Devon EX4 4PS, United Kingdom The functional morphology of the wings of Odonata is reviewed in th... more Devon EX4 4PS, United Kingdom The functional morphology of the wings of Odonata is reviewed in the light of recent detailed work on their structure, taken in conjunction with cinematographic analysis of dragonflies in unimpeded flight. Wing-corrugation, combined with a variety of types of crossvein and of cross-vein/longitudinal vein links, provides resistance to transverse bending while allowing torsion and the development of camber. Controlled torsion, essential to flapping flight, is kept within limits by the pterostigma and by the structure of the leading edge spar, which permits more supination than pronation, so allowing the wing to generate lift on the upstroke and permitting slow, manoeuvrable flight and hovering. Camber and angle of attack are automatically maintained under aerodynamic loading by an array of internal mechanisms including the arculus, the quadrilateral of Zygoptera, the triangle and supratriangle of Anisoptera, and vein-curvature in a variety of broad-winged forms. The slender-based wings of Zygoptera, and their relatively short antenodal spars compared with those of the broader-based Anisoptera, seem to be associated with their generally slower flight. 157 FUNCTIONAL morphology in odonata wings usually have internal supports and are adapted to deform in some ways, but not in others. All but the simplest wings are now better regarded as flexible aerofoils whose integrated design ensures that they deform predictably and usefully under loads. As such they are in a sense intermediate between "structures" and "mechanisms" in the orthodox meanings of engineers. The wings of dragonflies illustrate these principles particularly well. We will consider first the implications of corrugation. The corrugated wing Dragonfly wings, like those of Ephemeroptera, show complete corrugation, with the stems of the main longitudinal veins alternately occupying ridges and troughs in the membrane, and this corrugation is continued beyond the
Philosophical Transactions of the Royal Society of London. Series B: Biological Sciences, 2003
Insect wings lack internal muscles, and the orderly, necessary deformations which they undergo in... more Insect wings lack internal muscles, and the orderly, necessary deformations which they undergo in flight and folding are in part remotely controlled, in part encoded in their structure. This factor is crucial in understanding their complex, extremely varied morphology. Models have proved particularly useful in clarifying the facilitation and control of wing deformation. Their development has followed a logical sequence from conceptual models through physical and simple analytical to numerical models. All have value provided their limitations are realized and constant comparisons made with the properties and mechanical behaviour of real wings. Numerical modelling by the finite element method is by far the most time–consuming approach, but has real potential in analysing the adaptive significance of structural details and interpreting evolutionary trends. Published examples are used to review the strengths and weaknesses of each category of model, and a summary is given of new work us...
Insect wings are deformable airfoils, in which deformations are mostly achieved by complicated in... more Insect wings are deformable airfoils, in which deformations are mostly achieved by complicated interactions between their structural components. Due to the complexity of the wing design and technical challenges associated with testing the delicate wings, we know little about the properties of their components and how they determine wing response to flight forces. Here, we report an unusual structure from the hind-wing membrane of the beetle Pachnoda marginata . The structure, a transverse section of the claval flexion line, consists of two distinguishable layers: a bell-shaped upper layer and a straight lower layer. Our computational simulations showed that this is an effective one-way hinge, which is stiff in tension and upward bending but flexible in compression and downward bending. By systematically varying its design parameters in a computational model, we showed that the properties of the double-layer membrane hinge can be tuned over a wide range. This enabled us to develop a ...
