Wing Loading Research Articles

Lateral Bearing Capacity of a Hybrid Monopile: Combined Effects of Wing Configuration and Local Scour

Pile foundations for offshore wind turbines are subjected to large lateral loads. By mounting wings on the perimeter of regular monopiles, winged monopiles have shown better performance in resisting deformation under horizontal loading. However, the hazardous effect of local scour on the lateral bearing capacity of winged monopiles installed in the sandy seabed has not been systematically evaluated. In this study, a modified Mohr–Coulomb model considering the pre-peak hardening and post-peak softening behavior of dense sand is adopted to simulate laterally loaded winged monopiles in the locally scoured sandy seabed, using three-dimensional finite element analyses. The effect of local scour depth on the lateral capacity of winged monopiles is examined and explained by soil failure mechanisms. The enhancement of lateral capacity with wings attached to the monopile is demonstrated to be more effective than extending pile embedment length. The effects of the relative density of sand and the wing load orientation are also discussed. Finally, the wing efficiency is evaluated to determine the optimal configuration of winged monopiles.

Conceptual design of a third generation aerobatic aircraft

This paper presents the development of an aerobatic aircraft including the influence of platform configuration on performance, elegance and safety of aerobatic manoeuvres. Several aircraft of different wing loadings were compared and the reduction of wing loading on manoeuvring slowdown was studied. Advantages of the biplane configuration influence on the desired properties of aerobatic aircraft were discussed in detail. Results of numerical simulations obtained for HARNAS-3 aircraft were compared with corresponding results received for EXTRA 300 aircraft. Some original design solutions for HARNAS-3, enabling easier control of this aircraft during the manoeuvring phase, were presented. Numerical simulations, wind tunnel tests and free flight experimental results for scaled-down HARNAS-3 models were presented, compared and discussed.

Sizing and Analysis of a Lift-Plus-Cruise Aircraft with Electrified Propulsion

This paper demonstrates an integrated approach to the sizing and analysis of all-electric, hybrid-electric, and turboelectric variants of a lift-plus-cruise urban air mobility vertical takeoff and landing concept using the Parametric Energy-based Aircraft Configuration Evaluator. In lieu of assuming a point mass performance model, the aircraft is trimmed explicitly for nominal and off-nominal flight conditions for sizing propulsion system components and evaluating mission energy usage. In lieu of using historical tail volume ratio guidelines for stabilizer sizing, an explicit dynamic stability analysis is incorporated to determine the stabilizer size that achieves specified bare airframe handling qualities targets. The effects of varying battery specific energy, C-rate, wing loading, hover disk loading, mission range, and cruise speed on the sizing of the three propulsion architectures are explored. A comparison of the weight breakdown of the three propulsion variants when sized to the same maximum takeoff mass is presented. The sensitivity of the sizing results to the requirement of full vs reduced payload capability at high, hot hover conditions is also assessed. In addition to being insightful, the presented results reinforce the need to incorporate more physics-based analyses, additional stability and control considerations, and configuration optimization studies, which form natural avenues for follow-on work.

Flight capacity and human aversion in captive Amazon parrots: Related factors and the effects of pre-releasing training

