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Accurately evaluating the aerodynamic performance of the missile with damaged structures is very important for the subsequent flight control strategy. At present, few researchers have studied the aerodynamic characteristics of damaged supersonic cruise missiles. Based on CFD (computational fluid dynamics) solutions and the dynamic derivative identification method, the differences in static and dynamic characteristics between the damaged and undamaged models are compared. The results indicate that when the extent of damage increases, the change rate of drag coefficient at larger AoA (angle-of-attack) is greater than that at the smaller AoA. On the contrary, the change rate of lift coefficient at larger AoA is smaller than that at smaller AoA. Meanwhile, the absolute value of the static pitch moment decreases, but the absolute value of the roll moment increases. Damage causes a change in the absolute values of the pitch and roll dynamic derivatives, and the dynamic derivatives do not vary monotonically with the increase of AoA. The turning point occurs at about $\alpha$ = 5°. The areas of the hysteresis loops of the pitch-roll coupling moment increase, which makes the dynamic coupling characteristic between the pitch and roll directions increase. Finally, the maximum allowable damage extent of the missile wing that can achieve static trim is obtained and validated by controlling the deflection of the four rudders. [ABSTRACT FROM AUTHOR]

In this article, a fault-tolerant tracking control technique is developed for the ascent of hypersonic vehicles (HSV) experiencing wing damage and time-varying state constraints. The difficulty of control problem lies in handling state constraints associated with both state and time, while determining the unknown control directions of the multi-input multi-output (MIMO) nonlinear system. The presence of constraints in both state and time complicates the design of the control algorithm. This paper proposes the construction of a novel state transition function to establish a new unconstrained system, thereby eliminating the conservative feasibility conditions of Barrier Lyapunov Function (BLF) and integral BLF methods when dealing with time-varying constraints. The fusion of time-varying scaling functions and Nussbaum-type functions not only resolves the issue of unknown control directions in the MIMO nonlinear system but also enhances the transient and steady-state performance of the closed-loop system. Neural Networks are employed to approximate the unknown nonlinear functions. Using Lyapunov stability theory, it is proven that state constraints are not violated, and all signals in the closed-loop system are bounded. Simulation results demonstrate the merits of the designed fault-tolerant control (FTC) algorithm. • A unified fault-tolerant control scheme for the ascent hypersonic vehicle is designed. • Wing damage and function constraints on states are considered. • Nonlinear mapping eliminates the feasibility conditions in barrier Lyapunov functions. • The unknown control direction issue in multivariable nonlinear systems is resolved. [ABSTRACT FROM AUTHOR]

The patterns of recovery from injury or infection are not well studied in free-ranging animals. Bats that survive the fungal disease white-nose syndrome (WNS) often emerge from hibernation suffering from skin infections and wing damage. The extent of wing damage reflects physiological and immunological responses to WNS and may impact the ability of bats to fly, forage, and reproduce. Here, we built on previous studies of wing damage in both captive and free-ranging bats to better understand the patterns and extent of wing damage healing in little brown bats (Myotis lucifugus) post-hibernation. We quantified two main types of wing damage, black necrotic dots and white spots, and used the extent of damage to assign bats 1 of 6 wing damage scores. We found that the patterns of black dots and white spots on wing membranes of free-ranging bats aligned with the patterns observed in captive bats soon after emergence from hibernation. Black dot extent was highest at the beginning of the active season in May, while white spot extent peaked 3–4 weeks later. Our study also extends our knowledge of wing damage healing throughout the active season. Wing scores of bats recaptured within the summer decreased or stayed the same and >95% had negligible signs of wing damage by August. We found that black dots were more indicative of disease status than other types of wing damage and could be consistently quantified in the field and from photographs by multiple observers. These results suggest that black dots and our wing damage scoring system can be used to better understand the patterns of post-hibernation healing in little brown bats impacted by WNS. [ABSTRACT FROM AUTHOR]

