(A) Courtship indices of Gr33aGal4/+ and +/UAS-APP control males, Gr33aGal4/UAS-APP males, Gr33aGal4/UAS-APPΔCT males, Gr33aGal4/+; dfoxOΔ94/+ males and Gr33aGal4/UAS-APP; dfoxOΔ94/+ males in courtship choice assays towards younger mates (white) and older ones (grey), respectively. Box-and-whisker plots for CIs show 1–99 percentiles and mean (+), n = 22 for control males, 21 for +/UAS-APP males, 23 for Gr33aGal4/UAS-APP males, 25 for Gr33aGal4/UAS-APPΔCT males, 21 for Gr33aGal4/+; dfoxOΔ94/+ males and 21 for Gr33aGal4/UAS-APP; dfoxOΔ94/+ males. n.s., p > 0.05, two asterisks, p < 0.01, three asterisks, p < 0.001, Related-samples Wilcoxon Signed Rank test. (B) Preference indices of Gr33aGal4/+ and +/UAS-APP control males, Gr33aGal4/UAS-APP males, Gr33aGal4/UAS-APPΔCT males, Gr33aGal4/+; dfoxOΔ94/+ males and Gr33aGal4/UAS-APP; dfoxOΔ94/+ males in courtship choice assays. Mean ± standard error of the mean (SEM). n.s., p > 0.05, three asterisks, p < 0.001, Kruskal-Wallis test, Dunn's post-hoc. (C) Total courtship indices of Gr33aGal4/+ and +/UAS-APP control males, Gr33aGal4/UAS-APP males, Gr33aGal4/UAS-APPΔCT males, Gr33aGal4/+; dfoxOΔ94/+ males and Gr33aGal4/UAS-APP; dfoxOΔ94/+ males in courtship choice assays. Mean ± standard error of the mean (SEM). n.s., p > 0.05, Kruskal-Wallis test, Dunn's post-hoc.