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The forewing base structure of the orthopteran suborder Ensifera, a group of insects well known for their sound-producing behavior, was examined by using light microscopy, confocal laser scanning microscopy, and µCT. We detected significant novel characters, such as functional changes in the tpm9 muscle from the flexor to the extensor of the forewing that are likely associated with the acquisition of sound-producing behavior using forewings. Phylogenetic analysis based on the characters selected from the forewing base structure showed that the character system contains a strong phylogenetic signal supporting the monophyly of Ensifera, Tettigonioidea and Grylloidea as well as the sister-group relationship between Grylloidea and Gryllotalpoidea, but no apomorphies to resolve the deep phylogeny among superfamilies could be determined from this character system.

To elucidate the effect of Pleistocene climatic fluctuations on the historical distribution and geographical genetic structure of temperate Japanese species, we performed phylogeographical and demographic analyses using mitochondrial gene sequences obtained from the stonefly species Kamimuria tibialis, sampled from four main islands of the Japanese Archipelago (i.e. Hokkaido, Honshu, Shikoku and Kyushu) and Tsushima Island. We detected three main clades with distinct geographical distributions, including the Tsushima, Kyushu and Hokkaido–Honshu–Shikoku phylogroups. These groups were estimated to have diverged from one another 0.54–2.02 Mya, suggesting they have undergone several glacial cycles in different refugia. Our results showed that during the glacial epochs and with a fall in sea-level, gene flow was limited among Tsushima and Kyushu, and among Hokkaido and Honshu, probably because the straits between these islands are deep. The population in Kyushu and Shikoku, the southernmost islands, exhibited high genetic diversity, with two distinct haplotype lineages occurring sympatrically. These results suggest that the population division into multiple refugia and the existence of stable southern refugia have contributed to the high genetic diversity of the species in this region.

SUMMARYRadially anisotropic S-wave structures under the permanent seismic stations in Australia are reconstructed using multimode surface waves (SWs) and receiver functions (RFs) in a framework of the Bayesian inference. We have developed a fully nonlinear method of joint inversions incorporating P-RFs and multimode Rayleigh and Love waves, based on the transdimensional Hierarchical Bayesian formulation. The method allows us to estimate a probabilistic Earth model taking account of the complexity and uncertainty of Earth structure, by treating the model parameters and data errors as unknowns. The Parallel Tempering algorithm is employed for the effective parameter search based on the reversible-jump Markov Chain Monte Carlo method. The use of higher modes enables us to enhance the sensitivity to the depth below the continental asthenosphere. Synthetic experiments indicate the importance of higher mode SWs for the better recovery of radial anisotropy in the whole depth range of the upper mantle. The method is applied to five Global Seismographic Network stations in Australia. While the S-wave models in eastern Australia show shallow lithosphere–asthenosphere boundary (LAB) above 100 km depth, those in central and Western Australia exhibit both mid-lithosphere discontinuities (MLDs) and LAB. Also, seismic velocity jumps equivalent to the Lehmann discontinuity (L-D) are found in all seismic stations. The L-D under the Australian continents is found at around 200–300 km depth, depending on locations. Radial anisotropy in the depth range between LAB and L-D tends to show faster SH anomalies, which may indicate the effects of horizontal shear underneath the fast-moving Australian plate.

The Japanese species of the genus Strigiphilus Mjöberg, 1910 (Insecta: Phthiraptera: Philopteridae) are revised. Six species are recorded, including a new species belonging to the cursitans species-group: Strigiphilus stenocephalus new species, described from the type host Otus bakkamoena semitorques and based on specimens originally identified and reported by Uchida (1949) as Strigiphilus rostratus (Burmeister, 1838). A lectotype for Strigiphilus laticephalus (Uchida, 1949) (type host: Strix aluco yamadae) is designated and redescribed, and this louse species is synonymized under Strigiphilus cursor (Burmeister, 1838). Strigiphilus ceblebrachys (Denny, 1842), S. heterogenitalis Emerson & Elbel, 1957 and S. tuleskovi Balát, 1958 are recorded for the first time in Japan. Also, Strix uralensis and Otus sunia japonicus are recorded as new hosts for Strigiphilus heterogenitalis and S. tuleskovi respectively.

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The explosive eruption occurred at Hunga Tonga-Hunga Ha'apai on January 15, 2022, generating atmospheric waves, meteotsunamis, tsunamis, and seismic waves recorded worldwide. Energetic signals of seismic surface waves indicate multiple explosive events, but the detailed eruption episodes are hard to unravel from dispersive long-period surface waves. In this study, we performed the back-projection (BP) analysis using the teleseismic P-waves to clarify the sequence of multiple explosive eruptions. The BP results successfully detected the locations and timing of multiple explosions even though P-waves from each eruption were overlapped and masked by other seismic signals and noises. The results suggest that the series of explosive eruptions can be divided into two parts of eruption sequences. The first sequence started at 04:02 UTC, escalated into major explosions at 04:15 UTC and 200 -300 s afterward, and lasted at least until 04:35 UTC. The second sequence began about 4 hours later (08:26 UTC) and continued for about 6 -7 minutes, including a massive eruption at 08:31 UTC. The estimated origin times of each eruption episode determined in this study are consistent with successive arrivals of long-period surface wave trains at frequencies higher than 10 mHz. The time intervals of explosive eruptions in the first sequence suggested that the significant explosive eruptions intermittently occurred at around 270 -280 s intervals. This interval is nearly equivalent to the eigenfrequencies of the atmospheric resonant oscillation with the Earth at 3.7 mHz. Since the observed amplitude spectra of this eruption exhibit a conspicuous spectral peak at 3.7 mHz, our BP results indicate that the eruption cycle may be synchronized with the eigen-period of the atmosphere-lithosphere coupled mode. (c) 2022 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).

