Wing Form Research Articles

Revision of Australian Brachysandalus with the description of nine new species including one cavernicolous species (Hemiptera: Heteroptera: Reduviidae), and observations on male extragenital structure and leg teratology

The Australian species of the genus Brachysandalus Stål, 1867 (Hemiptera: Heteroptera: Reduviidae: Peiratinae) are revised. A total of 21 species are recognised, including nine new species: B. ayyammae Malipatil & Liu, sp. nov., B. flavidus Malipatil & Liu, sp. nov., B. fulvipes Malipatil & Liu, sp. nov., B. gunbalanyae Malipatil & Liu, sp. nov., B. howarthi Malipatil & Liu, sp. nov., B. longifemoratus Malipatil & Liu, sp. nov., B. maculatus Malipatil & Liu, sp. nov., B. pallidus Malipatil & Liu, sp. nov. and B. westraliensis Malipatil & Liu, sp. nov. Redescriptions of the genus Brachysandalus and all 12 previously described Australian species of the genus as recognised in this study, are presented. Lectotypes are designated for Brachysandalus helluo Stål, 1867, B. lurco Stål, 1867, B. punctorius Stål, 1867, Pirates (Brachysandalus) alutaceus Reuter, 1881, P. (Brachysandalus) brevicoxis Stål, 1874, P. (Brachysandalus) crassifemur Reuter, 1881, P. (Brachysandalus) flavo-pictus Stål, 1874, P. (Brachysandalus) limbatus Reuter, 1881, P. (Brachysandalus) melanolestoides Stål, 1874, P. (Brachysandalus) setosus Stål, 1874, P. fuliginosus Erichson, 1842, P. fulvipennis Walker, 1873, P. sepulchralis Distant, 1902 and Reduvius (Pirates) ephippiger White, 1843. Pirates fulvipennis Walker, 1873 is removed from synonymy with B. punctorius Stål, 1867, and revalidated with the new combination as B. fulvipennis (Walker, 1873), stat. rev. & comb. nov. Pirates (Brachysandalus) flavopictus Stål, 1874, is removed from synonymy with B. punctorius Stål, 1867, and confirmed as synonym of B. fulvipennis (Walker, 1873). Reduvius semifasciatus Walker, 1873 is removed from synonymy with Brachysandalus fuliginosus (Erichson, 1842), and because the former not considered to be a peiratine species is placed here as “Incertae sedis”. Pirates erythromelas Walker, 1873 is transferred to Brachysandalus as B. erythromelas (Walker, 1873), comb. nov. A key to species is provided together with images of the habitus of type specimens and some other males and females with different wing forms, and major structures of male genitalia to assist distinguishing these species. Based on morphology, brief comments are provided on putative species groups within the studied species. Brachysandalus howarthi Malipatil & Liu, sp. nov. collected from Bayliss Cave, north Queensland, is morphologically and behaviourally adapted to live in caves and is regarded to be an obligate subterranean species, further details and some biological information is provided. Detailed observations of the male extragenital structure that is present on the left side of sternite VII, were made in all species of Brachysandalus considered in the present study. Fourteen of the 21 species studied have been recorded to possess an externally visible extragenital process, that varies greatly in size, shape and development between species; these details are illustrated and discussed including their probable function in mating process, and potential value in species diagnoses. Cases of leg teratology, specifically morphological abnormalities of tarsi and tarsal claws, were observed in a few specimens of four species, i.e., Brachysandalus lurco Stål, 1867, B. helluo Stål, 1867, B. flavidus Malipatil & Liu, sp. nov. and B. gunbalanyae Malipatil & Liu, sp. nov.; details are illustrated and discussed.

