(A–B) Volume of 20% sucrose consumed by indicated flies during 24 hr using the Capillary Feeder (CAFE) assay (normalized with normal diet [ND] flies, n=3–15 biological replicates, each containing 20 flies). (C–D) Fractions of indicated flies showing proboscis extension reflex (PER) responses to different concentrations of sucrose (n=3–6 biological replicates, each containing 8–12 flies). The S50 indicated the sucrose concentration that induced PER responses in 50% of the tested flies. The flies in B and C were pre-starved for 12 hr (fasting) before the assay. (E–F) Fractions of flies showing PER responses to 1% hexanoic acid (n=8, each containing 5 flies). (G–H) Fractions of male flies showing PER responses to 20% sucrose (n=6, each containing 5 flies). (I) Fractions of indicated flies showing PER responses to different concentrations of sucrose (n=3–6 biological replicates, each containing 8–12 flies). The S50 indicated the sucrose concentration that induced PER responses in 50% of the tested flies. Data were shown as means ± SEM. ns p>0.05; * p<0.05; **p < 0.01; ***p < 0.001; ****p < 0.0001.