By using mu CT technology, we reconstructed 3D models of the female genital structures and associated muscles of seven species from three suborders of Psocodea (free-living species only, formerly known as independent insect order "Psocoptera"). The homology of the female genital structures and associated muscles of different species is discussed. A total of 21 muscle groups were observed, and except for one muscle, all were homologized throughout the order. Moreover, some of the homologous muscles could be identified confidently in holometabolan insects. Using the muscles as landmarks, we discuss the homology of the ovipositor valves between Psocodea and other neopteran insects. Most importantly, the ovipositor of the suborder Trogiomorpha was identified to consist of the well-developed external valve (V3) plus a remnant of the dorsal valve (V2). We also examined the phylogenetic information included in the female genital muscles and found that certain muscles provide useful information and support deeper nodes (e.g., monophyly of the suborder Psocomorpha). The present study of female genital muscles not only helps us to better understand the phylogeny of Psocodea but also provides a solid foundation for research on muscle evolution. (C) 2022 Elsevier Ltd. All rights reserved.

The divergence date and ancestral distributional area of the psocid subfamily Speleketorinae, which includes taxa with reversed genitalia (female penis and male vagina of Afrotrogla and Neotrogla, tribe Sensitibillini), were estimated. The most basal divergence of the subfamily (between the North American Speleketor and the tribe Sensitibillini) was estimated to have occurred according to the separation between the North American continent and Gondwana, ca. 175 Ma. The most basal divergence of Sensitibillini (between African Afrotrogla + Sensitibilla and Brazilian Neotrogla) was estimated to have occurred according to the split of West Gondwana (separation between the African and South American continents), ca. 127 Ma. The biome of the ancestral distributional area of Sensitibillini (inland of West Gondwana) is believed to be arid to semi-arid, which might strengthen the reversed sexual selection and then facilitate the origin of preadaptive features related to the evolution of a female penis. All extant Sensitibillini species inhabit carbonatic caves, but geological evidence suggested independent shifts of these genera to the carbonatic cave habitat in the Tertiary/Quaternary.

The systematic placement of an enigmatic psocid family restricted to Africa, Lesneiidae, was estimated by using a multiple gene data set. The candidates for its close relatives are now classified under two different infraorders, the family Archipsocidae of the infraorder Archipsocetae or the families Elipsocidae/Mesopsocidae of the infraorder Homilopsocidea. The maximum likelihood and Bayesian analyses of the molecular data set strongly suggested that the Lesneiidae belongs to Homilopsocidea and forms a clade with Elipsocidae/Mesopsocidae/Eolachesillinae (Lachesillidae). However, the relationships among these (sub)families and Lesneiidae, including the monophyly of Elipsocidae and Mesopsocidae, were ambiguous or questionable, showing the necessity of further investigations for elucidating their relationships and validating the status of these families. Two species, L. johnsoni Yoshizawa & Lienhard, n. sp. and L. testudinata Yoshizawa & Lienhard, n. sp. (Psocodea: Lesneiidae), were described from South Africa. There appears to be a tight association between the reproductive biology and morphological specialization of this group.

Many male animals donate nutritive materials during courtship or mating to their female mates. Donation of large-sized gifts, though costly to prepare, can result in increased sperm transfer during mating and delayed remating of the females, resulting in a higher paternity Nuptial gifting sometimes causes severe female-female competition for obtaining gifts (i.e., sex-role reversal in mate competition) and female polyandry, changing the intensity of sperm competition and the resultant paternity gains. We built a theoretical model to analyze such coevolutionary feedbacks between nuptial gift size (male trait) and propensity for multiple mating (female trait). Our genetically explicit, individual-based computer simulations demonstrate that a positive correlation between donated gift size and the resultant paternity gain is a requisite for the co-occurrence of large-sized gifts and females’ competitive multiple mating for the gifts. When donation of gifts imposes monandry, exaggeration in nuptial gift size also occurs under the assumption that the last male monopolizes paternity. We also analyzed the causes and consequences of the evolution of a female persistence trait in trading of nuptial gifts, that is, double receptacles for nuptial gifts known to occur in an insect group with a “female penis” (Neotrogla spp.).

