Differences In Wing Morphology Research Articles

Revision of the Genus Rhagastis Rothschild & Jordan, 1903 (Lepidoptera: Sphingidae) from China, Based on Morphological and Phylogenetic Analyses.

Here, the taxonomy of the genus Rhagastis Rothschild & Jordan, 1903 (Lepidoptera, Sphingidae, Macroglossinae, Macroglossini) from China is revised based on differences in wing morphology, male and female genitalia, and the phylogenetic relationship of the DNA barcodes. Subspecies of Rhagastis albomarginatus (Rothschild, 1894) and R. castor (Walker, 1856) are treated as "good" species, namely Rhagastis dichroae Mell, 1922 stat. nov.; R. everetti Rothschild & Jordan, 1903 stat. nov.; R. aurifera (Butler, 1875) stat. rev.; R. chinensis Mell, 1922 stat. nov.; R. formosana Clark, 1925 stat. nov.; and R. jordani Oberthür, 1904 stat. rev. The distribution maps, biological notes, and ecological records of the genus Rhagastis Rothschild & Jordan, 1903 from China are given, and a species inventory of genus Rhagastis in the world is also included.

Wing morphology of a damselfly exhibits local variation in response to forest fragmentation.

Environmental differences can lead to morphologically different subpopulations. The scale of the mosaic of morphologies should help shed light on the nature of the mechanisms at work. Previous work has shown that jewelwing damselflies have different wing sizes in different types of habitat. Our aim was to (1) describe the relationship between damselfly wing lengths and a gradient of forest fragmentation and (2) determine the spatial scale at which these morphological differences occur. We hypothesized that local adaptation would lead to differences in wing morphology over short distances. We herein test one of the several predictions that would need to be met to support this hypothesis: that wing morphology would show spatial autocorrelation at relatively short distances. We further predicted that the wing morphology would correlate to forest fragmentation. We collected jewelwing damselflies from across Indiana, USA, in habitats across a gradient of forest fragmentation. We examined the link between forest edge density and wing length using three biologically relevant landscape sizes. We then examined the distance to which wing length variation was autocorrelated using Moran's I. We found positive linear or unimodal relationships between wing length and edge density, in both males and females, at all three landscape scales. Spatial autocorrelation in wing length indicated that variation in wing length was autocorrelated at short distances, out to 1-5km. Our findings uphold one of the predictions stemming from the hypothesis that adaptations to local environments-habitat fragmentation here-can occur at relatively fine spatial scales.

CRISPR/Cas9-mediated NlInR2 mutants: Analyses of residual mRNA and truncated proteins

CRISPR/Cas9 technology is a powerful genome manipulation tool in insects. However, little is known about whether mRNA and protein of a target gene are completely cleared in homozygous mutants. This study generated homozygous mutants of the insulin receptor gene 2 (NlInR2) in the brown planthopper (Nilaparvata lugens) using CRISPR/Cas9 genome editing. Both frameshift mutants, E5_D17 and E6_I7, differentiated towards long wings, but there were differences in wing morphology, with E5_D17 showing wing deformities. Subsequent investigations revealed the presence of residual expression of NlInR2 mRNA in both mutants, as well as the occurrence of spliceosomes featuring exon skipping splicing in E5_D17. Additionally, the E5_D17 exhibited the detection of N-terminally truncated NlInR2 protein. RNA interference experiments indicated that the knockdown of NlInR2 expression in the E5_D17 mutant line increased the proportion of wing deformities from 11.1 to 65.6%, suggesting that the residual NlInR2 mRNA of the E5_D17 mutant might have retained some genetic functions. Our results imply that systematic characterization of residual protein expression or function in CRISPR/Cas9-generated mutant lines is necessary for phenotypic interpretation.

Natural history of the fishing bat Noctilio leporinus (Chiroptera: Noctilionidae) in the Gulf of Mexico

Abstract We report feeding behaviour, dates of peak reproduction, and sexual size dimorphism of the fishing bat, Noctilio leporinus, in the Gulf of Mexico. For the first time we document the size of cheek pouches in N. leporinus and fish species consumed in the water bodies of southern Mexico and analyse differences in wing morphology and biomechanical flight descriptors between the sexes. We found sexual dimorphism in size for most of the external measurements but not in wing characters. This species can consume prey up to a third of its size. We confirmed the presence of N. leporinus in localities in Tabasco, Mexico 60 years after the first report.

