Anopheles gambiae s.l. larval and adult population density in 2003. A. Density of A. gambiae s.l. larvae (N = 1,719) in habitats sampled twice along a 12 km transect from Asembo to Seme. B. Proportion of A. gambiae s.l. larvae that were A. gambiae s.s. (as opposed to A. arabiensis). C. Density of adult, female A. gambiae s.l. inside houses (line), and proportion of them identified by PCR as A. gambiae s.s. (bars), along the Asembo-Seme transect.