Mapping wing morphs of Tetrix subulata using citizen science data: Flightless groundhoppers are more prevalent in grasslands near water

Abstract The slender groundhopper (Orthoptera: Tetrigidae) Tetrix subulata (Linnaeus, 1758), like several other taxa of winged insects, has a long‐winged and a short‐winged form, the latter incapable of flight. The optimal habitat of T. subulata consists of wet meadows and flat shores, as they feed mostly on algae and mosses in damp, sun‐exposed, open patches. Contrasting hypotheses predict either short‐ or long‐winged morphs to be relatively more prevalent in optimal habitats. Previous investigations were limited in their spatial extent. To strongly increase the number of study locations, we obtained, through the Global Biodiversity Information Facility (GBIF), geo‐referenced observations made by citizen scientists in the Netherlands. We determined individuals' wing form based on photographs accompanying these observations and related wing‐form patterns to large‐ and medium‐scale landscape characteristics. Our analyses revealed that in grasslands near the major rivers, relatively more short‐winged individuals were found. In drier landscapes consisting of coniferous forests and heath on the higher sand areas, more long‐winged individuals were observed. Built‐up areas had no significant effect on the wing length. These patterns might be caused by the oogenesis‐flight syndrome or small‐scale spatial sorting, but the exact mechanism is yet unknown, as size‐dependency might also play a role. Although opportunistic observations are biased by where and when observers prefer to go, and by reporting probabilities varying between species groups, these biases are not likely to have affected our conclusions. Citizen science data appear to be suitable for analyses of spatial distribution and sorting of morphological types within species.

A szárny dimorfizmus/polimorfizmus a poloskáknál (hemiptera, heteroptera): áttekintés funkcionális nézőpontból

This is the second part of the article where the available information from the published literature on the wing dimorphism/polymorphism occurring among true bugs (Heteroptera) is reviewed from a functional viewpoint. This paper covers the case studies on phytophagous species and draws some general conclusions. Wing dimorphism/polymorphism has been studied in detail at the red firebug: Pyrrhocoris apterus (Linnaeus, 1758), at some blissid species - mainly at the Oriental chinch bug: Cavelerius saccharivorus (Okajima,1922) - at some lygaeid species and at the red-shouldered soapberry bug Jadera haematoloma (Herrich-Schäffer, 1847) (Rhopalidae). In general, the macropterous form has a delayed sexual maturation, which further enhances its dispersal ability but represents an obvious reproductive disadvantage. In most known cases of the hemipteran wing dimorphism/polymorphism the wing form is affected by environmental factors (polyphenism), but examples of genetically determined wing dimorphism also have been documented among Lygaeinae. Seasonal wing dimorphism/polymorphism is very common among the well-studied northern temperate species. Wing dimorphic/polymorphic phytophagous “outbreak” species (Blissidae, Leptoterna dolobrata) react with mass production of the otherwise rare macropters to high population density and altered food quality. An underlying wing muscle dimorphism/polymorphism frequently co-exists with the externally visible wing dimorphism/polymorphism. Known cases of full or partial de-alation are also mentioned and briefly discussed.

Tailoring the Mechanical Properties of High‐Fidelity, Beetle‐Inspired, 3D‐Printed Wings Improves Their Aerodynamic Performance

Miniature flapping drones can potentially operate in small spaces, using lightweight membranous wings. Designing these flexible wings appropriately is crucial for effective flight performance. 3D printing allows not only to fabricate high‐fidelity, insect‐inspired wings but also to further improve their design and shorten the development period for miniature flapping drones. Herein, a bioinspired approach is used to develop 3D‐printed wings based on the rose chafer beetle wings. By modulating the wing structure, 12 different wing models are designed that differ in the shape of the veins’ cross‐section, tapering geometry, and membrane thickness. The mechanical and aerodynamic properties of these models are compared, to establish guidelines linking wing form to function. It is shown that 1) the geometry of the veins’ cross‐section offers a powerful tool for engineering in‐plane and out‐of‐plane deformations; 2) tapering veins improve the wings’ mechanical stability, and 2) the membrane merges the mechanics of the individual veins into an integrated aerodynamically favorable structure. These result in 16% higher lift and 27% improvement in lift production efficiency (N/Watts) in a revolving wing setup. Designing light, flexible, robust, and aerodynamically efficient wings presents a formidable engineering challenge that insects have solved. Reverse engineering these intricate structures is empirically described herein.

