The evolutionary history of insect-associated xinmoviruses

Viruses are ubiquitous biological entities that shape host evolution and ecosystem dynamics. Among them, negative-sense single-stranded RNA (-ssRNA) viruses form a diverse group that includes well-characterized vertebrate pathogens and an expanding repertoire of invertebrate-infecting viruses. Recent advances in high-throughput sequencing have revealed numerous insect-associated -ssRNA viruses, reshaping our understanding of their diversity, transmission, and ecological significance. This study identified 22 novel xinmoviruses, expanding the known host range of this viral family to include Lepidoptera and Plecoptera for the first time. Additionally, xinmovirus-derived non-retroviral endogenous viral elements (nrEVEs) were identified in multiple insect lineages, expanding previous findings that were limited to mosquitoes. Phylogenetic analysis of the Xinmoviridae family revealed host-driven evolutionary patterns with potential cross-order transmission events. Similarly, nrEVEs provided evidence of specific viral-host interactions, with nrEVEs showing greater similarity to exogenous viruses infecting the same insect order and, in some cases, the same insect species. Together, these findings significantly expand the known diversity and evolutionary landscape of xinmoviruses. By uncovering new hosts, viral lineages, and genomic integrations, this study provides a more comprehensive framework for understanding their ecological distribution, transmission dynamics, and potential biological functions.