Sex-specific differences in pathogen susceptibility in honey bees (Apis mellifera)

PLoS One. 2014 Jan 17;9(1):e85261. doi: 10.1371/journal.pone.0085261. eCollection 2014.

Abstract

Sex-related differences in susceptibility to pathogens are a common phenomenon in animals. In the eusocial Hymenoptera the two female castes, workers and queens, are diploid and males are haploid. The haploid susceptibility hypothesis predicts that haploid males are more susceptible to pathogen infections compared to females. Here we test this hypothesis using adult male (drone) and female (worker) honey bees (Apis mellifera), inoculated with the gut endoparasite Nosema ceranae and/or black queen cell virus (BQCV). These pathogens were chosen due to previously reported synergistic interactions between Nosema apis and BQCV. Our data do not support synergistic interactions between N. ceranae and BQCV and also suggest that BQCV has limited effect on both drone and worker health, regardless of the infection level. However, the data clearly show that, despite lower levels of N. ceranae spores in drones than in workers, Nosema-infected drones had both a higher mortality and a lower body mass than non-infected drones, across all treatment groups, while the mortality and body mass of worker bees were largely unaffected by N. ceranae infection, suggesting that drones are more susceptible to this pathogen than workers. In conclusion, the data reveal considerable sex-specific differences in pathogen susceptibility in honey bees and highlight the importance of ultimate measures for determining susceptibility, such as mortality and body quality, rather than mere infection levels.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Bees / microbiology*
  • Bees / virology*
  • Body Weight
  • Dicistroviridae / physiology*
  • Female
  • Hierarchy, Social
  • Host-Pathogen Interactions*
  • Male
  • Nosema / physiology*
  • Sex Characteristics*
  • Species Specificity
  • Spores, Fungal / physiology
  • Survival Analysis

Grants and funding

The research has received funding from the European Union Seventh Framework Programme (FP7/2007-2013) under grant agreement no. (244956 CP-FP), BEEDOC (BEes in Europe and the Decline Of Colonies), as well as the Vinetum, Swiss National Science and Ricola foundations. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.