Fig. 1: Exposure of Drosophila to wasps accelerates sexual behavior.

a Courtship arena containing a male and virgin female fly with (left) and without (right) two wasps, one male and one female. b Copulation latency of D. melanogaster. p < 0.0001, two-tailed Mann–Whitney test, n = 105 for +Lb, i.e., exposed to wasps, n = 102 for unexposed, error bars = SEM. The experiment was allowed to run for 1 h. c Copulation latency of other Drosophila species while in arena. Four wasps, two males and two females, were used for exposure. Two-tailed Mann–Whitney test. D. simulans, p = 0.0035, n = 67 (exposed), n = 63 (unexposed); D. yakuba, p = 0.0001, n = 62, 63; D. biarmipes, p < 0.0001, n = 62, 62; D. willistoni, p = 0.0009, n = 93, 92. Error bars = SEM. d Competition paradigm. In the left vial, fluorescently labeled flies (green) are incubated with wasps; in the right vial, unlabeled flies are incubated without wasps; in the arena below, a labeled exposed fly and an unlabeled unexposed fly of the same sex are allowed to compete for a fly of the opposite sex. d′ Competition paradigm. In the left vial, unlabeled flies are incubated with wasps; in the right vial, labeled flies are incubated without wasps; in the arena below, an unlabeled exposed fly and a labeled unexposed fly of the same sex are allowed to compete for a fly of the opposite sex. e Left, competition between a male exposed to L. boulardi and an unexposed male for an unexposed female; dark shading indicates the percentage of competitions won by the exposed male (p = 0.843, chi-squared test, n = 102). Right, a female exposed to L. boulardi and an unexposed female are placed in an arena with an unexposed male; dark shading indicates the percentage of pairings in which the exposed female copulated (p = 0.0038, chi-squared test, n = 115). f Experiments comparing the mating success of an exposed and unexposed female of other species, placed with a male of the same species. Chi-squared test. D. simulans (p = 0.0129, n = 102); D. yakuba (p = 0.0350, n = 119); D. biarmipes (p = 0.0001, n = 84); D. willistoni (p = 0.0057, n = 119).