The complete genome of a novel virus found in Adelphocoris suturalis was determined by RNA-seq and named Adelphocoris suturalis-associated virus 1 (ASV1). ASV1 has a single-stranded RNA genome of 10,845 nucleotides in length and contains five putative open reading frames (ORFs). ORF1 encodes a polypeptide of 2592 amino acids (aa) and contains four conserved domains: a viral RNA methyltransferase domain, an FtsJ-like methyltransferase domain, a viral RNA helicase domain and an RNA-dependent RNA polymerase domain. ORF2, ORF3, ORF4 and ORF5 encode polypeptides of 190, 461, 103 and 159 aa, respectively, of which only ORF5 contains a conserved domain, the Tobacco mosaic virus-coat superfamily. Phylogenetic analysis with the deduced amino acid sequences indicated that ASV1 clusters with the Drosophila-related Boutonnet virus. The similar genomic structure and high bootstrap value identified in the maximum-likelihood tree suggest that ASV1 (possibly alongside Boutonnet virus) could be considered the prototype of a new taxon of unclassified insect viruses. The prevalence of ASV1 infection in wild populations of A. suturalis was at a low level (6.60%, 14 positives from 212 samples).