The maintenance of parrots in captivity, caused by the illegal traffic and illegal ownership of these animals, makes them lose essential abilities for free-living survival, such as flight capacity and human avoidance, which hinders the success of reintroduction programs. Here, we assessed the influence of physical features (body weight, wing load, and plumage condition), endoparasites, and a training protocol on flight capacity and aversion to humans in captive parrots which were candidates for reintroduction. In addition, we assessed the relations of flight capacity and aversion to humans with the parrots’ temperament. Therefore, 38 parrots were submitted to a flight training and human aversion training protocol for 10 weeks. The following variables were registered over time for each animal: human aversion score, flight score, flight time (in s), and latency to flight (in s). A GLMM was adjusted to analyze the flight performance of the parrots over time, as well as the effects of body weight, wing load, occurrence of intestinal parasites, and plumage condition. Pearson correlation coefficients were applied to evaluate the association of parrots’ temperament with flight capacity and responsiveness to humans. We have observed a significant increase in the flight time (P = 0.0016) and flight score (P < 0.0001), as well as in the human aversion score (P < 0.0001). Factors that influenced flight capacity were body weight, wing load, and plumage condition. The temperament dimension neophilia was negatively correlated to the human aversion scores, with neophiliac parrots showing less aversion. The risk-taking dimension was negatively correlated to flight capacity, i.e. risk-averse parrots had better flight capacity. Using the training procedures described in this study, it was possible to improve flight capacity and increase aversion to humans, these abilities are essential for the animals’ survivorship in wild. Furthermore, we identified factors (body weight, wing load, plumage condition, and the temperament dimensions neophilia and risk-taking) that must be treated cautiously and that aid in the selection of individuals which are suitable for reintroduction, an important process for the conservation of endangered species.

Inferred costs and functional consequences of stone morphometry in the stone‐carrying displays of Black Wheatear (Oenanthe leucura)

Post‐mating courtship displays are often viewed as forms of sexual selection that allow individuals to assess fitness benefits from their mates based on honest signalling. However, display costs are not always easy to identify and quantify. Before each breeding attempt, male Black Wheatears Oenanthe leucura carry tens of heavy stones with the bill to form piles near the nest. The consequent increase of wing loading is considered the key display cost, and stone mass a key signal of male quality. However, males must also cope with neck and bill torques, and with outward‐pushing forces that tend to slip stones out of the bill; these effects partly depend on stone morphometry. I evaluated the effects of stone morphometry by comparing stones from two territory types differing in density (thus volume for a given mass), i.e. abandoned houses (less dense) versus rock outcrops (more dense). The comparison included samples of available stones to collect (ground), and stones actually collected by the birds (display). Regardless of territory type, display stones were significantly thinner, and generated higher estimated torques but lower outward‐pushing forces, than ground stones of the same mass. On average, display stones were also thicker in abandoned houses than in rock outcrops, but their mass was also significantly lower, which resulted in transport costs being similar between territory types. This suggests that males randomly select the stones that they can handle within the limits of local availability and, in abandoned houses, they have more difficulties in handling the heaviest transportable stones because many of these have too great a volume. This study calls for further experimental research on male performance and the cues that females use to assess the display. A broader conceptual framework is also necessary to address the behavioural and morphological consequences of carrying rigid objects with the bill.

Light to intermediate oil sheens increase Manx shearwater feather permeability.

Oil pollution has profound negative impacts on the marine environment, with seabirds particularly vulnerable to oiling, due to the amount of time spent on the sea surface foraging or resting. Exposure to oil can affect feather structure and influence waterproofing, buoyancy and thermoregulation. We investigated the effects of surface crude oil on the feather structure of Manx shearwaters (Puffinus puffinus), a seabird species that spends a high proportion of time on the water surface. Sampled body contour feathers were exposed to varying thicknesses of surface crude oil before assessing their resistance to water permeation, increase in mass and clumping of feather barbules. Surface oil as thin as 0.1 µm was enough to increase feather permeability, while greatest impacts on permeability were caused by exposure to dark colour surface sheens 3 µm in thickness. Increases in feather mass of up to 1000% were noted in heavy oiling scenarios due to contact with thicker oil slicks, which may significantly affect wing loading and energetic expenditure.

