Dynamic changes in host-virus interactions associated with colony founding and social environment in fire ant queens (Solenopsis invicta)

Authors: MANFREDINI, FABIO - Pennsylvania State University; Shoemaker, David; GROZINGER, CHRISTINA - Pennsylvania State University

Submitted to: Ecology and Evolution
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/28/2015
Publication Date: 1/18/2016
Citation: Manfredini, F., Shoemaker, D.D., Grozinger, C.M. 2016. Dynamic changes in host-virus interactions associated with colony founding and social environment in fire ant queens (Solenopsis invicta). Ecology and Evolution. 6(1):233-244. doi:10.1002/ece3.1843.

Interpretive Summary: Fire ants are considered significant ecological, agricultural, and public health pest throughout their invasive range in the U.S.A. A research entomologist at the Center for Medical, Agricultural, and Veterinary Entomology, USDA-ARS, Gainesville, Florida, in collaboration with scientists from the University of London and Pennsylvania State University, describes here the results of study investigating the dynamics of host-viral interactions in fire ant queens. We found that viruses are widespread among fire ant queens but their prevalence changes over time. We also found that the two most prevalent viruses are associated with different fitness costs and patterns of gene expression in their ant host, a pattern possibly indicating two different co-evolutionary histories of these viruses with fire ants.

Technical Abstract: The dynamics of host-parasite interactions can change dramatically over the course of a chronic infection as the internal (physiological) and external (environmental) conditions of the host change. When a queen of social insect species founds a colony, she experiences changes in both her reproductive physiology and her social environment, making this an excellent model system for examining how these factors interact with chronic infections. Here, we investigated the dynamics of host-viral interactions in fire ant queens (Solenopsis invicta) from participating in mating flights to colony founding. We examined these dynamics in two different social environments, where queens either founded colonies as individuals or as pairs. We hypothesized that stress associated with colony founding plays an important role in the dynamics of host-parasite interactions. We found that viruses are widespread among queens but their prevalence changes over time, increasing during more stressful periods and in queens experiencing more challenging social environment. We also found that the two most prevalent viruses are associated with different fitness costs and patterns of gene expression in the host, possibly indicating two different co-evolutionary histories with S. invicta.