Co founding ant queens prevent disease by performing prophylactic undertaking behaviour Journal Article

Author(s): Pull, Christopher D; Cremer, Sylvia
Article Title: Co founding ant queens prevent disease by performing prophylactic undertaking behaviour
Affiliation IST Austria
Abstract: Background: Social insects form densely crowded societies in environments with high pathogen loads, but have evolved collective defences that mitigate the impact of disease. However, colony-founding queens lack this protection and suffer high rates of mortality. The impact of pathogens may be exacerbated in species where queens found colonies together, as healthy individuals may contract pathogens from infectious co-founders. Therefore, we tested whether ant queens avoid founding colonies with pathogen-exposed conspecifics and how they might limit disease transmission from infectious individuals. Results: Using Lasius niger queens and a naturally infecting fungal pathogen Metarhizium brunneum, we observed that queens were equally likely to found colonies with another pathogen-exposed or sham-treated queen. However, when one queen died, the surviving individual performed biting, burial and removal of the corpse. These undertaking behaviours were performed prophylactically, i.e. targeted equally towards non-infected and infected corpses, as well as carried out before infected corpses became infectious. Biting and burial reduced the risk of the queens contracting and dying from disease from an infectious corpse of a dead co-foundress. Conclusions: We show that co-founding ant queens express undertaking behaviours that, in mature colonies, are performed exclusively by workers. Such infection avoidance behaviours act before the queens can contract the disease and will therefore improve the overall chance of colony founding success in ant queens.
Keywords: social immunity; pleometrosis; Host-pathogen interactions; disease defence behaviour; entomopathogenic fungus
Journal Title: BMC Evolutionary Biology
Volume: 17
ISSN: 1471-2148
Publisher: BioMed Central  
Date Published: 2017-10-13
Start Page: Article number: 219
Copyright Statement: CC BY 4.0
Sponsor: This study was funded by a European Research Council Starting Grant to S.C. (240371) under the European Commission’s Seventh Framework Programme.
DOI: 10.1186/s12862-017-1062-4
Notes: We thank Barbara Casillas-PĂ©rez, Anna V. Grasse and Leila Masri for help setting up experiments and collecting data. We are also thankful to the whole IST Austria Social Immunity group for assistance in collecting queens and project discussion. Finally, we thank two anonymous referees for very helpful feedback on the manuscript.
Open access: yes (OA journal)