Previous work has shown that wing wear increases mortality in bumblebees. Although a proximate mechanism for this phenomenon has remained elusive, a leading hypothesis is that wing wear increases predation risk by reducing flight manoeuvrability. We tested the effects of simulated wing wear on flight manoeuvrability in Bombus impatiens bumblebees using a dynamic obstacle course designed to push bees towards their performance limits. We found that removing 22% wing area from the tips of both forewings (symmetric wear) caused a 9% reduction in peak acceleration during manoeuvring flight, while performing the same manipulation on only one wing (asymmetric wear) did not significantly reduce maximum acceleration. The rate at which bees collided with obstacles was correlated with body length across all treatments, but wing wear did not increase collision rate, possibly because shorter wingspans allow more room for bees to manoeuvre. This study presents a novel method for exploring extreme flight manoeuvres in flying insects, eliciting peak accelerations that exceed those measured during flight through a stationary obstacle course. If escape from aerial predation is constrained by acceleration capacity, then our results offer a potential explanation for the observed increase in bumblebee mortality with wing wear.

Predation is a powerful selective force shaping many behavioural and morphological traits in prey species. The deflection of predator attacks from vital parts of the prey usually involves the coordinated evolution of prey body shape and colour. Here, we test the deflection effect of hindwing (HW) tails in the swallowtail butterfly Iphiclides podalirius. In this species, HWs display long tails associated with a conspicuous colour pattern. By surveying the wings within a wild population of I. podalirius, we observed that wing damage was much more frequent on the tails. We then used a standardized behavioural assay employing dummy butterflies with real I. podalirius wings to study the location of attacks by great tits Parus major. Wing tails and conspicuous coloration of the HWs were struck more often than the rest of the body by birds. Finally, we characterized the mechanical properties of fresh wings and found that the tail vein was more fragile than the others, suggesting facilitated escape ability of butterflies attacked at this location. Our results clearly support the deflective effect of HW tails and suggest that predation is an important selective driver of the evolution of wing tails and colour pattern in butterflies. [ABSTRACT FROM AUTHOR]

Flying insects have a robust flight system that allows them to fly even when their forewings are damaged. The
insect must adjust wingbeat kinematics to aerodynamically compensate for the loss of wing area. However, the
mechanisms that allow insects with asynchronous flight muscle to adapt to wing damage are not well understood.
Here, we investigated the phase and amplitude relationships between thorax deformation and flapping angle in
tethered flying bumblebees subject to wing clipping and weighting. We used synchronized laser vibrometry and
high-speed videography to measure thorax deformation and flapping angle, respectively. We found that changes
in wing inertia did not affect thorax deformation amplitude but did influence wingbeat frequency. Increasing
wing inertia increased flapping amplitude and caused a phase lag between thorax deformation and flapping
angle, whereas decreasing wing inertia did not affect flapping amplitude and caused the flapping angle to lead
thorax deformation. Based on our findings, we proposed a qualitative model of the insect flight system. This
model suggests insects leverage a wing hinge-dominated vibration mode to fly, and highlights the possibility of a
disproportionate damping between the wing hinge and thorax when the insect's wings are clipped. The results
of our study provide insights into the robust design of insect-inspired flapping wing micro air vehicles., (Creative Commons Attribution license.)

Ground-dwelling species of birds, such as domestic chickens (Gallus gallus domesticus), experience difficulties sustaining flight due to high wing loading. This limited flight ability may be exacerbated by loss of flight feathers that is prevalent among egg-laying chickens. Despite this, chickens housed in aviary style systems need to use flight to access essential resources stacked in vertical tiers. To understand the impact of flight feather loss on chickens' ability to access elevated resources, we clipped primary and secondary flight feathers for two hen strains (brown-feathered and white-feathered, n = 120), and recorded the time hens spent at elevated resources (feeders, nest-boxes). Results showed that flight feather clipping significantly reduced the percentage of time that hens spent at elevated resources compared to ground resources. When clipping both primary and secondary flight feathers, all hens exhibited greater than or equal to 38% reduction in time spent at elevated resources. When clipping only primary flight feathers, brown-feathered hens saw a greater than 50% reduction in time spent at elevated nest-boxes. Additionally, brown-feathered hens scarcely used the elevated feeder regardless of treatment. Clipping of flight feathers altered the amount of time hens spent at elevated resources, highlighting that distribution and accessibility of resources is an important consideration in commercial housing.

