Submitted to: Entomological Society of America Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: 6/4/2018
Publication Date: N/A
Technical Abstract: Gamma irradiation has been known to inactivate bee-infectious pathogens that linger in combs. This two-year study was conducted to determine if the benefits of comb irradiation can be maximized by examining its effects on colony performance, mite population, and viral load in bees, mites and wax. Colony performance was measured by bee population, brood size and amount of stored pollen using Russian and Italian honey bees. The major differences found in this study concerned honey bee genotype confirming that Russian honey bee colonies support slow growth of varroa mite population. The effects of comb irradiation on colony performance and mite levels were inconsistent showing significant increase in adult bee population, amount of stored pollen, and varroa mite infestation on adult bees in 2015, but not apparent in 2016. Results of viral analyses of wax, newly emerged bees, and mite-infested pupae and their mites showed common detections (> 60% prevalence) of Deformed wing virus (DWV), Varroa destructor virus (VDV-1), Chronic bee paralysis virus (CBPV), and Black queen cell virus (BQCV). Wax samples had on average 3±1 viruses detected in both irradiated and non-irradiated combs. Although virus detection in all samples increased throughout the season, no major influence of comb irradiation on the number of detections was recorded. However, a decreased number of viral detections was observed in newly emerged bees reared in irradiated than in non-irradiated combs from August to October. Overall, the contribution of irradiating comb in improving honey bee health seems minimal, but may be useful as part of an integrated pest management strategy with the addition of using mite-resistant stocks.