Teiji Sota

• Dr of Agriculture
• Professor Emeritus at Kyoto University

The genus Carabus (Coleoptera: Carabidae: Carabinae) is a group of predacious ground beetles found throughout Holarctic temperate zones. The diversification of this group is attributed not only to allopatric speciation but also to diversification in life-history traits and morphological traits that are involved in ecological adaptation and reproduc...

The superfamily Dryopoidea is a diverse group of beetles with a mixture of aquatic, semiaquatic, and terrestrial life histories. These beetles exhibit remarkable morphological diversity, particularly in the larval stages, which is likely associated with their repeated adaptation to aquatic habitats. The phylogenetic relationships among Dryopoidea f...

Body shape and size diversity and their evolutionary rates correlate with species richness at the macroevolutionary scale. However, the molecular genetic mechanisms underlying the morphological diversification across related species are poorly understood. In beetles, which account for one-fourth of the known species, adaptation to different trophic...

Genetic basis underlying the biodiversity and phenotypic plasticity are fascinating questions in evolutionary biology. Such molecular diversity can be achieved at multi-omics levels. Here, we sequenced the first chromosome-level genome of assassin bug Rhynocoris fuscipes, a polyphagous generalist predator for biological control of agroecosystems. C...

To evaluate the utility of a deep-learning approach for monitoring amphibian reproduction, we examined the classification accuracy of a trained model and tested correlations between calling intensity and frog abundance. Field recording and count surveys were conducted at two sites in Kyoto City, Japan. A convolutional neural network (CNN) model was...

A new Carabus of the subgenus Apotomopterus Hope, 1838, from China (Coleoptera, Carabidae). Description of a new Carabus from China, belonging to the subgenus Apotomopterus Hope, 1838: C. (A.) roxane fengqingensis n. ssp., from Western Yunnan.

The endangered endemic ground beetle, Carabus nankotaizanus Kano, 1932 (Coleoptera: Carabidae), consists of 4 subspecies distributed across the lowlands to mountain forests of Taiwan. However, continuous morphological variation among the subspecies and large altitudinal range gaps between lowland and mountain populations of C. nankotaizanus raise q...

Despite the vast diversity of phytophagous insects that feed on vascular plants (tracheophytes), insects that feed on bryophytes remain understudied. Agromyzidae, one of the most species-rich phytophagous clades in Diptera, consists mainly of leaf-mining species that feed on tracheophytes. However, a recent discovery of thallus-mining species on li...

Insect speciation is among the most fascinating topics in evolutionary biology; however, its underlying mechanisms remain unclear. Allopatric speciation represents one of the major types of speciation and is believed to have frequently occurred during glaciation periods, when climatic oscillation may have caused suitable habitats to be fragmented r...

Megascolecid earthworms of the pheretimoid group are dominant detritivores of soil ecosystems in the Japanese Archipelago and East Asia. However, their diversity and phylogenetic relationships are poorly understood. We assembled whole mitogenome sequences for 197 megascolecid earthworms collected throughout Japan to study the phylogenetic relations...

Knowledge of population divergence history is key to understanding organism diversification mechanisms. The geotrupid dung beetle Phelotrupes auratus, which inhabits montane forests and exhibits three color forms (red, green, and indigo), diverged into five local populations (west/red, south/green, south/indigo, south/red, and east/red) in the Kink...

Mating rate optima often differ between the sexes: males may increase their fitness by multiple mating, but for females multiple mating confers little benefit and can often be costly (especially in taxa without nuptial gifts or mala parental care). Sexually antagonistic evolution is thus expected in traits related to mating rates under sexual selec...

Secondary contact between incipient species and selection against maladaptive hybridization can drive reinforcement between populations in contact and result in reproductive character displacement (RCD). Resultant divergence in mating traits within a species may generate downstream reproductive isolation between populations with displaced and non‐d...

Background The coevolutionary dynamics of corresponding male and female sexual traits, including genitalia, may be driven by complex genetic mechanisms. Carabus ( Ohomopterus ) ground beetles show correlated evolution in the size of their functionally corresponding male and female genital parts. To reveal the genetic mechanisms involved in the evol...

Macroplea japana (Jacoby, 1885) has not been collected in Japan since the 1960s and was thought to be locally extinct. Recently, we collected this species from submerged aquatic plants growing in the nearshore zone of Lake Biwa, Shiga Prefecture, where it had previously been recorded from the stomach contents of pochards in the 1950s. We conducted...

