Expanding the evidence for cross-species viral transmission from trophic interactions of parasitoid wasps and their hosts.

Parasitoid wasps act as natural biological control agents for several harmful insect species. However, there is a lack of information regarding the exogenous RNA viruses that infect parasitoids and may contribute to the success of their parasitism strategies. This study aimed to investigate the presence, abundance, and replication of known exogenous viruses in two parasitoid wasp species and their corresponding preys. Utilizing publicly available RNA deep-sequencing data, two previously validated viruses from the parasitoid Tetrastichus brontispae were assessed in the target beetles Brontispa longissima and Octodonta nipae from the same geographic region. This study revealed the presence of the iflavirus TbRV-3 in both T. brontispae and O. nipae-derived samples, suggesting a potential exchange of the virus between the parasitoid and its host. In addition, there is substantial evidence that the Halyomorpha halys virus infects the parasitoid Telenomus podisi. Thus, this study proposes a close evolutionary relationship between the HhV strain identified in the parasitoid Telenomus podisi and the original strain detected in the prey H. halys. The viral association between trophically related species, such as parasitoids and their hosts, is demonstrated using features such as abundance and the presence of double-stranded RNA, which serves as a proxy for virus replication. Therefore, RNA viruses may coexist at both trophic levels, conferring an evolutionary advantage to the parasitism strategy.