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1.
Zoolog Sci ; 38(5): 427-435, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34664917

RESUMO

No scales of most lepidopterans (butterflies and moths) detach from the wings through fluttering. However, in the pellucid hawk moth, Cephonodes hylas, numerous scales detach from a large region of the wing at initial take-off after eclosion; consequently, a large transparent region without scales appears in the wing. Even after this programmed detachment of scales (d-scales), small regions along the wing margin and vein still have scales attached (a-scales). To investigate the scale detachment mechanism, we analyzed the scale detachment process using video photography and examined the morphology of both d- and a-scales using optical and scanning electron microscopy. This study showed that d-scale detachment only occurs through fluttering and that d-scales are obviously morphologically different from a-scales. Although a-scales are morphologically common lepidopteran scales, d-scales have four distinctive features. First, d-scales are much larger than a-scales. Second, the d-scale pedicel, which is the slender base of the scale, is tapered; that of the a-scale is columnar. Third, the socket on the wing surface into which the pedicel is inserted is much smaller for d-scales than a-scales. Fourth, the d-scale socket density is much lower than the a-scale socket density. This novel scale morphology likely helps to facilitate scale detachment through fluttering and, furthermore, increases wing transparency.


Assuntos
Mariposas/anatomia & histologia , Asas de Animais/anatomia & histologia , Animais , Voo Animal/fisiologia , Metamorfose Biológica , Mariposas/crescimento & desenvolvimento , Asas de Animais/ultraestrutura
2.
J Insect Physiol ; 134: 104293, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34389411

RESUMO

Winged insects vary greatly in size, from tiny wasps (0.015 mg) to large moths (1.6 g). Previous studies on the power requirements of insect flight focused on relatively large insects; those of miniature insects remain relatively unknown. In this study the power requirements of a series of miniature insects were calculated, and changes with size across a range of insect sizes were investigated. Aerodynamic power was computed by numerically solving the Navier-Stokes equation, and inertial power was computed analytically. Comparison analysis was then conducted on the power requirements of miniature and large insects. Despite a 100,000-fold weight difference, the required power per unit insect mass, referred to as mass-specific power, was approximately equal for all the insects examined. This finding is explained as follows. Power is approximately proportional to the product of the wing speed and the wing drag per unit weight (i.e., "drag-to-lift ratio"). When insect size decreased, wing speed decreased (due to reduced wing-length), while wing drag increased (due to increased air-viscosity), resulting in an approximately unchanged mass-specific power. For large or small insects, flight power is derived from the same type of muscles (striated). Assuming that the mean power per unit muscle mass is the same under the same type of muscle, the above size/specific-power relation indicates that the ratio of flight-muscle mass to insect mass is the same for different sized insects.


Assuntos
Tamanho Corporal , Voo Animal/fisiologia , Insetos/fisiologia , Asas de Animais/fisiologia , Animais , Fenômenos Biomecânicos , Simulação por Computador , Modelos Biológicos
3.
J Insect Physiol ; 134: 104297, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34403656

RESUMO

Bumble bees are eusocial, with distinct worker and queen castes that vary strikingly in size and life-history. The smaller workers rely on energetically-demanding foraging flights to collect resources for rearing brood. Queens can be 3 to 4 times larger than workers, flying only for short periods in fall and again in spring after overwintering underground. These differences between castes in size and life history may be reflected in hypoxia tolerance. When oxygen demand exceeds supply, oxygen delivery to the tissues can be compromised. Previous work revealed hypermetric scaling of tracheal system volume of worker bumble bees (Bombus impatiens); larger workers had much larger tracheal volumes, likely to facilitate oxygen delivery over longer distances. Despite their much larger size, queens had relatively small tracheal volumes, potentially limiting their ability to deliver oxygen and reducing their ability to respond to hypoxia. However, these morphological measurements only indirectly point to differences in respiratory capacity. To directly assess size- and caste-related differences in tolerance to low oxygen, we measured critical PO2 (Pcrit; the ambient oxygen level below which metabolism cannot be maintained) during both rest and flight of worker and queen bumble bees. Queens and workers had similar Pcrit values during both rest and flight. However, during flight in oxygen levels near the Pcrit, mass-specific metabolic rates declined precipitously with mass both across and within castes, suggesting strong size limitations on oxygen delivery, but only during extreme conditions, when demand is high and supply is low. Together, these data suggest that the comparatively small tracheal systems of queen bumble bees do not limit their ability to deliver oxygen except in extreme conditions; they pay little cost for filling body space with eggs rather than tracheal structures.


