Sampling of mosquito larvae was carried out in three proximal villages of Minepa (-8.2665°S, 36.6775°E), Lupiro (- 8.3857º S, 36.6791º E), and Mavimba (- 8.3163°S, 36.6810°E), located in Ulanga district, south-eastern Tanzania (Figure 1). The minimum distance between villages was ~4km from Minepa to Mavimba, while the maximum distance was 9km from Minepa to Lupiro. All the villages lie between 120 and 350 meters above sea level, and are located in the flood plains of the Kilombero river, between the Udzungwa mountain ranges to the north, and Mahenge hills to the south. The main economic activity of the area is irrigated rice farming. The irrigation leaves rice paddies continuously flooded, creating permanent water bodies favourable for mosquito breeding habitats. It is also a perennially meso-endemic malaria area, where transmission is predominantly by An. funestus s.s and An. arabiensis . Recent multiple assessments conducted in the same area have revealed that 100% of the An. gambiae s.l mosquitoes in this study area, were An. arabiensis sibling species. As such, all field-collected An. gambiae s.l mosquitoes are henceforth referred to as An. arabiensis. The main malaria vector control intervention in the area is LLINs. Larval collections were carried out in the dry season between June and December 2015, and in the wet season between January and May 2016. For each village, between seven and nine breeding sites were identified, geo-referenced, and permanently established as larval sampling points for resistance monitoring during this study. Immediately after sampling, larvae were separated into anophelines and culicines to prevent cannibalism, and for easier adult morphological identifications. After morphological identification, larvae were pooled by village and reared into adults under standard insectary conditions (temperature of 27 ± 3°C and relative humidity 70-90%) in a semi-field screen house. During rearing, larvae were fed on mud, and algae collected from the respective breeding sites, and supplemented with Tetramin® fish food (Tetra, Melle, Germany). Each morning, pupae were transferred into a plastic cup and placed in a net-covered cage for adult emergence. After emergence, adults were separated by sex, transferred into individual small cages with provision of 10% glucose solution and maintained at 27-28°C and relative humidity of 70-90% for subsequent bioassays.
Larvae sampling of wild mosquitoes
Other
