PAPER: Virus Dynamics in Varroa-Infested Bee ...

Viral communities in the parasite Varroa destructor and in colonies of their honey bee host (Apis mellifera) in New Zealand

May 2022

Lester PJ, Felden A, Baty JW, Bulgarella M, Haywood J, Mortensen AN, Remnant EJ, Smeele ZE 2022. Viral communities in the parasite Varroa destructor and in colonies of their honey bee host (Apis mellifera) in New Zealand. Sci Rep 12(1): 8809. https://doi.org/10.1038/s41598-022-12888-w

ABSTRACT

The parasitic mite Varroa destructor is a leading cause of mortality for Western honey bee (Apis mellifera) colonies around the globe. We sought to confirm the presence and likely introduction of only one V. destructor haplotype in New Zealand, and describe the viral community within both V. destructor mites and the bees that they parasitise. A 1232 bp fragment from mitochondrial gene regions suggests the likely introduction of only one V. destructor haplotype to New Zealand. Seventeen viruses were found in bees. The most prevalent and abundant was the Deformed wing virus A (DWV-A) strain, which explained 95.0% of the variation in the viral community of bees. Black queen cell virus, Sacbrood virus, and Varroa destructor virus 2 (VDV-2) played secondary roles. DWV-B and the Israeli acute paralysis virus appeared absent from New Zealand. Ten viruses were observed in V. destructor, with > 99.9% of viral reads from DWV-A and VDV-2. Substantially more variation in viral loads was observed in bees compared to mites. Where high levels of VDV-2 occurred in mites, reduced DWV-A occurred in both the mites and the bees co-occurring within the same hive. Where there were high loads of DWV-A in mites, there were typically high viral loads in bees.

KEYWORDS

Mitochondrial DNA; Haplogroup assignment; Viral communities; RNA-Seq; DWV-A; Varroa destructor; Honey bees; Genetic variation; PCR; Viral replication