Expanding on olfactory communication in a butterfly: cuticular chemicals indicate sex and age in Bicyclus anynana

peer reviewedChemical (olfactory or gustatory) communication is fundamental to most living organisms but widely understudied compared to other channels of communication such as vision and audition, principally in sexual selection . Here we present the first extensive analysis of cuticular chemical diversity in a butterfly, and investigate whether molecules inform potential mating partners about sex and age. Bicyclus anynana was chosen for its well-known potentialities as a lab model in eco-evo-devo studies , . Chemical interactions have been investigated so far in this species with focus on volatile olfactory components: male sexual pheromones composition and their roles in sexual selection , , their change in ratio with male age, inbreeding coefficient, and other factors . Here we aim completing the picture fully and focus on gustatory non-volatile cuticular chemical diversity in this model species. Indeed, as for Drosophila, the courtship of this butterfly is composed of a series of steps that include short-range interactions during which various chemicals may be involved in mate-choice, through olfactory but also gustatory channels of communication (Nieberding et al., data not published). More than hundred cuticular chemicals were identified and quantified by GC-MS analyses on different parts (abdomen, antennae, head, legs and wings) of B. anynana individuals (n=42, 210 GC-MS analyses) of each sex and at different ages (from 1 to 21 days old). The analysis of the chemical distribution was realised by multivariate statistical analyses (perMANOVA). The results led to the conclusion that some cuticular chemicals are indicative for the body parts and can inform about sex and age