Recent fauna in his work on fossils, an effort that was informed by his early and continuing inte... more Recent fauna in his work on fossils, an effort that was informed by his early and continuing interest in the study of the living Heteroptera. His published works will serve as a lasting reminder of the energy he put into fieldwork and the detailed study of the specimens derived from it. May he rest in peace. Robin Wootton Although we have seldom met in the last five decades, I have always considered Yuri Alexandrovich to be one of my greatest friends. I came to work at PIN in 1963, on one of the first exchange fellowships between the Soviet Academy of Sciences and the Royal Society. The PIN staff were very welcoming, though Elena Ernestovna Bekker-Migdisova and Alexander Grigorievich Sharov both tended to lecture me about the wickedness of the West. Yuri, Alik Rasnitsyn, Sasha Ponomarenko, Iren Sukatsheva and Lyusi Pritykina were all about my age, and we had much to talk about, as you can imagine, preferably where nobody else could hear. It was all a great experience, at a very interesting time. The USSR had only recently begun to acknowledge that there was good science happening outside the Soviet block, and all the young scientists were learning English. Boris Borisovich Rohdendorf allocated Yuri to look after me and to act as liaison between myself and the authorities. He could not have made a better choice. We Dr. Yuri Popov, born 5 March 1936, passed away 16 November 2016. Upon graduation from the Entomology Department of Moscow State University, he joined the Arthropoda Lab of the Paleontological Institute, where he studied fossil and living true bugs and their kin and became a major expert in that area. He was a man of many talents and had lots of friends all over the world. The few flashbacks collected here are but a small tribute to his memory. Randall T. Schuh Yuri and I crossed paths two times. First, in my office at the American Museum of Natural History, sometime in the 1990s. We had a conversation about bugs and got acquainted. When he left, I felt like I had a new friend. The other time was at the second meeting of the International Heteropterists' Society in St. Petersburg in July 2002. Yuri was among the several Russian heteropterists who attended, and it was a pleasure to see him once again. His optimism and enthusiasm in his interpersonal interactions, as well as for the study of true bugs, were evident on both occasions. Yuri was, doubtless, the driving force in the modern study of Heteroptera fossils, and particularly his work on the Nepomorpha is a landmark publication in the study of the group and in insect paleontology and classification. He saw the real value in integrating data from the Yuri Popov-as we remember him
Charles Ellington graduated at Duke University, North Carolina, and came to Cambridge in 1973 to ... more Charles Ellington graduated at Duke University, North Carolina, and came to Cambridge in 1973 to work for a PhD on insect flight dynamics. He developed novel methodology and software for the kinematic analysis of freely hovering insects and applied them to his own high-speed films of a range of species. He identified five new non-steady-state mechanisms for lift generation, was the first to develop a vortex theory for flapping flight and developed and extended the use of morphometric parameters in calculating the forces and power requirements of flight. He remained in Cambridge, married a colleague, joined the staff of the Department of Zoology, became a fellow of Downing College and continued to work on insect aerodynamics and energetics, publishing on flight muscle efficiency, the factors limiting flight performance and the aerodynamic implications of the origin of insect flight. Building a closed-circuit wind tunnel connected with a sensitive oxygen analyser, he studied with colleagues how the aerodynamics and metabolic power input of bumblebees vary with flight speed, challenging the orthodox theory that this should follow a U-shaped curve. Outstanding among later research was the discovery that hawkmoths, and by implication many other insects, gain high levels of lift by generating a vortex above the leading edge, stabilized by spiralling out along the span—a major focus of animal flight research ever since. His many administrative roles included editorship of the Journal of Experimental Biology. He became a British citizen in 1995, was elected FRS in 1998 and to a chair of animal mechanics in 1999. Awards include the Scientific Medal of the Zoological Society and the University of Cambridge Pilkington Prize for teaching excellence. He was diabetic throughout his adult life, and suffered progressive ill health following a heart attack in 1996. He took early retirement in 2010, lived quietly with his wife and two sons at home near Newmarket, and died in July 2019.
Charles Ellington graduated at Duke University, North Carolina, and came to Cambridge in 1973 to ... more Charles Ellington graduated at Duke University, North Carolina, and came to Cambridge in 1973 to work for a PhD on insect flight dynamics. He developed novel methodology and software for the kinematic analysis of freely hovering insects and applied them to his own high-speed films of a range of species. He identified five new non-steady-state mechanisms for lift generation, was the first to develop a vortex theory for flapping flight and developed and extended the use of morphometric parameters in calculating the forces and power requirements of flight. He remained in Cambridge, married a colleague, joined the staff of the Department of Zoology, became a fellow of Downing College and continued to work on insect aerodynamics and energetics, publishing on flight muscle efficiency, the factors limiting flight performance and the aerodynamic implications of the origin of insect flight. Building a closed-circuit wind tunnel connected with a sensitive oxygen analyser, he studied with coll...
BIOGRAPHICAL MEMOIRS OF FELLOWS OF THE ROYAL SOCIETY, 2021
Charles Ellington graduated at Duke University, North Carolina, and came to Cambridge in 1973 to ... more Charles Ellington graduated at Duke University, North Carolina, and came to Cambridge in 1973 to work for a PhD on insect flight dynamics. He developed novel methodology and software for the kinematic analysis of freely hovering insects and applied them to his own high-speed films of a range of species. He identified five new non-steady-state mechanisms for lift generation, was the first to develop a vortex theory for flapping flight and developed and extended the use of morphometric parameters in calculating the forces and power requirements of flight. He remained in Cambridge, married a colleague, joined the staff of the Department of Zoology, became a fellow of Downing College and continued to work on insect aerodynamics and energetics, publishing on flight muscle efficiency, the factors limiting flight performance and the aerodynamic implications of the origin of insect flight. Building a closed-circuit wind tunnel connected with a sensitive oxygen analyser, he studied with coll...
