Genetic diversity among eight Dendrolimus species in Eurasia (Lepidoptera: Lasiocampidae) inferred from mitochondrial COI and COII, and nuclear ITS2 markers

Abstract

Background: Moths of genus Dendrolimus (Lepidoptera: Lasiocampidae) are among the major pests of coniferous forests worldwide. Taxonomy and nomenclature of this genus are not entirely established, and there are many species with a controversial taxonomic position. We present a comparative evolutionary analysis of the most economically important Dendrolimus species in Eurasia. Results: Our analysis was based on the nucleotide sequences of COI and COII mitochondrial genes and ITS2 spacer of nuclear ribosomal genes. All known sequences were extracted from GenBank. Additional 112 new sequences were identified for 28 specimens of D. sibiricus, D. pini, and D. superans from five regions of Siberia and the Russian Far East to be able to compare the disparate data from all previous studies. In total, 528 sequences were used in phylogenetic analysis. Two clusters of closely related species in Dendrolimus were found. The first cluster includes D. pini, D. sibiricus, and D. superans; and the second, D. spectabilis, D. punctatus, and D. tabulaeformis. Species D. houi and D. kikuchii appear to be the most basal in the genus. Conclusion: Genetic difference among the second cluster species is very low in contrast to the first cluster species. Phylogenetic position D. tabulaeformis as a subspecies was supported. It was found that D. sibiricus recently separated from D. superans. Integration of D. sibiricus mitochondrial DNA sequences and the spread of this species to the west of Eurasia have been established as the cause of the unjustified allocation of a new species: D. kilmez. Our study further clarifies taxonomic problems in the genus and gives more complete information on the genetic structure of D. pini, D. sibiricus, and D. superans.