The gain of foldable wings is regarded as one of the key innovations enabling the present-day diversity of neopteran insects. Wing folding allows compact housing of the wings and shields the insect body from damage. Wing-fixing systems have evolved in some insects, probably to increase the durability of the shielding function by the wings. Bark lice (Psocodea) are known to possess a unique wing-to-wing repose coupling system, but a detailed morphological and evolutionary study of this system is lacking. In this study, we examined this repose coupling structure by SEM in 32 species including representatives of all three suborders of bark lice (Trogiomorpha, Troctomorpha and Psocomorpha). We concluded that the repose wing-coupling apparatus independently evolved twice within Psocodea. In Trogiomorpha, the apparatus is located on the subcostal vein of the forewing and is composed of elongated rib-like structures. In Troctomorpha and Psocomorpha, in contrast, the repose coupling structure is located on the radius vein of the forewing and is formed by a swollen vein. These morphological and developmental differences in the repose coupling structures also provide phylogenetic information at different systematic levels.

Many four-winged insects have mechanisms that unite the forewings and hindwings in a single plane. Such an in-flight wing coupling apparatus may improve flight performance in four-winged insects, but its structure is variable among different insect groups. The wings of bark lice (Insecta: Psocodea: "Psocoptera") also have an in-flight wing coupling apparatus, but to date, its morphology has not been studied in detail. In this study, we examined the wing-coupling structure in representative species of the three suborders of bark lice (Trogiomorpha, Troctomorpha, and Psocomorpha) and inferred its origin and transformation. We conclude that the main component of the psocodean wing coupling apparatus evolved once in the common ancestor via modification of cuticular structures at the apex of the forewing CuP vein. Morphological differences in components of the coupling structures are phylogenetically informative at the intraorder level and include an autapomorphy that characterizes Troctomorpha and a synapomorphy that supports a sister relationship between Troctomorpha and Psocomorpha.

The mitochondrial genome arrangement in the insect order Psocodea (booklice, barklice, and parasitic lice) is extremely variable. Genome organization ranges from the rearrangement of a few tRNAs and protein coding genes, through extensive tRNA and protein coding gene rearrangements, to subdivision into multiple mini-chromosomes. Evolution of the extremely modified mitochondrial genome in parasitic lice (Phthiraptera) has been the subject of several studies, but limited information is available regarding the mitochondrial genome organization of the more plesiomorphic, free-living Psocodea (formerly known as the "Psocoptera"). In particular, the ancestral state of the psocodean mitochondrial genome arrangement and the evolutionary pathway to the rearranged conditions are still unknown. In this study, we addressed mitochondrial evolutionary questions within the Psocodea by using mitochondrial genome sequences obtained from a wide range of Psocoptera, covering all three suborders. We identified seven types of mitochondrial genome arrangements in Psocoptera, including the first example in Psocodea of retention of the ancestral pancrustacean condition in Prionoglaris (Prionoglarididae). Two methods (condition-based parsimony reconstruction and common-interval genome distances) were applied to estimate the ancestral mitochondrial arrangement in Psocodea, and both provided concordant results. Specifically, the common ancestor of Psocodea retained the ancestral pancrustacean condition, and most of the gene arrangement types have originated independently from this ancestral condition. We also utilized the genomic data for phylogenetic estimation. The tree estimated from the mitochondrial genomic data was well resolved, strongly supported, and in agreement with previously estimated phylogenies. It also provided the first robust support for the family Prionoglarididae, as its monophyly was uncertain in previous morphological and molecular studies.

International audience; Palaeosiamoglaris hkamtiensis sp. nov. of the family Prionoglarididae is described from Hkamti amber (ca. 110 Ma), together with Psyllipsocus myanmarensis sp. nov., the third fossil psyllipsocid species described from from Noije Bum Hill (ca. 98 Ma). Based on the current observations of Palaeosiamoglaris hkamtiensis sp. nov., we discuss the synapomorphic characters proposed to define the tribe Siamoglaridini. Palaeosiamoglaris hkamtiensis sp. nov. is, inter alia, characterized by the maxillary palpomere 3 ca. 0.66 time as long as maxillary palpomere 4, the second anal vein concavity turned toward posterior wing margin in forewing, Sc reaching R1 nearly at middle of radial cell. The new species Psyllipsocus myanmarensis sp. nov. is, inter alia, characterized by antennae with 11 segments, the radial cell closed and six-angled, and the quadrangular pterostigma.

Morphological and behavioral characters are frequently examined for comparative studies. Unlike morphology, a single behavioral trait is difficult to subdivide as multiple characters, even when achieved by many evolutionary changes. Therefore, when similar behavioral traits evolved independently among closely related taxa, their distinction is difficult. Almost all members of the suborder Auchenorrhyncha (Insecta: Hemiptera) possess a jumping ability that uses metathoracic muscles, and this behavioral trait has been regarded as a synapomorphy. In this study, the anatomical observations of metathoracic muscles revealed that highly elaborated jumping ability was gained independently within the suborder, although the evolution of jumping ability might have been initiated at their common ancestor. Our results provide an example of identifying a true evolutionary pathway by dissecting a behavioral character into mechanical elements.

A new barklouse species belonging to the Trichadenotecnum s.str. clade (Psocodea: “Psocoptera”: Psocidae) was described from southeastern Brazil (Minas Gerais state). This locality is highly isolated (about 3400 km) from the closest known distributional range of this clade. It also represents the southernmost distributional record of Trichadenotecnum s.str. Phylogenetic placement of the species and biogeography of Neotropical Trichadenotecnum were briefly discussed. Trichadenotecnum punctipenne New, 1972 described from Brazil was synonymized with Trichadenotecnum pardus Badonnel, 1955.

