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Interspecific hybridization has long been of interest to biologists due to its implications for species concepts, gene flow, and conservation. We found a putative hybrid between the endangered brown shrike (Lanius cristatus superciliosus) and the common bull-headed shrike (Lanius bucephalus) at the foot of Mt. Fuji, central Japan, where the adult sex ratio of brown shrikes is biased towards the male. Brown and bull-headed shrikes are closely related, and their hybridization is critical for the survival and conservation of the brown shrike. We tried to identify this individual based on genetic, morphological, plumage, and acoustic analysis. The hybrid had intermediate genetic, morphological, and plumage features between the two parental species. The maternal lineage of the hybrid was suggested to be the bull-headed shrike by COI analysis. We thus conclude that the hybrid resulted from interbreeding between a male brown shrike and a female bull-headed shrike, and a skewed sex ratio in the brown shrike may have contributed to this hybridization. Skewed sex ratio is a useful indicator of population viability and knowledge of this is helpful in rare species conservation. Genetic introgression between brown and bull-headed shrikes cannot be denied because the hybrid individual was fertile and backcrossing occurred. Exploring past and ongoing genetic relationships of the shrikes has led to insights into the evolutionary background and the potential of hybridization in an evolutionary context. [ABSTRACT FROM AUTHOR]

Dispersal and local adaptation play an important role in driving species distributions under climate change. Many studies aim to estimate relationships between species occurrences and environmental variables to predict range shift and biodiversity loss, ignoring dispersal and intraspecific variation contributing to complex spatial and temporal dynamics.We accounted for dispersal and intraspecific variation in forecasts of species distribution under climate change with species distribution models (SDMs) using two cold‐adapted, low‐dispersal Platycerus species (Coleoptera: Lucanidae), each with distinct subspecies distributions, as focus species. The results showed that the subspecies‐level model performed significantly better than the species‐level model when considering dispersal constraints in SDMs. Whether or not dispersal or intraspecific variation is accounted for, the predicted species range of Platycerus albisomni is expected to decrease in the future. For Platycerus takakuwai, accounting for dispersal constraints in SDMs indicated that its potential distribution area would increase at the subspecies level under climate change, but decrease at the species level.These divergent results show that SDMs at the subspecies level can detect impacts of climate change that may be overlooked in species‐level models. Therefore, models that consider intraspecific variation and dispersal constraints may provide a more realistic perspective on the impacts of climate change.Because accurate mapping of potential habitats is needed for conservation purposes, demographic studies should include dispersal explicitly and explore how and when intraspecific variation in dispersal affects local population dynamics. This approach could help evaluate species' habitat shifts, thus enabling suitable conservation strategies. [ABSTRACT FROM AUTHOR]

Character displacement is considered a key driver of evolutionary divergence and adaptation. Few examples of reproductive character displacement with a narrow contact zone have been identified. We examined the genetic structure, body length variation, and genital morphology in the contact and allopatric areas of Platycerus takakuwai and P. viridicuprus to investigate character displacement and gene flow. In the contact area, the species identifications based on endophallic morphology and nuclear genes were identical, whereas mitochondrial gene did not exhibit a perfect match. This incongruence suggests that interspecific hybridization followed by the mitochondrial introgression has likely occurred during historical secondary contact. The species are essentially parapatric in contact area, co-occurring at only one of 28 adjacent sampling sites despite being flying species, and no hybrids based on morphology have been found, which indicates a strongly exclusive distribution. The results showed that the body length variation was consistent with character displacement after controlling for variation along geographic and environmental gradients. Interspecific body size differentiation may have evolved to reduce incorrect mating between the species. Moreover, selective pressure caused by reproductive interference between the two species may act on body size that have likely resulted in strongly exclusive distribution at the edge of their ranges. [ABSTRACT FROM AUTHOR]

