemiology and Vector Biology of Invasive Anopheles stephensi Across Rural and Urban Landscapes in Ethiopia PROGRAM SUMMARY Anopheles stephensi is a major malaria vector species in South Asia. Since its first detection on the African continent 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 Africa. Knowledge gaps related to An. stephensi ecology and behavior and the effectiveness of intervention methods in Africa have impeded the development of effective malaria control programs. Lack of sensitive surveillance methods for An. stephensi has also hindered efforts to effectively track An. stephensi population spread over time. To date, only limited basic research has examined the biology of invasive An. stephensi mosquitoes and the impact of An. stephensi invasion on malaria epidemiology in Africa. Little translational research has been conducted to develop new surveillance and control tools for An. stephensi. To address the major knowledge gaps and challenges in malaria control and elimination in the face of An. stephensi invasion and rapid spread across sub-Saharan Africa, our ICEMR established a consortium of outstanding institutions and investigators from the U.S. and Ethiopia to study critical scientific questions regarding malaria control and elimination efforts in the Greater Horn of Africa. The overarching goals of this ICEMR are to 1) address the knowledge gaps in invasive An. stephensi vector biology and malaria epidemiology across the rural to urban continuum in Ethiopia; 2) develop surveillance tools and methods needed to track vector spread; and 3) identify cost-effective vector control methods that can be adapted to settings of varying malaria endemicity. The ICEMR has two projects, each with multiple specific objectives. Project 1 will assess the vector biology of An. stephensi, elucidate the extent of spread of invasive An. stephensi, and develop serological biomarkers for An. stephensi exposure surveillance. Project 2 will examine the impact of An. stephensi invasion on malaria risk and determine the epidemiological impact and cost-effectiveness of larviciding methods targeting areas of high malaria risk across the rural to urban landscape. The administrative and data management cores will provide support to the entire program. Knowledge gained through this ICEMR is important to malaria control and elimination, not only in Ethiopia, but also in other African countries with invasive An. stephensi.