Fig. 1

Semi-field enclosure for release–recapture studies. a Metallic framework of the enclosure around 2 modified West Africa experimental huts. b Top, insert inside an EaveTube (view from outside); bottom, treated insert with visible insecticide powder. c Netting walls and door, and tarpaulin roof. d White tarpaulin floor to facilitate collection of dead mosquitoes. Six clay pots (3 visible) containing 1 l water and cotton soaked in 10% sugar solution were installed in the enclosure the morning after the release to provide resting sites and sugar sources for mosquitoes