Periodical cicadas of the genus Magicicada exhibit a spectacular life-cycle phenomenon, with periodic mass emergence being observed every 13 or 17 years in the eastern United States. It is entirely unclear how their periodical life cycles are controlled. Here, I review previous knowledge and hypotheses about Magicicada life cycles and propose an in...

Background: The coevolutionary dynamics of corresponding male and female sexual traits, including genitalia, may be driven by complex genetic mechanisms. Carabus (Ohomopterus) ground beetles show correlated evolution in the size of their functionary corresponding male and female genital parts. To reveal the genetic mechanisms involved in the evolut...

Genital morphology reveals rapid diversification among species, and species-specific divergence in genital morphology may result in reproductive isolation and promote speciation. Natural selection against maladaptive hybridization may cause species-specific genital divergence. In this context, divergence in mating traits is expected to be greater b...

In this chapter, cases of natural hybridization between Ohomopterus species are reviewed, and the mechanisms of reproductive isolation are considered. Hybrid zones are found between parapatric species within species groups, which exhibit similar body sizes. Hybrids are recognized chiefly by the intermediate morphology of the copulatory pieces in ma...

This chapter introduces the main focus of this book, the subgenus Ohomopterus, which is endemic to Japan and classified into 17 species. All Ohomopterus beetles have a similar appearance, except for notable size differences. However, they have complex genital systems with corresponding male and female parts that function as a lock and key to ensure...

The diversification of corresponding male and female genital parts, copulatory pieces and vaginal appendices, characterizes the species radiation of Ohomopterus. The species-specific matching of genital parts between the sexes facilitates proper insemination during conspecific copulation, whereas it prevents insemination in heterospecific copulatio...

In this chapter, we explore the origin of Ohomopterus based on fossil data and a molecular phylogenetic analysis of the extant taxa using genome-wide sequence data. The fossil data suggest that an ancestral population of Ohomopterus may have existed in the late Miocene through the Pliocene. The divergence time estimation using a molecular phylogeny...

This chapter introduces ground beetles of the genus Carabus in terms of their taxonomic position, distribution, morphological characters, phylogeny, and life history. Carabus, or the subtribe Carabina, is a member of the subfamily Carabinae of the coleopteran family Carabidae. Carabus beetles are flightless owing to the degeneration of the hind win...

In this final chapter, the diversification history of Ohomopterus since their colonization of Japan is reviewed, which contains allopatric speciation, repeated dispersal/secondary contacts, and the formation of species assemblages. Their speciation has been driven by divergence in body size and genital morphology, which facilitate mechanical reprod...

The divergence of ecological traits adapted to different environmental conditions may promote the speciation and coexistence of species. Divergence in the seasonal life cycle is a prominent aspect of temperate insects that can promote niche partitioning even among closely related species. In Carabus, both spring and autumn breeders occur in tempera...

We have seen that body size and genital morphology are the key traits for reproductive isolation in Ohomopterus species because differences in these traits promote mechanical reproductive isolation. In particular, differences in body size are effective for preventing heterospecific copulation and thus hybridization and promote sympatric coexistence...

This book presents the whole picture of the ecological and evolutionary study on the ground beetle group, the subgenus Ohomopterus of the genus Carabus, endemic to Japan. This flightless beetle group consists of many geographic races. They show divergence in key traits for reproductive isolation—body size and genital morphology, which leads to coex...

Although allopatric speciation among areas segregated by dispersal barriers increases the regional species richness, sympatry of closely related species following secondary contacts of allopatrically diverged species increases the local species richness and may also increase the regional species richness by the formation of assemblages with differe...

The origin and diversification process of lineages of organisms that are currently widely distributed among continents is an interesting subject for exploring the evolutionary history of global species diversity. Ground beetles of the subfamily Carabinae are flightless except for one lineage, but nevertheless occur on all continents except Antarcti...

Apart from model organisms, 13- and 17-year periodical cicadas (Hemiptera: Cicadidae: Magicicada) are among the most studied insects in evolution and ecology. They are attractive subjects because they predictably emerge in large numbers; have a complex biogeography shaped by both spatial and temporal isolation; and include three largely sympatric,...

Aim Genetic differentiation of terrestrial organisms among islands is assumed to be affected by the geological history of the islands, such as the time elapsed since the formation of islands or straits. Cicadas are generally poor dispersers, but some cicada groups have colonised continental and oceanic islands and evolved into endemic species. Here...

Background Telmatochromis temporalis is a cichlid fish endemic to Lake Tanganyika. The normal and dwarf morphs of this fish are a clear example of ongoing ecological speciation, and body size plays an important role in this speciation event as a magic trait. However, the genetic basis underlying this trait has not been studied. Results Based on do...