The mechanics of Dipteran thorax is dictated by a network of exoskeletal linkages that, when deformed by the flight muscles, generate coordinated wing movements. In Diptera, the forewings power flight, whereas the hindwings have evolved into specialized structures called halteres, which provide rapid mechanosensory feedback for flight stabilization. Although actuated by independent muscles, wing and haltere motion is precisely phase-coordinated at high frequencies. Because wingbeat frequency is a product of wing-thorax resonance, any wear-and-tear of wings or thorax should impair flight ability. How robust is the Dipteran flight system against such perturbations? Here, we show that wings and halteres are independently driven, coupled oscillators. We systematically reduced the wing length in flies and observed how wing-haltere synchronization was affected. The wing-wing system is a strongly coupled oscillator, whereas the wing-haltere system is weakly coupled through mechanical linkages that synchronize phase and frequency. Wing-haltere link acts in a unidirectional manner; altering wingbeat frequency affects haltere frequency, but not vice versa. Exoskeletal linkages are thus key morphological features of the Dipteran thorax that ensure wing-haltere synchrony, despite severe wing damage.

Mass production of Coenosia attenuata Stein at low cost is very important for their use as a biological control agent. The present study reports the performance of C. attenuata adults when reared on Drosophila melanogaster Meigen or Bradysia impatiens (Johannsem). Different densities (6, 9, 15, 24 and 36 adults per predator) of D. melanogaster or (6, 12, 24, 36 and 48 adults per predator) of B. impatiens were used at 26 ± 1 °C, 14:10 (L:D) and 70 ± 5% RH. The results concluded that C. attenuata adults had higher fecundity, longer longevity and less wing damage when reared on B. impatiens adults compared to D. melanogaster adults. Additionally, C. attenuata adults demonstrated greater difficulty catching and carrying heavier D. melanogaster adults than lighter B. impatiens adults. In this case, 12 to 24 adults of B. impatiens daily per predator were considered optimal prey density in the mass rearing of adult C. attenuata.

Polygonia c-aureum females exhibit photoperiodically induced imaginal diapause, characterized by cessation of ovarian development. Females grown at a short daylength (SD) entered imaginal diapause, whereas those grown at a long daylength (LD) produced eggs rapidly after adult emergence at 21 °C. The termination of diapause was influenced by daylength: diapause ended faster at LD than SD. Complete termination of diapause took 30 days in unchilled females reared under LD at 21 °C. On the other hand, prompt, synchronized and strong diapause termination occurred at post-chilling periods. Photoperiods at post-chilling periods affected ovarian development, when the length of pre-chilling periods or the length of chilling periods was shorter, suggesting that these treatments were not enough to complete diapause development. Ovarian development proceeded earlier in chilled and subsequent warmed females than unchilled females. Wing damage was remarkable at post-chilling periods when females were reared under an adequate length of pre-chilling and chilling periods, especially comparing with females under pre-overwintering conditions without chilling, indicating that post-diapause reproductive development was weak in unchilled females. Thus, exposure to low temperatures is necessary for a strong diapause termination in this butterfly. [ABSTRACT FROM AUTHOR]

Pseudogymnoascus destructans is an ascomycetous fungus responsible for the disease dubbed white-nose syndrome (WNS) and massive mortalities of cave-dwelling bats. The fungus infects bat epidermal tissue, causing damage to integumentary cells and pilosebaceous units. Differences in epidermal lipid composition caused by P. destructans infection could have drastic consequences for a variety of physiological functions, including innate immune efficiency and water retention. While bat surface lipid and stratum corneum lipid composition have been described, the differences in epidermal lipid content between healthy tissue and P. destructans-infected tissue have not been documented. In this study, we analyzed the effect of wing damage from P. destructans infection on the epidermal polar lipid composition (glycerophospholipids [GPs] and sphingomyelin) of little brown bats (Myotis lucifugus). We hypothesized that infection would lead to lower levels of total lipid or higher oxidized lipid product proportions. Polar lipids from three damaged and three healthy wing samples were profiled by electrospray ionization tandem mass spectrometry. We found lower total broad lipid levels in damaged tissue, specifically etherlinked phospholipids, lysophospholipids, phosphatidylcholine, and phosphatidylethanolamine. Thirteen individual GP species from four broad GP classes were present in higher amounts in healthy tissue. Six unsaturated GP species were absent in damaged tissue. Our results confirm that P. destructans infection leads to altered lipid profiles. Clinical signs of WNS may include lower lipid levels and lower proportions of unsaturated lipids due to cellular and glandular damage. [ABSTRACT FROM AUTHOR]

