Wing Reduction Research Articles

Plio‐Pleistocene decline of mesic forest underpins diversification in a clade of Australian Panesthia cockroaches

AbstractThe progressive aridification of the Australian continent, and coincident decline of mesic forest, has been a powerful driver of allopatric and environmental speciation in native species. The relictual mesic forests of the eastern seaboard now harbour a diverse group of endemic fauna, including the wood‐feeding cockroaches of the genus Panesthia, which reached the continent via two separate invasions from Melanesia. The more recent of these colonization events gave rise to a group of five recognized species, occurring in mainland woodlands, sclerophylls and rainforests, as well as the forests and grasslands of the Lord Howe Island Group. Due to limited sampling in molecular studies and doubt regarding the standing taxonomy, there is little certainty about relationships among the species and poor understanding of the effects of ancient climatic change upon their evolution. We undertook a comprehensive phylogenetic analysis of the clade, using complete mitogenomes and nuclear ribosomal markers from nearly all known morphospecies and populations. Our time‐calibrated phylogenetic analyses reveal an additional six unrecognized, highly divergent lineages and suggest that these have arisen primarily through vicariance as rainforests fragmented during Plio‐Pleistocene glacial cycles (2–5 million years ago). Ancestral niche estimations also evidence a tropical rainforest origin for the group, followed by at least three niche transitions into drier forest, including one associated with the singular colonization of the Lord Howe Island Group. Finally, we find evidence of frequent, parallel wing reduction, in potential association with the contraction of forest habitats into small refugia. Our results reiterate the far‐reaching role of ancient aridification in driving speciation, niche expansion and morphological evolution in Australian fauna.

Immobilization secondary to cell death of muscle precursors with a dual transcriptional signature contributes to the emu wing skeletal pattern

Limb reduction has occurred multiple times in tetrapod history. Among ratites, wing reductions range from mild vestigialization to complete loss, with emus (Dromaius novaehollandiae) serving as a model for studying the genetic mechanisms behind limb reduction. Here, we explore the developmental mechanisms underlying wing reduction in emu. Our analyses reveal that immobilization resulting from the absence of distal muscles contributes to skeletal shortening, fusion and left-right intraindividual variation. Expression analysis and single cell-RNA sequencing identify muscle progenitors displaying a dual lateral plate mesodermal and myogenic signature. These cells aggregate at the proximal region of wing buds and undergo cell death. We propose that this cell death, linked to the lack of distal muscle masses, underlines the morphological features and variability in skeletal elements due to reduced mechanical loading. Our results demonstrate that differential mobility during embryonic development may drive morphological diversification in vestigial structures.

Numerical study on noise reduction of ground-effect wing with serrated trailing edge

This study proposes a passive bionic noise reduction strategy using serrated trailing edge (TE) designs to be applied to the aero-train's ground-effect wing. The aim is to mitigate TE noise by suppressing the tail vortex under high-speed and near-wall conditions. Three different serrated TE designs were numerically investigated via large eddy simulation, combined with Möhring acoustic analogy theory under Ma = 0.3 to reveal their noise reduction effects. The noise reduction mechanism was analyzed from the perspective of the flow characteristics in the TE boundary layer. The results indicate that all serrated TE designs achieve noise reduction, with the TE2 exhibiting superior performance. This outcome is linked to the ability of serrated TE designs to moderate boundary layer airflow separation and backpressure gradients, facilitating smoother transitions and lessening wake vortex intensity, thereby reducing turbulence-induced noise. Designs featuring wider serration gaps and sharper edges further enhance noise attenuation.

High-dimensional aerodynamic shape optimization framework using geometric domain decomposition and data-driven support strategy for wing design