The insect order Psocodea is a diverse lineage comprising both parasitic (Phthiraptera) and nonparasitic members (Psocoptera). The extreme age and ecological diversity of the group may be associated with major genomic changes, such as base compositional biases expected to affect phylogenetic inference. Divergent morphology between parasitic and nonparasitic members has also obscured the origins of parasitism within the order. We conducted a phylogenomic analysis on the order Psocodea utilizing both transcriptome and genome sequencing to obtain a data set of 2370 orthologous genes. All phylogenomic analyses, including both concatenated and coalescent methods suggest a single origin of parasitism within the order Psocodea, resolving conflicting results from previous studies. This phylogeny allows us to propose a stable ordinal level classification scheme that retains significant taxonomic names present in historical scientific literature and reflects the evolution of the group as a whole. A dating analysis, with internal nodes calibrated by fossil evidence, suggests an origin of parasitism that predates the K-Pg boundary. Nucleotide compositional biases are detected in third and first codon positions and result in the anomalous placement of the Amphientometae as sister to Psocomorpha when all nucleotide sites are analyzed. Likelihood-mapping and quartet sampling methods demonstrate that base compositional biases can also have an effect on quartet-based methods.[Illumina; Phthiraptera; Psocoptera; quartet sampling; recoding methods.]

The Ontong Java Plateau in the western Pacific Ocean is the world’s largest oceanic plateau. It was formed 122 million years ago by a massive volcanic event that significantly affected Earth’s environment. The cause of the magmatic event remains controversial because the upper mantle structure beneath the plateau is poorly known. Here we use passive seismic data obtained through seafloor observations, alongside existing seismic data, to determine the three-dimensional radially anisotropic shear wave velocity to depths of up to 300 km. We find that the lithosphere–asthenosphere boundary is approximately 40 km deeper beneath the centre of the Ontong Java Plateau than beneath the surrounding seafloor. Based on our results and petrological and rheological constraints, we propose that the lithosphere–asthenosphere boundary has deepened as a result of underplating of dehydrated residual material beneath the pre-existing lithosphere during formation of the Ontong Java Plateau by a thermochemical mantle plume. The lithosphere beneath the Ontong Java Plateau is thickened by up to 40 km relative to the surrounding ocean floor which suggests it formed through the ascent of a mantle plume, according to analyses of seafloor seismic observations.

Trichadenotecnum is one of the most diverse genera among the non-parasitic members of Psocodea (Insecta: "Psocoptera"). The genus shows a world-wide distribution (excluding the Australian Region, where only one introduced species is known) with its center of diversity in southern to eastern Asia. Several species groups had been proposed for this large genus based on morphology, but their validity and phylogenetic relationships are still unclear because of great morphological diversity in the genitalia, systematically the most relevant character. In this study, we estimated the molecular phylogeny of the Old World species of Trichadenotecnum based on extensive taxon sampling. As a result, the monophyly of morphology-based species groups was very strongly supported in most cases. However, two groups were recovered as non-monophyletic, which had been inadequately defined on the basis of plesiomorphies or convergences of genital characters. First, the monophyly of the sexpunctatum group was not supported because the medium group was found to be embedded within this group. The simpler genitalia observed in the medium group were considered to be derived from the more complicated genitalia present in the sexpunctatum group. Second, the monophyly of the majus group was not supported for two reasons: (1) It was divided into two distant clades which initially had been united on the basis of convergent similarities of the male genitalia. (2) Two species groups were revealed to be embedded within the main clade of the majus group; the initial separation of these groups had been based on reversals to the ancestral genital condition.

Hemipteroid insects (Paraneoptera), with over 10% of all known insect diversity, are a major component of terrestrial and aquatic ecosystems. Previous phylogenetic analyses have not consistently resolved the relationships among major hemipteroid lineages. We provide maximum likelihood-based phylogenomic analyses of a taxonomically comprehensive dataset comprising sequences of 2,395 single-copy, protein-coding genes for 193 samples of hemipteroid insects and outgroups. These analyses yield a well-supported phylogeny for hemipteroid insects. Monophyly of each of the three hemipteroid orders (Psocodea, Thysanoptera, and Hemiptera) is strongly supported, as are most relationships among suborders and families. Thysanoptera (thrips) is strongly supported as sister to Hemiptera. However, as in a recent large-scale analysis sampling all insect orders, trees from our data matrices support Psocodea (bark lice and parasitic lice) as the sister group to the holometabolous insects (those with complete metamorphosis). In contrast, four-cluster likelihood mapping of these data does not support this result. A molecular dating analysis using 23 fossil calibration points suggests hemipteroid insects began diversifying before the Carboniferous, over 365 million years ago. We also explore implications for understanding the timing of diversification, the evolution of morphological traits, and the evolution of mitochondrial genome organization. These results provide a phylogenetic framework for future studies of the group.