The process of phenotypic adaptation to the environments is widely recognized. However, comprehensive studies integrating phylogenetic, phenotypic, and ecological approaches to assess this process are scarce. Our study aims to assess whether local adaptation may explain intraspecific differentiation by quantifying multidimensional differences among populations in closely related lucanid species, Platycerus delicatulus and Platycerus kawadai, which are endemic saproxylic beetles in Japan. First, we determined intraspecific analysis units based on nuclear and mitochondrial gene analyses of Platycerus delicatulus and Platycerus kawadai under sympatric and allopatric conditions. Then, we compared differences in morphology and environmental niche between populations (analysis units) within species. We examined the relationship between morphology and environmental niche via geographic distance. P. kawadai was subdivided into the "No introgression" and "Introgression" populations based on mitochondrial COI gene – nuclear ITS region discordance. P. delicatulus was subdivided into "Allopatric" and "Sympatric" populations. Body length differed significantly among the populations of each species. For P. delicatulus, character displacement was suggested. For P. kawadai, the morphological difference was likely caused by geographic distance or genetic divergence rather than environmental differences. The finding showed that the observed mitochondrial–nuclear discordance is likely due to historical mitochondrial introgression following a range of expansion. Our results show that morphological variation among populations of P. delicatulus and P. kawadai reflects an ecological adaptation process based on interspecific interactions, geographic distance, or genetic divergence. Our results will deepen understanding of ecological specialization processes across the distribution and adaptation of species in natural systems. [ABSTRACT FROM AUTHOR]

The effects of climate change on species distribution are typically inferred based on species distribution models (SDMs) that do not account for the dispersal ability of species.Here we investigated the utility of dispersal ability measures in predicting the distribution of 10 Platycerus species in Japan, which are cold‐adapted stag beetles sharing ecological and morphological features.We generated three SDMs based on environmental variables without dispersal constraint and incorporating two alternative dispersal constraint scenarios. We compared these three models with respect to SDM performance and the predicted degree of range overlap between neighbouring species. Using the best models among three SDMs, we predicted range shifts under climate change. Additionally, we characterised environmental differences among species distributional areas.Our results revealed that models incorporating dispersal constraints had better predictive performance. Platycerus delicatulus occupied a largest suitable habitat and P. sue had a narrow range in Japan. Most of Platycerus taxa in 2070 were predicted to lose large portions of present suitable areas. Moreover, environment was confirmed to affect the distribution of the targeted species.Incorporating dispersal ability to better understand the effects of climate change on the species ranges is a crucial step towards developing policies for insect management and conservation of vulnerable species. [ABSTRACT FROM AUTHOR]

Intraspecific variation provides insight into heterogeneous demography and adaptive history across distribution ranges of organisms. Most species distribution models assume that species respond to the environment as a single undifferentiated entity across their entire distribution. However, populations occupying different niches might differ in their ability to cope with climate change. Here, we assessed potential climatic niche differentiation at the species and subspecies levels and identified the palaeoclimatic range of three cold-adapted, low-dispersal beetle species: Carabus irregularis , Platycerus albisomni and Platycerus takakuwai. Our results showed that: (1) MaxEnt models incorporating information derived from intraspecific variation outperformed the species-level models; (2) tests of niche similarity revealed niche conservatism in most subspecies, except for two subspecies of C. irregularis , C. i. irregularis and C. i. bucephalus ; and (3) historical predictions suggested substantial shifts within species ranges, with multiple glacial refugia during the Last Glacial Maximum. In conclusion, we recommend closer examination of intraspecific variation when predicting species distributions, in order to obtain more accurate generalizations regarding range shifts under climate change. [ABSTRACT FROM AUTHOR]