Traditional aerodynamic shape optimization methods usually suffer from difficulties in optimization and modeling for high-dimensional aerodynamic optimization problems. To overcome these difficulties, a new high-dimensional aerodynamic shape optimization framework is proposed from the perspectives of geometric domain decomposition for dimensionality reduction and a data-driven model support strategy for changing the role of surrogate model and assisting the optimizer. Geometric domain decomposition uses proper orthogonal decomposition to transform the high-dimensional Class-Shape Function Transformation method into low-dimensional geometric modes to reduce design dimensions for parameterizing the geometric shape, which reduces optimization and modeling difficulties. Also, a data-driven support strategy is proposed to improve the effectiveness and efficiency of the optimizer by learning from historical aerodynamic data; this strategy modifies the role of surrogate model in the optimization framework to assist the optimizer; the surrogate model, serving as an auxiliary role, can reduce the dependence on model accuracy, which overcomes the difficulty of high-dimensional modeling to some extent. We applied the developed framework to transonic drag reduction of wings to validate its performance. The optimization results show that the developed framework converges faster and offers better designs compared to direct optimization and state-of-the-art surrogate-based optimization frameworks for high-dimensional aerodynamic shape optimization.

Rapid sexual signal diversification is facilitated by permissive females

The initial process by which novel sexual signals evolve remains unclear, because rare new variants are susceptible to loss by drift or counterselection imposed by prevailing female preferences.1,2,3,4 We describe the diversification of an acoustic male courtship signal in Hawaiian populations of the field cricket Teleogryllus oceanicus, which was brought about by the evolution of a brachypterous wing morph ("small-wing") only 6 years ago.5 Small-wing has a genetic basis and causes silence or reduced-amplitude signaling by miniaturizing male forewings, conferring protection against an eavesdropping parasitoid, Ormia ochracea.5 We found that wing reduction notably increases the fundamental frequency of courtship song from an average of 5.1 kHz to 6.4 kHz. It also de-canalizes male song, broadening the range of peak signal frequencies well outside normal song character space. As courtship song prompts female mounting and is sexually selected,6,7,8,9 we evaluated two scenarios to test the fate of these new signal values. Females might show reduced acceptance of small-wing males, imposing counterselection via prevailing preferences. Alternatively, females might accept small-wing males as readily as long-wing males if their window of preference is sufficiently wide. Our results support the latter. Females preferred males who produced some signal over none, but they mounted sound-producing small-wing males as often as sound-producing long-wing males. Indiscriminate mating can facilitate the persistence of rare, novel signal values. If female permissiveness is a general characteristic of the earliest stages of sexual signal evolution, then taxa with low female mate acceptance thresholds should be more prone to diversification via sexual selection.

Morphology of the wings and attachment apparatus in the evolution of the family Hippoboscidae (Diptera).

Using a complex analysis of the molecular genetics, morphological, and ecological characteristics of Hippoboscidae flies, the phylogenetic structure and trends in the evolution of morphological characters that contribute to the ectoparasitic lifestyle of hippoboscid flies of the north of Eurasia were studied for the first time. The research was carried out on 26 Palearctic species from 10 genera. The analysis of molecular phylogeny revealed the levels of clustering of the family with the species predominantly parasitizing mammals or birds, the time of cluster formation, and the divergence of species in the Palearctic conditions. An independent adaptation to birds occurred in the genera Icosta, Pseudolynchia, Ornithoica, and others. Bird parasites are characterized by bifid tarsal claws, long hooks on pulvilli, and long empodium setae (except genus Ornithoica). Mammalian parasites are characterized by simple tarsal claws, short lobes of hooks on pulvilli, and zones on empodium with short setae. Specialization in empodium and pulvillus morphotypes and wing reduction are higher diverged in mammalian parasites than in bird parasites. The decrease of flight ability and wing reduction independently arose in different subfamilies of Hippoboscidae flies. Our results assume that the tribe Ornithomyini is a paraphyletic group, since, according to the complex of morphological features, the genus Ornithoica can be considered a separate lineage of evolution.

Numerical Study on Aerodynamic and Aeroacoustic Performances of Bioinspired Wings

