Ant colonies have developed prophylactic and sanitary behavioural strategies, at the individual and collective level, that prevent exposure and spread of pathogens. Although pathogen transmission directly depends on colony size and nest structure, their influence on social immunity remains unknown. This research project will aim at determining the influence of nest structure and demography on the prophylactic and hygienic strategies of three ants species exposed to an entomopathogenic fungus, Metarhizium anisopliae.
With regards to colony size, we will study its influence not only on the immune activity of Lasius niger workers but also on their pathogen-induced avoidance strategies when selecting and excavating nesting sites. We will analyse how Myrmica rubra demography acts upon the waste management of healthy or infected items and we will compare the dynamics of waste removal according to the species’ ecology. Finally, we will examine whether the size of a colony influences its ability to develop a social memory of specific sanitary risks such as a lowered presence in contaminated areas or an improved discrimination of wastes.
With regards to nest topology, we shall draw a sanitary map of the microbial load in relation with the different activity areas within the colony. We shall determine the influence of nest structure on colony survival as well as on the spatial reorganisation of ants exposed to a pathogen. We will test whether the deposition of organic waste is guided by temperature and humidity in order to limit pathogen development. Finally, the polycalic nests of Linepithema humile will alow to quantify the dynamics of isolation, spatial reorganisation or diffusion of infectious sources among the different subunits of an ant supra-colony.
Unité d’Ecologie Sociale (USE)
ULB CP 231
Campus de la Plaine
bd du Triomphe, B-1050 Bruxelles
Tel: 02.650.60.12 (from abroad +32.2.650.60.12)
Fax: 02.650.59.87 (from abroad +32.2.650.59.87)