Unveiling the RNA virus landscape of Cotesia chilonis: geographic distribution, diversity, and potential roles in parasitoid-host interactions.

Cotesia chilonis, a key parasitoid wasp of the important rice pest Chilo suppressalis, plays a critical role in the biological control of its host larvae. While previous studies have predominantly focused on polydnaviruses, associated with this species, the RNA virome of C. chilonis remains largely uncharacterized. To address this gap, we conducted a comprehensive viromic analysis across 17 geographically distinct populations of C. chilonis, identifying nine novel RNA viruses phylogenetically affiliated with eight families: Xinmoviridae, Artoviridae, Rhabdoviridae, Qinviridae, Orthomyxoviridae, Phenuiviridae, Narnaviridae, and Virgaviridae. These viruses include seven negative-sense single-stranded RNA (-ssRNA) viruses and two positive-sense single-stranded RNA (+ssRNA) viruses. Analysis of their geographic distribution revealed significant distribution patterns, with two -ssRNA viruses (C. chilonis Xinmo-like virus, CcXLV, and C. chilonis Arto-like virus, CcALV) demonstrating broad prevalence and stable spatiotemporal persistence. This study not only expands the diversity of RNA viruses in parasitoid wasps but also provides foundational insights into potential virus-host interactions, offering potential avenues for optimizing parasitoid-based pest management strategies.