Assuntos
Abelhas , Voo Animal/fisiologia , Oxigênio/metabolismo , Animais , Abelhas/metabolismo , Abelhas/fisiologia , Hipóxia , Respiração , Fenômenos Fisiológicos Respiratórios
4.
Nature ; 596(7872): 404-409, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34381211

RESUMO

As animals navigate on a two-dimensional surface, neurons in the medial entorhinal cortex (MEC) known as grid cells are activated when the animal passes through multiple locations (firing fields) arranged in a hexagonal lattice that tiles the locomotion surface1. However, although our world is three-dimensional, it is unclear how the MEC represents 3D space2. Here we recorded from MEC cells in freely flying bats and identified several classes of spatial neurons, including 3D border cells, 3D head-direction cells, and neurons with multiple 3D firing fields. Many of these multifield neurons were 3D grid cells, whose neighbouring fields were separated by a characteristic distance-forming a local order-but lacked any global lattice arrangement of the fields. Thus, whereas 2D grid cells form a global lattice-characterized by both local and global order-3D grid cells exhibited only local order, creating a locally ordered metric for space. We modelled grid cells as emerging from pairwise interactions between fields, which yielded a hexagonal lattice in 2D and local order in 3D, thereby describing both 2D and 3D grid cells using one unifying model. Together, these data and model illuminate the fundamental differences and similarities between neural codes for 3D and 2D space in the mammalian brain.


Assuntos
Quirópteros/fisiologia , Percepção de Profundidade/fisiologia , Córtex Entorrinal/citologia , Córtex Entorrinal/fisiologia , Células de Grade/fisiologia , Modelos Neurológicos , Animais , Comportamento Animal/fisiologia , Voo Animal/fisiologia , Masculino
5.
PLoS Comput Biol ; 17(8): e1009195, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34379622

RESUMO

Animals rely on sensory feedback to generate accurate, reliable movements. In many flying insects, strain-sensitive neurons on the wings provide rapid feedback that is critical for stable flight control. While the impacts of wing structure on aerodynamic performance have been widely studied, the impacts of wing structure on sensing are largely unexplored. In this paper, we show how the structural properties of the wing and encoding by mechanosensory neurons interact to jointly determine optimal sensing strategies and performance. Specifically, we examine how neural sensors can be placed effectively on a flapping wing to detect body rotation about different axes, using a computational wing model with varying flexural stiffness. A small set of mechanosensors, conveying strain information at key locations with a single action potential per wingbeat, enable accurate detection of body rotation. Optimal sensor locations are concentrated at either the wing base or the wing tip, and they transition sharply as a function of both wing stiffness and neural threshold. Moreover, the sensing strategy and performance is robust to both external disturbances and sensor loss. Typically, only five sensors are needed to achieve near-peak accuracy, with a single sensor often providing accuracy well above chance. Our results show that small-amplitude, dynamic signals can be extracted efficiently with spatially and temporally sparse sensors in the context of flight. The demonstrated interaction of wing structure and neural encoding properties points to the importance of understanding each in the context of their joint evolution.


Assuntos
Voo Animal/fisiologia , Insetos/anatomia & histologia , Insetos/fisiologia , Modelos Biológicos , Asas de Animais/anatomia & histologia , Asas de Animais/inervação , Potenciais de Ação/fisiologia , Animais , Evolução Biológica , Fenômenos Biomecânicos , Biologia Computacional , Simulação por Computador , Retroalimentação Sensorial/fisiologia , Manduca/anatomia & histologia , Manduca/fisiologia , Mecanorreceptores/fisiologia , Modelos Neurológicos , Rotação , Asas de Animais/fisiologia
6.
PLoS Comput Biol ; 17(7): e1009260, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-34319987

