Fig. 4.

Bioassay of cuticular extracts from queens and infertile workers. Twenty workers were exposed to 1/100th of cuticular extracts of nestmate queens and to the matching quantity of nestmate worker extracts. Total lipid extracts as well as their HC and non-HC fractions were tested. We monitored the preference of the workers for each extract in terms of cumulated number of antennal inspection in 5 min (^* indicates significant differences, Wilcoxon test, P < 0.05). Five microliters of hexane applied on two cover slides constituted the solvent control. Because the attention elicited was not significantly different for the two control slides (Wilcoxon test), results were pooled for clarity. The number of replications was six for each category.