Occurrence and genetic analysis of picorna-like viruses infecting worker bees of Apis mellifera L. populations in Devon, South West England

Viruses of the European honeybee, Apis mellifera L. are known to reside at low levels in colonies, typically showing no apparent signs of infection. Using reverse transcription-PCR (RT-PCR), 23 apiaries in Devon were screened for the presence of 6 honeybee viruses, with positive colonies being analysed for viral genetic diversity. Ninety-seven percent of the colonies were positive for deformed wing virus (DWV), 29% were positive for acute bee paralysis virus (ABPV) and 1.4% were positive for both sacbrood virus (SBV) and black queen cell virus (BQCV). Multiple infections were common, with 32% of the colonies were infected by more than one virus.