Larvae of the stag beetle, Dorcus rectus, feed on decaying wood, which they digest with the aid of symbiotic yeasts; however, they can be successfully reared on artificial diets containing only fungal tissue. In this study we tested whether D. rectus larvae can utilize fungal cell walls, which are an insoluble component of mycelium. Lyophilized Bjerkandera adusta mycelium cultured in potato-dextrose liquid medium consisted of a 47.6% hot-water insoluble fraction by mass, which contains 53.7% of the total nitrogen in the mycelium. D. rectus larvae that hatched from surface-sterilized eggs were reared for 14 days on agar-based diets containing either the soluble fraction, insoluble fraction or both, extracted from 100 mg of mycelium. The larvae increased in mass most on the mixed diet, and there was no difference in their growth on the mixed and positive control diets. Both the soluble and insoluble fractions improved larval growth compared to the negative control diet; however, the growth rates were much lower than those expected from the nitrogen dose-growth response curve obtained in a previous study. Addition of β-chitin to the soluble fraction did not positively affect larval growth. Therefore, we conclude that (1) D. rectus larvae need both the soluble and insoluble fractions of mycelium and (2) the larvae digest the insoluble fraction using their own enzymes. [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]

The male endophallic morphology and mitochondrial cytochrome oxidase subunit I ( COI) gene of two parapatric species of the acuticollis species group, Platycerus acuticollis and P. albisomni, were examined at the border between the two species. No morphologically inferred hybrid was found. The endophallic and mitochondrial types of each individual were significantly linked, and the two species inferred by both types were essentially parapatric even at a very local level. We inferred that the reproductive isolation between them is high, although introgressive hybridization occurred rarely. The taxonomical assignment of P. acuticollis and P. albisomni as two distinct species is considered appropriate. [ABSTRACT FROM AUTHOR]

We constructed a phylogeny of the ground beetle subgenus Nialoe ( s. lat.), genus Pterostichus (Coleoptera: Carabidae) based on two mitochondrial (cytochrome oxidase I and 16S ribosomal DNA) and one nuclear (28S ribosomal DNA) gene sequences. Thirty-three representative species of the group and three outgroup species were analyzed. The resultant trees (maximum parsimonious, maximum likelihood and Bayesian trees of the combined data of the three gene sequences) indicated that there are two large and three small lineages in the group, some of which were supported by a previous morphology-based phylogeny. In all the analyses, the small lineage composed of two Korean species is sister to the rest of the subgenus, but relationships of other four lineages differed among the analyses and remained unresolved. The implications of the present results are discussed in terms of taxonomy and biogeography of the group. [ABSTRACT FROM AUTHOR]

We studied the effects of small-scale vegetation disturbances on biodiversity in an abandoned coppice forest in central Japan during 2004-2006. We assessed biodiversity by examining vegetation regeneration and by changes in the diversity and abundance of ground beetles after experimental manipulations including tree felling, vegetation clearing, and litter removal. Our experimental design was dictated by the need of producing only small disturbances; therefore we could not replicate plots. Instead, we used a repeated measures approach during three years to document the consistency of experimental effects. We found that the diversity of regenerating vegetation increased dramatically due to recruitment of many new species after clearing ground vegetation. Tree cutting caused strong environmental changes and affected vegetation regeneration rate but not diversity. Tree cutting also significantly increased the diversity of ground beetle species, while litter removal affected the abundance of ground beetles. Our results suggest that a sound conservation practice shall combine tree cutting with ground vegetation clearing and litter removal. Besides, conservation of abandoned forests may be based on low-intensity labor, including tree cutting on restricted areas. Finally, ground beetles appeared to be surprisingly sensitive to vegetation disturbance on a restricted area and thus can be suggested for monitoring such small-scale-disturbance-based conservation practices. [ABSTRACT FROM AUTHOR]

The phylogeny and genital evolution of carabid beetles in the tribe Pterostichini, mainly the genus Pterostichus (Coleoptera: Carabidae), were studied using two nuclear gene sequences: wingless and 28SrDNA. Phylogenetic results suggest that the genera Molops, Poecilus, Stomis, Myas, Lesticus, and Trigonotoma and the subgenus Bothriopterus of the genus Pterostichus form basal lineages, with genus Molops sister to the rest of the tribe. The genus Pterostichus, with the exception of the subgenus Bothriopterus, was monophyletic and occupied more derived lineages. Examinations of the membranous parts of the genitalia (male endophallus and female spermatheca) revealed that endophalli and spermathecae are classified into four and five types, respectively. Reconstructions of genital character evolution on the trees obtained suggest that the ancestor of Pterostichini had a straight endophallus and a short cylindrical spermatheca and that the elaborated genitalia seen in some species evolved in more derived lineages. [ABSTRACT FROM AUTHOR]