In this study, we performed successive unilateral and bilateral wing shearing to simulate wing damage in droneflies ( Eristalis tenax ) and measured the wing kinematics using high-speed photography technology. Two different shearing types were considered in the artificial wing damage. The aerodynamic force and power consumption were obtained by numerical method. Our major findings are the following. Different shearing methods have little influence on the kinematics, forces and energy consumption of insects. Following wing damage, among the potential strategies to adjust the three Euler angles of the wing, adjusting stroke angle ( φ ) in isolation, or combing the adjustment of stroke angle ( φ ) with pitch angle ( ψ ), contributed most to the change in vertical force. The balance of horizontal thrust can be restored by the adjustment of deviation angle ( θ ) under the condition of unilateral wing damage. Considering zero elastic energy storage, the mass-specific power ( P ) increases significantly following wing damage. However, the increase in mass-specific power with 100% elastic energy storage ( 1 ) is very small. The extra cost of the unilateral wing damage is that the energy consumption of the damaged wing and intact wing is highly asymmetrical when zero elastic energy storage is considered. The insects may alleviate the problems of increasing power consumption and asymmetric power distribution by storage and reuse of the negative inertial work of the wing.P 2 ) is very small. The extra cost of the unilateral wing damage is that the energy consumption of the damaged wing and intact wing is highly asymmetrical when zero elastic energy storage is considered. The insects may alleviate the problems of increasing power consumption and asymmetric power distribution by storage and reuse of the negative inertial work of the wing., (© 2023 IOP Publishing Ltd.)

Male field crickets acoustically signal to attract females by raising their forewings and rubbing them together to produce 'regular' (lemon-shaped) pulse sound waveforms. In contrast, we have observed that spring field crickets, Gryllus veletis, often produce an irregularly shaped pulse that exhibits a complete drop in amplitude near the center of the pulse, termed 'gap pulses.' We tracked the occurrence of regular and gap pulses temporally. Males change how they signal through time, producing increasingly more gap pulses later in the night and in the morning than through the afternoon and evening. Wing wear did not explain variation in gap pulse production. However, variation in gap pulse production is attributable to variation in body size, with larger males that signal with longer chirps and at lower carrier frequencies producing relatively more gap pulses than smaller males. We hypothesize possible proximate and ultimate causes for the production of gap pulses. [ABSTRACT FROM AUTHOR]

Infection of North American bats with the keratin-digesting fungus Geomyces destructans often results in holes and ruptures of wing membranes, yet it is unknown whether flight performance and metabolism of bats are altered by such injuries. I conducted flight experiments in a circular flight arena with Myotis albescens and M. nigricans individuals with an intact or ruptured trailing edge of one of the plagiopatagial membranes. In both species, individuals with damaged wings were lighter, had a higher aspect ratio (squared wing span divided by wing area) and an increased wing loading (weight divided by wing area) than conspecifics with intact wings. Bats with an asymmetric reduction of the wing area flew at similar speeds to conspecifics with intact wings but performed fewer flight manoeuvres. Individuals with damaged wings showed lower metabolic rates during flight than conspecifics with intact wings, even when controlling for body mass differences; the difference in mass-specific metabolic rate may be attributable to the lower number of flight manoeuvres (U-turns) by bats with damaged wings compared with conspecifics with intact wings. Possibly, bats compensated for an asymmetric reduction in wing area by lowering their body mass and avoiding flight manoeuvres. In conclusion, it may be that bats suffer from moderate wing damage not directly, by experiencing increased metabolic rate, but indirectly, by a reduced manoeuvrability and foraging success. This could impede a bat's ability to gain sufficient body mass before hibernation. [ABSTRACT FROM AUTHOR]

