Fig. 1

Pictorial illustration of the semi-field chambers and experimental huts used inside the VectorSphere. The semi-field chamber was designed to mimic local mosquito ecosystems in rural villages in Ulanga and Kilombero district, south-eastern Tanzania. There were two experimental huts with brick walls and thatched roofs inside the chamber, which enabled assessment of indoor and outdoor mosquito-biting risk. Each evening, 500 hungry-female Anopheles arabiensis mosquitoes were released inside the chamber. Adult male volunteers sat in the peri-domestic space of each of the huts and collected mosquitoes attempting to bite them between 1800 and 2200 h, before going indoors to sleep under intact bed nets. CDC-light traps were used to catch mosquitoes attempting to bite the sleeper between 2200 and 0630 h the next morning. Photograph by Emmanuel Mwanga