Although the great genital diversity of the barklouse genus Trichadenotecnum has been described in previous studies, the specific function of the genital structures during the copulation process has received less investigative attention. We reconstructed 3D-models of each structure of the male and female genitalia of Trichadenotecnum incognitum in copula and those of uncopulated male and female of Trichadenotecnum pseudomedium. By comparing the changes in male and female genital structures and related muscles in copulated and uncopulated states, the function of each genital structure can be described. During the copulation, we found that the female subgenital plate was hooked into the male body by the distal process on the male paraproct and was fixed by the male epiproct, hypandrium and phallosome. In addition, sexual coevolution was suggested by tightly contacting structures, that is, thorny male hypandrium and thickened membrane around the female spermapore plate. These results not only give us a new understanding copulation process of Trichadenotecnum, but also explain the reasons why genital structures are so divers in the genus.

The cave-dwelling psocid tribe Sensitibillini ( Afrotrogla , Neotrogla and Sensitibilla ) is of special morphological and evolutionary interest because of its possession of reversed copulatory organs: i.e. females of Afrotrogla and Neotrogla have a penis-like organ. The female penis structure is highly variable among taxa, as is the case of the male penis in animals with normal copulatory organs. Here, we present the first molecular phylogeny of Sensitibillini and analyse the evolutionary pattern of their genitalia. Afrotrogla and Neotrogla did not form a monophyletic clade, and their female penis structures are significantly different, suggesting two independent origins of the female penis within Sensitibillini. In Neotrogla , the species that has a simple female penis is embedded among species that have an elaborate penis, and detailed structures of the female penis elaborations are in exact agreement among species, suggesting a secondary simplification of the female penis. A correlated evolutionary pattern between male and female genitalia was also detected. This coevolution of genitalia may suggest that sexual conflict or cryptic ‘male’ choice drove the diversity of the female penis, as is the case of male penile diversity in animals with conventional genitalia.

We report a functional switching valve within the female genitalia of the Brazilian cave insect Neotrogla. The valve complex is composed of two plate-like sclerites, a closure element, and in-and-outflow canals. Females have a penis-like intromittent organ to coercively anchor males and obtain voluminous semen. The semen is packed in a capsule, whose formation is initiated by seminal injection. It is not only used for fertilization but also consumed by the female as nutrition. The valve complex has two slots for insemination so that Neotrogla can continue mating while the first slot is occupied. In conjunction with the female penis, this switching valve is a morphological novelty enabling females to compete for seminal gifts in their nutrient-poor cave habitats through long copulation times and multiple seminal injections. The evolution of this switching valve may have been a prerequisite for the reversal of the intromittent organ in Neotrogla., eLife digest In dry caves of southeastern Brazil, live a group of insects named Neotrogla that are perhaps best known because the egg-producing females have penises while the sperm-producing males have vaginas. The sex roles of these Brazilian cave insects are also reversed: females compete over the males, who in turn are selective of their female partners. This sex role reversal likely evolved within Neotrogla because the males’ semen represents a rich and reliable source of energy within a nutrient-poor cave environment. When females are not using semen to fertilize their eggs, they consume it. Yet, while other animals show sex role reversal, Neotrogla species alone have reversed sexual organs. Neotrogla penises are spiky and may have evolved so that females can anchor themselves to males and then mate for prolonged periods. This would allow the females to stock up on the nutritious semen. Compared to their closest relatives, Neotrogla species can hold twice as much semen within their sperm storage organs. Scientists have speculated that a valve-like structure within this organ enables this extra storage by allowing the female to redirect semen into two separate chambers. But the organ’s small size has made it difficult to determine its inner workings, and scientists have yet to discover a switching valve that serves such a purpose within the animal kingdom. Yoshizawa et al. examined three Neotrogla species using advanced imaging technology and detected the first example of a biological switching valve. Neotrogla females can control this valve, switching the flow of semen between two slots. In this way, females can store two batches of semen at once. Seemingly exploiting this adaptation, the females’ spiky penises help them restrain males until they have received multiple semen injections. Yoshizawa et al. therefore suggest the emergence of this valve within the sperm storage organ may have promoted the evolution of the female penis. Along with giving insight into the lives of cave insects, these findings are of interest to engineers, who face challenges when constructing valves on a microscopic scale. The unique switching valve of female Neotrogla may one day inspire new man-made machinery that could advance a range of industries.

The elytral base sclerites (= sclerites located at the articular region between the forewing and thorax in Coleoptera) of selected taxa were examined and homologized. Although the elytral base sclerites are highly modified compared to the wing base sclerites of the other neopterans, they can be homologized by using the conservative wing flapping and folding lines as landmarks. A reduction of the first axillary sclerite was identified as a general trend of the elytral base sclerites, although the sclerite usually has a very important function to mediate flight power from the notum to the wing. This result indicates that the functional constraint against the basal sclerites is relaxed because of the lack of an ability to produce flight power by elytra. In contrast, the elytral folding system formed by the basal sclerites is well retained, which probably occurs because proper wing folding is a key for the shelter function of the elytra. The elytral base sclerites apparently contain more homoplasies than the serially homologous hindwing base sclerites of Coleoptera, which suggests that the structure is less useful for higher-level systematics. However, the faster evolutionary rate of the elytral base sclerites suggests there is potential for studying the lower-level phylogeny of Coleoptera.