Pterostichus thunbergi Morawitz and its related species of Japan are revised based on the structure of membranous parts of their genitalia for the first time, under the name of the thunbergi species group. This species group is monophyletic and is placed in the subgenus Morphnosoma Lutshnik. The monotypic subgenus Moritapterus Berlov, erected for P. thunbergi, is synonymized with Morphnosoma. Comparative study of the endophallus revealed that P. thunbergi michinoku Nakane is a junior synonym of P. habui and that four species should be recognized in this group. Three of them are sympatric with P. thunbergi and one of them, Pterostichus (Morphnosoma) robustistylis, is described as a new species. Molecular phylogeny based on the COI gene (mitochondrial [mt]DNA) supported its independence as a distinct species. The resultant trees of mtDNA and comparative study of morphology revealed that P. thunbergi is probably non-monophyletic. In the present study we suggest the presence of further cryptic species of Morphnosoma in Japan. [ABSTRACT FROM AUTHOR]

Simple Summary: Neolucanus swinhoei is a widespread species of stag beetle distributed across the subtropical Taiwan Island. The biological features of weak flying capability, two-week adult lifespan, and strong dependence on forests are the key factors determining its genetic differentiation. We investigated the influence of historical climatic oscillations in Pleistocene on the distribution of N. swinhoei. The complex population genetic structure and dispersal routes of eastern populations are affected by the geographic isolation of the north/south-oriented Central Mountain Range (CMR) during periodical Pleistocene glaciations. Four possible shelters were inferred for the distribution of N. swinhoei in each geographic region during the periodical glaciations. The coexistence of widely distributed ancestral haplotypes and the locally derived ones are deduced to be the possible explanation of long-distance dispersal events for N. swinhoei. In the presence of the CMR, the northern and southern low mountains are proposed as alternative routes for N. swinhoei. The present study proposes dispersal routes from eastern to western Taiwan, in contrast to the more common scenarios of western-to-eastern dispersal found in other studies. The present study demonstrates that the complicated genetic structure of the hilly lineage of the Neolucanus swinhoei complex was driven by its biological features and habitat requirements as well as hindrance by the CMR during periodical Pleistocene glaciations. The results revealed a tendency of geographical differentiation and major and sub- lineage divergences before and after the Riss glaciation, followed by stable population growth during Würm glaciation. At least four refugia were inferred for N. swinhoei during the Riss–Würm glaciations. The ancestral haplotype retention in the cytochrome oxidase subunit I (COI) gene and compensated substitution in 16S rRNA gene is a possible evolutionary scenario resulting in the inconsistent evolution pattern between COI and 16S rRNA gene coupled with the long-distance dispersal of N. swinhoei. Although the CMR did hinder the dispersal of N. swinhoei, its ancestors may have dispersed to eastern Taiwan through the northern and southern low mountains of the CMR before the Riss glaciation. Our finding suggests that the population growth in the Würm glaciation led a dispersal back to western Taiwan, which is contrast to the more common dispersal scenario from western Taiwan to eastern populations proposed in other studies. [ABSTRACT FROM AUTHOR]

