Fig. 5. Drosophila larvae avoid CO₂ and prefer vinegar. (A) Mean distribution of groups of 10 larvae after 10 min when air is delivered in the four fields (N=18). (B) Mean distributions after 10 min when CO₂ is added to one field (black) at two concentrations (N_0.1%=24; N_1%=25). (C) Mean distribution at four time points when one field (gray) is laced with vinegar odor (N=17). Abbreviations and statistics are as in Fig. 1. The broken line at 25% indicates an equal distribution in all fields. In contrast to the results in Figs 1 and 2 the test field is not significantly different from all control fields (Friedman-ANOVA, P<0.01 for CO₂, P<0.001 for vinegar; Wilcoxon-Wilcox: P<0.05); ns, no significant difference. Values are means ± s.e.m.