Characterization of assemblages in neotropical cave dwelling bats based on their diet, wing morphology, and flight performance

Bats have a great variety of wing morphologies that determines the bat’s flight performance, and this in turn conditions the forage aerosphere and the food it can obtain. Several studies have shown differences in wing morphology, flight performance, and forage aerospheres among species from different trophic guilds. However, for species that share a guild this is not entirely clear. It is possible that these species have differences in their diet and show changes in wing morphology that modify their flight performance and forage areas. Determining this will allow a better understanding of spatial segregation among species that share a trophic guild. These studies allow the identification of species assemblages based on wing morphological differences and flight performance that would not be distinguished only by guild membership. Our goal was to define the species assemblages that make up a community of Neotropical cave dwelling bats based on their trophic guild, flight performance, and forage zone. A community of Neotropical cave dwelling bats from a cave in Veracruz, Mexico was analyzed. The diet of each species was determined by means of their stomach contents and bibliographic review. In addition, aspect ratio, wing loading and tip index were calculated. Based on the wing characteristics and diet, multivariate groupings and orders were performed, as well as to define the assemblages present. According to the wing characteristics and the dietary composition, four groups of species were found that represent four different flight characteristics in terms of agility and maneuverability. There was agreement between diet and wing characteristics, and the four trophic groups were identified through canonical correspondence analysis. Correlating wing morphology, diet and forage area allows us to adequately define the assemblages of a community of bats. Regarding the hypothesis, it was found that species that share a food guild show differences in the composition of their food and wing morphology, which generate differences in flight performance and forage areas. Four assemblages differing in forage aerospheres among three trophic guilds are described: understory and facultative artrhopodivorous, semi-clearing hematophages, and facultative nectarivores. Finally, spatial segregation between the species of the families Mormoopidae and Natalidae was recognized.

Changes in the wing shape and size in Drosophila melanogaster treated with food grade titanium dioxide nanoparticles (E171) – A multigenerational study

Drosophila is among the most commonly used models for toxicity assessment of different types of nanoparticles. This study aims to examine the effects of a constant exposure to the low concentration of human food grade titanium dioxide nanoparticles (TiO2 E171) on Drosophila melanogaster wing morphology over multiple generations. Subsequently, the Geometric Morphometrics Analysis was employed to examine possible changes in the wing shape and size of the treated flies. The treatment resulted in the diminishment but not a disruption in the sexual dimorphism in wings. Consequently, the female flies were clearly separated from the male flies by the differences in wing morphology as in the control group. A splitting by generations was overly similar within the control and the treatment, but it was slightly more pronounced in the treatment. However, the observed generational differences seemed mostly random between generations, irrespective of the treatment. Specifically, the treated groups displayed slightly higher splitting by generations in females than in males. Regardless of the generation, the results show a clear splitting by the differences in the wing shape between the treated flies and the flies from control. The mean value of centroid size, which refers to the wing size, of both female and male wings was smaller in the treatment when compared to the control. The overall effect of TiO2 was to induce significant difference in Drosophila wing morphology but it did not alter the general wing morphology pattern. Therefore, the change in the wings occurred only within the normally allowed wing variation.

Assessing the Use of Wing Morphometrics to Identify Fall Armyworm (Lepidoptera: Noctuidae) Host Strains in Field Collections.