Elmidae (Coleoptera: Byrrhoidea) comprises diverse groups of specialized aquatic beetles, but the phylogenetic positions of the intrafamilial taxonomic groups remain unclear. We performed phylogenetic analyses of 26 genera and 73 elmid species and subspecies representing four of the five currently recognized tribes from Holarctic region (Japan, Eur...

Consumer-resource interactions between trophic levels are ubiquitous and important factors in shaping the diversity of insects. However, dietary patterns such as host specificity and conservatism have been insufficiently examined in fungivorous insects. Here we reconstructed the evolutionary history of host use in fungivorous ciid beetles (Coleopte...

Some sexual traits, including genitalia, have undergone coevolutionary diversification toward exaggerated states in both sexes among closely related species, but the underlying genetic mechanisms that allow correlated character evolution between the sexes are poorly understood. Here, we studied interspecific differences in gene expression timing pr...

Background-matching camouflage is a widespread adaptation in animals; however, few studies have thoroughly examined its evolutionary process and consequences. The tiger beetle Chaetodera laetescripta exhibits pronounced variation in elytral colour pattern among sandy habitats of different colour in the Japanese Archipelago. In this study, we perfor...

The periodical cicadas of the genus Magicicada Davis, 1925 inhabiting eastern United States are characterized by a long juvenile period of 17 or 13 years and periodical mass emergence of adults. In this genus, only seven species are distinguished and are distributed into three species groups, Decim, Cassini and Decula. We performed comparative cyto...

Biological invasion has been a serious global threat due to increasing international trade and population movements. Tracking the source and route of invasive species and evaluating the genetic differences in their native regions have great significance for the effective monitoring and management, and further resolving the invasive mechanism. The s...

Phenotypic evolution driven by sexual selection can impact the fitness of individuals and thus population performance through multiple mechanisms, but it is unresolved how and when sexual selection affects offspring production by females.We examined the effects of sexual selection on offspring production by females using replicated experimental evo...

Ecological character displacement predicts that interspecific resource competition results in greater trait divergence between species in sympatry than in allopatry. However, other processes, such as ecological sorting, result in the same pattern of trait variation. In this study, we characterize character displacement in eight species of snail-fee...

We studied the population genetic structure underlying the geographic variation in the structural colour of the geotrupid dung beetle, Phelotrupes auratus, which exhibits metallic body colours of different reflectance wavelengths perceived as red, green and indigo. These forms occur parapatrically in an area of Japan. The colour variation was not r...

Aposematic organisms are often unprofitable to predators (e.g. because of defensive chemicals) which they advertise with a conspicuous signal (e.g. bright and conspicuous colour signals). Aposematism is thought to reduce predation of prey because the colour signal increases the ability of predators to learn, recognize and remember the prey’s defens...

Some highly isolated oceanic islands harbour endemic ground beetles that have lost the ability to fly. Here, we investigated the origin of the possibly extinct flightless giant ground beetle Aplothorax burchelli on St Helena Island in the South Atlantic. Aplothorax burchelli was initially considered to be a member of the subtribe Calosomina (=genus...

Some highly isolated oceanic islands harbour endemic ground beetles that have lost the ability to fly. Here, we investigated the origin of the possibly extinct flightless giant ground beetle Aplothorax burchelli on St Helena Island in the South Atlantic. Aplothorax burchelli was initially considered to be a member of the subtribe Calosomina (=genus...

The bitterling Tanakia lanceolata is a primary freshwater fish with wide distribution range in Japan; therefore, analysis of this species will yield much information on the formation of Japanese freshwater fish fauna. However, populations of this species are threatened by several human activities. To reveal the genetic population structure of T. la...

To investigate the developmental genetics of genital formation in the carabid beetle Carabus maiyasanus, we compared gene expression patterns among five stages using transcriptomic RNA sequencing data from abdominal segments and genitalia in the third (last) larval instar (including prepupa) and pupal stages. We identified 18 839 genes, of which 10...

Interspecific interactions are contingent upon organism phenotypes, and thus phenotypic evolution can modify interspecific interactions and affect ecological dynamics. Recent studies have suggested that male–male competition within a species selects for capability to reproductively interfere with a closely related species. Here, we examine the effe...

The diversity of genital morphology among closely related animals with internal fertilization is well known, but the genetic backgrounds are unclear. Here, we show that, in Carabus ( Ohomopterus ) beetles showing correlated evolution of male and female genital parts, only a few major quantitative trait loci (QTLs) determine differences in genital d...

