Activation of A. gambiae sperm by applied compounds. Activation indices (y axes; + SEM) at given log10[M] (x axes) for (A) Orco modulators: VUANT (black bar, n = 8), VUAA0 (gray bar, n = 11), VUAA1 (pink bars, n = 8, 10, and 9, respectively), VUAA4 (aqua bars, n = 7, 10, and 5, respectively) or buffer (white bar, n = 27), VUAA1 plus VUANT [1 × 10−2 M] (pink/black striped bar, n = 7), and VUAA4 plus VUANT (aqua/black striped bar, n = 10) activation. (B) Indole-3-carboxyaldehyde (blue bars, n = 4, 3, and 5, respectively), plus VUANT (blue/black striped bar, n = 8) or buffer (white bar, n = 14). (C) Fenchone (green bars, n = 8, 11, 12, 10, and 6, respectively), plus VUANT (green/black striped bar, n = 10) or buffer (white bar, n = 27). (D) 8-Br-cAMP (orange bars, n = 6, 6, 6, 8, and 9, respectively), plus VUANT (orange/black striped bar, n = 7) or buffer (white bar, n = 27). Asterisks indicate significant differences between compound and control buffer samples or between compound with or without VUANT (Mann–Whitney U, P < 0.01).