Figure 1.

Attribution of anticipated food rewards to discrete odor stimuli by fed larvae. (A–D) Third-instar fed larvae (74 h after egg laying, AEL) were exposed to an odor stimulus for 5 minutes in a sealed chamber, fumigated with defined concentrations of monomolecular odorants PA, Hep, T2H or natural odorants balsamic vinegar, prior to the feeding test in 10% glucose liquid media. The odor effects on larval feeding rate were quantified by counting mouth hook contractions of each larva over a 30 s period. The rate of mouth hook contraction is positively correlated to the amount of dyed food ingested⁷. n ≥ 15. (E) Two binary odor mixtures were used instead: PA plus Hep and PA plus T2H. n ≥ 17. All behavioral quantifications for this and other figures were performed under blind conditions. Unless indicated otherwise, all the statistical analyses were performed using One-way ANOVA followed by a Dunnett’s test. *P < 0.05; **P < 0.001.