RESUMO

Central place foraging pollinators tend to develop multi-destination routes (traplines) to exploit patchily distributed plant resources. While the formation of traplines by individual pollinators has been studied in detail, how populations of foragers use resources in a common area is an open question, difficult to address experimentally. We explored conditions for the emergence of resource partitioning among traplining bees using agent-based models built from experimental data of bumblebees foraging on artificial flowers. In the models, bees learn to develop routes as a consequence of feedback loops that change their probabilities of moving between flowers. While a positive reinforcement of movements leading to rewarding flowers is sufficient for the emergence of resource partitioning when flowers are evenly distributed, the addition of a negative reinforcement of movements leading to unrewarding flowers is necessary when flowers are patchily distributed. In environments with more complex spatial structures, the negative experiences of individual bees on flowers favour spatial segregation and efficient collective foraging. Our study fills a major gap in modelling pollinator behaviour and constitutes a unique tool to guide future experimental programs.


Assuntos
Abelhas/fisiologia , Modelos Biológicos , Animais , Comportamento Animal/fisiologia , Biologia Computacional , Simulação por Computador , Comportamento Alimentar/fisiologia , Voo Animal/fisiologia , Flores , Aprendizagem/fisiologia , Polinização , Reforço Psicológico , Análise de Sistemas
7.
PLoS One ; 16(7): e0255117, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34293059

RESUMO

In this study, we describe an inexpensive and rapid method of using video analysis and identity tracking to measure the effects of tag weight on insect movement. In a laboratory experiment, we assessed the tag weight and associated context-dependent effects on movement, choosing temperature as a factor known to affect insect movement and behavior. We recorded the movements of groups of flightless adult crickets Gryllus locorojo (Orthoptera:Gryllidae) as affected by no tag (control); by light, medium, or heavy tags (198.7, 549.2, and 758.6 mg, respectively); and by low, intermediate, or high temperatures (19.5, 24.0, and 28.3°C, respectively). Each individual in each group was weighed before recording and was recorded for 3 consecutive days. The mean (± SD) tag mass expressed as a percentage of body mass before the first recording was 26.8 ± 3.7% with light tags, 72 ± 11.2% with medium tags, and 101.9 ± 13.5% with heavy tags. We found that the influence of tag weight strongly depended on temperature, and that the negative effects on movement generally increased with tag weight. At the low temperature, nearly all movement properties were negatively influenced. At the intermediate and high temperatures, the light and medium tags did not affect any of the movement properties. The continuous 3-day tag load reduced the average movement speed only for crickets with heavy tags. Based on our results, we recommend that researchers consider or investigate the possible effects of tags before conducting any experiment with tags in order to avoid obtaining biased results.


Assuntos
Voo Animal/fisiologia , Gryllidae/fisiologia , Movimento/fisiologia , Gravação em Vídeo , Animais , Peso Corporal , Modelos Lineares , Descanso , Telemetria , Temperatura
8.
Commun Biol ; 4(1): 737, 2021 06 15.
Artigo em Inglês | MEDLINE | ID: mdl-34131288

RESUMO

For flying insects, stability is essential to maintain the orientation and direction of motion in flight. Flight instability is caused by a variety of factors, such as intended abrupt flight manoeuvres and unwanted environmental disturbances. Although wings play a key role in insect flight stability, little is known about their oscillatory behaviour. Here we present the first systematic study of insect wing damping. We show that different wing regions have almost identical damping properties. The mean damping ratio of fresh wings is noticeably higher than that previously thought. Flight muscles and hemolymph have almost no 'direct' influence on the wing damping. In contrast, the involvement of the wing hinge can significantly increase damping. We also show that although desiccation reduces the wing damping ratio, rehydration leads to full recovery of damping properties after desiccation. Hence, we expect hemolymph to influence the wing damping indirectly, by continuously hydrating the wing system.


Assuntos
Voo Animal/fisiologia , Odonatos/anatomia & histologia , Asas de Animais/anatomia & histologia , Animais , Odonatos/fisiologia , Asas de Animais/fisiologia
9.
Elife ; 102021 06 21.
Artigo em Inglês | MEDLINE | ID: mdl-34151772