The genus Platycerus is a cool temperature zone taxon widely distributed in the Northern Hemisphere. In East Asia, 10, one and 28 species are known in Japan, Korea and China, respectively. Recent studies of Platycerus have revealed the divergence pattern in Japan and South Korea, but that of Chinese Platycerus is unknown. We conducted a phylogenetic and biogeographical study of Platycerus in East Asia, including China, using 68, 87 and 296 sequence data of the nuclear wingless gene, internal transcribed spacer (ITS) region and mitochondrial COI gene, respectively. Although the introgression of mitochondrial genes had been known in Japanese Platycerus, the essential contradiction was not recognized between the phylogenetic trees of nuclear genes and COI in Chinese Platycerus. In the COI tree, the Japanese clade and Asian continental clade diverged around 10.84 million years ago, and four major clades were recognized in the latter. For the shape of the posterolateral corner of the Platycerus pronotum, sharp (S)‐type species are distributed in higher latitudinal and lower altitudinal areas than round (R)‐type species in the Asian continent. S‐type species have evolved from R‐type species at least three times in more northerly areas, where the annual amplitude of temperature change is large. The genus Platycerus has been differentiated and speciated by a process unique to South Korea, Japan and China, according to regional topography. Thus, genetic differentiation and speciation in Platycerus are related to latitudinal and altitudinal gradients, as well as the site topographical profile and niche differentiation. [ABSTRACT FROM AUTHOR]

We examined the genetic divergence of Platycerus hongwonpyoi Imura & Choe, 1989 in South Korea using the nuclear wingless (Wg) gene, internal transcribed spacer (ITS) region and mitochondrial cytochrome oxidase subunit I (COI) gene. We found no variation in Wg or ITS. Based on COI, P. hongwonpyoi was split into four well defined and one weakly supported clades, which were inferred to have diverged 2.11–1.33 Ma. The Platycerus hongwonpyoi population size seems to have decreased during the past several tens of thousands of years. The divergence times of major clades of P. hongwonpyoi were comparable with those involved in the speciation of certain Japanese species. Frequent overlapping of different clades at the same sites suggests the occurrence of secondary gene flow following differentiation in South Korea. In conclusion, the genus Platycerus underwent strikingly different divergence patterns in South Korea compared with Japan according to the disparate topographies of these two geographical areas. This study aims to examine the genetic divergence of Platycerus hongwonpyoi in South Korea and compare its divergence patterns with certain speciation of Japanese species. [ABSTRACT FROM AUTHOR]

Among insect-fungus relationships, xylose-fermentingScheffersomycesyeasts are well known for their potential in utilizing wood hemicelluloses and their association with various wood-feeding insects. However, their specificity to host insects or strain-level diversity within host species has not been clearly elucidated. In the insect family Lucanidae, larvae usually feed on decaying wood, and adult females consistently possess a fungus-storage organ, called the mycangium, near the abdominal tip. Here the authors investigated host-symbiont relationships betweenScheffersomycesyeast symbionts and small blue stag beetles of the genusPlatycerus(Coleoptera: Lucanidae) in East Asia by using intergenic spacer (IGS) region as a genetic marker. All yeast strains isolated from the female mycangium of threePlatycerusspecies,P. hongwonpyoifrom Korea andP. acuticollisandP. delicatulusfrom Japan, were allied toScheffersomyces segobiensisbased on the sequences of the nrDNA 26S and internal transcribed spacer (ITS), in which no sequence difference was observed among those strains. However, IGS regions showed clear genetic differentiation within the yeast symbionts ofP. hongwonpyoi, as well as between those of Korean and JapanesePlatycerusspecies. In the IGS sequences, nucleotide substitutions were mainly distributed in the whole stretch of IGS1 and the anterior half of IGS2, whereas nucleotide gaps were localized at IGS1 and the middle of IGS2. Despite the conserved association between thePlatycerusbeetles and the specific strains ofS. segobiensisin East Asia, geophylogenetic divergence patterns of the yeast symbionts were not concordant with those of the insect hosts. [ABSTRACT FROM PUBLISHER]

A macrocephalic pterostichine carabid, Pterostichus ishikawai Nemoto, endemic to the Korean Peninsula, is taxonomically revised based mainly on the membranous parts of the genitalia (male endophallus and female vagina). Two species are separated from P. ishikawai (type locality: Mount Taebaegsan) and newly described: P. ishikawaioides (type locality: Mount Sobaeksan) and P. jiricola (type locality: Mount Jirisan). Since comparative male genital morphology does not support monophyly for these three species, the two novel species should be treated as distinct species, not subspecies of P. ishikawai. [ABSTRACT FROM AUTHOR]