Noise control has become one of the key issues to be considered in modern aeronautical machinery design. Many efforts have been devoted to noise reduction of airfoils and wings, including traditional flow control methods. In fact, some animals in wild nature exhibit superior aerodynamic and aeroacoustic performance, providing novel ideas for solving this engineering problem. In this research, bionic technology is used to obtain quiet and efficient wing. Inspired by the owl’s wing, we propose two bionic configurations, one coupled with leading edge waves and trailing edge serrations. The Large Eddy Simulation and the Ffowcs-Williams and Hawkings equation is applied to simulate the aerodynamic and aeroacoustic characteristics of wings at low-Reynolds number flow. Numerical results demonstrate that the bioinspired wings have excellent aerodynamic performances and remarkable lower overall sound pressure level compared to NACA 0016 which has similar relative thickness. In addition, the unsmooth structure of leading edge waves and trailing edge serrations provide an additional 4.27 dB noise suppression effect, with little impact on aerodynamic characteristics at small angle of attack. The detailed analysis reveals that, due to the special owl-based profile, the flow around two bioinspired wings is mainly turbulent on the upper and lower surfaces, and no laminar separation bubble is detected at the trailing edge. Moreover, the unsmooth structure modifications successfully weaken the scale and scope of coherent vortex structures. These factors contribute to reducing the associated pressure fluctuation, thereby controlling the aeroacoustic noise of wing. Consequently, a coupled bionic wing is presented with the excellent aerodynamic and aeroacoustic characteristics. The conclusions are envisioned to be beneficial to the design of new generation low-noise aeronautical machinery.

Independent wing reductions and losses among stick and leaf insects (Phasmatodea), supported by new Cretaceous fossils in amber

BackgroundPhasmatodea (stick and leaf insects) play a central role on the debate regarding wing reduction and loss, and its wings are putative reacquisition from secondarily wingless ancestors based solely on extant species. A pivotal taxon in this respect is the species-poor Timematodea, consisting of approximately 21 wingless extant species, which form the sister group of all remaining winged or wingless stick and leaf insects, the Euphasmatodea.ResultsHerein, the new fossils of Timematodea from mid-Cretaceous Kachin amber are reported, with winged and wingless species co-occurring. The palaeogeographic distributions of all fossils of Holophasmatodea are summarized, showing their wide paleo-distributions. The phylogenetic analysis based on morphological characters confirms the earliest-diverging lineage of winged Breviala cretacea gen. et sp. nov. in Timematodea, and the possible relationships among all families of Holophasmatodea. These are critical for the reconstruction of patterns of wing evolution in early Phasmatodea.ConclusionsThe new fossils suggest that Timematodea once had wings, at least during the mid-Cretaceous. The palaeogeographic occurrences imply that Timematodea probably have been widely distributed since at least the Jurassic. The phylogenetic analysis with the ancestral-state reconstruction of wings indicates that the common ancestors of Holophasmatodea were winged, the reductions and losses of wings among Timematodea and Euphasmatodea have occurred independently since at least the Cretaceous, and the reduction or loss of the forewing earlier than the hind wings.

Adaptive shifts in Neotropical planthoppers: new troglobitic species and the first surface species of Ferricixius Hoch & Ferreira, 2012 (Hemiptera: Fulgoromorpha: Cixiidae) from Brazilian caves.

Here we describe three cixiid species new to science which we assign to the hitherto monotypic genus Ferricixius Hoch & Ferreira, 2012 from Brazil. Ferricixius michaeli sp. nov. and F. goliathi sp. nov. of the new species arelike the type species Ferricixius davidi Hoch &Ferreira, 2012obligately cavernicolous and display varying degrees of troglomorphy, such as the reduction of compound eyes, wings, and bodily pigmentation, while F. urieli sp. nov. displays well developed compound eyes and wings, andalthough so far only found inside cavesis ecologically classified as either epigean, or subtroglophile. We provide a modified diagnosis for the genus and an identification key to the species of Ferricixius, as well as information on the distribution, ecology, and habitat of the three new species herein described. Evolutionary implications are discussed, and adaptive shifts from epigean to subterranean habitat are presumed to be the most likely scenario underlying the evolution of cave dwelling Ferricixius.

Cell death and wing reduction during the metamorphosis of sex-specific flightless morphs in winter geometrid moths.

