Molecular detection and phylogenetic analysis of six bee viruses from Varroa destructor in Korea

In the beekeeping industry, the control of Varroa destructor and viruses is a crucial factor in maintaining the health of the western honey bee Apis mellifera L. Recently, in Korea, beekeepers suffered for high colony losses during the overwintering, and the presence of V. destructor and viruses has been considered an important factor for honey bee health. In this study, we investigated the presence of six honey bee viruses [deformed wing virus (DWV), sacbrood virus (SBV), Kashmir bee virus (KBV), Israeli acute paralysis virus (IAPV), chronic bee paralysis virus (CBPV), and black queen cell virus (BQCV)] in V. destructor in Korea. V. destructor was collected from 46 apiaries in nine provinces in Korea, and viruses were detected using reverse transcription–polymerase chain reaction. DWV was most predominantly detected at 87% of apiaries, followed by IAPV, SBV, KBV, BQCV, and CBPV that were detected in 65.2%, 17.4%, 13%, 8.7%, and 6.5% of apiaries in Korea. Phylogenetic analysis revealed that five viruses (IAPV, SBV, BQCV, and CBPV) were grouped into clades of viruses originating from China, Russia, and Australia, but KBV showed no distinct clades of countries. This study confirmed the presence of various types of bee viruses in V. destructor in Korea, indicating that domestic honey bees are exposed to multiple viruses via V. destructor.