Phenomic analysis of the honey bee pathogen-web and its dynamics on colony productivity, health and social immunity behaviors

PLoS One. 2022 Jan 31;17(1):e0263273. doi: 10.1371/journal.pone.0263273. eCollection 2022.

Abstract

Many pathogens and parasites have evolved to overwhelm and suppress their host's immune system. Nevertheless, the interactive effects of these agents on colony productivity and wintering success have been relatively unexplored, particularly in large-scale phenomic studies. As a defense mechanism, honey bees have evolved remarkable social behaviors to defend against pathogen and parasite challenges, which reduce the impact of disease and improve colony health. To investigate the complex role of pathogens, parasites and social immunity behaviors in relation to colony productivity and outcomes, we extensively studied colonies at several locations across Canada for two years. In 2016 and 2017, colonies founded with 1-year-old queens of diverse genetic origin were evaluated, which represented a generalized subset of the Canadian bee population. During each experimental year (May through April), we collected phenotypic data and sampled colonies for pathogen analysis in a standardized manner. Measures included: colony size and productivity (colony weight, cluster size, honey production, and sealed brood population), social immunity traits (hygienic behavior, instantaneous mite population growth rate, and grooming behavior), as well as quantification of gut parasites (Nosema spp., and Lotmaria passim), viruses (DWV-A, DWV-B, BQCV and SBV) and external parasites (Varroa destructor). Our goal was to examine: 1) correlations between pathogens and colony phenotypes; 2) the dynamics of pathogens and parasites on colony phenotypes and productivity traits; and 3) the effects of social immunity behaviors on colony pathogen load. Our results show that colonies expressing high levels of some social immunity behaviors were associated with low levels of pathogens/parasites, including viruses, Nosema spp., and V. destructor. In addition, we determined that elevated viral and Nosema spp. levels were associated with low levels of colony productivity, and that five out of six pathogenic factors measured were negatively associated with colony size and weight in both fall and spring periods. Finally, this study also provides information about the incidence and abundance of pathogens, colony phenotypes, and further disentangles their inter-correlation, so as to better understand drivers of honey bee colony health and productivity.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Bees / parasitology*
  • Bees / virology*
  • Behavior, Animal / physiology*
  • Canada
  • Geography
  • Health*
  • Honey
  • Host-Pathogen Interactions*
  • Linear Models
  • Parasites
  • Phenomics*
  • Phenotype
  • Sample Size
  • Seasons
  • Social Behavior
  • Varroidae

Grants and funding

This work was supported by a Large-Scale Applied Research Project Grant from Genome Canada, Genome British Columbia, Genome Alberta, Genome Prairie, Ontario Genomics and Genome Quebec through the “BeeOMICS” Project (227Bee) awarded to LJF/AZ/SFP/SEH/MMG/RWC/PG. Additional cash and in-kind co-funding was provided by: the University of British Columbia; the British Columbia Ministry of Agriculture, Food and Fisheries; the British Columbia Honey Producers Association; Bruker Daltonics; the Alberta Crop Industry Development Fund; Manitoba Agriculture, Food and Rural Initiatives (MAFRI); York University; the Ontario Ministry of Agriculture, Food and Rural Affairs; the Ontario Ministry of Colleges and Universities; the Ontario Beekeepers Association; and the Centre de recherche en sciences animales de Deschambault.