The elmid beetle Orientelmis parvula (Nomura & Baba, 1961) is a rare and endangered species in Japan. Mouth parts and genitalia in adults of both sexes and larval morphology are described based on scanning electron microscope observations. The larva of the genus Orientelmis Shepard, 1998 is described for the first time. The systematic position of t...

The mass application of whole-mitogenome sequencing has great potential for resolving complex phylogeographic patterns that cannot be resolved by partial mitogenomic sequences or nuclear markers. North American periodical cicadas (Magicicada) are well known for their periodical mass emergence at 17-and 13-year intervals in the north and south, resp...

Understanding how landscape structure influences biodiversity patterns and ecological processes are essential in ecological research and conservation practices. Forest discontinuity is a primary driver affecting the population persistence and genetic structure of forest‐dwelling species. However, the actual impacts on populations are highly species...

Many species within Elmidae (Coleoptera: Byrrhoidea) have plastrons composed of flattened setae. However, some genera display fine plastrons on the epicuticle, called plastron hairs. In Japanese elmids, members of the genera Stenelmis, Ordobrevia, Nomuraelmis and Leptelmis bear ventral plastron hairs. Based on a maximum likelihood tree including mo...

Insect–host fungus associations are important ecological features that affect population dynamics and interspecific interactions. However, details of host fungus relationships in fungivorous beetles remain unclear due to incompletely revised taxonomy and insufficient host records. We conducted a taxonomic study of the ciid beetle Octotemnus laminif...

The bitterling Acheilognathus melanogaster is a critically endangered primary freshwater fish endemic to the Pacific side of eastern Japan. To elucidate A. melanogaster genetic structure, we investigated phylogeography in nine populations, using gene sequences of mitochondrial Cytochrome b (Cytb), as well as nuclear Rhodopsin (Rho) and glycosyltran...

Interspecific variation in genital morphology contributes to prezygotic reproductive isolation in many insect species. However, developmental genes affecting genital morphology are poorly understood. We undertook larval RNA interference (RNAi) experiments with rotund (rn) gene in the ground beetle Carabus (Ohomopterus) maiyasanus to examine the kno...

The aquatic larvae of the family Elmidae (Coleoptera) have been considered unable to swim because they lack swimming setae on their body and legs. We discovered that riffle beetle larvae (Leptelmis gracilis Sharp) are in fact able to swim. After opening the tuft‐like gills on the last abdominal segment they swim by repeatedly bending the abdomen in...

The periodical cicadas of North America ( Magicicada spp.) are well-known for their long life cycles of 13 and 17 years and their mass synchronized emergences. Although periodical cicada life cycles are relatively strict, the biogeographic patterns of periodical cicada broods, or year-classes, indicate that they must undergo some degree of life cyc...

Body size is a multi‐functional trait related to various fitness components, but the relative importance of different selection pressures is seldom resolved. In Carabus japonicus beetles, of which the larvae exclusively prey on earthworms, adult body size is related to the presence/absence of a larger congener and habitat temperature. In sympatry,...

Periodical cicadas comprise three species groups containing three pairs of 13- and 17-year life cycle species showing parallel divergence, along with a more anciently diverged 13-year species (Magicicda tredecim). The mechanism and genetic basis of this parallel divergence is unknown. Here we use orthologous transcriptome sequences to explore the d...

Batesian mimicry protects animals from predators when mimics resemble distasteful models. The female-limited Batesian mimicry in Papilio butterflies is controlled by a supergene locus switching mimetic and nonmimetic forms. In Papilio polytes, recent studies revealed that a highly diversified region (HDR) containing doublesex (dsx-HDR) constitutes...

Dytiscus sharpi is a critically endangered diving beetle endemic to Japan that is distributed in five distant areas today. Information on the population genetics of this species is crucial for its conservation. We investigated the genetic differentiation and divergence of the D. sharpi in seven populations in North and South Hokuriku on the Sea of...

Female-limited Batesian mimicry may have evolved because of stronger predation pressure on females than on males, but some physiological costs of mimicry may also hinder the evolution of mimicry in males. In Papilio memnon, which possesses a female-limited Batesian mimicry polymorphism, two alleles at the doublesex (dsx) locus strictly control fema...

Body size is a key trait in diversification among animal species, and revealing the gene regions responsible for body size diversification among populations or related species is important in evolutionary biology. We explored the genomic regions associated with body size differences in Carabus japonicus ground beetle populations by quantitative tra...

Tracking allele frequencies is essential for understanding how polymorphisms of adaptive traits are maintained. In Papilio memnon butterflies, which exhibit a female-limited Batesian mimicry polymorphism (wing-pattern polymorphism), two alleles at the doublesex (dsx) locus correspond to mimetic and non-mimetic forms in females; males carry both dsx...