Sex specificity of dispersal behaviour and flight morphology varies among tree hollow beetle species

BackgroundFlight performance and dispersal behaviour can differ between sexes, resulting in sex-biased dispersal. The primary sex ratio of populations may also explain dispersal bias between sexes, as this bias may evolve with the primary sex ratio to reduce intrasexual competition. Although dispersal bias between sexes is relevant to population dynamics, there are few studies on sex-biased dispersal in insects. We studied the flight performance and dispersal behaviour of seven saproxylic beetle species associated with tree hollows from a sex perspective. We also analysed the possible coevolution of flight performance with the primary sex ratio.MethodsWing loading and wing aspect ratio were used as measures of the flight performance of species and sexes. Dispersal behaviour was explored by analysing the frequency of each sex in interception traps versus the primary sex ratio obtained by tree hollow emergence traps using contingency tables and posthoc standardized residuals. A more active flight behaviour was expected for the sex with higher capture frequency in the interception traps. To explore the causes of flight performance bias between sexes, we searched for possible correlations between wing loading or wing aspect ratio and primary sex ratio using Pearson’s correlation coefficient.ResultsWing loading and wing aspect ratio differed between species and sexes, with flight performance being higher in males than in females for four of the seven species analysed. Dispersal behaviour and flight performance matched in the case of Elater ferrugineus; males showed higher flight performance and were the most collected sex in the interception traps (more active flyers). In contrast, the higher flight activity of Cetonia carthami aurataeformis females was not correlated with a higher flight performance than that of males. Moreover, we found that a bias in the primary sex ratio towards females is often correlated with a decrease in female flight performance.ConclusionsWe stress that flight performance and dispersal behaviour of sexes do not always go hand in hand. Moreover, the relationship between the sex ratio and flight performance bias between sexes is not driven by competition within the most abundant sex. The inclusion of a sex perspective in insect dispersal studies would be useful to detect dispersal bias between sexes and its causes and would allow for further analysis of its effects on population dynamics.

A Comparison of Aerodynamic Parameters in Two Subspecies of the American Barn Owl (Tyto furcata).

Simple SummaryMorphology and function depend on the ecological niche in which an animal lives. Barn owls, occurring on all continents, occupy a nocturnal niche. These birds prey mainly on small rodents but include other small vertebrates and invertebrates in the diet. The size of the barn-owl species and subspecies varies considerably. The American continent harbors the species Tyto furcata. The body mass of the subspecies in North America (T.f.pratincola) is about a factor of two higher than that of the subspecies living on the Galapagos archipelago (T.f.puncatissima). We asked how this difference translates into aerodynamic parameters. The key question was whether there is so-called similarity scaling or not. In other words, whether important aerodynamic parameters scale according to body mass. This is called isometric scaling. Deviation from isometric scaling is called allometric scaling. If we use the subspecies from the continent as a reference, we find that the Galapagos barn owl has relatively larger wings than expected from isometric scaling. This translates into a lower wing loading in punctatissima than in pratincola. A lower wing loading means higher maneuverability. We speculate that the higher maneuverability allows the Galapagos owl to catch smaller prey, especially insects.Aerodynamic parameters, such as wing loading, are important indicators of flight maneuverability. We studied two subspecies of the American Barn owl (Tyto furcata), the North American subspecies, T.f.pratincola, and the Galapagos subspecies, T.f.punctatissima, with respect to aerodynamic parameters and compared our findings with those in other owl and bird species. The body mass of T.f.pratincola is about two times higher than that of T.f.punctatissima. Wing loading between the two subspecies scales allometrically. Wing loading in T.f.pratincola is about 50% higher than in T.f.punctatissima. The scaling of wing length is not statistically different from the prediction for isometric scaling. By contrast, the wing chord in T.f.punctatissima is larger than predicted by isometric scaling, as is the wing area. The scaling of wing loading observed here for T.f.punctatissima differs considerably from the scaling in other owl and bird species as available in the literature. We speculate that the allometric scaling helps T.f.punctatissima to catch smaller prey such, as insects that are found in many pellets of T.f.punctatissima, despite the fact that in both subspecies, small rodents make up most of the diet.

