Pupal cocoons affect sanitary brood care and limit fungal infections in ant colonies.

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Serval ID
serval:BIB_05791B72831B
Type
Article: article from journal or magazin.
Collection
Publications
Institution
Title
Pupal cocoons affect sanitary brood care and limit fungal infections in ant colonies.
Journal
BMC Evolutionary Biology
Author(s)
Tragust S., Ugelvig L.V., Chapuisat M., Heinze J., Cremer S.
ISSN
1471-2148 (Electronic)
ISSN-L
1471-2148
Publication state
Published
Issued date
2013
Peer-reviewed
Oui
Volume
13
Pages
225
Language
english
Abstract
BACKGROUND: The brood of ants and other social insects is highly susceptible to pathogens, particularly those that penetrate the soft larval and pupal cuticle. We here test whether the presence of a pupal cocoon, which occurs in some ant species but not in others, affects the sanitary brood care and fungal infection patterns after exposure to the entomopathogenic fungus Metarhizium brunneum. We use a) a comparative approach analysing four species with either naked or cocooned pupae and b) a within-species analysis of a single ant species, in which both pupal types co-exist in the same colony.
RESULTS: We found that the presence of a cocoon did not compromise fungal pathogen detection by the ants and that species with cocooned pupae increased brood grooming after pathogen exposure. All tested ant species further removed brood from their nests, which was predominantly expressed towards larvae and naked pupae treated with the live fungal pathogen. In contrast, cocooned pupae exposed to live fungus were not removed at higher rates than cocooned pupae exposed to dead fungus or a sham control. Consistent with this, exposure to the live fungus caused high numbers of infections and fungal outgrowth in larvae and naked pupae, but not in cocooned pupae. Moreover, the ants consistently removed the brood prior to fungal outgrowth, ensuring a clean brood chamber.
CONCLUSION: Our study suggests that the pupal cocoon has a protective effect against fungal infection, causing an adaptive change in sanitary behaviours by the ants. It further demonstrates that brood removal-originally described for honeybees as "hygienic behaviour"-is a widespread sanitary behaviour in ants, which likely has important implications on disease dynamics in social insect colonies.
Keywords
Social immunity, Sanitary brood care, Grooming, Hygienic behaviour, Metarhizium fungus, Formicidae
Pubmed
Web of science
Open Access
Yes
Create date
02/09/2013 7:38
Last modification date
20/08/2019 12:27
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