The nature, occurrence, morphological basis and functions of insect wing deformation in flight ar... more The nature, occurrence, morphological basis and functions of insect wing deformation in flight are reviewed. The importance of relief in supporting the wing is stressed, and three types are recognized, namely corrugation, an M-shaped section and camber, all of which need to be overcome if wings are to bend usefully in the morphological upstroke. How this is achieved, and how bending, torsion and change in profile are mechanically interrelated, are explored by means of simple physical models which reflect situations that are visible in high speed photographs and films. The shapes of lines of transverse flexion are shown to reflect the timing and roles of bending, and their orientation is shown to determine the extent of the torsional component of the deformation process. Some configurations prove to allow two stable conditions, others to be monostable. The possibility of active remote control of wing rigidity by the thoracic musculature is considered, but the extent of this remains u...
Subtle details of engineering and design, which no man-made airfoil can match, reveal how insect ... more Subtle details of engineering and design, which no man-made airfoil can match, reveal how insect wings are remarkably adapted to the acrobatics of flight AN APPROACH TO THE MECHANICS OF PLEATING IN DRAGONFLY WINGS. D.j.S.
Some structural characters and morphometric variables-size, body shape and proportions, wing shap... more Some structural characters and morphometric variables-size, body shape and proportions, wing shape and structure-that appear in insects to be linked with flight performance, are discussed and evaluated, and methods are described for deriving these from fossil material. Some wing design categories associated with particular flight techniques and capabilities are identified. Their use in reconstructing the flight performance of extinct insects is illustrated with reference to Carboniferous palaeodictyopteroids and Mesozoic palaeontinoid Hemiptera.
Representatives of six butterfly species, flying freely in the field or in simulated field condit... more Representatives of six butterfly species, flying freely in the field or in simulated field conditions, were filmed with a high-speed cin6 camera and subjected to kinematic and morphometric analysis. This is the first detailed investigation on an insect performing the varied patterns of 'natural' flight. Kinematic parameters in representative sequences of selected flight modes were calculated and compared, and wing shapes were characterized using aspect ratio and non-dimensional moment parameters. The analyses and field observations of these and other butterflies suggest possible correlations between flight performance and wing shape. The behaviour of individual species conforms reasonably well with crude predictions based on aspect ratio, wing loading and wing inertia.
Insect wings are mounted on hinges, restricting the extent to which their bases can be supinated ... more Insect wings are mounted on hinges, restricting the extent to which their bases can be supinated for the upstroke. The forewings of many insects therefore include devices that allow the distal part of the wing to twist relative to the base under aerodynamic loading in the upstroke, but restrict such twisting in the downstroke where the effect would be detrimental. In the broad forewings of butterflies, this asymmetric resistance to aerodynamic twisting seems to be a consequence of the curved section of the leading edge. The wing can be modelled as a cantilevered, thin cambered plate. Torsional tests on the forewings of four butterfly species and on a paper wing of curved section confirm the effect. Differences between the results for the four species appear to fit their morphological and kinematic differences. The nature of the mechanism is outlined.
Devon EX4 4PS, United Kingdom The functional morphology of the wings of Odonata is reviewed in th... more Devon EX4 4PS, United Kingdom The functional morphology of the wings of Odonata is reviewed in the light of recent detailed work on their structure, taken in conjunction with cinematographic analysis of dragonflies in unimpeded flight. Wing-corrugation, combined with a variety of types of crossvein and of cross-vein/longitudinal vein links, provides resistance to transverse bending while allowing torsion and the development of camber. Controlled torsion, essential to flapping flight, is kept within limits by the pterostigma and by the structure of the leading edge spar, which permits more supination than pronation, so allowing the wing to generate lift on the upstroke and permitting slow, manoeuvrable flight and hovering. Camber and angle of attack are automatically maintained under aerodynamic loading by an array of internal mechanisms including the arculus, the quadrilateral of Zygoptera, the triangle and supratriangle of Anisoptera, and vein-curvature in a variety of broad-winged forms. The slender-based wings of Zygoptera, and their relatively short antenodal spars compared with those of the broader-based Anisoptera, seem to be associated with their generally slower flight. 157 FUNCTIONAL morphology in odonata wings usually have internal supports and are adapted to deform in some ways, but not in others. All but the simplest wings are now better regarded as flexible aerofoils whose integrated design ensures that they deform predictably and usefully under loads. As such they are in a sense intermediate between "structures" and "mechanisms" in the orthodox meanings of engineers. The wings of dragonflies illustrate these principles particularly well. We will consider first the implications of corrugation. The corrugated wing Dragonfly wings, like those of Ephemeroptera, show complete corrugation, with the stems of the main longitudinal veins alternately occupying ridges and troughs in the membrane, and this corrugation is continued beyond the
Philosophical Transactions of the Royal Society of London. Series B: Biological Sciences, 2003
Insect wings lack internal muscles, and the orderly, necessary deformations which they undergo in... more Insect wings lack internal muscles, and the orderly, necessary deformations which they undergo in flight and folding are in part remotely controlled, in part encoded in their structure. This factor is crucial in understanding their complex, extremely varied morphology. Models have proved particularly useful in clarifying the facilitation and control of wing deformation. Their development has followed a logical sequence from conceptual models through physical and simple analytical to numerical models. All have value provided their limitations are realized and constant comparisons made with the properties and mechanical behaviour of real wings. Numerical modelling by the finite element method is by far the most time–consuming approach, but has real potential in analysing the adaptive significance of structural details and interpreting evolutionary trends. Published examples are used to review the strengths and weaknesses of each category of model, and a summary is given of new work us...
