Wolbachia-infected ant colonies have increased reproductive investment and an accelerated life cycle

Wolbachia is a widespread group of maternally-transmitted endosymbiotic bacteria that often manipulates the reproductive strategy and life history of its hosts to favor its own transmission. Wolbachia mediated phenotypic effects are well characterized in solitary hosts, although evidence of similar effects are rare in eusocial insects, such as ants. The invasive pharaoh ant, Monomorium pharaonis, shows natural variation in Wolbachia infection between colonies and can be readily bred under laboratory conditions. We previously showed that Wolbachia-infected pharaoh ant colonies had a queen-biased sex ratio, which is expected to favor the spread of maternally-transmitted Wolbachia. Here, we further characterize the effects of Wolbachia on the short- and longer-term reproductive and life history traits of pharaoh ant colonies. First we characterized reproductive differences between naturally infected and uninfected colonies at three discrete time points and found that infected colonies had higher reproductive investment (i.e. infected colonies produce more new queens), in particular when colony queens were three months old. Next, we compared the long-term growth and reproduction dynamics of infected and uninfected colonies across their whole life cycle. Infected colonies had increased colony-level growth and early colony reproduction, resulting in a shorter colony life cycle, when compared to uninfected colonies.We have provided details of our statistical analysis in R in the following documents - SuppFile-s4-script-assay1: R script used for statistical analysis for Assay 1 SuppFile-s5-script-assay2: R script used for statistical analysis for Assay 2 SuppFile-s6-script-relatedness-comparisons: R script used for comparing colony relatedness SuppFile-s7-script-assay1-output: output from the statistical analysis done in R for Assay 1. These values have been quoted in the article to support our claim. SuppFile-s8-script-assay2-output: output from the statistical analysis done in R for Assay 2. These values have been quoted in the article to support our claim. Funding provided by: National Science FoundationCrossref Funder Registry ID: http://dx.doi.org/10.13039/100000001Award Number: IOS-1452520We have provided 3 datasets, all of which include the raw values collected over the course of the experiment and have been used in the article to support our conclusions. Please refer to the article for details about experimental design and data collection. These raw valued were analyzed to assess fitness differences between Wolbachia-infected and uinfected pharaoh ant colonies in two different experimental regimes. SuppFile-S1-assay 1: contains the raw census values collected for Assay 1 SuppFile-S2-assay 2: contains the raw census and dry mass of worker pupae collected for Assay 2 SuppFile-S3-colony-relatedness: raw values of relatedness among heterogenous lab stock colonies used to create experimental colonies in the current article