Winter geometrid moths show striking sexual dimorphism by having female-specific flightless morphs. The evolutionary grades of wing reduction in winter geometrid moths vary and range from having short wings, vestigial wings, to being wingless. Although the ontogenetic processes underlying the development of the wingless or short-wing morphs in Lepidoptera has been well studied, the mechanisms underlying the development of vestigial wing morphs in winter geometrid moths during metamorphosis are poorly understood. In the winter geometrid moth Sebastosema bubonaria Warren, 1896, the males have functional wings, but the females have vestigial wings. Here, we studied the ontogenetic processes affecting wing reduction in the winter geometrid moth S. bubonaria using light microscopy and transmission electron microscopy, and compared the ontogenetic process of wing reduction in this species with that in another species of the wingless-female winter moth that we investigated previously. Our results showed that, in the vestigial-wing morphs, the loss of pupal wing epithelium was terminated in the middle of the wing degeneration process, whereas in the wingless morph, the pupal wing epithelium disappeared almost completely and the final appearance of the wings differed slightly among flightless morphs. We propose that the extent and location of cell death in the pupal wing play an important role in the various patterns of reduced wings that are observed in flightless moths.

An extraordinary case of elytra loss in Coleoptera (Elateroidea: Lycidae): discovery and placement of the first anelytrous adult male beetle

AbstractInsects are one of the few groups of animals that developed the ability of active flight. Such mobility allowed the group to successfully explore and thrive in nearly all kinds of ecological niches. At the same time, during the evolutionary history of insects, due to high costs of wing development, flight was lost independently in many groups. In beetles, the reduction or complete loss of hind wings has been reported in multiple lineages, especially in several extreme paedomorphic and larviform females, mainly in Elateroidea, in which not only the hind wings but also the elytra are lost. However, the complete absence of elytra in adult males was hitherto unknown, despite nearly half a million described species in Coleoptera. In this study, we report the discovery of Xenomorphon baranowskii gen. et sp. nov., the first completely anelytrous and wingless adult male beetle, belonging to the family Lycidae (Coleoptera: Elateroidea). Xenomorphon baranowskii is illustrated, described, and provisionally placed in Calopterini, based on our morphology-based phylogenetic analyses. We discuss the possible scenarios that could lead to such a rare event, when a beetle loses its elytra, and its evolutionary consequences.

Pullimosina (Pullimosina) turfosa sp. nov. and other Sphaeroceridae (Diptera) from peat bogs in the North Caucasus (Russia).

The first data about Sphaeroceridae occurring on eight montane and foothill peat bogs of various types in the North Caucasus (Russia) are presented. A total of 38 species has been recorded and their affinity to peat-bog habitats is discussed. A single species is classified as a tyrphobiont, viz. the strongly brachypterous Pullimosina (Pullimosina) turfosasp. nov. being strictly associated with Sphagnum hummocks in peat bogs. This new species is described and illustrated in detail and its relationships, biology, and wing reduction are discussed. Only three species are considered tyrphophilous or probably tyrphophilous, viz. Ischioleptanitida (Duda, 1920), Phthitia (Kimosina) longisetosa (Dahl, 1909), and Spelobiaibrida Roháček, 1983. The majority of recorded species do not have close affinity to peat bogs and are treated as tyrphoneutral, and Rachispodahostica (Villeneuve, 1917) is probably tyrphoxenous due to occasional occurrence in a peat bog. Species composition of Sphaeroceridae on Caucasian peat bogs is discussed in comparison to those known from peat bogs in other parts of Europe. Taxonomic notes are given on Minilimosina (Svarciella) species of the M.vitripennis group. Six species (including P.turfosa sp. nov.) are new additions to the fauna of Russia.

Repeated Alpine Flight Loss Within the Widespread New Zealand StoneflyNesoperla fulvescensHare (Plecoptera: Gripopterygidae)

AbstractFlight loss is a common feature of upland insect assemblages, with recent studies detecting parallel wing reduction events across independent alpine lineages. However, the geographic scale over which such repeated evolution can operate remains unclear. In this study, we use genotyping-by-sequencing to assess the genomic relationships among vestigial-winged and full-winged populations of the widespread New Zealand stonefly Nesoperla fulvescens, to test for repeated wing loss events over small spatial scales. Biogeographic analyses indicate that alpine wing loss in this widespread species is restricted to a single, narrow mountain range. Intriguingly, our coalescent analyses indicate that upland vestigial-winged N. fulvescens populations are not sister to one another, suggesting wings have been lost independently in disjunct populations of this species, over a <30 km scale. Our results suggest that selection against flight above the alpine treeline can drive rapid and repeated adaptation even across narrow spatial scales. We propose that such repetitive processes may represent a far more pervasive feature of alpine insect adaptation than is currently recognized.