A new method of fully nonlinear waveform fitting to measure interstation phase speeds and amplitude ratios is developed and applied to USArray. The Neighbourhood Algorithm is used as a global optimizer, which efficiently searches for model parameters that fit two observed waveforms on a common great-circle path by modulating the phase and amplitude terms of the fundamental-mode surface waves. We introduce the reliability parameter that represents how well the waveforms at two stations can be fitted in a time-frequency domain, which is used as a data selection criterion. The method is applied to observed waveforms of USArray for seismic events in the period from 2007 to 2010 with moment magnitude greater than 6.0. We collect a large number of phase speed data (about 75 000 for Rayleigh and 20 000 for Love) and amplitude ratio data (about 15 000 for Rayleigh waves) in a period range from 30 to 130 s. The majority of the interstation distances of measured dispersion data is less than 1000 km, which is much shorter than the typical average path-length of the conventional single-station measurements for source-receiver pairs. The phase speed models for Rayleigh and Love waves show good correlations on large scales with the recent tomographic maps derived from different approaches for phase speed mapping; for example, significant slow anomalies in volcanic regions in the western Unites States and fast anomalies in the cratonic region. Local-scale phase speed anomalies corresponding to the major tectonic features in the western United States, such as Snake River Plains, Basin and Range, Colorado Plateau and Rio Grande Rift have also been identified clearly in the phase speed models. The short-path information derived from our interstation measurements helps to increase the achievable horizontal resolution. We have also performed joint inversions for phase speed maps using the measured phase and amplitude ratio data of vertical component Rayleigh waves. These maps exhibit better recovery of phase speed perturbations, particularly where the strong lateral velocity gradient exists in which the effects of elastic focussing can be significant; that is, the Yellowstone hotspot, Snake River Plains, and Rio Grande Rift. The enhanced resolution of the phase speed models derived from the interstation phase and amplitude measurements will be of use for the better seismological constraint on the lithospheric structure, in combination with dense broad-band seismic arrays.

A new 3-D S wave speed model for the Australian region derived from multimode surface waves allows us to examine the nature of the lithosphere-asthenosphere transition (LAT) and its relation to radial anisotropy. In eastern Phanerozoic Australia the estimated depths of the LAT tie well with those from receiver functions. However, in the Archean and Proterozoic lithosphere in western and central Australia, the LAT derived from the surface wave model is generally much deeper than the discontinuities recognized from receiver functions and shows a smooth transition. There is significant radial anisotropy (SH>SV) in the upper lithosphere as well as in the LAT and the underlying asthenosphere. Strong anisotropy in the asthenosphere reflects the effects of present shear flow in the mantle beneath the continent. The lateral variation of lithospheric anisotropy correlates well with the suture zones between cratonic blocks, representing frozen anisotropy associated with the ancient tectonics of Australia.

The genus Cryptopsocus Li, 2002 is synonymized with Trichadenotecnum Enderlein, 1909. The type species of Cryptopsocus, T. cynostigmus (Li, 2002) n. comb., is considered to be a close relative of T. marginatum New & Thornton, 1976. These species cannot be assigned to any species group previously established in Trichadenotecnum so that the marginatum species group is here proposed for them. Three new species belonging to this species group are described: T. tigrinum and T. sharkeyi from Thailand and T. sabahense from Sabah, Malaysia. The phylogenetic position of the marginatum group is discussed using morphological data.

Zoraptera are a cryptic and enigmatic group of insects. The species diversity is lower than in almost all other groups of Hexapoda, but may be distinctly higher than presently known. Several new species were described from different regions recently. The systematic placement was discussed controversially since the group was discovered 100 years ago. Affinities with Isoptera and Psocoptera were discussed in earlier studies. A sister group relationship with Acercaria (Psocodea, Thysanoptera, Hemiptera) was proposed by W. Hennig, for the first time based on a strictly phylogenetic argumentation. More recent studies consistently suggest a placement among the “lower neopteran orders” (Polyneoptera). Close affinities to Dictyoptera were proposed and alternatively a sister group relationship with Embioptera or with Embioptera + Phasmatodea (Eukinolabia), respectively. The precise placement is still controversial and the intraordinal relationships are largely unclear. Recent transcriptome analyses tentatively suggest a clade Zoraptera + Dermaptera as sister group of all other polyneopteran orders. The oldest fossils are from Cretaceous amber. An extinct genus from this era may be the sister group of all the remaining zorapterans. The knowledge of the morphology, development and features related to the reproductive system greatly increased in recent years. The general body morphology is very uniform, whereas the genitalia differ strongly between species. This is likely due to different kinds of selection, i.e. sexual selection in the case of the genital organs. The mating pattern also differs profoundly within the order. A unique external sperm transfer occurs in Zorotypus impolitus. A species-level phylogeny and more investigations of the reproductive system should have high priority.

