Expression profiles and phylogenetic properties of venom gland-specific viruses in some aculeate bees and wasps

To identify viruses and compare their abundance levels in the venom glands of hymenopteran species, we conducted venom gland-specific transcriptome assemblies and analyses of 22 aculeate bees and wasps and identified the RNA genomes of picornaviruses. Additionally, we investigated the expression patterns of viruses in the venom glands over time following capture. Honeybee-infecting viruses, including the black queen cell virus (BQCV), the deformed wing virus (DWV) and the Israeli acute paralysis virus (IAPV), were highly expressed in the venom glands of Apis mellifera and social wasps. This finding suggests that the venom of bees and wasps is likely to contain these viruses, which can be transmitted horizontally between species through stinger use. Apis mellifera exhibited an increasing pattern of abundance levels for BQCV, DWV, IAPV and Triatovirus, whereas the social wasp Vespa crabro showed increasing abundance levels of IAPV and Triatovirus over different capture periods. This suggests that the venom glands of honeybees and wasps may provide suitable conditions for active viral replication and may be an organ for virus accumulation and transmission. Some viral sequences clearly reflected the phylogeny of aculeate species, implying host-specific virus evolution. On the other hand, other viruses exhibited unique evolutionary patterns of phylogeny, possibly caused by specific ecological interactions. Our study provides insights into the composition and evolutionary properties of viral genes in the venom glands of certain aculeate bees and wasps, as well as the potential horizontal transmission of these viruses among bee and wasp species.