Speaker
Description
The Hymenoptera present the highest number of eusocial species in insects and up to 9 independent origins of eusociality. By contrast, the eusocial lifestyle is virtually absent in other taxa, suggesting the existence of facilitating factors leading to advanced social organisation within Hymenoptera. As eusocial evolution is explained by the concept of inclusive fitness and the theory of kin selection, an ability to distinguish kin from non-kin could be instrumental for the advent of higher levels of sociality, by preventing costly altruistic acts towards unrelated individuals. Recent studies suggest that eusocial ants possess an olfactory subsystem that is specialised in the detection of cuticular hydrocarbons, providing a potential mechanism to detect social identity. It involves a particular type of sensilla on the antenna, the basiconic sensilla. They house olfactory sensory neurons (OSN) that are thought to express a group of odorant receptor genes with a distinctive 9-exon structure. These OSNs project to a segregated region of the primary olfactory centre in the brain, the antennal lobe. Strikingly, a similar suite of features has been observed in Vespid wasps which independently evolved a eusocial lifestyle, suggesting a potential link between this olfactory subsystem and advanced forms of social organization. By combining broad taxonomic sampling of Hymenoptera species with detailed neuroanatomical, functional and molecular characterisation of their olfactory structures, we aim to address the potential role of the basiconic-sensilla subsystem in social evolution.