Wing Dimorphism/polymorphism in True Bugs (Heteroptera) From a Functional Viewpoint: A review

In this review article the available information on the wing dimorphism/polymorphism occurring at non-phytophagous Heteroptera is reviewed from a functional viewpoint. This meant practically the information about the wing dimorphism/polymorphism of the superfamily Gerroidea, as hardly anything has been published on this theme of other non-phytophagous Heteroptera. Seasonal and concurrent wing dimorphism/polymorphism are treated and discussed separately. Heritability and phenotypical plasticity of the wing form, and the effects of different modifying environmental factors are briefly reviewed and discussed. The superior reproductive ability of the non-macropterous form is well documented at female gerroid bugs; there are less available data on the males. The seasonal wing polymorphism directed by photoperiod and affected by temperature is usually well adapted to the current environmental conditions. The effects of the population density and that of the food quantity and quality on wing form of the gerroid bugs have not been well understood yet; and it is arguable, whether the macropterous/non macropterous ratio of the natural gerroid populations corresponds to the temporal stability of their actual habitats in an adaptive way. Wing dimorphism/polymorphism has to be evaluated within the wider concept of dispersal polymorphism, which includes other related phenomena like wing muscle polymorphism and behavioural differences.

Transient use of hemolymph for hydraulic wing expansion in cicadas

Insect wings must be flexible, light, and strong to allow dynamic behaviors such as flying, mating, and feeding. When winged insects eclose into adults, their wings unfold, actuated hydraulically by hemolymph. Flowing hemolymph in the wing is necessary for functioning and healthy wings, both as the wing forms and as an adult. Because this process recruits the circulatory system, we asked, how much hemolymph is pumped into wings, and what happens to the hemolymph afterwards? Using Brood X cicadas (Magicicada septendecim), we collected 200 cicada nymphs, observing wing transformation over 2 h. Using dissection, weighing, and imaging of wings at set time intervals, we found that within 40 min after emergence, wing pads morphed into adult wings and total wing mass increased to ~ 16% of body mass. Thus, a significant amount of hemolymph is diverted from body to wings to effectuate expansion. After full expansion, in the ~ 80 min after, the mass of the wings decreased precipitously. In fact, the final adult wing is lighter than the initial folded wing pad, a surprising result. These results demonstrate that cicadas not only pump hemolymph into the wings, they then pump it out, producing a strong yet lightweight wing.

Revision of Australian Ectomocoris with the description of nine new species (Hemiptera: Heteroptera: Reduviidae)

The Australian species of the genus Ectomocoris Mayr, 1865 (Hemiptera: Heteroptera: Reduviidae: Peiratinae), are revised. A total of 13 species are recognised, including nine new species: E. binotatus Malipatil & Liu, sp. nov., E. borealis Malipatil & Liu, sp. nov., E. fuscatus Malipatil & Liu, sp. nov., E. fuscifemoralis Malipatil & Liu, sp. nov., E. interiorius Malipatil & Liu, sp. nov., E. latus Malipatil & Liu, sp. nov., E. luteolus Malipatil & Liu, sp. nov., E. major Malipatil & Liu, sp. nov. and E. spinosus Malipatil & Liu, sp. nov. Redescriptions of E. australicus (Reuter, 1881), E. decoratus (Stål, 1863), E. ornatus (Stål, 1863) and E. truculentus (Stål, 1863) are presented. Callisphodrus patricius Stål, 1867 is treated as a new junior synonym of E. ornatus (Stål, 1863). Lectotypes are designated for Eumerus (Eumerus) australicus Reuter, 1881, Pirates decoratus Stål, 1863, P. ornatus Stål, 1863, P. truculentus Stål, 1863 and C. patricius Stål, 1867. A key to species is provided together with images of dorsal habitus of males and females of different wing forms and major structures of the male genitalia to assist distinguishing these species. Based on morphology, brief comments are provided on putative species groups within the studied species. A male extragenital structure, present in almost half of the species studied, is described in detail and its potential value in diagnosis and analysis of phylogenetic relationships within the genus as well as between related peiratine genera is discussed.

Functional characterization of five developmental signaling network genes in the white-backed planthopper: Potential application for pest management.