Postembryonic development of the tracheal system of beetles in the context of aptery and adaptations towards an arid environment.

The tracheal system comprises one of the major adaptations of insects towards a terrestrial lifestyle. Many aspects such as the modifications towards wing reduction or a life in an arid climate are still poorly understood. To address these issues, we performed the first three-dimensional morphometric analyses of the tracheal system of a wingless insect, the desert beetle Gonopus tibialis and compared it with a flying beetle (Tenebrio molitor). Our results clearly show that the reduction of the flight apparatus has severe consequences for the tracheal system. This includes the reduction of the tracheal density, the relative volume of the trachea, the volume of the respective spiracles and the complete loss of individual tracheae. At the same time, the reduction of wings in the desert beetle allows modifications of the tracheal system that would be impossible in an animal with a functional flight apparatus such as the formation of a subelytral cavity as a part of the tracheal system, the strong elongation of the digestive tract including its tracheal system or the respiration through a single spiracle. Finally, we addressed when these modifications of the tracheal system take place during the development of the studied beetles. We can clearly show that they develop during pupation while the larvae of both species are almost identical in their tracheal system and body shape.

Reduced olfactory acuity in recently flightless insects suggests rapid regressive evolution

BackgroundInsects have exceptionally fast smelling capabilities, and some can track the temporal structure of odour plumes at rates above 100 Hz. It has been hypothesized that this fast smelling capability is an adaptation for flying. We test this hypothesis by comparing the olfactory acuity of sympatric flighted versus flightless lineages within a wing-polymorphic stonefly species.ResultsOur analyses of olfactory receptor neuron responses reveal that recently-evolved flightless lineages have reduced olfactory acuity. By comparing flighted versus flightless ecotypes with similar genetic backgrounds, we eliminate other confounding factors that might have affected the evolution of their olfactory reception mechanisms. Our detection of different patterns of reduced olfactory response strength and speed in independently wing-reduced lineages suggests parallel evolution of reduced olfactory acuity.ConclusionsThese reductions in olfactory acuity echo the rapid reduction of wings themselves, and represent an olfactory parallel to the convergent phenotypic shifts seen under selective gradients in other sensory systems (e.g. parallel loss of vision in cave fauna). Our study provides evidence for the hypothesis that flight poses a selective pressure on the speed and strength of olfactory receptor neuron responses and emphasizes the energetic costs of rapid olfaction.

Three new Opogona species with wing reduction from St Helena Island, South Atlantic Ocean (Lepidoptera: Tineidae: Hieroxestinae)

Three new species of Opogona Zeller, 1853 from St Helena Island with wing reduction are described; Opogona ashmolei Karisch & Fowler, sp. nov., Opogona squamata Karisch & Stevens, sp. nov. and Opogona exiguata Karisch & Dutton, sp. nov. All these species were found in the semi-desert areas in the Eastern Part of the island, where the larva of O. ashmolei Karisch & Fowler, sp. nov. feeds on Suaeda fruticosa.

A CFD study on the structural parameters of NACA 2412 airfoil based air-wing using different composite materials

Weight is one of the important factors in aerodynamics; we need to reduce the weight of any flying object in order to get the higher lift force. Wight reduction of wing helps us to get better air craft efficiency and high performance. Aluminum alloys are used to make aircraft wing as it is suitable but in this study, we have used few light weighted composite materials for making the aircraft wing and other alloys as well where aluminum is used as the base material and it is mixed with other materials with different proportions for testing the performance. In this study, NACA 2412 airfoil has been chosen and the wing has been designed in Design Modeler 19. The model has been imported to ANSYS Workbench; the static structural analysis has been carried out by putting the required parameters. The objective of the study is to find out which material will be suitable for making aircraft wing among Carbon Fibers, Alpha-Beta Titanium alloy and Al-Zn-Mg alloy.

