Molecular phylogeny and diversification timing of the Nemouridae family (Insecta, Plecoptera) in the Japanese Archipelago

Abstract

The generation of the high species diversity of insects in Japan was profoundly influenced by the formation of the Japanese Archipelago. We explored the species diversification and biogeographical history of the Nemouridae Billberg, 1820 family in the Japanese Archipelago using mitochondrial DNA and nuclear DNA markers. We collected 49 species among four genera: Indonemoura Baumann, 1975; Protonemura Kempny, 1898; Amphinemura, Ris 1902 and Nemoura Latreille, 1796 in Japan, China, South Korea and North America. We estimated their divergence times—based on three molecular clock node calibrations—using Bayesian phylogeography approaches. Our results suggested that Japanese Archipelago formation events resulted in diversification events in the middle of the Cretaceous (<120 Ma), speciation in the Paleogene (<50 Ma) and intra-species diversification segregated into eastern and western Japan of the Fossa Magna region at late Neogene (20 Ma). The Indonemoura samples were genetically separated into two clades—that of Mainland China and that of Japan. The Japanese clade clustered with the Nemouridae species from North America, suggesting the possibility of a colonisation event prior to the formation of the Japanese Archipelago. We believe that our results enhanced the understanding both of the origin of the species and of local species distribution in the Japanese Archipelago.

A remarkable new genus and species of Nemourinae (Plecoptera, Nemouridae) from Sichuan, China, with systematic notes on the related genera

“…During the following decades, the genus Paranemoura Needham & Claassen, 1925 [4] and ten further subgenera [5,6] were described, and Illies [7] elevated all twelve subgenera of Nemoura to generic level. However, Nemoura remained as a poorly defined assemblage with paraphyletic taxa in agreement with molecular analyses [8].…”

“…Morphological studies are based on previously published extensive molecular analysis [8]. In addition to raise several other questions about the systematics of the Nemourinae, the molecular studies already supported the new species as a well separated lineage within the related genera [8]. Herein, we describe a new genus, and compare to other Nemourinae that possess lateral knobs and a basal cushion on the epiproct.…”

“…The morphological analysis was performed on the dissected genitalia of KOH cleared specimens. Molecular studies and analysis related to the present work were published by Gamboa et al [8] and the sequences were deposited to GenBank (accession number: MK132446, MK132447).…”

“…The molecular analysis indicated the new genus belonged to the paraphyletic assemblage of Nemoura sensu lato. The specimens of Illiesonemoura were not available for molecular studies [8]. Thus, the phylogenetic position is not completely clear, because similarities of male genitalia would place the new genus close to the pakistani group of Illiesonemoura.…”

“…We determined that an assignment of this new species to either Nemoura, Illiesonemoura, or Zapada would necessitate broadening of morphological diagnoses of these genera. Morphological studies are based on previously published extensive molecular analysis [8]. In addition to raise several other questions about the systematics of the Nemourinae, the molecular studies already supported the new species as a well separated lineage within the related genera [8].…”