White-nose syndrome (WNS) is having an unprecedented impact on hibernating bat populations in the eastern United States. While most studies have focused on widespread mortality observed at winter hibernacula, few have examined the consequences of wing damage that has been observed among those bats that survive hibernation. Given that WNS-related wing damage may lead to life-threatening changes in wing function, we tested the hypothesis that reduced abundance of free-ranging little brown myotis ( Myotis lucifugus) with severe wing damage as the summer progresses is due to healing of wing tissue. Photographs of captured and recaptured adult females were examined for wing damage and healing rates were calculated for each category of wing damage index (WDI = 0-3). We found that free-ranging bats with severe wing damage were able to heal to a lower WDI score within 2 weeks. Bats with the most severe wing damage had faster healing rates than did individuals with less damage. We also found a significant relationship between body condition and WDI for adult females captured in the early weeks of the active season. Our results support the hypothesis that some bats can heal from severe wing damage during the active season, and thus may not experience increased mortality associated with reduced functions of wings. We urge researchers and wildlife managers to use caution when interpreting data on WDI to assess the impact of WNS on bat populations, especially during the later months of the active season. [ABSTRACT FROM AUTHOR]

Nonrepairable body damage such as tooth and wing wear commonly occur in animals and can dramatically alter their behaviour. We critically examined the effects of nonrepairable damage in a model system that enabled us to separate the effects of damage from other correlated effects of senescence. Compared to sham controls, honeybees with 20% of their front wings trimmed continued to forage at similar rates and reduced their net rate of food delivery by approximately 20%. The changes in flight behaviour allowing the foragers to cope with the substantial wing damage probably occurred immediately following wing trimming. Bees showed no increase in foraging performance either in successive trips or during the 2 days following wing trimming. The cost of maintaining relatively high foraging performance after sustaining severe wing damage was approximately a 20% increase in mortality rate, most likely owing to predation. Our results illustrate a remarkable versatility of honeybees’ flight behaviour, which allows them to handle the inevitable nonrepairable body damage that naturally occurs with ageing. [Copyright &y& Elsevier]

The article presents a study that deals with the dynamics of animal movement in an ecological context. It highlights the role of dragonfly wing damage in reducing flight performance and predation. The authors linked experiments on simple motions in the laboratory to studies of more complex behaviours in natural settings. Based on the results, the authors concluded that wing damage can reduce both reproductive success and survival.

The moth Rothschildia lebeau uses three tree species as its primary larval hosts in the tropical dry forest of northwestern Costa Rica. These hosts were shown previously to have different relative effects on caterpillar performance, resulting in an apparent host-related life history trade-off between large adult body size on the one hand but low offspring survival on the other. To further assess the potential ecological and evolutionary importance of this trade-off, an observational field study of the relationship between male body size and mating success was conducted. Across mating trials, larger males had a higher probability of being observed mating. Independent of the effect of size, the amount of wing damage an individual had sustained (a measure of relative age) was negatively correlated with the probability a male was observed mating. Within mating trials, the mated male tended to be larger than the average unmated male, but there was no difference in wing damage. Overall, results of this study were consistent with a positive effect of male body size on mating success, consistent with the idea that larval host plant history and its effects on adult body size matters in terms of adult male fitness. However, all sized males were observed mating over the course of the study, and the size advantage did not appear to be particularly strong. Abstract in Spanish is available at [ABSTRACT FROM AUTHOR]

The article discusses a study which assessed healing rates of wing punch wounds in little brown myotis in Pennsylvania using calipers and digital photographs. Results showed that wounds created with 3.0 millimeter sterile biopsy punches displayed little healing in the first 6-7 days after wound creation. Wound size decreased in all bats after the first week although the individual rates of healing varied among recaptured bats. Factors such as photoperiod, energy stores and stress affect both the immune system and allocation of energy in bats. The time course of healing indicates that it progressed through the inflammatory stage, proliferative stag and remodeling stage.

