Effects of honey bee queen exposure to deformed wing virus-A on queen and juvenile infection and colony strength metrics

Abstract

Varroa destructor and the pathogens they vector have contributed significantly to high annual honey bee colony losses. Deformed wing virus (DWV) is the most prevalent honey bee virus and has been associated with overwintering colony loss. DWV is capable of infecting honey bees at all life stages and castes via horizontal and vertical transmission. Few studies have been conducted to determine the effect that pathogens have on honey bee queen health and performance. Our results suggest that queens may have mechanisms that reduce the establishment of DWV infection following a single exposure event. A queen’s exposure to DWV-A prior to colony establishment did not significantly negatively impact colony strength metrics for two of three queen genotypes tested. Additionally, brood showed little subsequent infection. These findings suggest that when queens experience a single oral or venereal inoculation of DWV-A, vertical transmission may not result in significant brood infection and that overall colony strength may be largely unaffected. Increased colony loss experienced by colonies derived from one queen source indicates that differences in susceptibility exist due to factors that need to be investigated more fully. These findings contribute to a greater understanding of host-pathogen interactions in honey bees and suggest a context-dependent variability on the influence of queen exposure to viruses on colony health.