Premium
Sick ants become unsociable
Author(s) -
BOS N.,
LEFÈVRE T.,
JENSEN A. B.,
D’ETTORRE P.
Publication year - 2012
Publication title -
journal of evolutionary biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.289
H-Index - 128
eISSN - 1420-9101
pISSN - 1010-061X
DOI - 10.1111/j.1420-9101.2011.02425.x
Subject(s) - biology , brood , generalist and specialist species , nest (protein structural motif) , inclusive fitness , host (biology) , insect , zoology , ecology , social evolution , evolutionary biology , habitat , biochemistry
Parasites represent a severe threat to social insects, which form high‐density colonies of related individuals, and selection should favour host traits that reduce infection risk. Here, using a carpenter ant ( Camponotus aethiops ) and a generalist insect pathogenic fungus ( Metarhizium brunneum ), we show that infected ants radically change their behaviour over time to reduce the risk of colony infection. Infected individuals (i) performed less social interactions than their uninfected counterparts, (ii) did not interact with brood anymore and (iii) spent most of their time outside the nest from day 3 post‐infection until death. Furthermore, infected ants displayed an increased aggressiveness towards non‐nestmates. Finally, infected ants did not alter their cuticular chemical profile, suggesting that infected individuals do not signal their physiological status to nestmates. Our results provide evidence for the evolution of unsociability following pathogen infection in a social animal and suggest an important role of inclusive fitness in driving such evolution.