The fall armyworm (Spodoptera frugiperda) (J. E. Smith) (Lepidoptera: Noctuidae), a major agricultural pest in the Western Hemisphere, has recently become established in Africa and Asia. This highly polyphagous species has potential to economically harm multiple crops. Contributing to this host range are two fall armyworm populations historically called 'host strains' that differ in host specificity. Understanding behaviors of the two strains is crucial to effective management of this pest. A major difficulty in such studies is that strains have long been considered morphologically indistinguishable, with molecular markers the only reliable means of identification. However, studies of fall armyworm in Colombia reported strain differences in wing morphology sufficiently large to potentially provide a more economical alternative method to determine strain. This study tested whether a similar phenotypic difference was present in Florida populations using geometric morphometric analysis of 15 anatomical landmarks on forewings of 182 specimens from three habitats associated with different host plants. Principle component and linear discriminant analyses identified significant differences in wing size and shape in comparison of strains from different habitats, but not between strains within the same habitat. Data indicate that apparent strain distinctions in wing phenotype are most likely a secondary consequence of differences in developmental growth patterns on different host plants combined with strain-biased host choice. Furthermore, Florida specimens showed much larger phenotypic overlap than observed for strains from Colombia. Together these findings suggest that wing morphology is probably not a reliable indicator of strain identity in field populations where different host plants are available.

Clutter negotiating ability in an ensemble of forest interior bats is driven by body mass.

Differences in wing morphology are predicted to reflect differences in bat foraging strategies. Experimental tests of this prediction typically assess the relationship between wing morphology and a measures of flight performance on an obstacle course. However, studies have lacked measures of obstacle avoidance ability true scores, which may confound interpretation of ability across the range of presented tasks. Here, we used Rasch analysis of performance in a collision-avoidance experiment to estimate the ability of bat species to fly through vegetative clutter. We refer to this latent trait as 'clutter negotiating ability' and determined the relationships between clutter negotiating ability and wing morphology in 15 forest insectivorous bat species that forage in the densely cluttered rainforests of Malaysia. The clutter negotiating ability scores were quantified based on individual responses of each species to 11 different obstacle arrangements (four banks of vertical strings 10-60 cm apart). The tasks employed for the collision-avoidance experiment were reliable and valid, although Rasch analysis suggested that the experiment was too easy to discriminate completely among the 15 species. We found significant negative correlations between clutter negotiating ability and body mass, wingspan, wing loading and wing area but a positive significant correlation with wingtip area ratio. However, in stepwise multiple regression analyses, only body mass and wing loading were significant predictors of clutter negotiating ability. Species fell into clusters of different clutter negotiating ability, suggesting a potential mechanism for resource partitioning within the forest interior insectivorous ensemble.

Differences in wing morphology between juvenile and adult European Turtle Doves Streptopelia turtur: implications for migration and predator escape

Behaviour has direct links to wing morphology in bird species. Many studies have postulated migration to be one of the most important forces of selection acting on wing morphology, particularly in relation to wing pointedness. Studies in passerines have found that adults have longer and more pointed wings than juveniles, especially in migratory species. We analysed differences in wing morphology between age groups of the European Turtle Dove, a non‐passerine migratory species that benefits from rounded wings during their daily activity, due to its ground‐feeding behaviour and acrobatic flight style. Our results show that adults of this species have longer but more rounded wings than juveniles. This suggests that in this species wing morphology in juveniles is selected to facilitate the first migration, whereas other selection forces (e.g. flight manoeuvrability) are more important after the first moult. These data also explain why juveniles are not as adept at escaping from predators or hunters as adults.

Migration distance as a selective episode for wing morphology in a migratory insect

BackgroundSelective pressures that occur during long-distance migration can influence morphological traits across a range of taxa. In flying insects, selection should favour individuals that have wing morphologies that increase energy efficiency and survival. In monarch butterflies, differences in wing morphology between migratory and resident populations suggest that migratory populations have undergone selection for larger (as measured by length and area) and more elongated (as measured by roundness and aspect ratio) forewings. However, selection on wing morphology may also occur within migratory populations, particularly if individuals or populations consistently migrate different distances.ResultsUsing 613 monarch butterflies that were collected on the Mexican wintering grounds between 1976 – 2014, we tested whether monarch wing traits were associated with migratory distance from their natal areas in eastern North America (migration range: 774–4430 km), as inferred by stable-hydrogen (δ2H) and -carbon (δ13C) isotopic measurements. Monarchs that migrated farther distances to reach their overwintering sites tended to have longer and larger wings, suggesting positive selective pressure during migration on wing length and area. There was no relationship between migration distances and either roundness or aspect ratio.ConclusionsOur results provide correlative evidence that the migratory period may act as a selective episode on monarch butterfly wing morphology, although selection during other portions of the annual cycle, as well as extensive mixing of individuals from various natal locations on the breeding grounds, likely counteracts directional selection of migration on morphology.

