Diverse RNA Viruses Discovered in Three Parasitoid Wasps of the Rice Weevil .

In this study, many virus-like fragments were obtained from transcriptomes of three wasp species, including (8), (3), and (18), which can parasitize and control rice weevil , a serious insect pest of farm-stored grains. By further bioinformatic analysis and sequencing, we identified six novel RNA viruses with complete genomes and named them WWPSRV-1, WWPSRV-2, AcPSRV-1, AcNSRV-1, AcNSRV-2, and LdNSRV-1. PCR-based detection revealed that WWPSRV-1 and WWPSRV-2 had the possibility of interspecies virus transmission, especially WWPSRV-2, which was also present in the rice weevil adults. Phylogenetically, three out of these six viruses appeared to be members of order : WWPSRV-1 belonged to unassigned virus families of this order, whereas WWPSRV-2 and AcPSRV-1 belonged to families and , respectively. The conserved picornavirus-typical domains helicase, protease, and RNA-dependent RNA polymerase could be found in the nonstructural protein encoded by the three viruses, whose genomes consisted of the different numbers of open reading frames (ORFs). The other three RNA viruses could be classified to order : AcNSRV-1 and AcNSRV-2 belonged to family , whereas LdNSRV-1 belonged to a big family The genomes of the three viruses contained at least five ORFs, encoding deduced proteins in the following order: 3'-N-P-M-G-L-5'. All the ORFs were separated by conserved intergenic sequences which likely regulated the transcription termination and initiation. Our findings enhance the understanding of RNA viruses in weevil wasps and set the foundation for the future study of the association among weevils, weevil wasps, and RNA viruses. The enormous diversity of RNA viruses in insects is continuously validated. Parasitoid wasps, as biocontrol insects which are widely used against insect pests in agroecosystems, may also carry many "good" RNA viruses. Some RNA viruses in parasitoid wasps have been reported to affect the host wasps or the wasps' host. Here, six novel RNA viruses with complete genomes were identified in three parasitoid wasps of the rice weevil. One of these viruses was also detected in the rice weevil adults. Phylogenetically, WWPSRV-1 was the first unambiguous detection of Nora-like virus in insect parasitoids. WWPSRV-2 and AcPSRV-1 belong to families and , some viruses of which can result in lethal infections in silkworms and honeybees. The other three RNA viruses belong to order , which comprises many well-known insect-associated viruses.