Does fungal infection produce cheaper workers

Cuticle quality is of vital importance in insects. Amongst others, it prevents desiccation, and protects against pathogens. Therefore the development of thicker cuticle would be advantageous. The within-species variation of cuticle structure is affected by many factors, both physiological and ecological. Parasites can also affect the exoskeleton structure either to facilitate intrusion or to aid transmission to the next host. In the frame of our study we investigated the effect of an ectoparasitic fungus, Rickia wasmannii on the cuticle of its host. We measured the thickness of the exoskeleton in infected and uninfected ants originating from three European populations. Infected ants had thinner cuticle than uninfected ones, while there were also differences among populations. It is unclear though, whether this is the host’s response investing less into cuticle formation, or the fungus infects colonies with thin cuticle. Either way, within-species variation is linked to response to parasitic pressure.