Does wing morphology affect recolonization of restored farmland by ground‐dwelling beetles?

Revegetation of previously cleared land is widely used to increase habitat area and connectivity of remnant vegetation for biodiversity conservation. Whether new habitat attracts or supports fauna depends on the dispersal traits of those fauna as well as the structure and composition of the surrounding landscape. Here, we examined wing morphology as a key dispersal trait for beetles in a revegetated landscape and asked, first, how it was related to phylogeny (family), trophic position, and body size. Second, we asked if wing morphology of recolonizing (or persisting) beetles varied with habitat characteristics at multiple scales, from microhabitat to landscape context. Third, we examined how common winged and wingless species responded to habitat at multiple scales. We measured the wing morphology of ground‐dwelling beetles from a restoration chronosequence, including paddocks, “young” revegetation (8–11 years old), “old” revegetation (14–19 years old), and fenced remnant vegetation. We found that body size and family membership were significant predictors of winglessness, with wingless species of carabids and curculionids being larger than their winged counterparts. We found no difference in the number of sites occupied by winged and wingless species, and no relationship between the wing morphology traits represented in different locations and habitat characteristics or landscape context. Furthermore, the most abundant species of both winged and wingless ground‐dwelling beetles had relatively little affinity to any habitat successional stage. Thus, despite intrinsic differences in wing morphology among species of ground‐dwelling beetle, we found no evidence that flight‐related dispersal limitations influenced recolonization (or persistence) in this landscape.

Will climate change leave some desert bat species thirstier than others?

The combined effects of global climate change and increased anthropogenic use of free water are likely to cause decreases in availability and surface area of water in arid environments. Climate change and water loss are predicted to alter community dynamics, but identifying mechanisms underlying differential responses of species remains a critical conservation challenge. Bats drink in flight and rely on accessible water sources, yet the ability to access water is a function of flight maneuverability. By reducing the size of water sources (to simulate predicted water loss due to climate change/increased human use), we demonstrated species-specific responses by desert bats based on differences in morphology and flight maneuverability. Under natural conditions, less-maneuverable bats selected larger water sources while maneuverable bats exhibited no preference. When we experimentally reduced surface area, larger, less-maneuverable bats experienced a 69% decrease in the proportion of drinking attempts that were successful (p<0.05) and increased competition with smaller, maneuverable bats. Our study illustrates how morphology can mediate access to a resource and highlights conservation implications as water becomes more limited in arid environments. Selection for differences in wing morphology and flight ability in insectivorous bats has allowed for coexistence and high species richness at a local scale. However, anticipated reductions in the sizes of water sources due to climate disruption may lead to species with less maneuverability being unable to access water efficiently and facing increased competition from more agile bats.

Intra-specific variation in wing morphology and its impact on take-off performance in blue tits (Cyanistes caeruleus) during escape flights.

ABSTRACTDiurnal and seasonal increases in body mass and seasonal reductions in wing area may compromise a bird's ability to escape, as less of the power available from the flight muscles can be used to accelerate and elevate the animal's centre of mass. Here, we investigated the effects of intra-specific variation in wing morphology on escape take-off performance in blue tits (Cyanistes caeruleus). Flights were recorded using synchronised high-speed video cameras and take-off performance was quantified as the sum of the rates of change of the kinetic and potential energies of the centre of mass. Individuals with a lower wing loading, WL (WL=body weight/wing area) had higher escape take-off performance, consistent with the increase in lift production expected from relatively larger wings. Unexpectedly, it was found that the total power available from the flight muscles (estimated using an aerodynamic analysis) was inversely related to WL. This could simply be because birds with a higher WL have relatively smaller flight muscles. Alternatively or additionally, variation in the aerodynamic load on the wing resulting from differences in wing morphology will affect the mechanical performance of the flight muscles via effects on the muscle's length trajectory. Consistent with this hypothesis is the observation that wing beat frequency and relative downstroke duration increase with decreasing WL; both are factors that are expected to increase muscle power output. Understanding how wing morphology influences take-off performance gives insight into the potential risks associated with feather loss and seasonal and diurnal fluctuations in body mass.

