Transcriptome analysis of Spodoptera RNA-seq data unveils new viruses within the family Rhabdoviridae.

The genus Spodoptera (Lepidoptera: Noctuidae) includes several major agricultural pests of crops of economic importance worldwide. Some of its species are widely distributed, while others are mainly found in Africa and Asia. Unfortunately, the use of insecticides and Bt transgenic crops is not environmentally suitable for beneficial insects and human health, as it contributes to the rapid selection of resistant insects. For this reason, viruses infecting Spodoptera spp. become promising biological control strategies, as they allow for targeted and specific pest management with significantly lower environmental impact. As part of an investigation to identify potential viral control agents for Spodoptera, we examined the diversity of rhabdoviruses associated with Spodoptera species through a meta-analysis of 1,457 public RNA-seq datasets. Our results revealed a tentative new Alphapaprhavirus associated with S. frugiperda and S. exigua, as well as two newly identified viruses not previously described and associated with S. litura and S. littoralis that likely represent a new genus within the subfamily Deltarhabdovirinae. Our results also revealed new Spodoptera frugiperda rhabdovirus (Betapaprhavirus frugiperda) sequences, including subclades associated with S. exigua and S. litura.