Ant queens increase their reproductive efforts after pathogen infection Journal Article

Author(s): Giehr, Julia; Grasse, Anna V; Cremer, Sylvia; Heinze, Jürgen; Schrempf, Alexandra
Article Title: Ant queens increase their reproductive efforts after pathogen infection
Affiliation IST Austria
Abstract: Infections with potentially lethal pathogens may negatively affect an individual's lifespan and decrease its reproductive value. The terminal investment hypothesis predicts that individuals faced with a reduced survival should invest more into reproduction instead of maintenance and growth. Several studies suggest that individuals are indeed able to estimate their body condition and to increase their reproductive effort with approaching death, while other studies gave ambiguous results. We investigate whether queens of a perennial social insect (ant) are able to boost their reproduction following infection with an obligate killing pathogen. Social insect queens are special with regard to reproduction and aging, as they outlive conspecific non-reproductive workers. Moreover, in the ant Cardiocondyla obscurior, fecundity increases with queen age. However, it remained unclear whether this reflects negative reproductive senescence or terminal investment in response to approaching death. Here, we test whether queens of C. obscurior react to infection with the entomopathogenic fungus Metarhizium brunneum by an increased egg-laying rate. We show that a fungal infection triggers a reinforced investment in reproduction in queens. This adjustment of the reproductive rate by ant queens is consistent with predictions of the terminal investment hypothesis and is reported for the first time in a social insect.
Keywords: Reproduction; Terminal investment; social insect; infection
Journal Title: Royal Society Open Science
Volume: 4
ISSN: 2054-5703
Publisher: Royal Society, The  
Date Published: 2017-07-05
Start Page: Article number: 170547
Copyright Statement: CC BY 4.0
DOI: 10.1098/rsos.170547
Notes: We thank two anonymous reviewers for helpful suggestions on the manuscript.
Open access: yes (OA journal)