Insect wings are deformable airfoils, in which deformations are mostly achieved by complicated in... more Insect wings are deformable airfoils, in which deformations are mostly achieved by complicated interactions between their structural components. Due to the complexity of the wing design and technical challenges associated with testing the delicate wings, we know little about the properties of their components and how they determine wing response to flight forces. Here, we report an unusual structure from the hind-wing membrane of the beetle Pachnoda marginata . The structure, a transverse section of the claval flexion line, consists of two distinguishable layers: a bell-shaped upper layer and a straight lower layer. Our computational simulations showed that this is an effective one-way hinge, which is stiff in tension and upward bending but flexible in compression and downward bending. By systematically varying its design parameters in a computational model, we showed that the properties of the double-layer membrane hinge can be tuned over a wide range. This enabled us to develop a ...
Recent fauna in his work on fossils, an effort that was informed by his early and continuing inte... more Recent fauna in his work on fossils, an effort that was informed by his early and continuing interest in the study of the living Heteroptera. His published works will serve as a lasting reminder of the energy he put into fieldwork and the detailed study of the specimens derived from it. May he rest in peace. Robin Wootton Although we have seldom met in the last five decades, I have always considered Yuri Alexandrovich to be one of my greatest friends. I came to work at PIN in 1963, on one of the first exchange fellowships between the Soviet Academy of Sciences and the Royal Society. The PIN staff were very welcoming, though Elena Ernestovna Bekker-Migdisova and Alexander Grigorievich Sharov both tended to lecture me about the wickedness of the West. Yuri, Alik Rasnitsyn, Sasha Ponomarenko, Iren Sukatsheva and Lyusi Pritykina were all about my age, and we had much to talk about, as you can imagine, preferably where nobody else could hear. It was all a great experience, at a very interesting time. The USSR had only recently begun to acknowledge that there was good science happening outside the Soviet block, and all the young scientists were learning English. Boris Borisovich Rohdendorf allocated Yuri to look after me and to act as liaison between myself and the authorities. He could not have made a better choice. We Dr. Yuri Popov, born 5 March 1936, passed away 16 November 2016. Upon graduation from the Entomology Department of Moscow State University, he joined the Arthropoda Lab of the Paleontological Institute, where he studied fossil and living true bugs and their kin and became a major expert in that area. He was a man of many talents and had lots of friends all over the world. The few flashbacks collected here are but a small tribute to his memory. Randall T. Schuh Yuri and I crossed paths two times. First, in my office at the American Museum of Natural History, sometime in the 1990s. We had a conversation about bugs and got acquainted. When he left, I felt like I had a new friend. The other time was at the second meeting of the International Heteropterists' Society in St. Petersburg in July 2002. Yuri was among the several Russian heteropterists who attended, and it was a pleasure to see him once again. His optimism and enthusiasm in his interpersonal interactions, as well as for the study of true bugs, were evident on both occasions. Yuri was, doubtless, the driving force in the modern study of Heteroptera fossils, and particularly his work on the Nepomorpha is a landmark publication in the study of the group and in insect paleontology and classification. He saw the real value in integrating data from the Yuri Popov-as we remember him
Charles Ellington graduated at Duke University, North Carolina, and came to Cambridge in 1973 to ... more Charles Ellington graduated at Duke University, North Carolina, and came to Cambridge in 1973 to work for a PhD on insect flight dynamics. He developed novel methodology and software for the kinematic analysis of freely hovering insects and applied them to his own high-speed films of a range of species. He identified five new non-steady-state mechanisms for lift generation, was the first to develop a vortex theory for flapping flight and developed and extended the use of morphometric parameters in calculating the forces and power requirements of flight. He remained in Cambridge, married a colleague, joined the staff of the Department of Zoology, became a fellow of Downing College and continued to work on insect aerodynamics and energetics, publishing on flight muscle efficiency, the factors limiting flight performance and the