(A) Schematic drawing of a two-choice assay. (B) Behavioral responses to pyrethrum delivered in 50 μL of various dilutions (v v-1) in a two-choice assay (H = 32.15, d.f. = 4, P < 0.001; **P < 0.01 compared to control; One-Way ANOVA on Ranks, n = 11 for 10−2, n = 12 for control, n = 19 for 10−4 and 10−3, and n = 20 for 0.5 dilution). (C) Orco-dependency of repellency to pyrethrum at 50 μL of the 0.5 dilution (v v-1) (F(2,18) = 40.60, P < 0.001; ***P < 0.001 compared to w1118; One-Way ANOVA, n = 9 for w1118, and n = 6 for the rest). (D) Orco-dependency of EAG responses to pyrethrum at 30 μL of the 10−2 dilution (v v-1) (H = 15.07, d.f. = 2, P < 0.001; **P < 0.01 compared to w1118; One-Way ANOVA on Ranks, n = 8 for w1118, n = 11 for Orco-/- 1, and n = 10 for Orco-/- 2).