DWV and honey bee genotypes determine infection level

Authors: Penn, Hannah; Simone-Finstrom, Michael; HEALY, KRISTEN - LSU Agcenter

Submitted to: Entomological Society of America, Southwestern and Southeastern Branch
Publication Type: Abstract Only
Publication Acceptance Date: 2/25/2021
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: Varroa mite vectored diseases such as Deformed wing virus (DWV) are of great concern for honey bee health as they can cause deformities in individuals and increase colony mortality. Two genotypes of DWV (A & B) are common in the United States and may have differential virulence and mortality rates. Honey bee genetic stocks bred to resist varroa mites also exhibit differential infection responses to mite-vectored diseases. The goal of this project was to determine if DWV genetics interact with host genetics to influence overall titer levels and dissemination within adult honey bees. To do this, we injected DWV into mite-free newly emerged bees from five different genetic stocks with varying levels of resistance to varroa mites. We then tracked DWV-A and DWV-B dissemination to various body segments indicative of different routes of transmission for ten days post-inoculation. We found that injection injury alone did not increase DWV-A levels but did induce increases in DWV-B infections. DWV injection increased both DWV-A and DWV-B levels over time with significant host stock interactions. While we did not observe any host stock differences in dissemination, we did find virus genotype differences in dissemination. DWV-A exhibited highest initial levels in heads and legs while DWV-B’s highest initial levels were found in heads and abdomens with the lowest initial levels in legs. These interactions underscore the need to evaluate host genotype in addition to viral genotype, particularly when the host has been selected for traits relative to virus-vector and virus resistance.