Sexual selection sometimes favors male traits that benefit their bearers, but harm their mates. The harmful effects of male traits may also extend to females of other species via heterospecific mating interactions. This could affect the coexistence of closely related species during secondary contact. We examined the evolution of the interspecific i...

We performed a molecular phylogenetic analysis of the ground beetles Apatrobus (Carabidae), endemic to Japan, using the mitochondrial cytochrome c oxidase subunit I (COI) and the nuclear 28S rRNA (28S) genes. We focused on the species divergence in Kyushu, Shikoku and western Honshu and used 15 of 19 species and three populations with undetermined...

Seasonal polyphenism in adults may be a season-specific adaptation of the adult stage and/or a by-product of adaptive plasticity of the juvenile stages. The swallowtail butterfly Papilio xuthus L. exhibits seasonal polyphenism controlled by photoperiod. Adults emerging in spring from pupae that spend winter in diapause have smaller bodies than adul...

To understand geographic body size variation in an insect species, various factors including habitat temperature, correlation between life history traits, and food availability must be examined. Carabus (Ohomopterus) japonicus is univoltine, feeds exclusively on earthworms during its larval stage, and shows a clinal body size variation along the ha...

Interspecific mating interactions, or reproductive interference, can affect population dynamics, species distribution and abundance. Previous population dynamics models have assumed that the impact of frequency-dependent reproductive interference depends on the relative abundances of species. However, this assumption could be an oversimplification...

Larvae of 10 elmid species of the genera Stenelmis, Ordobrevia and Nomuraelmis were described based on SEM observation. Of these, S. hisamatsui, S. ishiharai, S. hayashii, O. amamiensis were described for the first time, and N. amamiensis was redescribed. The morphological types of the larvae corresponded to the monophyletic groups defined by the m...

The female-limited Batesian mimicry polymorphism in Papilio butterflies is an intriguing system for investigating the mechanism of maintenance of genetic polymorphisms. In Papilio polytes, an autosomal region encompassing the sex-determinant gene doublesex controls female-limited mimicry polymorphism. In the closely related species P. memnon, which...

Life-history evolution spurred by post-Pleistocene climatic change is hypothesized to be responsible for the present diversity in periodical cicadas (Magicicada), but the mechanism of life-cycle change has been controversial. To understand the divergence process of 13-y and 17-y cicada life cycles, we studied genetic relationships between two synch...

We investigated the phylogenetic relationships and divergence times within the genus Auritibicen(Cicadidae: Cicadinae: Cryptotympanini), analyzing five Japanese species (A. japonicus, A. bihamatus,A. kyushyuensis, A. esakii and A. flammatus) and three species from East Asian mainland and Taiwan (A. atrofasciatus, A. intermedius and A. chujoi) using...

We evaluated how dispersal limitation affected spatial variation in the species composition of fungivorous insect communities inhabiting fruiting bodies of bracket fungi on scattered deadwoods. The insect communities showed significant distance decay of similarity pattern among deadwoods, which was not fully explained by differences in environmenta...

The huge monophyletic group of the East African cichlid radiations (EAR) consists of thousands of species belonging to 12-14 tribes; the number of tribes differs among studies. Many studies have inferred phylogenies of EAR tribes using various genetic markers. However, these phylogenies partly contradict one another and can have weak statistic supp...

We investigated the phylogenetic relationships among tiger beetles of the subtribe Cicindelina (=Cicindela s. lat.; Coleoptera: Cicindelidae) mainly from the Oriental and Sino-Japanese zoogeographic regions using one mitochondrial and three nuclear gene sequences to examine the position of the subgenus Sophiodela, currently classified in the genus...

Source program of periodicity evolution in periodical cicadas

Periodical cicadas (Magicicada spp.) in the USA are famous for their unique prime-numbered life cycles of 13 and 17 years and their nearly perfectly synchronized mass emergences. Because almost all known species of cicada are non-periodical, periodicity is assumed to be a derived state. A leading hypothesis for the evolution of periodicity in Magic...

Winter geometrid moths belonging to the genus Inurois comprise nine species that reproduce during early winter, three species that reproduce in late winter, and polymorphic species with genetically diverged early and late winter populations that co-occur widely across the species' range. In our previous studies, we demonstrated that differences in...

Aim We tested the hypothesis of character release in body size among allopatric populations of the carabid beetle Carabus japonicus by analysing geographical variation in body size in relation to habitat temperature and sympatry/allopatry with the larger congeneric species Carabus dehaanii . Location The main and satellite islands of Kyushu in the...