Genomic signatures of parallel alpine adaptation in recently evolved flightless insects

Natural selection along elevational gradients has potential to drive predictable adaptations across distinct lineages, but the extent of such repeated evolution remains poorly studied for many widespread alpine taxa. We present parallel genomic analyses of two recently evolved flightless alpine insect lineages to test for molecular signatures of repeated alpine adaptation. Specifically, we compare low-elevation vs. alpine stonefly ecotypes from parallel stream populations in which flightless upland ecotypes have been independently derived. We map 67,922 polymorphic genetic markers, generated across 176 Zelandoperla fenestrata specimens from two independent alpine stream populations in New Zealand's Rock and Pillar Range, to a newly developed plecopteran reference genome. Genome-wide scans revealed 31 regions with outlier single nucleotide polymorphisms (SNPs) differentiating lowland vs. alpine ecotypes in Lug Creek, and 37 regions with outliers differentiating ecotypes in Six Mile Creek. Of these regions, 13% (8/60) yielded outlier SNPs across both within-stream ecotype comparisons, implying comparable genomic shifts contribute to this repeated alpine adaptation. Candidate genes closely linked to repeated outlier regions include several with documented roles in insect wing-development (e.g., dishevelled), suggesting that they may contribute to repeated alpine wing reduction. Additional candidate genes have been shown to influence insect fecundity (e.g., ovo) and lifespan (e.g., Mrp4), implying that they might contribute to life history differentiation between upland and lowland ecotypes. Additional outlier genes have potential roles in the evolution of reproductive isolation among ecotypes (hedgehog and Desaturase 1). These results demonstrate how replicated outlier tests across independent lineages can potentially contribute to the discovery of genes underpinning repeated adaptation.

Morphometric changes in wings of bess beetles (Coleoptera: Passalidae) related to elevation: a case of study in the Colombian Andes

ABSTRACT Flight is a crucial evolutionary novelty for insect diversification. Despite its importance, some insects lose this ability. Flight loss is related to the reduction in the veins and membrane of hind wings (brachypterism), often related to high elevations. Brachypterism evolved independently in some lineages of beetles, like in the family Passalidae. Due to the double function of the passalid hind wings (dispersion and acoustic communication), the wing reduction process is partial and apparently constrained by the stridulatory apparatus. The tribe Proculini is a good model to study brachypterism due to the number of flightless species and its distribution between low land and high montane ecosystems. We evaluated the relationship between wing reduction and elevation in the elytra and hind wings of 25 Proculini species distributed in Colombia, using linear measurements and geom-25etric morphometry. Specimens were categorized in three elevation ranges: low (0–999 m), middle (1000–1999 m), and high (<2000 m). In conclusion, this study demonstrates that elevation is most likely the factor that has driven size and shape modifications of the Passalidae hind wings and elytra. The present work is the first study that tests the relationship between brachypterism and elevation using Proculini species belonging to different genera.

Two New Platynus Bonelli (Coleoptera: Carabidae: Platynini) from Nevis and St. Kitts, Lesser Antilles

Platynus (Dyscolus) racquelae Liebherr and Ivie, new species is described from the Crater Rim, in the Parish of St. John Capisterre, St. Kitts, and Platynus (Dyscolus) duportei Liebherr and Ivie, new species is described from Nevis Peak, Nevis. These species are placed in the Platynus (Dyscolus) memnonius (Dejean) group, with their addition to the group extending the group's aggregate distribution northward from Basse-Terre, Guadeloupe to St. Kitts. Based on extensive collections of the Coleoptera of St. Kitts, P. racquelae appears to be restricted to only the wettest areas at highest elevations, suggesting that this species requires rather specific conditions present only in the most extreme montane sites. The beetles also exhibit moderate flight wing reduction involving diminution of wing veins associated with wing-folding—specifically, veins associated with the wedge and oblongum cells—and foreshortening of the alar surface due to loss of membrane along the wing's apical margin. This suggests that individuals of P. racquelae are at best weak fliers, and that this species is not able to colonize isolated patches of suitable habitat by flight. Platynus duportei is likewise known from only the highest and wettest point on Nevis Peak, but this species exhibits fully developed flight wings. Additional records of Platynus (Dyscolus) luciae Liebherr from St Lucia, and of Glyptolenus chalybaeus (Dejean) are reported, allowing elucidation of flight wing configuration and male and female genitalia for the former, and new island records of Nevis and Saba for the latter.