Environmental niche and flight intensity are associated with molecular evolutionary rates in a large avian radiation

BackgroundMetabolic activity and environmental energy are two of the most studied putative drivers of molecular evolutionary rates. Their extensive study, however, has resulted in mixed results and has rarely included the exploration of interactions among various factors impacting molecular evolutionary rates across large clades. Taking the diverse avian family Furnariidae as a case study, we examined the association between several estimates of molecular evolutionary rates with proxies of metabolic demands imposed by flight (wing loading and wing shape) and proxies of environmental energy across the geographic ranges of species (temperature and UV radiation).ResultsWe found weak evidence of a positive effect of environmental and morphological variables on mitochondrial substitution rates. Additionally, we found that temperature and UV radiation interact to explain molecular rates at nucleotide sites affected by selection and population size (non-synonymous substitutions), contrary to the expectation of their impact on sites associated with mutation rates (synonymous substitutions). We also found a negative interaction between wing shape (as described by the hand-wing index) and body mass explaining mitochondrial molecular rates, suggesting molecular signatures of positive selection or reduced population sizes in small-bodied species with greater flight activity.ConclusionsOur results suggest that the demands of flight and environmental energy pose multiple evolutionary pressures on the genome either by driving mutation rates or via their association with natural selection or population size. Data from whole genomes and detailed physiology across taxa will bring a more complete picture of the impact of metabolism, population size, and the environment on avian genome evolution.

Association of the Female Flight Ability of Asian Spongy Moths (Lymantria dispar asiatica) with Locality, Age and Mating: A Case Study from China

The spongy moth (formerly known as a gypsy moth), Lymantria dispar L. (Lepidoptera: Erebidae), is a polyphagous pest that defoliates various species of trees in the genera Populus, Salix, Quercus, Acer and Pinus. Egg masses of Asian spongy moths (Lymantria dispar asiatica) were obtained from five geographically distinct locations in China (Chengdu, Xifeng, Heilongjiang, Kuduer and Longhua regions) and were carried to the lab for incubation and rearing larvae up to adult emergence. The aim was to see how locality, age and mating status influenced the flying activity of female Asian spongy moths. The findings demonstrate that age significantly affects L. dispar asiatica flying activity, with flight period and distance decreasing dramatically as age increases. Locality also significantly impacts flight ability, and mating status does not affect the L. dispar asiatica female flight ability (p &gt; 0.05). The maximum speed was observed for females from Xifeng (7.19 ± 0.34 km/h). The females from Heilongjiang were recorded as having the maximum average speed (2.35 ± 0.08 km/h). Females from Xifeng exhibited the maximum flight duration and distance (0.94 ± 0.04 h and 1.87 ± 0.18 km). Morphological features, i.e., thorax width (cm) and wing loading, significantly influenced the L. dispar asiatica flight ability (R2 = 0.93 and R2 = −0.98). The overall pattern observed for female L. dispar asiatica flight duration was Xifeng &gt; Kuder &gt; Chengdu &gt; Heilongjiang &gt; Longhua, and for flight distance, it was Xifeng &gt; Longhua &gt; Heilongjiang &gt; Kuder &gt; Chengdu. This research offers detailed information on the dispersion rate of Spongy moths in a known or newly introduced habitat, which can help us limit the spread of this polyphagous pest.

Conceptual Research on a Mono-Biplane Aerodynamics-Driven Morphing Aircraft

The operation of aircrafts with high aspect ratio wings is usually vulnerable to low-standard airports and bad weather. A new concept for a mono-biplane aerodynamics-driven morphing aircraft is proposed. The movable and fixed wings form a biplane mode during takeoff and landing, while they form a high aspect ratio monoplane mode when cruising. This novel form of morphing can obtain a high cruise L/D while reducing nearly 50% of the takeoff and landing wingspan. However, the wing area is kept unchanged while morphing. The aerodynamic force on the movable wing is controlled by the deflection of the flaps to drive the morphing. No additional driving actuator is needed. In this way, although the morphing scale is large, the penalty on the complexity, structural strength, weight, and internal space of the wing is low. Taking the RQ-4A “Global Hawk” as the design baseline, morphing of the mono-biplane could further extend the cruise wingspan and aspect ratio for a better range without increasing the takeoff and landing span. When the wingspan was restricted, it was shown that this morphing scheme could reach a range extension of more than 50% when compared with an aircraft with the same wing load and different layouts. The feasibility of this mono-biplane aerodynamics-driven morphing concept was initially verified through ground vehicle tests. The possible influence of the morphing process on aircraft stability and control is also discussed.