RESUMO

Long-term flight depends heavily on intensive energy metabolism in animals; however, the neuroendocrine mechanisms underlying efficient substrate utilization remain elusive. Here, we report that the adipokinetic hormone/corazonin-related peptide (ACP) can facilitate muscle lipid utilization in a famous long-term migratory flighting species, Locusta migratoria. By peptidomic analysis and RNAi screening, we identified brain-derived ACP as a key flight-related neuropeptide. ACP gene expression increased notably upon sustained flight. CRISPR/Cas9-mediated knockout of ACP gene and ACP receptor gene (ACPR) significantly abated prolonged flight of locusts. Transcriptomic and metabolomic analyses further revealed that genes and metabolites involved in fatty acid transport and oxidation were notably downregulated in the flight muscle of ACP mutants. Finally, we demonstrated that a fatty-acid-binding protein (FABP) mediated the effects of ACP in regulating muscle lipid metabolism during long-term flight in locusts. Our results elucidated a previously undescribed neuroendocrine mechanism underlying efficient energy utilization associated with long-term flight.


Assuntos
Voo Animal/fisiologia , Hormônios de Inseto , Metabolismo dos Lipídeos/fisiologia , Locusta migratoria/fisiologia , Neuropeptídeos , Migração Animal/fisiologia , Animais , Feminino , Técnicas de Inativação de Genes , Hormônios de Inseto/genética , Hormônios de Inseto/metabolismo , Proteínas de Insetos/genética , Proteínas de Insetos/metabolismo , Masculino , Neuropeptídeos/genética , Neuropeptídeos/metabolismo , Oxirredução
10.
Proc Natl Acad Sci U S A ; 118(23)2021 06 08.
Artigo em Inglês | MEDLINE | ID: mdl-34074786

RESUMO

Turbulent winds and gusts fluctuate on a wide range of timescales from milliseconds to minutes and longer, a range that overlaps the timescales of avian flight behavior, yet the importance of turbulence to avian behavior is unclear. By combining wind speed data with the measured accelerations of a golden eagle (Aquila chrysaetos) flying in the wild, we find evidence in favor of a linear relationship between the eagle's accelerations and atmospheric turbulence for timescales between about 1/2 and 10 s. These timescales are comparable to those of typical eagle behaviors, corresponding to between about 1 and 25 wingbeats, and to those of turbulent gusts both larger than the eagle's wingspan and smaller than large-scale atmospheric phenomena such as convection cells. The eagle's accelerations exhibit power spectra and intermittent activity characteristic of turbulence and increase in proportion to the turbulence intensity. Intermittency results in accelerations that are occasionally several times stronger than gravity, which the eagle works against to stay aloft. These imprints of turbulence on the bird's movements need to be further explored to understand the energetics of birds and other volant life-forms, to improve our own methods of flying through ceaselessly turbulent environments, and to engage airborne wildlife as distributed probes of the changing conditions in the atmosphere.


Assuntos
Águias/fisiologia , Voo Animal/fisiologia , Aceleração , Animais , Atmosfera , Feminino , Vento
11.
J Insect Physiol ; 132: 104248, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-33945808

RESUMO

Since 2016, the fall armyworm (FAW, Spodoptera frugiperda) has invaded large parts of Africa and Asia, impacting millions of hectares of maize crops and thereby posing a major threat to food security. The rapid geographic spread and outbreak dynamics of S. frugiperda are tied to its unique dispersal ability and long-distance migration capability. Yet, up till present, limited research has been conducted on the physiological determinants of S. frugiperda flight and migration. In this study, we used laboratory experiments to assess whether mating and oviposition affect S. frugiperda flight ability and wingbeat frequency. During 2019-2020, migratory FAW females were trapped in Yunnan (China) and dissected to assess ovarian development. Tethered flight assays showed that gravid S. frugiperda females exhibited strong flight ability at 1-3 days following the onset of oviposition. Flight distance and duration negatively correlated with the number of deposited eggs. Ovarian dissections further showed that over 50% of migrant females were mated and 46-54% had initiated oviposition. Our study shows the complex, yet nuanced effects of reproductive status on flight capacity, with possibly a facultative trade-off between flight and reproduction. These novel insights into S. frugiperda physiology and migration behavior can guide future monitoring and integrated pest management (IPM) programs against this newly-invasive pest in China and abroad.


