Twelve isolates of lactic acid bacteria (LAB) were obtained in the course of a bumble bee gut microbiota study and grouped into four matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry clusters. Comparative 16S rRNA gene sequence analysis revealed that cluster 1 isolates, represented by strain LMG 28288(T), are most closely related to Lactobacillus apis (97.0% sequence similarity to that of L. apis LMG 26964(T)). Cluster 2 isolates represented by strain LMG 28290(T) are most closely related to Weissella hellenica (99.6% sequence similarity to that of W. hellenica LMG 15125(T)). The single cluster 3 and 4 isolates had identical 16S rRNA gene sequences which were 94.8% similar to that of Leuconostoc mesenteroides subsp. mesenteroides LMG 6893(T), their nearest phylogenetic neighbour. A polyphasic taxonomic study additionally including comparative pheS sequence analysis, DNA-DNA hybridization experiments, DNA G+C content analysis, (GTG)5-PCR fingerprinting and a biochemical characterization, demonstrated that cluster 1 isolates represent a novel Lactobacillus species for which we propose the name Lactobacillus bombicola sp. nov. with LMG 28288(T) (= DSM 28793(T)) as the type strain; and that cluster 2 isolates represent a novel Weissella species for which we propose the name Weissella bombi sp. nov. with LMG 28290(T) (= DSM 28794(T)) as the type strain. Cluster 3 and 4 isolates, in contrast, represented a very distinct, novel taxon that could be distinguished from members of the genera Leuconostoc and Fructobacillus, its nearest phylogenetic neighbours, by its cellular morphology, non-fructophilic metabolism and DNA G+C content. We therefore classify both isolates into a novel species representing a novel LAB genus for which the name Convivina intestini gen. nov., sp. nov. is proposed with LMG 28291(T) (= DSM 28795(T)) as the type strain.