Fitness and microbial networks of the common wasp, Vespula vulgaris (Hymenoptera: Vespidae), in its native and introduced ranges

1. Variation in microbial communities between populations is increasingly hypothesised to affect animal fitness and performance, including for invasive species. Pathogenic species may be lost during the introduction process, enhancing invader fitness and abundance. 2. This study assessed fitness, immune gene expression, and microbial network complexity of invasive common wasps, Vespula vulgaris. Microbial networks were assayed using 16S and 18S sequencing and gene expression arrays in the native (Belgium) and introduced range (New Zealand). The immune gene expression of the wasp Down syndrome cell adhesion molecule (Dscam) gene homologue was examined. Dscam expression can be induced by viruses, Gram-positive and Gram-negative bacteria, and parasites. 3. Individual nest fitness was higher in the native range of Belgium than in the introduced New Zealand range. Microbial communities of wasps in the introduced range were more diverse with more complex networks, although some microorganisms were range-specific. Microbial networks in the introduced range showed higher clustering coefficients, number of connected paths, network centralisation, number of neighbours and network density. 4. Larvae, workers, virgin and foundress queens had higher expression of Dscam in the New Zealand samples. These immune gene expression patterns were associated with higher pathogen pressure and lower relative fitness. 5. Epidemiological theory predicts that a high density of pathogen and microbial hosts should result in a high rate of disease infection, prevalence, and highly connected microbial networks. The results of this study support these predictions. Wasps displayed lower relative fitness and more highly connected microbial networks in New Zealand than in Belgium

A diverse viral community from predatory wasps in their native and invaded range, with a new virus infectious to honey bees

Wasps of the genus Vespula are social insects that have become major pests and predators in their introduced range. Viruses present in these wasps have been studied in the context of spillover from honey bees, yet we lack an understanding of the endogenous virome of wasps as potential reservoirs of novel emerging infectious diseases. We describe the characterization of 68 novel and nine previously identified virus sequences found in transcriptomes of Vespula vulgaris in colonies sampled from their native range (Belgium) and an invasive range (New Zealand). Many viruses present in the samples were from the Picorna-like virus family (38%). We identified one Luteo-like virus, Vespula vulgaris Luteo-like virus 1, present in the three life stages examined in all colonies from both locations, suggesting this virus is a highly prevalent and persistent infection in wasp colonies. Additionally, we identified a novel Iflavirus with similarity to a recently identified Moku virus, a known wasp and honey bee pathogen. Experimental infection of honey bees with this novel Vespula vulgaris Moku-like virus resulted in an active infection. The high viral diversity present in these invasive wasps is a likely indication that their polyphagous diet is a rich source of viral infections

Viral and fungal pathogens associated with Pneumolaelaps niutirani (Acari: Laelapidae): a mite found in diseased nests of Vespula wasps

© 2019, International Union for the Study of Social Insects (IUSSI). Introduced social wasps (Vespula spp.) are a pest in many parts of the world. Recently, a mite species (Pneumolaelaps niutirani) was described and associated with disease symptoms in wasps. The mite does not appear to directly parasitise the wasps, but has been observed in high abundance, feeding on exudates from the mouths of larvae. We investigated the viral and fungal pathogens community in these mites and wasps. We found known viruses including Moku virus in both wasps and mites. Moku virus replicated in mites, likely indicating parasitism. Deformed wing virus, commonly found in wasps, was also detected in mite samples. Furthermore, the presence of putative viral transcripts related to 38 distinct viruses, including seven viruses previously isolated from arthropods, indicated that there may be many more viruses associated with the mite that are potentially shared with Vespula wasps. We also found generalist entomopathogenic fungus Aspergillus to infect both mites and wasps. Twelve distinct Aspergillus species were observed, all of which were found in wasp larvae from nests displaying symptoms of disease, with only one species in larvae from apparently healthy nests. Aspergillus novofumigatus was the most common of these species observed in wasps. Six Aspergillus species, including A. novofumigatus were detected in mites. Aspergillus loads were significantly higher in larvae from diseased nests. Our exploratory study indicates that mites can harbour both viruses and fungi that infect wasps, providing avenues of research into biological control using mites as infection vectors

Erratum: High-quality assemblies for three invasive social wasps from the vespula genus (G3: Genes, Genomes, Genetics (2020) 10 (3479-3488) DOI: 10.1534/g3.120.401579)

In the originally published version of this manuscript, funding information and disclosures were omitted. The following information should have been included after the Acknowledgments section. Funding This project was supported by Genomics Aotearoa (to PKD) and the Biological Heritage National Science Challenge (to PJL) both funded by the Ministry of Business Innovation and Employment (Hı¯kina Whakatutuki), Government of New Zealand, as well as US National Science Foundation Grant #1655963 and UC Riverside Seed Grant to JP and EWR; Dovetail Genomics Matching Funds Grant to JP. Availability of data and materials Raw reads are hosted in the NCBI Sequence Read Archive under accession PRJNA643352. The version of the assemblies and annotations described in this paper is hosted on Zenodo under DOI 10.5281/zenodo.4001020. The genomes and annotations have also been uploaded to GenBank under accessions JACSDY000000000 (Vespula pensylvanica), JACSDZ000000000 (Vespula germanica) and JACSEA000000000 (Vespula vulgaris). The annotations used in this paper and the annotations hosted by GenBank differ because records were removed to pass NCBI validation. Authors' contributions PJL and PKD conceived and designed the project. All authors aided in obtaining and analysing the genomic data. PJL, PKD, TWRH, JG, EJR and EJD wrote the manuscript draft, and all authors participated in the revision of the final version. All authors read and approved the final manuscript. Ethics approval and consent to participate Common wasps (V. vulgaris) were collected under the permit National Authorisation Number 38337-RES from the Department of Conservation in New Zealand. Samples of other wasps were collected from private land where no permit was required. No other ethical approval was required. Competing interests The authors declare that they have no competing interests. The above information has now been updated in the online article