1. Nectar-foraging honeybees ( Apis mellifera) on lavender ( Lavandula stoechas) appear to forage so as to maximise net energy return from foraging bouts; however, evidence from other studies suggests that foraging has a detrimental effect on survival, due at least in part to physiological deterioration of the flight mechanism. But foragers also acquire wing damage during foraging, which may increase foraging effort and reduce foraging lifespan. 2. The accumulation of damage over time and its effects on foraging flight and flower choice were studied in the field using a system in which the criteria for flower preference by foragers was known from previous work. Wing damage accumulated exponentially over time and resulted in foragers becoming less choosy about the flowers they visited. 3. Damage added experimentally contributed independently to the effect on choosiness. Effects of wing damage (natural and added experimentally) were also independent of those of a relative measure of age, which related in an inconsistent way to changes in foraging preferences. [ABSTRACT FROM AUTHOR]

Simple Summary: The predaceous fly Coenosia attenuata Stein has received attention because of its ability to effectively suppress a wide range of agricultural pests, such as fungus gnats, whiteflies and leaf miners. An effective level of control requires large numbers of C. attenuata to be available at low cost for release. Adult fungus gnats and drosophilids are now the main prey used to rear C. attenuata adults. However, previous studies showed C. attenuata fertility is lower when fed drosophilids compared to fungus gnats. The current study investigated the performance of C. attenuata adults when reared on different densities of adult Drosophila melanogaster Meigen or Bradysia impatiens (Johannsem). Results showed that the optimal prey density in the mass rearing of adult C. attenuata was 12–24 adult B. impatiens daily per predator. Additionally, C. attenuata adults suffered more wing damage, at some of the prey densities, when reared on D. melanogaster compared to B. impatiens. This information will be used to optimize rearing methods and decrease the cost of mass rearing in C. attenuata. Mass production of Coenosia attenuata Stein at low cost is very important for their use as a biological control agent. The present study reports the performance of C. attenuata adults when reared on Drosophila melanogaster Meigen or Bradysia impatiens (Johannsem). Different densities (6, 9, 15, 24 and 36 adults per predator) of D. melanogaster or (6, 12, 24, 36 and 48 adults per predator) of B. impatiens were used at 26 ± 1 °C, 14:10 (L:D) and 70 ± 5% RH. The results concluded that C. attenuata adults had higher fecundity, longer longevity and less wing damage when reared on B. impatiens adults compared to D. melanogaster adults. Additionally, C. attenuata adults demonstrated greater difficulty catching and carrying heavier D. melanogaster adults than lighter B. impatiens adults. In this case, 12 to 24 adults of B. impatiens daily per predator were considered optimal prey density in the mass rearing of adult C. attenuata. [ABSTRACT FROM AUTHOR]

Wing integrity is crucial to the many insect species that spend distinct portions of their life in flight. How insects cope with the consequences of wing damage is therefore a central question when studying how robust flight performance is possible with such fragile chitinous wings. It has been shown in a variety of insect species that the loss in lift-force production resulting from wing damage is generally compensated by an increase in wing beat frequency rather than amplitude. The consequences of wing damage for flight performance, however, are less well understood, and vary considerably between species and behavioural tasks. One hypothesis reconciling the varying results is that wing damage might affect fast flight manoeuvres with high acceleration, but not slower ones. To test this hypothesis, we investigated the effect of wing damage on the manoeuvrability of hummingbird hawkmoths ( Macroglossum stellatarum ) tracking a motorised flower. This assay allowed us to sample a range of movements at different temporal frequencies, and thus assess whether wing damage affected faster or slower flight manoeuvres. We show that hummingbird hawkmoths compensate for the loss in lift force mainly by increasing wing beat amplitude, yet with a significant contribution of wing beat frequency. We did not observe any effects of wing damage on flight manoeuvrability at either high or low temporal frequencies., Competing Interests: Competing interestsThe authors declare no competing or financial interests., (© 2021. Published by The Company of Biologists Ltd.)