Wing pattern morphology of three closely related Melitaea (Lepidoptera, Nymphalidae) species reveals highly inaccurate external morphology-based species identification

Wing morphology of the three closely related species of Melitaea - M. athalia (Rottemburg, 1775), M. aurelia (Nickerl, 1850) and M. britomartis Assmann, 1847 - co-occurring in the Balkans (SE Europe) was investigated in detail through visual inspection, morphometric analysis and multivariate statistical analysis. Results are compared to recent phylogenetic studies, searching for concordant patterns and discrepancies between the two approaches. The morphology of the genitalic structures is also com- pared with the results of the other two approaches. The main conclusions are as follows: (1) small albeit significant differences in wing morphology exist among the three species and (2) while the structure of male genitalia and phylogenetic position of the three species are concordant, they are (3) in discordance with the wing morphology. The present study represents another example where identification based on external morphology would lead to highly unreliable determinations, hence identification based on phy- logenetic studies and/or genitalia is strongly recommended not only for the three studied species but also more broadly within the genus. Furthermore, we show that some of the characters generally used in the identification of these three Melitaea species should be avoided in future.

Describing Sexual Dimorphism in Inner Wings of Brontispa longissima Using Landmark Based Geometric Morphometric Analysis

 Abstract—Sexual dimorphism is a widespread phenomenon among groups of animals that describe variation in morphology between individuals of different sexes. Differences in wing shape morphology among sexes of the same species of insects often reflects disparity in flight performance and flight range which might be of considerable significance in the monitoring and control of pest species. This study was conducted to determine the differences in wing morphology between sexes of coconut hispid beetle (Brontispa longissima) by looking at the variations in the shapes of the entire wing using geometric morphometrics. The results obtained showed noticeable variation in the left and right inner wings between female and male samples as shown in the relative warp analysis. Discriminant function analysis, MANOVA/CVA scores, and Kruskal-Wallis test showed statistically significant variation between sexes establishing the presence of sexual dimorphism within the species of coconut hispid beetles.

Longitudinal data reveal ontogenetic changes in the wing morphology of a long‐distance migratory bird

In migratory bird species, juveniles normally have shorter and more rounded wings than adults. The causes of this age‐specific difference in wing morphology, however, are largely unknown. Here, we used longitudinal data collected over 3 years from a Pied Flycatcher Ficedula hypoleuca population to assess whether age‐related differences in wing morphology are a consequence of ontogenetic changes or of selection favouring birds with longer and more pointed wings. Our study provides evidence of ontogenetic changes in wing length and shape, whereby birds grow longer and more pointed wings as they grow older. Age‐dependent variation is likely to be adaptive and may partly explain age differences in spring migration phenology and breeding success.

The depth of edge influence among insectivorous bats at forest–field interfaces

Species-specific variations in wing morphology and echolocation call characteristics often define which of three structural habitat types (open, cluttered, and edge) different bat species most frequently and efficiently use for foraging. Although edges are recognized as important habitats for commuting and foraging bats, no study to date has examined the depth of edge influence (DEI), the extent of quantitative changes in activity with distance from an edge, for any bat species. We focused our study on five species: northern long-eared bat, Myotis septentrionalis (Trouessart, 1897); hoary bat, Lasiurus cinereus (Beauvois, 1796); little brown bat, Myotis lucifugus (LeConte, 1831); silver-haired bat, Lasionycteris noctivagans (LeConte, 1831); big brown bat, Eptesicus fuscus (Beauvois, 1796). We predicted DEI would vary with species-specific differences in wing morphology and echolocation call characteristics. From June to August in 2010 and 2011, we passively recorded echolocation calls three to four times per month at eight sites in eastern Ontario, Canada. We found that species’ activity was highest at the edge, regardless of wing morphology and echolocation call characteristics. The DEI for all species was approximately 40 m into both forests and fields. Understanding the effects of DEI on bats will enable more effective acoustic monitoring in future studies and may provide crucial information for management decisions.

