rsos.royalsocietypublishing.org Research Cite this article: Schär S, Larsen LLM, Meyling NV, Nash DR. 2015 Reduced entomopathogen abundance in Myrmica ant nests—testing a possible immunological benefit of myrmecophily using Galleria mellonella as a model. R. Soc. open sci. 2: 150474. http://dx.doi.org/10.1098/rsos.150474 Received: 10 September 2015 Accepted: 25 September 2015 Subject Category: Biology (whole organism) Subject Areas: evolution Keywords: symbiosis, immunocompetence, hygiene Author for correspondence: Sämi Schär e-mail: saemi.schaer@gmail.com Electronic supplementary material is available at http://dx.doi.org/10.1098/rsos.150474 or via http://rsos.royalsocietypublishing.org. Reduced entomopathogen abundance in Myrmica ant nests—testing a possible immunological benefit of myrmecophily using Galleria mellonella as a model Sämi Schär 1 , Louise L. M. Larsen 1,2 , Nicolai V. Meyling 1,2 and David R. Nash 1 1 Centre for Social Evolution, Department of Biology, University of Copenhagen, Universitetsparken 15, 2100 Copenhagen Ø, Denmark 2 Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, 1871 Frederiksberg C, Denmark Social insects such as ants have evolved collective rather than individual immune defence strategies against diseases and parasites at the level of their societies (colonies), known as social immunity. Ants frequently host other arthropods, so-called myrmecophiles, in their nests. Here, we tested the hypothesis that myrmecophily may partly arise from selection for exploiting the ants’ social immunity. We used larvae of the wax moth Galleria mellonella as ‘model myrmecophiles’ (baits) to test this hypothesis. We found significantly reduced abundance of entomopathogens in ant nests compared with the surrounding environment. Specific entomopathogen groups (Isaria fumosorosea and nematodes) were also found to be significantly less abundant inside than outside ant nests, whereas one entomopathogen (Beauveria brongniartii) was significantly more abundant inside nests. We therefore hypothesize that immunological benefits of entering ant nests may provide us a new explanation of why natural selection acts in favour of such a life-history strategy. 1. Introduction Group life has many advantages compared with a solitary lifestyle, and some of the ecologically most dominant organisms 2015 The Authors. Published by the Royal Society under the terms of the Creative Commons Attribution License http://creativecommons.org/licenses/by/4.0/, which permits unrestricted use, provided the original author and source are credited. Downloaded from https://royalsocietypublishing.org/ on 22 February 2022