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Summary: Bursaphelenchus tadamiensis , which was initially isolated from a stag beetle, Dorcus striatipennis , collected from sap flow of Quercus crispula in Fukushima, north-eastern Japan, was re-isolated three times from sap flow of Quercus spp. in western Japan. The re-isolated populations were mostly morphologically consistent with the type population, but the male bursal flap showed high variations in the newly collected populations. Molecularly, the type and new populations showed differences in the internal transcribed spacer region of ribosomal DNA and mitochondrial cytochrome oxidase subunit I gene, suggesting that the species is genetically divided into several local populations. The isolation pattern of B. tadamiensis , i.e. , the species was initially isolated from sap flow-associated beetles and subsequently isolated from sap flow, suggests that the species prefers and is adapted to the sap flow environment as its habitat. [ABSTRACT FROM AUTHOR]

Simple Summary: The red-necked longhorn beetle, Aromia bungii, is a pest that damages Rosaceae trees such as peach and cherry. This beetle has been introduced into Japan and expanded its distribution rapidly during the last decade. Currently, Japanese populations of A. bungii are widely distributed in six non-contiguous regions. The DNA sequences of partial mitochondrial DNA were analysed in Japanese populations of A. bungii in order to discuss whether multiple introductions or human-mediated long-distance dispersal have contributed to the non-contiguous distribution of A. bungii. Seven haplotypes were detected in Japanese populations. Haplotype composition differed among the six non-contiguous regions. These results suggest that multiple introductions have contributed to the non-contiguous distribution of A. bungii in Japanese populations. Aromia bungii (Faldermann) (Coleoptera: Cerambycidae) is an invasive pest, damaging Rosaceae trees (particularly Prunus) in Japan and Europe. The establishment of this beetle in Japan was first detected in 2012, and subsequently, it has rapidly expanded its distribution. Currently, Japanese populations of A. bungii are widely distributed in six non-contiguous regions. In this study, we compared the nucleotide sequences of mitochondrial cytochrome oxidase subunit 1 of the populations in these six regions in Japan to examine whether multiple introductions or human-mediated long-distance dispersal have contributed to the non-contiguous distribution of A. bungii. Seven haplotypes were detected from Japanese populations, and one of these was identical to a sequence deposited from China. One to two haplotypes were detected in each region, suggesting a genetic bottleneck. Detected haplotypes differed between introduced regions, although two regions shared a single haplotype. These results suggest that multiple independent introductions of A. bungii have contributed to its non-contiguous distribution in Japan. Quarantine measures for wood-packing materials in trade need to be strengthened to prevent the establishment of further populations of A. bungii. [ABSTRACT FROM AUTHOR]

The phylogenetic relationships among the Japanese members of the genus Eubrianax (Coleoptera: Psephenidae) were examined using the mitochondrial cytochrome oxidase subunit I ( COI) gene and nuclear 28S rRNA gene sequences. Based on the molecular phylogeny as well as morphological features, the species status of Eubrianax brunneicornisNakane, 1952 was proposed. The phylogenetic analyses recovered monophyly of the previously proposed pellucidus species group with four Japanese species, whereas a single Japanese species of the granicollis group was included in the lineage of the ramicornis group with five Japanese species. The divergence times of the species were estimated by dating the phylogenetic tree against the fossil record and a molecular clock based on the COI gene. The divergence of the Japanese species was inferred to have occurred during the Pliocene epoch. [ABSTRACT FROM AUTHOR]

Molecular phylogenies of the genus Platycerus in Japan were characterized based on the nuclear 28S ribosomal RNA and mitochondrial cytochrome oxidase subunit I ( COI) genes. These analyses, combined with our previous morphological information, revealed a detailed diversification process of Platycerus in Japan, as well as estimates of their divergence times. Japanese species were monophyletic and were inferred to have diverged to the acuticollis species group and all other species ca 1.69 Mya. The acuticollis species group then appeared to split into P. viridicuprus and a group including P. takakuwai, P. albisomni and P. acuticollis ca 1.26 Mya. Other specific divergences have occurred primarily since ca 0.33 Mya. Comparing the molecular trees and the morphological tree, we also found introgression of the COI gene in some species. Genetic divergence of Platycerus has occurred intensely in southwestern Japan. [ABSTRACT FROM AUTHOR]