SummarySex-specific elaborations are common in animals and have attracted the attention of many biologists, including Darwin [1]. It is accepted that sexual selection promotes the evolution of sex-specific elaborations. Due to the faster replenishment rate of gametes, males generally have higher potential reproductive and optimal mating rates than females. Therefore, sexual selection acts strongly on males [2], leading to the rapid evolution and diversification of male genitalia [3]. Male genitalia are sometimes used as devices for coercive holding of females as a result of sexual conflict over mating [4, 5]. In contrast, female genitalia are usually simple. Here we report the reversal of intromittent organs in the insect genus Neotrogla (Psocodea: Prionoglarididae) from Brazilian caves. Females have a highly elaborate, penis-like structure, the gynosome, while males lack an intromittent organ. The gynosome has species-specific elaborations, such as numerous spines that fit species-specific pouches in the simple male genital chamber. During prolonged copulation (∼40–70 hr), a large and potentially nutritious ejaculate is transferred from the male via the gynosome. The correlated genital evolution in Neotrogla is probably driven by reversed sexual selection with females competing for seminal gifts. Nothing similar is known among sex-role reversed animals.

Very unusual genitalia of the species Zorotypus caudelli are described. It contains the unique configuration of two different intromittent organs, one of them strongly elongated. Hyper elongated genitalia are known in different groups of insects. Males have to accommodate these unwieldy structures in the limited spaces of the abdomen and manipulate them acutely during copulation. A crucial question is how do species with elongated genitalia cope with these requirements? To investigate this, we studied key features enabling storage, insertion, and withdrawal of the elongated genitalia. The co-existence of an elongated narrow tube and a bulky spermatophore is a highly unusual and apparently paradoxical condition. However, we demonstrate that the tube is not involved in sperm transmission, whereas the large spermatophore is transferred to females by a membranous fold of the genitalia. The movement of the spermatophore is caused by haemolymph pressure, which likely also promotes the insertion of both intromittent organs. A comparison with the genital anatomy and reproductive mode in related groups suggests that the elongated tube and its accommodating pouch is a de novo structure, and that the ancestral sperm transport via spermatophore is a preadaptive condition for the acquisition of this unusual structure

The phylogenetic relationships of bark lice and parasitic lice (Insecta: Psocodea) have been studied in a number of recent molecular phylogenetic analyses based on DNA sequences. Many of these studies have focused on the position of parasitic lice within the free-living bark lice. However, fewer such studies have examined the relationships among major groups of free-living bark lice and their implications for classification. In this study we focus on the infraorder Caeciliusetae, a large group of bark lice (˜1000 species) within the suborder Psocomorpha. Using sequences of two mitochondrial and two nuclear genes, we estimated the phylogeny for relationships among the five recognized families within the infraorder Caeciliusetae. Based on the results, the sister-group relationship and respective monophyly of Stenopsocidae and Dasydemellidae is strongly supported. Monophyly of the larger families Amphipsocidae and Caeciliusidae was not supported, although the causes of this were the placement of two distinct subfamilies (Paracaeciliinae and Calocaeciliinae). The monophyly of Asiopsocidae could not be tested because it was sampled only by one species. Based on these results and consideration of morphological characters, we propose a new classification for Caeciliusetae, recognizing six families: Amphipsocidae, Stenopsocidae, Dasydemellidae, Asiopsocidae, Paracaeciliidae and Caeciliusidae. We expect that this new classification will stabilize the higher-level taxonomy of this group and help to identify groups in need of further work among these insects.

The evolution of a female penis is an extremely rare event and is only known to have occurred in a tribe of small cave insects, Sensitibillini (Psocodea: Trogiomorpha: Prionoglarididae). The female penis, which is protrudable and inserted into the male vagina-like cavity during copulation to receive semen, is thought to have evolved independently twice in this tribe, in the Brazilian Neotrogla and the African Afrotrogla. These findings strongly suggest that there are some factors unique to Sensitibillini that have facilitated female penis evolution. Here, several hypothetical factors are presented that may have enabled the evolution of the female penis in Sensitibillini. The female-female competition for nutritious semen, the oligotrophic environment, and the twin insemination slots with switching valve are considered to be the driving factors for female penis evolution. Additionally, the following factors are considered responsible for relaxing the constraint against female penis evolution: preexistence of the female-above mating position, the elongated duct connecting the female pre-penis with the sperm storage organ, and the small male genital cavity accepting the female genital tubercle bearing the opening of this duct. Understanding the factors enabling female penis evolution may also shed light on the evolution of the male penis.

While it is well known that changes in the general processes of molecular evolution have occurred on a variety of timescales, the mechanisms underlying these changes are less well understood. Parasitic lice ("Phthiraptera") and their close relatives (infraorder Nanopsocetae of the insect order Psocodea) are a group of insects well known for their unusual features of molecular evolution. We examined changes in base composition across parasitic lice and bark lice. We identified substantial differences in percent GC content between the clade comprising parasitic lice plus closely related bark lice (=Nanopsocetae) versus all other bark lice. These changes occurred for both nuclear and mitochondrial protein coding and ribosomal RNA genes, often in the same direction. To evaluate whether correlations in base composition change also occurred within lineages, we used phylogenetically controlled comparisons, and in this case few significant correlations were identified. Examining more constrained sites (first/second codon positions and rRNA) revealed that, in comparison to the other bark lice, the GC content of parasitic lice and close relatives tended towards 50 % either up from less than 50 % GC or down from greater than 50 % GC. In contrast, less constrained sites (third codon positions) in both nuclear and mitochondrial genes showed less of a consistent change of base composition in parasitic lice and very close relatives. We conclude that relaxed selection on this group of insects is a potential explanation of the change in base composition for both mitochondrial and nuclear genes, which could lead to nucleotide frequencies closer to random expectation (i.e., 50 % GC) in the absence of any mutation bias. Evidence suggests this relaxed selection arose once in the non-parasitic common ancestor of Phthiraptera + Nanopsocetae and is not directly related to the evolution of the parasitism in lice.