The white-backed planthopper (WBPH, Sogatella furcifera) is a major rice pest that exhibits condition dependent wing dimorphisms - a macropterous (long wing) form and a brachypterous (short wing) form. Although, the gene cascade that regulates wing development and dimorphic differentiation has been largely defined, the utility of these genes as targets for pest control has yet to be fully explored. Five genes typically associated with the developmental signaling network, armadillo (arm), apterous A (apA), scalloped (sd), dachs (d), and yorkie (yki) were identified from the WBPH genome and their roles in wing development assessed following RNA interference (RNAi)-mediated knockdown. At 5 days-post injection, transcript levels for all five targets were substantially decreased compared with the dsGFP control group. Among the treatment groups, those injected with dsSfarm had the most pronounced effects on transcript reduction, mortality (95 ± 3%), and incidence (45 ± 3%) of wing deformities, whereas those injected with dsSfyki had the lowest incidence (6.7 ± 4%). To assess the utility of topical RNAi for Sfarm, we used a spray-based approach that complexed a large-scale, bacteria-based double-stranded RNA (dsRNA) expression pipeline with star polycation (SPc) nanoparticles. Rice seedlings infested with third and fourth instar nymphs were sprayed with SPc-dsRNA formulations and RNAi phenotypic effects were assessed over time. At 2 days post-spray, Sfarm transcript levels decreased by 86 ± 9.5% compared with dsGFP groups, and the subsequent incidences of mortality and wing defects were elevated in the treatment group. This study characterized five genes in the WBPH developmental signaling cascade, assessed their impact on survival and wing development via RNAi, and developed a nanoparticle-dsRNA spray approach for potential field control of WBPH. © 2023 Society of Chemical Industry.

Kütle ve Kanat Alanı Grafiğinden Kanat Formlarının İncelenmesi

The wing loading parameter depending on the wing area and weight and the aspect ratio parameter, which is the wing shape factor, are the main parameters that determine the fixed-wing flight mechanics. In this study, the relationship between wing forms and flight style of 195 bird species was evaluated using wing area and mass scatter plot. The slope of the mass and wing area chart is proportional to the 1/wing loading. The results showed that birds with more wing area per unit mass tended to perform unpowered flight styles such as soaring and gliding; and birds with less wing area per unit mass tended to have powered flight styles, such as flapping and hovering. In general, it has been found that the slope of the trendline curve is more inclined tended to expend more energy in flight. Unlike the fixed-wing flight mechanics, hand-wings and arm-wings should also be examined to understand the flight mechanics of flapping wings as different effects occur during flapping flight in terms of the lift and thrust forces. In addition, scythe-shaped wings differ from high-speed wings in terms of the ratio of hand wing length/arm wing length according to their wing structure.

静岡県の露地栽培キクおよびその周辺雑草におけるクロゲハナアザミウマの翅型

In 2015–2016, we investigated the wing forms of adult females of Thrips nigropilosus collected from chrysanthemums and nearby weeds in open fields in Shizuoka Prefecture, Central Japan. At all collection sites, the proportion of brachypterous female adults increased in October and February. Therefore, the populations collected in this study were noted to be brachypterous under a short-day photoperiod. Additionally, the proportion of individuals entering reproductive diapause was higher than that under long-day photoperiods.

Relating wing morphology and immune function to patterns of partial and differential bat migration using stable isotopes.

Migration is energetically expensive and is predicted to drive similar morphological adaptations and physiological trade-offs in migratory bats and birds. Previous studies suggest that fixed traits like wing morphology vary among species and individuals according to selective pressures on flight, while immune defences can vary flexibly within individuals as energy is variably reallocated throughout the year. We assessed intraspecific variation in wing morphology and immune function in silver-haired bats Lasionycteris noctivagans, a species that follows both partial and differential migration patterns. We hypothesized that if bats experience energy constraints associated with migration, then wing morphology and immune function should vary based on migratory tendency (sedentary or migratory) and migration distance. We predicted that long-distance migrants would have reduced immune function and more migration-adapted wing shapes compared to resident or short-distance migrating bats. We estimated breeding latitude of spring migrants using stable hydrogen isotope techniques. Our sample consisted primarily of male bats, which we categorized as residents, long-distance northern migrants, short-distance northern migrants and southern migrants (apparent breeding location south of capture site). Controlling for individual condition and capture date, we related wing characteristics and immune indices among groups. Some, but not all, aspects of wing form and immune function varied between migrants and residents. Long-distance northern migrants had larger wings than short-distance northern migrants and lower wing loading than southern migrants. Compared with resident bats, short-distance northern migrants had reduced IgG while southern migrants had heightened neutrophils and neutrophil-to-lymphocyte ratios. Body fat, aspect ratio, wing tip shape and bacteria killing ability did not vary with migration status or distance. In general, male silver-haired bats do not appear to mediate migration costs by substantially downregulating immune defences or to be under stronger selection for wing forms adapted for fast, energy-efficient flight. Such phenotypic changes may be more adaptive for female silver-haired bats, which migrate farther and are more constrained by time in spring than males. Adaptations for aerial hawking and the use of heterothermy by migrating bats may also reduce the energetic cost of migration and the need for more substantial morphological and physiological trade-offs.