Two psephenid beetles, Eubrianax granicollis Lewis and E. ramicornis Kiesenwetter, are common species on the main islands of Japan (i.e. Honshu, Shikoku and Kyushu), but diagnostic characters for larval identification are unknown. Two types of field-collected Eubrianax larvae from Honshu and Kyushu were discriminated based on the distributions of granules on the dorsal surface. These larvae were assigned to E. granicollis and E. ramicornis by comparing them with larvae of the two species obtained via laboratory rearing. The two species were also identified unambiguously on the basis of their mitochondrial cytochrome oxidase subunit I (COI) gene sequences. Larval and pupal morphology are described based on laboratory-reared specimens. [ABSTRACT FROM AUTHOR]

We examined the genetic structures of 13 Japanese populations of an ambrosia beetle, Xylosandrus germanus (Curculionidae: Scolytinae), to understand the effects of geographical barriers on the colonization dynamics of this species. The genetic structure was studied using portions of the mitochondrial cytochrome oxidase I ( COI) gene. A phylogenetic analysis revealed three distinct lineages (clades A, B and C) within X. germanus. Clade A contained 21 haplotypes from all 13 populations; whereas clade B contained eight haplotypes from Hokkaido (Sapporo and Furano), Iwate and Nagano populations; and clade C contained only a single a haplotype from the Hokkaido (Furano) population. In the analysis of molecular variance (amova), the greatest amount of genetic variation was detected between populations in Hokkaido and those in Honshu and other southern islands. Between these two groups of populations, all the values of the coefficient of gene differentiation were significantly larger than zero, except for the Hokkaido (Sapporo) versus Nagano comparison. Our results confirm that for X. germanus, gene flow has been interrupted between Hokkaido and Honshu since the last glacial maximum. [ABSTRACT FROM AUTHOR]

Aim In an attempt to use molecular and fossil data interactively in historical biogeography, we studied the phylogeography of five Plateumaris leaf beetles in Japan using mitochondrial cytochrome oxidase subunit I (COI) sequence data to explore interspecific differences in phylogeographical patterns and estimate the timings of colonization and geographical differentiation. Location A total of 461 beetles from five species on Hokkaido, Honshu and Kyushu islands of Japan were analysed with 117 beetles from three conspecies and two congeners from the mainland (Russia, including Sakhalin; Korea; Mongolia; Belgium; France; hereafter, the continent). Methods Using the sequence data from a 750-bp portion of the COI gene, we studied the phylogeny of COI haplotypes, intraspecific population differentiation using analysis of molecular variance and the Mantel test, and intraspecific phylogeography using nested clade analysis. In addition, divergence times between the continental and Japanese lineages, as well as among the various Japanese lineages, were estimated using a Bayesian approach with node constraints based on fossil records of extant species. Results Three widely distributed species showed different degrees of geographical differentiation corresponding to their different colonization history in Japan. Bayesian estimates of divergence time revealed that one of two endemic species, which originated before the late Pliocene, attained intraspecific differentiation through the Pliocene and Pleistocene, whereas another endemic species has been confined in one locality, and three non-endemic species colonized Japan after the mid-Pleistocene. Main conclusions Molecular analyses of an insect group with relatively abundant fossil data can contribute greatly to the understanding of diverse biogeographical histories of related species in a region. Bayesian estimates of divergence time could be used to assess the variable evolutionary rates of the COI gene, and may be applied to other related insect species. [ABSTRACT FROM AUTHOR]