Fig. 3

Residual activity of Tenebenal™ WP applied at four concentrations as a prototype WP IRS to four surface materials, in comparison to an untreated control, measured as mortality in adult female Anopheles gambiae of the Kisumu strain 24 h after exposure. Mosquitoes were exposed to mud, cement, ceramic tiles or wood treated with 0.025, 0.05, 0.1 or 0.2% solutions of Tenebenal™ WP or an untreated negative control, and mortality observed 24 h after exposure. Values shown are average mortality in 30 mosquitoes, 10 exposed to each of three replicate surfaces. Mud blocks with 0.025 and 0.05% were withdrawn after month 14 due to low activity, but assays were continued with higher concentrations until month 20. Mortality in the negative control ceramic tile for month 10 was anomalously high but returned to expected value at subsequent time points; this datapoint is omitted from the Figure