Early cellular development induced by ecdysteroid in sex-specific wing degeneration of the wingless female winter moth.

The winter moth, Nyssiodes lefuarius, exhibits striking sexual dimorphism in wing form; males have functional wings of normal size, whereas females lack wings. We previously found that the steroid hormone 20-hydroxyecdysone (20E) triggered massive programmed cell death (PCD) only in the female pupal wing epithelium; however, when and how early sexual trait development of the pupal wings is initiated during pupal-adult metamorphosis remains obscure. To clarify the detailed morphological changes and mechanisms underlying early sexual trait development and cell death, we examined the effects of 20E on early ultrastructural and histological changes in the pupal wing epithelium of both sexes. Before the onset of adult differentiation, no morphological differences were observed in the epithelial cells of both sexes at an ultrastructural level. When 5.4µg of 20E was injected into pupae of both sexes at 15days after the onset of pupation, retraction of the wing epithelium from the pupal cuticle was initiated at day 2 after 20E injection in both sexes. Although overt degeneration of wing tissue was not still obvious, apoptotic body-like structures and auto-phagosomes were visible at day 3 after 20E injection in females, whereas development of scale precursor cells started on day 4 after injection in males. Our results suggest that (1) the injection of 20E induced sexually dimorphic changes in the pattern of organelle distribution in wing epithelial cells, and (2) abnormally shaped mitochondria in the cytoplasm of the female wing epithelium might be involved in the PCD that occurs during wing tissue degeneration.

Discovery of cockroach specimens of the genus Squamoptera (Ectobiidae: Pseudophyllodromiinae) from Okinawa, Japan, showing wing polymorphism

Cockroach specimens of the genus, Squamoptera were collected from the Iriomote island of Okinawa prefecture, Japan. The morphological features of the specimens were characterized as having a white band on the dorsal surface of its thorax, its tegmen reduced into a tiny scale-like structure and the hindwing was absent. Ocelli was also absent and the small compound eyes not extending to apex of the head nor to the frontal face but extend further lower than the base of the antennae. When the specimens were reared in the laboratory, besides the short wing form, the long wing form began to appear in the rearing colony. In our reproductive biological study, we observed that hatching of the ootheca from the short wing female takes about 30 days, with an average of 6.6 nymphs being hatched from one ootheca. The male to female ratio of the offspring was 36:30. However, the frequency appearance of the offspring from the ootheca of the short wing female was 98.5% short wing and 1.5% long wing form. Our specimens occasionally show body polymorphism in the form of individuals having long wings instead of the usual short one. The long wing form does not show the white band on the dorsal surface of its thorax.

Powered flight in hatchling pterosaurs: evidence from wing form and bone strength

