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Negeviruses are a group of insect-specific viruses that have a wide geographic distribution and broad host range. In recent years, nege-like viruses have been discovered in aphids of various genera of the family Aphididae, including Aphis, Rhopalosiphum, Sitobion, and Indomegoura. Here, we report the complete genome sequence of a nege-like virus isolated from Astegopteryx formosana aphids collected in Guangdong, China, which we have designated as "Astegopteryx formosana nege-like virus" (AFNLV). AFNLV has a genome length of 10,107 nt (excluding the polyA tail) and possesses the typical conserved domains of negeviruses. These include a viral methyltransferase, an S-adenosylmethionine-dependent methyltransferase, a viral helicase, and an RNA-dependent RNA polymerase (RdRP) domain in open reading frame 1 (ORF1), a DiSB-ORF2_chro domain in ORF2, and a SP24 domain in ORF3. The genome of AFNLV shares the highest nucleotide sequence identity (74.89%) with Wuhan house centipede virus, identified in a mixture of barley aphids. As clearly revealed by RdRP-based phylogenetic analysis, AFNLV, together with other negeviruses and nege-like viruses discovered in aphids, formed a distinct "unclassified clade" closely related to members of the proposed genus "Sandewavirus" and the family Kitaviridae. In addition, small interfering RNAs (siRNAs) derived from AFNLV did not exhibit typical characteristics of virus-derived siRNAs processed by the host RNAi-based antiviral pathway. However, the extremely high abundance of viral transcripts (average read coverage 73,403X) strongly suggested that AFNLV might actively replicate in the aphid host. AFNLV described in this study is the first nege-like virus discovered in aphids of the genus Astegopteryx, which will contribute to future study of the co-evolution of nege/nege-like viruses and their host aphids.

Arlivirus is currently the only genus in the newly established viral family Lispiviridae. In this study, the complete genome sequence of a novel arlivirus, tentatively named "Nbu stink bug virus 1" (NbuSBV-1), was identified in an individual yellow spotted stink bug, Erthesina fullo (family Pentatomidae, order Hemiptera), which is a widely distributed phytophagous pest in Asia. NbuSBV-1 has a single negative-stranded RNA genome of 13,605 nucleotides in length, and it was predicted to contain six open reading frames (ORFs). Conserved domains of NbuSBV-1 were predicted in ORF1 (a nucleoprotein), ORF4 (a glycoprotein domain), ORF5 (a zinc-finger domain), and ORF6 (an RNA-directed RNA polymerase [RdRP] domain, an mRNA cap domain, and a methyltransferase domain). NbuSBV-1 shares 50.54% amino acid sequence identity in the RdRP region with its closest homolog, Lĭshì spider virus 2. In RdRP-based phylogenetic analysis, NbuSBV-1 was clearly clustered in a clade with other arliviruses. Furthermore, NbuSBV-1-derived small interfering RNAs (siRNAs) showed typical patterns of virus-derived siRNAs produced by the host antiviral RNA interference pathway. As far as we know, NbuSBV-1 is the first arlivirus identified in an insect of the family Pentatomidae.

The leaf beetle Aulacophora lewisii (family Chrysomelidae, order Coleoptera) is a common insect pest of cucurbitaceous vegetables. In this study, the complete genome sequence of a novel virus from a single leaf beetle was determined using metagenomic sequencing and rapid amplification of cDNA ends. A homology search and phylogenetic analysis suggested that the new virus belongs to the genus Iflavirus, family Iflaviridae, and it was tentatively named “Aulacophora lewisii iflavirus 1” (ALIV1). ALIV1 has a single positive-stranded RNA genome of 9655 nucleotides in length (excluding the polyA tail) that is predicted to encode typical conserved domains of iflaviruses, including two picornavirus-like capsid protein domains, a helicase domain, and an RNA-dependent RNA polymerase (RdRp) domain. Sequence comparisons showed that the full genome sequence of ALIV1 is most similar to that of Brevicoryne brassicae picorna-like virus, with 42.4% sequence identity, and it shares 60% sequence identity in the coat protein region with its closest homolog, Watson virus. The average coverage of the ALIV1 sequence was approximately 5000X, suggesting that it might actively replicate in the host. Phylogenetic analysis based on deduced amino acid sequences suggested that ALIV1 is closely related to Dinocampus coccinellae paralysis virus. To the best of our knowledge, ALIV1 is the first virus discovered in A. lewisii and is also the first iflavirus identified in a member of the genus Aulacophora.