Assuntos
Voo Animal/fisiologia , Reprodução/fisiologia , Spodoptera/fisiologia , Distribuição Animal/fisiologia , Animais , Feminino , Oviposição , Controle de Pragas
12.
Science ; 372(6542): 601-609, 2021 05 07.
Artigo em Inglês | MEDLINE | ID: mdl-33958471

RESUMO

Reptiles, including birds, exhibit a range of behaviorally relevant adaptations that are reflected in changes to the structure of the inner ear. These adaptations include the capacity for flight and sensitivity to high-frequency sound. We used three-dimensional morphometric analyses of a large sample of extant and extinct reptiles to investigate inner ear correlates of locomotor ability and hearing acuity. Statistical analyses revealed three vestibular morphotypes, best explained by three locomotor categories-quadrupeds, bipeds and simple fliers (including bipedal nonavialan dinosaurs), and high-maneuverability fliers. Troodontids fall with Archaeopteryx among the extant low-maneuverability fliers. Analyses of cochlear shape revealed a single instance of elongation, on the stem of Archosauria. We suggest that this transformation coincided with the origin of both high-pitched juvenile location, alarm, and hatching-synchronization calls and adult responses to them.


Assuntos
Adaptação Fisiológica , Evolução Biológica , Dinossauros/anatomia & histologia , Dinossauros/fisiologia , Orelha Interna/anatomia & histologia , Locomoção , Vocalização Animal/fisiologia , Animais , Aves/anatomia & histologia , Aves/classificação , Aves/fisiologia , Dinossauros/classificação , Voo Animal/fisiologia , Audição/fisiologia , Filogenia
13.
Science ; 372(6542): 646-648, 2021 05 07.
Artigo em Inglês | MEDLINE | ID: mdl-33958477

RESUMO

Billions of nocturnally migrating songbirds fly across oceans and deserts on their annual journeys. Using multisensor data loggers, we show that great reed warblers (Acrocephalus arundinaceus) regularly prolong their otherwise strictly nocturnal flights into daytime when crossing the Mediterranean Sea and the Sahara Desert. Unexpectedly, when prolonging their flights, they climbed steeply at dawn, from a mean of 2394 meters above sea level to reach extreme cruising altitudes (mean 5367 and maximum 6267 meters above sea level) during daytime flights. This previously unknown behavior of using exceedingly high flight altitudes when migrating during daytime could be caused by diel variation in ambient temperature, winds, predation, vision range, and solar radiation. Our finding of this notable behavior provides new perspectives on constraints in bird flight and might help to explain the evolution of nocturnal migration.


Assuntos
Altitude , Migração Animal/fisiologia , Voo Animal/fisiologia , Fotoperíodo , Aves Canoras/fisiologia , África do Norte , Animais , Mar Mediterrâneo , Vento
14.
Parasitol Res ; 120(7): 2323-2332, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33893548

RESUMO

Culicoides biting midges are small dipterous insects (Diptera: Ceratopogonidae) which are known to be vectors of arboviruses, bacteria, protozoan and helminth parasites that can cause disease and mortality in livestock and poultry globally. Detailed knowledge of the Culicoides species composition and biology is essential to assess the risk of the introduction and transmission of pathogens. The aim of this study was to obtain data on Culicoides species composition and flying activity in southeastern Lithuania and to determine the meteorological variables related to the abundance of Culicoides biting midges. Biting midges were collected in Verkiai Regional Park, southeastern Lithuania, using an Onderstepoort trap once a week from April to October 2016 and 2018, and from April to July 2019; 7332 Culicoides females belonging to 22 species were identified. Both morphology and DNA barcoding were used for identification. The number of specimens trapped was highest for the Obsoletus Group, followed by Culicoides kibunensis and Culicoides impunctatus. The highest relative abundance and diversity of biting midges were found in May and June. The number of trapped biting midges correlated positively with the mean air temperature. The first biting midges in spring were caught when the mean daily temperature rose higher than 10 °C. No Culicoides were detected when the air temperature dropped below 5 °C in autumn. Wind speed and air humidity had no statistically significant effect on Culicoides abundance.