Competing views exist on the behaviour and lifestyle of pterosaurs during the earliest phases of life. A ‘flap-early’ model proposes that hatchlings were capable of independent life and flapping flight, a ‘fly-late’ model posits that juveniles were not flight capable until 50% of adult size, and a ‘glide-early’ model requires that young juveniles were flight-capable but only able to glide. We test these models by quantifying the flight abilities of very young juvenile pterosaurs via analysis of wing bone strength, wing loading, wingspan and wing aspect ratios, primarily using data from embryonic and hatchling specimens of Pterodaustro guinazui and Sinopterus dongi. We argue that a young Sinopterus specimen has been mischaracterised as a distinct taxon. The humeri of pterosaur juveniles are similar in bending strength to those of adults and able to withstand launch and flight; wing size and wing aspect ratios of young juveniles are also in keeping with powered flight. We therefore reject the ‘fly-late’ and ‘glide-early’ models. We further show that young juveniles were excellent gliders, albeit not reliant on specialist gliding. The wing forms of very young juveniles differ significantly from larger individuals, meaning that variation in speed, manoeuvrability, take-off angle and so on was present across a species as it matured. Juveniles appear to have been adapted for flight in cluttered environments, in contrast to larger, older individuals. We propose on the basis of these conclusions that pterosaur species occupied distinct niches across ontogeny.

Optimal flapping wing shape and kinematics are different for different flight velocities: an analysis on local relative wind

Different species of insects and birds fly differently. Their wing forms and wing motion are different. Understanding the purpose of this difference will lead to successful development of flapping wing vehicles for different purposes. This paper discusses the influence of one of the important factors which affects the aerodynamic performance of a flapping wing: the local instantaneous relative wind. Its distribution along the span of a flapping wing has been analyzed for the practical flight range of advance ratios ranging from 0 to 1.5 and stroke plane orientations ranging from 0 to 90°. In this domain, the variation of spanwise distributions of magnitude and direction of relative wind are presented separately for downstroke and upstroke of a flapping cycle. Accordingly, qualitative suggestions are given for wing planform design, orientation and twist of the wing, and actuation of wing for effective utilization of the relative wind and obtaining the necessary force distributions for different flight phases. The formulation presented will be helpful for experimenting flapping wings in hovering and forward flight; especially for setting the wing twist for a required angle of attack distribution and designing the flapping kinematics in upstroke and downstroke.

Crowding leads to higher incidence of brachypterous females in the tobacco thrips, Frankliniella fusca (Hinds) (Thysanoptera: Thripidae)

• In wing-polyphenic insects, crowding generally promotes to macropter production. • Female of F. fusca exhibits wing diphenism governed by environmental conditions . • Effect of larval density on wing form determination was detected by rearing trials. • Percentage of female macropters decreased as larval density increased. • Developmental time and body length did not differ between two wing morphs. The effects of larval density on the wing form determination of female tobacco thrips, Frankliniella fusca , were investigated by rearing thrips on leaf disks at 27.5 °C. The developmental period, head width, body length, and forewing length of individuals in each wing morph were determined to assess the relationships among larval density, growth, and wing form. Data showed that higher rearing densities increased the production of female F . fusca brachypters. There was no consistent difference in the mean developmental periods between the two wing morphs or among all 5 density treatments. The body length of females tended to decrease with increasing rearing density, but there was no significant difference in body size between the two wing morphs when they were reared under the same density level.

Narrow versus broad: sexual dimorphism in the wing form of western European species of the subgenus Avaritia (Culicoides, Ceratopogonidae).

While wing form is known to differ between males and females of the genus Culicoides, detailed studies of sexual dimorphism are lacking. In this study, we analyze sex-specific differences in the wing form of 5 species of the subgenus Avaritia, using geometric morphometrics and comparative phylogenetic methods. Our results confirm the existence of marked sexual dimorphism in the wing form of the studied species and reveal for the first time that while there is a shared general pattern of sexual shape dimorphism within the subgenus, sexual size dimorphism, and particular features of sexual shape dimorphism differ among species. Sexual shape dimorphism was found to be poorly associated to size and the evolutionary history of the species. The tight association of sexual shape dimorphism with aspect ratio suggests that the shape of the wing is optimized for the type of flight of each sex, that is, dispersal flight in females versus aerobatic flight in males. Moreover, the fact that interspecific shape differences are greater and more strongly associated to aspect ratio in males than in females might be indicating that in males the selective pressures affecting flight performance characteristics are more heterogeneous and/or stronger than in females among the studied species.

Identification and Analysis of MicroRNAs Associated with Wing Polyphenism in the Brown Planthopper, Nilaparvata lugens.

