The multispecies stinkbug iflavirus Halyomorpha halys virus detected in the multispecies stinkbug egg parasitoid microwasp, Telenomus podisi (Ashmead) (Hymenoptera: Platygastridae).

Wasps are important parasitoids of stinkbugs and frequently exposed to various types of microorganisms through environmental contact and fecal-oral transmission route. Many parasitize stinkbug eggs and are commercially used in the field to control insect population. The parasitoid T. podisi is known for its high parasitism capacity and ability to target multiple species of stinkbugs. In this study we asked whether T. podisi exposed to eggs infected by a multispecies asymptomatic stinkbug virus, the Halyomorpha halys virus (HhV) would get infected. HhV is a geographically distributed multispecies iflavirus previously found to infect four stinkbug hosts, including three Brazilian species, Chinavia ubica, Euschistus heros and Diceraeus melacanthus, and T. posidi can parasitize all of them. As results, RT-PCR screening revealed positive samples for the HhV genome in two out of four tested pools of T. podisi, whereas the antigenome, indicative of replicative activity, was not detected. The wasps were raised in E. heros eggs that presented both the genome and the antigenome forms of the HhV genome. Subsequent RNA-deep sequencing of HhV positive T. podisi RNA pools yielded a complete genome of HhV with high coverage. Phylogenetic analysis positioned the isolate HhV-Tp (isolate Telenomus podisi) alongside with the stinkbug HhV. Analysis of transcriptomes from several hymenopteran species revealed HhV-Tp reads in four species. However, the transmission mechanism and the ecological significance of HhV remain elusive, warranting further studies to illuminate both the transmission process and its capacity for environmental propagation using T. podisi as a potential vector.

A Nymphalid-Infecting Group I Alphabaculovirus Isolated from the Major Passion Fruit Caterpillar Pest Dione juno juno (Lepidoptera: Nymphalidae).

Baculoviruses are capable of infecting a wide diversity of insect pests. In the 1990s, the Dione juno nucleopolyhedrovirus (DijuNPV) was isolated from larvae of the major passionfruit defoliator pest Dione juno juno (Nymphalidae) and described at ultrastructural and pathological levels. In this study, the complete genome sequence of DijuNPV was determined and analyzed. The circular genome presents 122,075 bp with a G + C content of 50.9%. DijuNPV is the first alphabaculovirus completely sequenced that was isolated from a nymphalid host and may represent a divergent species. It appeared closely related to Orgyia pseudotsugata multiple nucleopolyhedrovirus (OpMNPV) and other Choristoneura-isolated group I alphabaculoviruses. We annotated 153 open reading frames (ORFs), including a set of 38 core genes, 26 ORFs identified as present in lepidopteran baculoviruses, 17 ORFs unique in baculovirus, and several auxiliary genes (e.g., bro, cathepsin, chitinase, iap-1, iap-2, and thymidylate kinase). The thymidylate kinase (tmk) gene was present fused to a dUTPase (dut) gene in other baculovirus genomes. DijuNPV likely lost the dut portion together with the iap-3 homolog. Overall, the genome sequencing of novel alphabaculoviruses enables a wide understanding of baculovirus evolution.

A Novel Betabaculovirus Isolated from the Monocot Pest Mocis latipes (Lepidoptera: Noctuidae) and the Evolution of Multiple-Copy Genes.

In this report, we described the genome of a novel baculovirus isolated from the monocot insect pest Mocis latipes, the striped grass looper. The genome has 134,272 bp in length with a G + C content of 38.3%. Based on the concatenated sequence of the 38 baculovirus core genes, we found that the virus is a betabaculovirus closely related to the noctuid-infecting betabaculoviruses including Pseudaletia unipuncta granulovirus (PsunGV), Trichoplusia ni granulovirus (TnGV), Helicoverpa armigera granulovirus (HearGV), and Xestia c-nigrum granulovirus (XecnGV). The virus may constitute a new Betabaculovirus species tentatively named Mocis latipes granulovirus (MolaGV). After gene content analysis, five open reading frames (ORFs) were found to be unique to MolaGV and several auxiliary genes were found including iap-3, iap-5, bro-a, bro-b, and three enhancins. The virus genome lacked both chitinase and cathepsin. We then looked at the evolutionary history of the enhancin gene and found that betabaculovirus acquired this gene from an alphabaculovirus followed by several duplication events. Gene duplication also happened to an endonuclease-like gene. Genomic and gene content analyses revealed both a strict collinearity and gene expansion into the genome of the MolaGV-related species. We also characterized the granulin gene using a recombinant Autographa californica multiple nucleopolyhedrovirus (AcMNPV) and found that occlusion bodies were produced into the nucleus of infected cells and presented a polyhedral shape and no occluded virions within. Overall, betabaculovirus genome sequencing is of importance to the field as few genomes are publicly accessible. Mocislatipes is a secondary pest of maize, rice, and wheat crops in Brazil. Certainly, both the discovery and description of novel baculoviruses may lead to development of greener and safer pesticides in order to counteract and effectively control crop damage-causing insect populations.