RNAseq Analysis Reveals Virus Diversity within Hawaiian Apiary Insect Communities

Abstract

Deformed wing virus (DWV) is the most abundant viral pathogen of honey bees and has been associated with large-scale colony losses. DWV and other bee-associated RNA viruses are generalists capable of infecting diverse hosts. Here, we used RNAseq analysis to test the hypothesis that due to the frequency of interactions, a range of apiary pest species would become infected with DWV and/or other honey bee-associated viruses. We confirmed that DWV-A was the most prevalent virus in the apiary, with genetically similar sequences circulating in the apiary pests, suggesting frequent inter-species transmission. In addition, different proportions of the three DWV master variants as indicated by BLAST analysis and genome coverage plots revealed interesting DWV-species groupings. We also observed that new genomic recombinants were formed by the DWV master variants, which are likely adapted to replicate in different host species. Species groupings also applied when considering other viruses, many of which were widespread in the apiaries. In social wasps, samples were grouped further by site, which potentially also influenced viral load. Thus, the apiary invertebrate community has the potential to act as reservoirs of honey bee-associated viruses, highlighting the importance of considering the wider community in the apiary when considering honey bee health.

RNAseq of Deformed Wing Virus and Other Honey Bee-Associated Viruses in Eight Insect Taxa with or without Varroa Infestation

“…A potential absence of recombinants from other insects may be a result of the benefits or detriments of recombinant forms being specific to the honey bee host. The data in the present study differ to our previous findings [17], where we saw a number of non-honey bee samples containing high DWV levels and recombinants. We suggest this may be a result of different collection methodologies.…”

“…and a solitary bee Ceratina smaragdula increases compared to islands without Varroa, mirroring the situation in the honey bees [14]. Additionally, Brettell et al [17] showed that DWV was frequently detected in pest species that share the same space as honey bees, such as social wasps, hive beetles and ants, but variations in genetic variants between the bees and pest species existed, indicating that the situation was more complex than a simple spillover event. Loope at al.…”

Genetic Strain Diversity of Multi-Host RNA Viruses that Infect a Wide Range of Pollinators and Associates is Shaped by Geographic Origins

“…In case of the more recently discovered viruses, such as MKV and LhuBLV1, the knowledge of disease symptoms, dynamics, or host range is very limited [36,37]. Studies suggest that the predatory wasp V. pensylvanica may represent an MKV reservoir on Hawaii [16,36]. We confirmed active MKV replication in three different wasp species and an overall high prevalence in Vespinae, supporting the potential virus reservoir.…”

“…Increasing evidence suggests that many of these pathogens are not specific to honey bees and instead are shared between many pollinator species and associated arthropods, including bumble bees and other wild bees [10][11][12]; bee predators, such as wasps [10,11]; and scavenging insects, such as ants, cockroaches, and beetles [10,[13][14][15]. Many of these host species have been found cohabiting in bee hives [13,15,16] or share floral resources with honey bees [17][18][19][20]. Although arthropods harbour an enormous diversity of viruses [21,22], little is known about the host range and dynamics of viruses within pollinator communities.…”

Accumulation and Competition Amongst Deformed Wing Virus Genotypes in Naïve Australian Honeybees Provides Insight Into the Increasing Global Prevalence of Genotype B

“…Three DWV genotypes have been described: DWV-A, DWV-B, and DWV-C (Mordecai et al, 2016b); only DWV-A (formally DWV) and DWV-B [formally V. destructor virus 1 or VDV-1 (Ongus et al, 2004)] are currently recognized by the International Committee on Taxonomy of Viruses. For clarity, we have employed the types A and B nomenclature widely adopted in recent publications (Martin et al, 2012;McMahon et al, 2016;Mordecai et al, 2016a,b;Brettell and Martin, 2017;Kevill et al, 2017;Gisder et al, 2018;Brettell et al, 2019;Dubois et al, 2019;Kevill et al, 2019;Remnant et al, 2019;Tehel et al, 2019).…”