Hybridization and sequential components of reproductive isolation between parapatric walnut-infesting sister speciesRhagoletis completaandRhagoletis zoqui

Hybridization can provide a window into how populations diverge to form new species. Here, we confirm hybridization between Rhagoletis completa Cresson, 1929 and Rhagoletis zoqui Bush, 1966, two species of walnut husk-infesting flies that geographically overlap in a narrow area of parapatry in Northeastern Mexico. Rhagoletis completa and R. zoqui are members of a species group (Rhagoletis suavis) that has been hypothesized to speciate in allopatry. Sexual selection has been argued to be a potentially important factor for generating pre-mating isolation among walnut husk flies, because of the differences in wing morphology and body coloration, and the existence of sexual dimorphism within species. However, there was no evidence for pre-mating isolation between R. completa and R. zoqui, based on choice and no-choice mating experiments conducted on adults of fly populations outside the contact zone. There was also no support for reduced fertility of hybrid matings or for F1 inviability; however, F1 hybrids appeared to have lower fertility and F2 offspring have reduced survivorship. Postzygotic isolation in later generation hybrids of mixed ancestry therefore appears to be the first intrinsic barrier to gene flow evolving between R. completa and R. zoqui. We discuss the implications of our results for allopatric speciation in walnut flies and the potential evolutionary fate of R. zoqui and R. completa if they were to come into broad geographic contact in the future. © 2012 The Linnean Society of London, Biological Journal of the Linnean Society, 2012, ••, ••–••.

Decision-making conditions for intra- or inter-nest mating of winged males in the male-dimorphic ant Cardiocondyla minutior

Only winged male and female ants generally mate through nuptial flight during the reproductive season. In the ants of Cardiocondyla, the males show wing dimorphism and their reproductive strategies differ depending on the differences in wing morphology. It has been suggested that wingless “ergatoid” males bearing very similar external morphologies to workers mate within natal nests, whereas winged males bearing typical ant male morphology disperse from their nests to mate. However, some behavioral observations suggest that the winged males of some Cardiocondyla ants such as C. obscurior and C. minutior may mate within natal nests before dispersion. We evaluated the factors affecting the mating behaviors of the winged males of C. minutior under laboratory conditions. We found that (1) the winged males remained and mated with virgin females in natal nests when either virgin winged females or the relatively mature pupae of winged females (i.e., at least 10 days) were present in the nest, (2) the winged males dispersed to adjacent nests with virgin winged females when only mated queens and the relatively young pupae of winged females (i.e., <9 days) were present in the nest, and (3) all winged males were accepted by the workers of non-natal nests irrespective of the distance from the natal nests in the field. Although most ergatoid males were accepted by the workers of close non-natal nests, they were all attacked and killed by the workers of distant non-natal nests. These results suggest that intra-nest mating and the dispersion of the winged males of C. minutior are facultatively determined by the condition of winged females (virginity and relative pupal age) in natal nests. Furthermore, our results suggest that winged males are likely to seek mating partners chemically and to mate with virgin winged females.

Intraspecific Variation in the Wing Shape and Genetic Differentiation of Reed WarblersAcrocephalus scirpaceusin Croatia

Wing shape plays a major role in determining the aerodynamics and performance of avian flight. Intraspecific variation in wing shape reflects different migratory strategies or distances between breeding and wintering areas. Differences in the wing morphology and genotypes between coastal and inland breeding populations of the Reed Warbler in Croatia were studied. A total of 105 adult birds were measured, while blood samples were taken from 59 individuals. The results showed that the two geographically close populations of Reed Warblers differ in wing morphology, with birds from the inland population having more pointed and more slotted wings than those from the coastal population. There was a slight but significant difference in microsatellite allele frequencies between the two populations (FST = 0.015), suggesting that gene flow between the two populations is partly restricted. The differences in wing morphology imply that the two populations use different migratory routes and/or winter in different areas. Consequently, this migratory pattern may have influenced the contemporary genetic differentiation of the two populations.