Many insects are capable of developing two types of wings (i.e., wing polyphenism) to adapt to various environments. Though the roles of microRNAs (miRNAs) in regulating animal growth and development have been well studied, their potential roles in modulating wing polyphenism remain largely elusive. To identify wing polyphenism-related miRNAs, we isolated small RNAs from 1st to 5th instar nymphs of long-wing (LW) and short-wing (SW) strains of the brown planthopper (BPH), Nilaparvata lugens. Small RNA libraries were then constructed and sequenced, yielding 158 conserved and 96 novel miRNAs. Among these, 122 miRNAs were differentially expressed between the two BPH strains. Specifically, 47, 2, 27 and 41 miRNAs were more highly expressed in the 1st, 3rd, 4th and 5th instars, respectively, of the LW strain compared with the SW strain. In contrast, 47, 3, 29 and 25 miRNAs were more highly expressed in the 1st, 3rd, 4th and 5th instars, respectively, of the SW strain compared with the LW strain. Next, we predicted the targets of these miRNAs and carried out Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway analysis. We found that a number of pathways might be involved in wing form determination, such as the insulin, MAPK, mTOR, FoxO and thyroid hormone signaling pathways and the thyroid hormone synthesis pathway. Thirty and 45 differentially expressed miRNAs targeted genes in the insulin signaling and insect hormone biosynthesis pathways, respectively, which are related to wing dimorphism. Among these miRNAs, Nlu-miR-14-3p, Nlu-miR-9a-5p and Nlu-miR-315-5p, were confirmed to interact with insulin receptors (NlInRs) in dual luciferase reporter assays. These discoveries are helpful for understanding the miRNA-mediated regulatory mechanism of wing polyphenism in BPHs and shed new light on how insects respond to environmental cues through developmental plasticity.

Trait-Specific Responses of Carabid Beetle Diversity and Composition in Pinus densiflora Forests Compared to Broad-Leaved Deciduous Forests in a Temperate Region

Since successful reforestation after the 1970s, Korean red pine (Pinus densiflora) forests have become the most important coniferous forests in Korea. However, the scarcity of evidence for biodiversity responses hinders understanding of the conservation value of Korean red pine forests. This study was conducted to explore the patterns of carabid beetle diversity and assemblage structures between broad-leaved deciduous forests and P. densiflora forests in the temperate region of central Korea. Carabid beetles were sampled by pitfall trapping from 2013 to 2014. A total of 66 species were identified from 9541 carabid beetles. Species richness in broad-leaved deciduous forests was significantly higher than that in pine forests. In addition, the species composition of carabid beetles in broad-leaved deciduous forests differed from that of P. densiflora forests. More endemic, brachypterous, forest specialists, and carnivorous species were distributed in broad-leaved deciduous forests than in P. densiflora forests. Consequently, carabid beetle assemblages in central Korea are distinctively divided by forest type based on ecological and biological traits (e.g., endemisim, habitat types, wing forms, and feeding guilds). However, possible variation of the response of beetle communities to the growth of P. densiflora forests needs to be considered for forest management based on biodiversity conservation in temperate regions, because conifer plantations in this study are still young, i.e., approximately 30–40-years old.

Ultrabithorax is a key regulator for the dimorphism of wings, a main cause for the outbreak of planthoppers in rice.

Rice planthoppers, the most devastating rice pests, occur in two wing forms: the short-wing form for rapid population growth and long-wing form for long-distance migration, which together create the mechanism for outbreak. Here we show that Ultrabithorax (Ubx) is a key regulator for switching between the long- and short-wing forms of rice planthoppers. Ubx is expressed in both forewing and hindwing pads, which is different from the canonical model of Ubx expression. In brown planthoppers, expression of Ubx (NlUbx) is regulated by nutritional status of the rice host. High-quality young plants induce NlUbx expression leading to the short-wing form; low-quality ripe plants reduce NlUbx expression resulting in long-wing form. We also showed that NlUbx is regulated by the insulin receptors NlInR1 and NlInR2. The default expression of NlInR1 inhibits NlUbx resulting in long-wings, while high-quality hosts induce NlInR2 expression, which represses NlInR1 thus promoting NlUbx expression to produce short-wings.