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Simple Summary: Spongy moth, formerly known as European gypsy moth, is an invasive forest pest in the United States and is under quarantine in the eastern part of the country. The flighted spongy moth complex, a group of related spongy moths formerly known as Asian gypsy moth, are pests that are not currently present in the United States. As part of our research to characterize spongy moth pathogens, we determined the genome sequences and relative amounts of genomes of an iflavirus, an RNA-based virus, from spongy moths in two locations in the USA and flighted spongy moths in two locations in China. The iflaviruses from the USA and China spongy moth populations were distinguishable from each other on the basis of their genome sequences. Iflavirus genome levels in all moth samples were very high, but these high genome levels were not associated with any obvious disease symptoms. The information in this study raises questions about the effect of RNA viruses such as iflaviruses on their hosts, and will be of interest to scientists who work with iflaviruses, spongy moth, and other forest pests. The spongy moth virus Lymantria dispar iflavirus 1 (LdIV1), originally identified from a Lymantria dispar cell line, was detected in 24 RNA samples from female moths of four populations from the USA and China. Genome-length contigs were assembled for each population and compared with the reference genomes of the first reported LdIV1 genome (Ames strain) and two LdIV1 sequences available in GenBank originating from Novosibirsk, the Russian Federation. A whole-genome phylogeny was generated for these sequences, indicating that LdIV1 viruses observed in North American (flightless) and Asian (flighted) spongy moth lineages indeed partition into clades as would be expected per their host's geographic origin and biotype. A comprehensive listing of synonymous and non-synonymous mutations, as well as indels, among the polyprotein coding sequences of these seven LdIV1 variants was compiled and a codon-level phylogram was computed using polyprotein sequences of these, and 50 additional iflaviruses placed LdIV1 in a large clade consisting mostly of iflaviruses from other species of Lepidoptera. Of special note, LdIV1 RNA was present at very high levels in all samples, with LdIV1 reads accounting for a mean average of 36.41% (ranging from 1.84% to 68.75%, with a standard deviation of 20.91) of the total sequenced volume. [ABSTRACT FROM AUTHOR]

In this study,Lymantria dispar disparlarvae, collected from three different localities in Turkey, were examined for the presence of inclusion bodies under phase contrast and electron microscopes. Inclusion bodies from infected larvae were subjected to polymerase chain reaction using the conserved primers forpolyhedrin(polh),late expression factor8 (lef-8) andlate expression factor9 (lef-9) genes. Sequence analysis confirmed that larvae collected from the three different localities contained multiple nucleopolyhedrosis viruses (MNPVs). These isolates were designated LdMNPV-T1, LdMNPV-T2 and LdMNPV-T3. Phylogenetic analyses of these isolates were performed using target genespolh,lef-8 andlef-9. Restriction endonuclease analysis of the three geographic isolates withEcoRI andPstI enzymes demonstrated some differences existed among the isolates. According to theEcoRI profile, the mean estimated size for the complete genome of each isolate (LdMNPV-T1, LdMNPV-T2 and LdMNPV-T3) was calculated to be approximately 170, 153 and 170 kb,respectively. Insecticidal activities of each isolate were tested onL. d. disparlarvae using four different viral concentrations between 103and 106 OBs/ml. Results showed that the mortalities for LdMNPV-T1, -T2 and -T3 ranged between 13–53%, 47–100% and 46–93%, respectively. The LC50and LC95values of LdMNPV-T2 were not significantly different from the respective corresponding values of the other two isolates. However, isolate LdMNPV-T2 killed larvae with a LC50value that was lower than the other two isolates. Our results suggested there are promising LdMNPV isolates in Turkey that can be used for microbial control ofL. d. disparlarvae. [ABSTRACT FROM AUTHOR]