Extreme elongation of a part of the intromittent organ, the flagellum, has occurred several times in Criocerinae (Chrysomelidae). These leaf beetles have acquired a specialized pocket to store the flagellum in the abdominal cavity, at the same time allowing a quick control of movements of this structure during copulation. We investigated the morphogenesis of the intromittent organs of species with and without a flagellum to discuss the evolutionary background of parallel evolution of novel structures. We found that the specialized pocket is formed by the invagination of an epidermal layer and a resultant rotation of the primary gonopore. Invagination itself is a well-known phenomenon in morphogenetic processes, which leads us to hypothesize that the novelty is formed by co-opting a previously acquired genetic system. A large open-space is present within the intromittent organ during the entire morphogenesis in species without a flagellum, and the invagination in the species with a flagellum grows in the corresponding area. This means that there are no physical impediments for the growth of a large pocket. In addition the sites of muscular attachments in the species with a flagellum are also different from those without it. The differentiation of muscles is completed immediately before adult emergence, which means the muscles are adjustable during the entire morphogenesis in this group. Simple modifications probably based on a co-option of previously acquired genetic systems, the potential space for adding a new element, and an adjustable factor in morphogenesis of the intromittent organ facilitate the parallel evolution of the extreme elongation.

The seismicity of the Pacific coast of Tohoku, Japan, has been investigated in detail and characterized into regional seismic segments. The 2011 megathrust earthquake of Mw 9.0 on 11 March ruptured almost all of the segments in that area, causing devastating tsunamis. The prime factor that had not been recognized before is the double segmentation along the Japan trench: The apparent absence of earthquakes in the trench-ward segments as opposed to the Japan Island-ward segments that have repeated smaller earthquakes. We term this pattern of seismic activity ‘along-dip double segmentation (ADDS)’. The 2011 Tohoku megathrust earthquake is typical of a class of great earthquakes different from that of the 1960 Chile earthquake, in which a young and buoyant plate is subducting rapidly under the continental plate. In the 1960 Chile case, the seismic activity is characterized by ‘along-strike single segmentation (ASSS)’, where there is weak seismic activity before the main event all over the plate interface of the subduction zone. We study the greatest earthquakes around the world and find that there is a variety of megathrust earthquakes characterized by ASSS to ADDS, where the 2004 Sumatra-Andaman, the 1960 Chile, the 1964 Alaska and the 2011 Tohoku-oki earthquakes are typical end-members.

The mantle component of the Australian Seismological Reference Model (AuSREM) has been constructed from Australian-specific sources, primarily exploiting the wealth of seismic sources at regional distances around Australia recorded at portable and permanent stations on the continent. AuSREM is designed to bring together the existing information on Australia, from both body wave and surface wave studies and provide a synthesis in the form of a 3-D model that can provide the basis for future refinement. The model is grid based with a 0.5° sampling in latitude and longitude, and is designed to be fully interpolable, so that properties can be extracted at any point. For the upper mantle the primary source of information comes from seismic surface wave tomography, supplemented by analysis of body wave arrivals and regional tomography which provide useful constraints on the relation between P- and S-wave speeds in the mantle lithosphere. A representative model has been developed to capture the features of mantle structure drawing on a range of studies. The mantle structure is represented by grid values at 25 km intervals in depth from 75 to 300 km. Shallower structure is linked to the AuSREM crust through the recent Moho depth model of Kennett et al., which exploits all available sources of seismological information. Below 300 km depth and in the surrounding area AuSREM is linked to the S40RTS model of Ritsema et al.

Acoustic waves from volcanic eruptions are often observed as infrasound in near fields. Part of them propagate upward and disturb the ionosphere, and can be observed with Total Electron Content (TEC) data from Global Navigation Satellite System (GNSS) receivers. Here we report TEC variations after the 13 February 2014 Plinian eruption of the Kelud volcano, East Java, Indonesia, observed with regional GNSS networks. Significant disturbances in TEC were detected with six GNSS satellites, and wavelet analysis showed that harmonic oscillations started at ∼16:25 UT and continued for ∼2.5 h. The amplitude spectrum of the TEC time series showed peaks at 3.7 mHz, 4.8 mHz and 6.8 mHz. Long-wavelength standing waves with a wide range of wavelength trapped in the lower atmosphere are excited by the Plinian eruption. Amplitude spectra of the ground motion recorded by seismometers, however, had frequency components at discrete wave-periods. The condition for the resonant oscillations between the atmosphere and the solid Earth is satisfied only at these discrete wave-period and horizontal wavelength pairs, therefore efficient energy transfer from the atmospheric standing waves to the solid Earth Rayleigh waves occurred at discrete periods and resulted in the harmonic ground motion.