Choice.

<p>(A) Larvae are allowed to chose between one side of a Petri dish that contains agarose added with 5 mM quinine (QUI), and pure agarose (PURE) on the other side. A gustatory preference (PREF_Gustatory) is calculated at different time points after the experiment has started. Negative PREF_Gustatory values indicate avoidance of QUI which is statistically significant already from 1 min on. Based on these results we chose 8 min as time point of scoring choice in subsequent experiments, as for this time point avoidance was apparently strongest. (B) Gustatory preference either between both sides of a Petri dish filled with agarose-only (CONTROL) or between a QUI- and a PURE-filled side of a split Petri dish, at the indicated concentrations of QUI. Scores are taken after 8 min. At concentrations from 0.005 mM to 5 mM QUI is avoided by the larvae. Avoidance differs between the two highest concentrations of QUI, thus arguing that the point of asymptote should be above 5 mM. Shading of the boxes indicates significant differences from chance behaviour (i.e. zero, one-sample sign tests) (A) <i>P</i><0.05/4; (B) <i>P</i><0.05/7; keeping the experiment-wide error rate at 5% (i.e. Bonferroni correction). Labelling of * refers to <i>P</i><0.05 in a Mann-Whitney U-test. Box plots represent the median as the middle line and 25%/75% and 10%/90% as box boundaries and whiskers, respectively. Sample sizes: (A) N = 101; (B) from left to right N = 110, 150, 120, 95, 101.