Boeing ve Airbus uçaklarının kütle, boyut ve motor özellikleri arasındaki ilişkinin incelenmesi

In the study, it is aimed to analyze the mass, size, and engine characteristics of different Boeing and Airbus aircraft models, which are the duopoly in air transportation market, and to decipher the correlations between the conceptual design parameters of these aircraft. For this purpose, data on the production year, mass, size, and engine characteristics of 36 Boeing and 20 Airbus aircraft were collected. The fuselage length, cabin width, wingspan and wing area were considered as the size characteristics. In order to compare the mass characteristics of aircraft, the operational empty mass, engine mass and maximum take-off weight (MTOW) were examined. Since commercial jets are important in terms of aerodynamic design, that is, they determine the status of these aircraft models in the matching table, thrust weight and wing loading characteristics are also examined. Th fineness ratios decreased linearly as the wingspan/fuselage length ratios increased. Similarly, as MTOW increases, the operational empty weight/MTOW ratio tends to decrease. Both engine mass and the total thrust of the engines tended to increase linearly with MTOW. The correlations obtained on mass size and engine relations will contribute to the conceptual aircraft design and engine selection.

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.

Use of the helium ion microscope in small crack fractography

Highly stressed aerospace structures, such as the wing attachment points and load carry-through bulkheads of fighter aircraft, often grow fatigue cracks from micro-scale discontinuities. These cracks spend much of their lives close to these discontinuities in the small crack regime. The accurate prediction of fatigue crack growth in this small crack regime leads to setting realistic inspection thresholds for the aircraft and assisting in accurate risk-based assessment of the lives of such cracks. Fractography can greatly aid the assessment of the growth of small cracks. It has traditionally been carried out using optical and Scanning Electron Microscopes to gather the necessary small crack growth rate data, however, limitations on the resolution and the surface sensitivity of these instruments restricts the gathering of crack growth rate data at small crack lengths. As an extension to the current capabilities, the newly introduced Helium Ion Microscope offers improved nano-scale resolution and topographical sensitivity. As a result, the Helium Ion Microscope offers the potential for both quantitative and qualitative analysis of small fatigue crack growth about nucleating discontinuities at resolutions previously unobtainable. This paper presents an overview of the technology and gives three different fractographic examples of its possible applications to failure analysis. These examples include extension of small crack fractography, extension of near initiation fractographic feature analysis, and extension of nano-scale feature analysis. To demonstrate these capabilities, fatigue fractures produced by experimental loading spectra that were applied to the aluminium alloy AA7050-T7451 have been investigated.

Dietary salt supplementation adversely affects thermal acclimation responses of flight ability in Drosophila melanogaster