Assuntos
Ceratopogonidae/fisiologia , Voo Animal/fisiologia , Insetos Vetores/fisiologia , Animais , Ceratopogonidae/classificação , Análise por Conglomerados , Feminino , Insetos Vetores/classificação , Lituânia , Estações do Ano , Temperatura
15.
J Insect Physiol ; 132: 104233, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-33831433

RESUMO

The primary function of hearing in mosquitoes is believed to be intraspecific communication. This view dictated the principle of many behavioral studies, namely, the attraction of male mosquitoes to the sounds that mimicked a female tone. However, after the avoidance response to certain frequencies of sound was demonstrated, it became clear that attraction tests cannot fully account for all the capabilities of the mosquito auditory system. In addition, the tuning curves obtained by electrophysiological measurements differ from the behavioral ones. We designed a simple but robust field test based on responses of swarming mosquitoes to sound stimulation, but not limited to the attraction response. Here we report the auditory thresholds over a wide range of sound frequencies measured in the field from swarms of Aedes communis mosquitoes. In parallel, the auditory sensitivity of male mosquitoes taken from the same swarms was measured electrophysiologically. Surprisingly, we found high acoustic sensitivity; 26 dBSPL on average, in the frequency range 180-220 Hz (ambient temperature 12 °C). In addition, responses were found in the high-frequency range, 500-700 Hz (the so-called 'mirror channel'). Two types of auditory units were recorded: more sensitive broadband neurons and less sensitive units with distinct narrow (quality factor Q6 = 7.4) frequency tunings in the range 180-350 Hz. We propose that the former provides the detection of signal while the latter are used for frequency identification in order to make a behavioral choice.


Assuntos
Aedes/fisiologia , Percepção Auditiva/fisiologia , Comportamento Animal/fisiologia , Voo Animal/fisiologia , Acústica , Animais , Eletrofisiologia , Audição/fisiologia , Masculino , Neurônios , Comportamento Sexual Animal/fisiologia , Som
16.
Nat Commun ; 12(1): 2091, 2021 04 07.
Artigo em Inglês | MEDLINE | ID: mdl-33828099

RESUMO

Complex animals build specialised muscles to match specific biomechanical and energetic needs. Hence, composition and architecture of sarcomeres and mitochondria are muscle type specific. However, mechanisms coordinating mitochondria with sarcomere morphogenesis are elusive. Here we use Drosophila muscles to demonstrate that myofibril and mitochondria morphogenesis are intimately linked. In flight muscles, the muscle selector spalt instructs mitochondria to intercalate between myofibrils, which in turn mechanically constrain mitochondria into elongated shapes. Conversely in cross-striated leg muscles, mitochondria networks surround myofibril bundles, contacting myofibrils only with thin extensions. To investigate the mechanism causing these differences, we manipulated mitochondrial dynamics and found that increased mitochondrial fusion during myofibril assembly prevents mitochondrial intercalation in flight muscles. Strikingly, this causes the expression of cross-striated muscle specific sarcomeric proteins. Consequently, flight muscle myofibrils convert towards a partially cross-striated architecture. Together, these data suggest a biomechanical feedback mechanism downstream of spalt synchronizing mitochondria with myofibril morphogenesis.


Assuntos
Mitocôndrias/metabolismo , Morfogênese/fisiologia , Músculo Esquelético/metabolismo , Miofibrilas/metabolismo , Animais , Fenômenos Biomecânicos , Drosophila , Proteínas de Drosophila , Drosophila melanogaster , Retroalimentação , Voo Animal/fisiologia , Masculino , Fenômenos Mecânicos , Mitocôndrias/ultraestrutura , Desenvolvimento Muscular , Músculo Esquelético/citologia , Miofibrilas/ultraestrutura , Fatores de Regulação Miogênica , Sarcômeros/metabolismo , Fatores de Transcrição
17.
J Anat ; 239(1): 59-69, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-33650143

RESUMO

Flying is the main means of locomotion for most avian species, and it requires a series of adaptations of the skeleton and of feather distribution on the wing. Flight type is directly associated with the mechanical constraints during flight, which condition both the morphology and microscopic structure of the bones. Three primary flight styles are adopted by avian species: flapping, gliding, and soaring, with different loads among the main wing bones. The purpose of this study was to evaluate the cross-sectional microstructure of the most important skeletal wing bones, humerus, radius, ulna, and carpometacarpus, in griffon vultures (Gyps fulvus) and greater flamingos (Phoenicopterus roseus). These two species show a flapping and soaring flight style, respectively. Densitometry, morphology, and laminarity index were assessed from the main bones of the wing of 10 griffon vultures and 10 flamingos. Regarding bone mineral content, griffon vultures generally displayed a higher mineral density than flamingos. Regarding the morphology of the crucial wing bones involved in flight, while a very slightly longer humerus was observed in the radius and ulna of flamingos, the ulna in griffons was clearly longer than other bones. The laminarity index was significantly higher in griffons. The results of the present study highlight how the mechanics of different types of flight may affect the biomechanical properties of the wing bones most engaged during flight.


