Fig. 1: Changes in physiology and behavior of food-deprived larvae.

a–d Analysis of larval locomotion. Box plots display the median, interquartile range (IQR), and whiskers up to 1.5 × IQR. Outliers are plotted individually. e–h, j, k Larval feeding on different substrates was quantified, in control animals fed ad libitum, in animals fed on sucrose, or subjected to starvation during 90 min. Data are presented as mean values +/− SEM. e Starved animals increased their feeding on a standard food medium as compared to fed animals. f Both animals fed on sucrose only and starved animals increase their yeast feeding as compared to normally fed larvae. g While starved animals consume a similar amount of water as fed ones, animals fed on sucrose only double their water consumption (h) Consumption of yeast was similar between larvae fed on normal food and those fed on food with 20% sucrose. i Place preference assay for sucrose. Larvae fed on 20% sucrose exhibit a decreased sucrose preference compared to normally fed and starved larvae. j Sucrose intake in larvae in different feeding states upon gustatory neurons inhibition (Gr43a-Gal4 > TNT) and in intact larvae. k Consumption of sucralose was similar among conditions. l–m Concentration of glucose and trehalose in larval hemolymph. n–u Manipulating the feeding state modulates behavioral responses to mechanosensory stimuli. Behavior in response to an air-puff for larvae fed on sucrose only (n–q) and starved larvae (r–u). n–p, r–t Hunch and Static-bend are presented as population probability during the first five seconds upon stimulus onset and 95 % confidence interval, Head Cast as post-stimulus probability corrected by baseline probability. q, u Behavioral transitions over the first two seconds of stimulation in sucrose fed larvae (q) or starved (u) compared to fed larvae (Statistics: a–d two-sided Mann-Whitney test with Bonferroni correction; (e–g, k–m) one-way ANOVA with Tukey post-hoc test (two-sided); (j) one-sided Mann-Whitney test with Bonferroni correction; (h) two-tailed T-test. (i, n, o, r, s Chi-square (one-sided) test. p, t Numerical simulation test; q, u Maximum likelihood test (one-sided, chi-square approximation); ****p < 0.0001, ***p < 0.001, **p < 0.01, *p < 0.05). See also Supplementary Fig. 1.The source data and p-values are provided in Source Data 1–5.