Patterns of viral prevalence and load show independent circulation of some honey bee viruses in wild bees

Honey bee ( Apis mellifera ) – associated viruses are increasingly detected in wild bees, but the extent and direction of transmission between wild bees and honey bees remain unclear. We surveyed wild bees from 23 genera alongside sympatric A. mellifera across seasons in north-central Florida, USA, quantifying prevalence, viral load, and co-occurrence of four common viruses: Black queen cell virus (BQCV), Deformed wing virus (DWV), Israeli acute paralysis virus (IAPV), and Sacbrood virus (SBV). At least one virus was detected in 98% of honey bees and 58% of wild bees. DWV and BQCV dominated overall, but IAPV occurred more frequently, and at higher levels in wild bees, particularly Halictidae than in honey bees. Seasonal dynamics differed markedly between groups: IAPV and SBV persisted year-round in wild bees but were undetectable in honey bees in spring. Co-infections were common, particularly in honey bees, and showed phylogenetic structuring among wild bee families. Therefore, while BQCV and DWV in wild bees likely reflects spillover from managed bees, IAPV and possibly SBV may circulate independently within wild bee communities. These results challenge assumptions of unidirectional pathogen flow from honey bees to wild bees, highlighting the value of seasonal sampling and virus quantification for understanding transmission.