(A) Quantification and positions of eggs laid over ∼23 hr in the 1% agarose arena with apple cider vinegar-only control or naturally deposited aggregation pheromone (A: p = 0.4836; n = 10; A′: p < 0.001; n = 9; one-way ANOVA test) (B) Quantification and positions of eggs laid over ∼23 hr in the agarose arena in blank control or with 9-tricosene (yellow, 0.001%) (B: p = 0.9499; n = 11; p < 0.001; t-test, n = 9 per trial, One-way ANOVA test). (C) The effect of 9-tricosene on female oviposition site selection was assayed in Or7a neuron ablated flies (C: UAS-hid/+, p < 0.001, n = 9 per trial; C′: Or7a-Gal4/UAS-hid, p = 0.384; n = 9, One-way ANOVA test). (D) 9-Tricosene guided oviposition site selection assayed in Or7a−/− mutant flies (p = 0.69; n = 9, One-way ANOVA test). (E) Positional recording throughout the 23 hr course of female oviposition behavior with a 9-tricosene hybrid gel (p = 0.1; n = 6, One-way ANOVA test). (F) Oviposition site selection using a 7-tricosene hybrid gel. (p = 0.28; n = 8, One-way ANOVA test). (G) Box plots indicating the total number of eggs laid in A–D (p = 0.0021 comparing WT and Or7a > hid, p = 0.0001 comparing WT and Or7a−/−, p = 0.68 comparing Or7a > hid and Or7a−/− ; t-test ; n = 9–11). In all panels, colored dots indicate actual egg locations. Different colors represent different experiment trials. Error bars indicate ±2.5 s.e.m. throughout. Data points not within this range are plotted as circles.