山田 量崇

The Qinghai–Tibetan Plateau, the core of the Eurasian mountain belt, has repeatedly reshaped the formation and pattern of biodiversity through episodic uplift and associated geoclimatic changes. Despite its central role in shaping biotic evolution across Eurasia, genus‐level studies that jointly evaluate the effects of orogeny, hybridization and ecological adaptation remain scarce. Here, we integrate multilocus phylogenomics (nuclear and mitochondrial), network‐based reticulation inference, divergence dating, macroevolutionary modelling and codon‐based molecular adaptation tests (branch‐site dN/dS on protein‐coding genes) to reconstruct the spatiotemporal diversification of the predatory insect genus Anthocoris across Eurasia. We identified two episodes of rapid lineage diversification: a basal radiation (BR; late Oligocene–Miocene, ~25–15 Ma) and a terminal radiation (TR; mid‐Miocene to Pleistocene), supported by independent evidence from diversification rate shifts (e.g., ClaDS, CoMET) and dense clusters of short branches, with the strongest signals in high‐elevation lineages. Genome‐scale phylogenomic discordance points to incomplete lineage sorting and ancient introgression as joint drivers of these patterns, gauged by the extent of deep gene‐tree conflict and independent genome‐wide tests (quartet analyses and D‐statistics), with network inference corroborating reticulation. The timing and geography of BR and TR align with major geoclimatic episodes: the formation of the modern Qinghai–Tibetan Plateau (~25–15 Ma), the subsequent formation of the Himalayas–Hengduan Mountains (~15 Ma onward), the closure of the Tethys Sea, Central Asian aridification and the Miocene cooling. Ancestral‐range reconstructions place the origin of Anthocoris in northern Eurasia, and coupled with retention and sorting of ancestral polymorphism under niche conservatism, likely facilitated repeated high‐elevation adaptation. This study provides new evidence and a theoretical framework showing that the repeated uplift of the Qinghai–Tibetan Plateau—acting with continent‐wide geographic and climatic shifts and ancestral gene flow—jointly drove diversification and generated complex spatiotemporal patterns within genera across Eurasia.

The molecular phylogeny of the Cimicoidea was reconstructed from an expanded sampling based on mitochondrial (16S, COI) and nuclear (18S, 28SD3) genes. The data were analyzed using maximum likelihood (ML), maximum parsimony (MP), and Bayesian inference (BI) phylogenetic frameworks. The phylogenetic relationships inferred by the model-based analyses (ML and BI) were largely congruent with those inferred by the MP analysis in terms of the monophyly of most of the higher taxonomic groups and the species-level relationships. The following clades were recovered in all analyses: Cimiciformes; Nabidae: Prostemmatinae; Nabidae: Nabinae; Plokiophilidae; Microphysidae; Lasiochilidae; Cimicidae: Cacodminae; Cimicidae; Lyctocoridae; Anthocoridae s. str.; Cardiastethini excluding Amphiareus; Almeidini; Scolopini; Anthocorini; Oriini; Curaliidae + Lasiochilidae; Almeidini + Xylocorini; Oriini + Cardiastethini; and Anthocorini + Amphiareus. Reconstructions of ancestral copulation states based on Bayesian and parsimony inference indicated that at least one shift from standard insemination (SI) to traumatic insemination (TI) occurred within Cimicoidea, and an investigation of the evolutionary correlation between TI and paragenitalia (PG) revealed that the acquisition of PG in cimicoid females was correlated with the TI habit. Additionally, our morphological examination of various types of PG suggested that even the same PG type may not constitute a homologous feature at various taxonomic levels, indicating the convergent evolution of female morphology to adapt to TI.

A new genus and species of cimicoid true bug, Ecpaglocoris ditomeus Yamada & Yamamoto, gen. et sp. nov., is described and illustrated from mid-Cretaceous (Cenomanian–Albian) amber in the Kachin State of northern Myanmar (Burma). This new fossil genus and species is reminiscent of members of Anthocoridae by the strongly flattened and elongated body, four-segmented labium, distinct costal fracture and presence of fossula spongiosa on fore tibiae, but should not be ascribed to this family. The new taxon cannot be placed in any extant cimicoid families, based upon hemelytral, male genital and other morphological structures. Based on the hemelytral membrane venation and presence of dorsal laterotergites on abdominal segments I to VIII, it can be assumed that this new genus belongs to the extinct family Vetanthocoridae. Ecpaglocoris ditomeusgen. et sp. nov. has aberrant male genitalia characterised by sickle-shaped left and right parameres and grooves running throughout the paramere. This characteristic indicates that traumatic insemination occurred in this genus. The peculiar combination of male genital characteristics seen in Ecpaglocorisgen. nov. prevents its placement in any of the extant cimicoid families.

Japanese Anthocorini are reviewed. A total of five genera and 13 species were identified, including two new species described below: Temnostethus mirificus sp. nov. and Anthocoris venustus sp. nov. Previous records of Anthocoris miyamotoi Hiura, 1959 from Japan are considered to be confused with A. venustus sp. nov. Anthocoris nemoralis (Fabricius, 1794), which is a common and widespread species in Europe, is recorded in Japan for the first time; it is assumed to have been accidentally introduced into Japan recently. Temnostethus distans Kerzhner, 1973 and Anthocoris kalopanacis Kerzhner, 1977 are newly recorded in Japan proper. Male and female genitalia are illustrated and described for most of the treated species. Identification keys to the genera and species that occur in Japan are provided. Bionomics are provided for each species. Detailed locality information and distribution maps in Japan are presented for all Japanese species and their zoogeography is discussed.

The genus Alpagut Kıyak, 1995, is recorded from East Asia for the first time based on the description of A. masakazui sp. nov. from Japan. Habitus images and illustrations of diagnostic features, including genitalia structures, are provided. The loculus capsulae of A. masakazui sp. nov. is discussed. The presence of a metacoxal adhesive pad is reconfirmed in Dipsocoridae along with a discussion of its morphology.

Cryptostemma miyamotoi sp. nov. and C. pavelstysi sp. nov. from Japan are described. Habitus images and illustrations of diagnostic features, including genitalic structures, are provided. A key to the Eastern Palaearctic species is offered to facilitate identification. Habitats and behavior of the two new species are discussed based on the field and laboratory observations. The gender agreement of Pachycoleus japonicus (Miyamoto, 1964) is corrected.

A new genus and species of cimicomorphan bug, Aphrastomedes anthocoroides Yamada and Yamamoto, gen. and sp. nov., is described and illustrated based on two specimens preserved in Upper Cretaceous (Cenomanian) amber from the Hukawng Valley of northern Myanmar (Burma). This remarkable cimicomorphan species is tentatively assigned to the family Velocipedidae primarily on the basis of the structure of the labium, forewings, and genitalia. Aphrastomedes is considered best placed in the Cimiciformes as a member of the Velocipedidae, and it also has a close relationship to the Medocostidae.