The effect of Rickia wasmannii (Ascomycota, Laboulbeniales) on the aggression and boldness of Myrmica scabrinodis (Hymenoptera, Formicidae)

The interactions of parasitic Laboulbeniales (Ascomycetes) fungi and their hosts are rather understudied. Rickia wasmannii is the commonest ant parasitizing Laboulbeniales species in Europe, frequently infecting the relatively common Myrmica scabrinodis (Hymenoptera: Formicidae) ant in high density. These make M. scabrinodis and R. wasmannii to be ideal model organisms for studies on fungal host-parasite interactions. Aggressiveness and boldness of infected and uninfected M. scabrinodis workers were studied under lab conditions. Infected workers were significantly less aggressive and bold than the uninfected ones, which suggests that R. wasmannii has considerable effects on the behaviour of M. scabrinodis. Although the nature of this effect is still unclear, it might have a negative influence on the success of infected ants in competitive situations.