Convivina is a specialised core gut symbiont of the invasive hornet Vespa velutina

We provide a culturomics analysis of the cultivable bacterial communities of the crop, midgut and hindgut compartments, as well as the ovaries, of the invasive insect Vespa velutina, along with a cultivation‐independent analysis of samples of the same nest through 16S rRNA amplicon sequencing. The Vespa velutina bacterial symbiont community was dominated by the genera Convivina, Fructobacillus, Lactiplantibacillus, Lactococcus, Sphingomonas and Spiroplasma. Lactococcus lactis and Lactiplantibacillus plantarum represented generalist core lactic acid bacteria (LAB) symbionts, while Convivina species and Fructobacillus fructosus represented highly specialised core LAB symbionts with strongly reduced genome sizes. Sphingomonas and Spiroplasma were the only non‐LAB core symbionts but were not isolated. Convivina bacteria were particularly enriched in the hornet crop and included Convivina intestini, a species adapted towards amino acid metabolism, and Convivina praedatoris sp. nov. which was adapted towards carbohydrate metabolism. Culturomics and 16S rRNA amplicon sequencing of crop, midgut, hindgut and ovary samples revealed Convivina, Fructobacillus, Lactiplantibacillus, Lactococcus, Sphingomonas and Spiroplasma as predominant bacterial symbionts of Vespa velutina in Belgium. Lactococcus lactis and Lactiplantibacillus plantarum represented generalist core symbionts, while Convivina species and Fructobacillus fructosus represented highly specialised core symbionts with strongly reduced genome sizes. Convivina bacteria were enriched in the crop and included Convivina intestini, a species adapted towards amino acid metabolism, and Convivina praedatoris sp. nov. a species was adapted towards carbohydrate metabolism.