Cold acclimation may enhance low temperature flight ability, and salt loading can alter an insects’ cold tolerance by affecting their ability to maintain ion balance in the cold. Presently however, it remains unclear if dietary salt impacts thermal acclimation of flight ability in insects. Here, we examined the effect of a combination of dietary salt loading (either NaCl or KCl) and low temperature exposure on the flight ability of Drosophila melanogaster at low (15 °C) and benign (optimal, 22 °C) temperatures. Additionally, we determined whether dietary salt supplementation translates into increased K+ and Na+ levels in the bodies of D. melanogaster. Lastly, we determined whether salt supplementation impacts body mass and wing morphology, to ascertain whether any changes in flight ability were potentially driven by flight-related morphometric variation. In control flies, we find that cold acclimation enhances low temperature flight ability over non-acclimated flies confirming the beneficial acclimation hypothesis. By contrast, flies supplemented with KCl that were cold acclimated and tested at a cold temperature had the lowest flight ability, suggesting that excess dietary KCl during development negates the beneficial cold acclimation process that would have otherwise taken place. Overall, the NaCl-supplemented flies and the control group had the greatest flight ability, whilst those fed a KCl-supplemented diet had the lowest. Dietary salt supplementation translated into increased Na+ and K+ concentration in the body tissues of flies, confirming that dietary shifts are reflected in changes in body composition and are not simply regulated out of the body by homeostasis over the course of development. Flies fed with a KCl-supplemented diet tended to be larger with larger wings, whilst those reared on the control or NaCl-supplemented diet were smaller with smaller wings. Additionally, the flies with greater flight ability tended to be smaller and have lower wing loading. In conclusion, dietary salts affected wing morphology as well as ion balance, and dietary KCl seemed to have a detrimental effect on cold acclimation responses of flight ability in D. melanogaster.

Inverse size‐dependent phenology of female spruce budworms along reproductive and behavioral classes: an empirical study

AbstractThe incidence and causality of inverse size‐dependent phenology was investigated for spruce budworm, Choristoneura fumiferana (Clemens) (Lepidoptera: Tortricidae), in part due to large sample size [&gt;22000 feral females with known body size (wing area) and timing of emergence/occurrence]. Data collected in three Canadian provinces (New Brunswick, Nova Scotia, Quebec) between 1976 and 2019 included a wide array of sampling procedures grouped along gradients of reproductive classes. (1) For resident females of local origin (collected as pupae and allowed to emerge in the laboratory), body size declined over time at seven of seven sites, indicative of inverse size‐dependent timing of emergence. (2) Females foraging on trees (collected by fogging host trees or with sweep nets) exhibited declines in body size over time at five of five sites. (3) For behaviorally active females collected at traps (malaise, light, and canopy traps), inverse size‐dependent phenology of flight was observed at 20 of 23 combination of trap types/sites; partition of variance indicated limited variation in body size as a function of trap type, thus all inflight females were pooled in subsequent analyses. (4) In contrast to other sampling procedures, dead females collected on drop trays exhibited size‐dependent timing of mortality at only one of five sites. The article includes first body size measurements of migrant females captured in the troposphere with a kite balloon; as with other sampling procedures, body size decreased during the interval of sampling. Ongoing studies combining measurements of body size and dry weight of females (wing load) aim at inferring consequences of inverse size‐dependent phenology on reproduction and migration of budworms, including linkages with population dynamics.

Sexual Dimorphism in Body Size and Wing Loading for Three Cicada Species

Abstract Sexual dimorphism in body size has been observed for many insect species. However, whether dimorphism influences the flight performance for closely related insects or between the genders of conspecifics has seldom been examined. Wing loading (i.e., body mass/total wing area, WL = M/A) is an important indicator of flight efficiency and maneuverability. We examined the potential for sexual dimorphism and interspecific differences in wing loading for three cicada species (Cryptotympana atrata, Meimuna mongolica, and Platypleura kaempferi) and tested the hypothesis that females have higher WLs than males possibly because they must carry the extra weight of eggs. There were significant dimorphic differences in body mass and WL for each of the three species. However, there were no significant dimorphic differences in total wing area for C. atrata and M. mongolica, whereas P. kaempferi females had larger mean total wing area than males. Among the three cicada species, males had lower WLs (and by inference, greater maneuverability) than females. In addition, the M vs. A scaling exponent (i.e., α) was numerically significantly greater than unity (i.e., α &amp;gt; 1). Thus, WL should scale with respect to M with α &amp;gt; 1, which accounts for why females have a larger WL than males. We interpret these results to indicate that gender dimorphism in body size and flight performance likely reflect selection on traits affecting reproductive success that, in turn, likely depend on flight maneuverability.