Assuntos
Osso e Ossos/anatomia & histologia , Falconiformes/anatomia & histologia , Voo Animal/fisiologia , Asas de Animais/anatomia & histologia , Animais , Osso e Ossos/fisiologia , Falconiformes/fisiologia , Asas de Animais/fisiologia
18.
J Insect Physiol ; 131: 104212, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33662377

RESUMO

The small white cabbage butterfly (Pieris rapae) flaps its fore- and hindwings in synchrony as the wings are coupled using a wing "coupling mechanism". The coupling mechanism of butterflies includes an enlarged humeral area located at the anterior of the hindwing base and a corresponding basal posterior part of the forewing, of which the former component dorsally contacts the ventral side of the latter one. The coupling mechanism allows for the fore- and hindwings sliding in contact along the span and chord. It is of interest that butterflies still take off successfully and fly, when their wing couplings are clipped, but they are unable to properly synchronize the fore- and hindwing motions. Compared with the regular takeoff trajectory of intact butterflies that always first fly backwards and then forwards, the coupling-clipped butterflies took off in a random trajectory. Due to the clipping of the coupling mechanism, the initiation of the hindwing flapping and the abdomen rotation from upward to downward during takeoff was postponed. The coupling-clipped butterflies changed their stroke plane in upstroke to a more vertical position and strengthened the abdominal undulation. We believe our work, which for the first time investigates the influence of coupling mechanism removal on insect flight, extends our understanding on the working principle of wing coupling in insects and its significance on the flapping flight.


Assuntos
Borboletas/fisiologia , Voo Animal/fisiologia , Asas de Animais/fisiologia , Animais , Borboletas/ultraestrutura , Asas de Animais/ultraestrutura
19.
Sci Rep ; 11(1): 6992, 2021 03 26.
Artigo em Inglês | MEDLINE | ID: mdl-33772058

RESUMO

Flapping flight is one of the most costly forms of locomotion in animals. To limit energetic expenditures, flying insects thus developed multiple strategies. An effective mechanism to reduce flight power expenditures is the harvesting of kinetic energy from motion of the surrounding air. We here show an unusual mechanism of energy harvesting in an insect that recaptures the rotational energy of air vortices. The mechanism requires pronounced chordwise wing bending during which the wing surface momentary traps the vortex and transfers its kinetic energy to the wing within less than a millisecond. Numerical and robotic controls show that the decrease in vortex strength is minimal without the nearby wing surface. The measured energy recycling might slightly reduce the power requirements needed for body weight support in flight, lowering the flight costs in animals flying at elevated power demands. An increase in flight efficiency improves flight during aversive manoeuvring in response to predation and long-distance migration, and thus factors that determine the worldwide abundance and distribution of insect populations.


Assuntos
Movimentos do Ar , Fenômenos Biomecânicos/fisiologia , Metabolismo Energético/fisiologia , Voo Animal/fisiologia , Asas de Animais/fisiologia , Animais , Drosophila/fisiologia , Modelos Biológicos
20.
Arthropod Struct Dev ; 61: 101031, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33711678

RESUMO

Just one superorder of insects is known to possess a neuronal network that mediates extremely rapid reactions in flight in response to changes in optic flow. Research on the identity and functional organization of this network has over the course of almost half a century focused exclusively on the order Diptera, a member of the approximately 300-million-year-old clade Holometabola defined by its mode of development. However, it has been broadly claimed that the pivotal neuropil containing the network, the lobula plate, originated in the Cambrian before the divergence of Hexapoda and Crustacea from a mandibulate ancestor. This essay defines the traits that designate the lobula plate and argues against a homologue in Crustacea. It proposes that the origin of the lobula plate is relatively recent and may relate to the origin of flight.


Assuntos
Crustáceos , Fluxo Óptico , Animais , Crustáceos/anatomia & histologia , Voo Animal/fisiologia , Insetos/anatomia & histologia , Neurônios , Neurópilo , Fluxo Óptico/fisiologia
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