Meeting Abstract
Cuticular hydrocarbons (CHCs) play a dual role in insects: they prevent against water loss across the cuticle and they are a medium for chemical communication. In eusocial insects the use of CHCs in chemical communication takes on an additional dimension in that the CHCs are used not only for recognition of conspecifics but also for the recognition of members of the same colony. While the complex CHC signature allows ants to identify the majority of nest intruders, a large number of arthropods have nonetheless evolved to live inside of ant colonies via a number of different mechanisms. Of these so called myrmecophiles or ant lovers, the most intimately integrated species often mimic the CHC profile of the host colony, thus reducing, and in some cases entirely avoiding, detection within the colony. Within the colonies of the ant Liometopum occidentale two species of myrmecophile rove beetles have evolved to mimic the CHC profile of their host ant. Using a combination of GCMS and stable isotope mass spectrometry we analyzed the CHCs in the two beetle species to identify the mechanism by which the beetles obtained the compounds. In agreement with behavioural observations, we found that the beetle Sceptobius lativentris steals its CHCs from L. occidentale via a specialized grooming behavior whereas the beetle Platyusa sonomae synthesizes a large fraction of its own CHCs. These beetles embody two radically different approaches to chemical mimicry, either via modification of CHC synthesis machinery or through the modification of behavior, and represent a useful system for studying convergence in symbiotic systems.