Coandă-Type Flow Actuation for Load Alleviation

Circulation control has the potential to improve current gust and maneuver load alleviation schemes, with the ultimate goal of reducing wing structure weight and saving fuel. A Coandă-type flow actuator is integrated on the pressure side of a two-dimensional airfoil model, and its load alleviation performance and dynamic behavior are determined experimentally. Quasi-steady force and wake measurements are conducted in a wind tunnel to quantify the effect of the actuator on lift and drag. Lift decrements of are reached for steady blowing, exceeding typical gust-induced wing loads in magnitude. For pulsed blowing, only moderate mass flow reductions of up to 25% are achieved, caused by discontinuous flow turning around the Coandă surface. Unsteady force and pressure measurements characterize the dynamic lift response to the actuation. The total onset time of the lift response, normalized by the ratio of chord length to freestream velocity, is for actuator activation and for actuator deactivation. These values are below typical onset times for gust loads (). The present results show a high-lift reduction potential and fast dynamic behavior of the Coandă-type flow actuator, making it a viable candidate for fast and effective load alleviation.

A nondestructive method of calculating the wing area of insects.

Most insects engage in winged flight. Wing loading, that is, the ratio of body mass to total wing area, has been demonstrated to reflect flight maneuverability. High maneuverability is an important survival trait, allowing insects to escape natural enemies and to compete for mates. In some ecological field experiments, there is a need to calculate the wing area of insects without killing them. However, fast, nondestructive estimation of wing area for insects is not available based on past work. The Montgomery equation (ME), which assumes a proportional relationship between leaf area and the product of leaf length and width, is frequently used to calculate leaf area of plants, in crops with entire linear, lanceolate leaves. Recently, the ME was proved to apply to leaves with more complex shapes from plants that do not have any needle leaves. Given that the wings of insects are similar in shape to broad leaves, we tested the validity of the ME approach in calculating the wing area of insects using three species of cicadas common in eastern China. We compared the actual area of the cicadas’ wings with the estimates provided by six potential models used for wing area calculation, and we found that the ME performed best, based on the trade‐off between model structure and goodness of fit. At the species level, the estimates for the proportionality coefficients of ME for three cicada species were 0.686, 0.693, and 0.715, respectively. There was a significant difference in the proportionality coefficients between any two species. Our method provides a simple and powerful approach for the nondestructive estimation of insect wing area, which is also valuable in quantifying wing morphological features of insects. The present study provides a nondestructive approach to estimating the wing area of insects, allowing them to be used in mark and recapture experiments.

\u201cPhoenix in Flight\u201d: an unique fruit morphology ensures wind dispersal of seeds of the phoenix tree (Firmiana simplex (L.) W. Wight)

BackgroundMany seed plants produce winged diaspores that use wind to disperse their seeds. The morphology of these diaspores is directly related to the seed dispersal potential. The majority of winged diaspores have flat wings and only seeds; however, some angiosperms, such as Firmiana produce winged fruit with a different morphology, whose seed dispersal mechanisms are not yet fully understood. In this study, we observed the fruit development of F. simplex and determined the morphological characteristics of mature fruit and their effects on the flight performance of the fruit.ResultsWe found that the pericarp of F. simplex dehisced early and continued to unfold and expand during fruit development until ripening, finally formed a spoon-shaped wing with multiple alternate seeds on each edge. The wing caused mature fruit to spin stably during descent to provide a low terminal velocity, which was correlated with the wing loading and the distribution of seeds on the pericarp. When the curvature distribution of the pericarp surface substantially changed, the aerodynamic characteristics of fruit during descent altered, resulting in the inability of the fruit to spin.ConclusionsOur results suggest that the curved shape and alternate seed distribution are necessary for the winged diaspore of F. simplex to stabilize spinning during wind dispersal. These unique morphological characteristics are related to the early cracking of fruits during development, which may be an adaptation for the wind dispersal of seeds.