aerodynamic implications of the origin of insect flight. Building a closed-circuit wind tunnel connected with a sensitive oxygen analyser, he studied with colleagues how the aerodynamics and metabolic power input of bumblebees vary with flight speed, challenging the orthodox theory that this should follow a U-shaped curve. Outstanding among later research was the discovery that hawkmoths, and by implication many other insects, gain high levels of lift by generating a vortex above the leading edge, stabilized by spiralling out along the span—a major focus of animal flight research ever since. His many administrative roles included editorship of the Journal of Experimental Biology. He became a British citizen in 1995, was elected FRS in 1998 and to a chair of animal mechanics in 1999. Awards include the Scientific Medal of the Zoological Society and the University of Cambridge Pilkington Prize for teaching excellence. He was diabetic throughout his adult life, and suffered progressive ill health following a heart attack in 1996. He took early retirement in 2010, lived quietly with his wife and two sons at home near Newmarket, and died in July 2019.
Charles Ellington graduated at Duke University, North Carolina, and came to Cambridge in 1973 to ... more Charles Ellington graduated at Duke University, North Carolina, and came to Cambridge in 1973 to work for a PhD on insect flight dynamics. He developed novel methodology and software for the kinematic analysis of freely hovering insects and applied them to his own high-speed films of a range of species. He identified five new non-steady-state mechanisms for lift generation, was the first to develop a vortex theory for flapping flight and developed and extended the use of morphometric parameters in calculating the forces and power requirements of flight. He remained in Cambridge, married a colleague, joined the staff of the Department of Zoology, became a fellow of Downing College and continued to work on insect aerodynamics and energetics, publishing on flight muscle efficiency, the factors limiting flight performance and the aerodynamic implications of the origin of insect flight. Building a closed-circuit wind tunnel connected with a sensitive oxygen analyser, he studied with coll...
BIOGRAPHICAL MEMOIRS OF FELLOWS OF THE ROYAL SOCIETY, 2021
Charles Ellington graduated at Duke University, North Carolina, and came to Cambridge in 1973 to ... more Charles Ellington graduated at Duke University, North Carolina, and came to Cambridge in 1973 to work for a PhD on insect flight dynamics. He developed novel methodology and software for the kinematic analysis of freely hovering insects and applied them to his own high-speed films of a range of species. He identified five new non-steady-state mechanisms for lift generation, was the first to develop a vortex theory for flapping flight and developed and extended the use of morphometric parameters in calculating the forces and power requirements of flight. He remained in Cambridge, married a colleague, joined the staff of the Department of Zoology, became a fellow of Downing College and continued to work on insect aerodynamics and energetics, publishing on flight muscle efficiency, the factors limiting flight performance and the aerodynamic implications of the origin of insect flight. Building a closed-circuit wind tunnel connected with a sensitive oxygen analyser, he studied with coll...
The nature, occurrence, morphological basis and functions of insect wing deformation in flight ar... more The nature, occurrence, morphological basis and functions of insect wing deformation in flight are reviewed. The importance of relief in supporting the wing is stressed, and three types are recognized, namely corrugation, an M-shaped section and camber, all of which need to be overcome if wings are to bend usefully in the morphological upstroke. How this is achieved, and how bending, torsion and change in profile are mechanically interrelated, are explored by means of simple physical models which reflect situations that are visible in high speed photographs and films. The shapes of lines of transverse flexion are shown to reflect the timing and roles of bending, and their orientation is shown to determine the extent of the torsional component of the deformation process. Some configurations prove to allow two stable conditions, others to be monostable. The possibility of active remote control of wing rigidity by the thoracic musculature is considered, but the extent of this remains u...
Subtle details of engineering and design, which no man-made airfoil can match, reveal how insect ... more Subtle details of engineering and design, which no man-made airfoil can match, reveal how insect wings are remarkably adapted to the acrobatics of flight AN APPROACH TO THE MECHANICS OF PLEATING IN DRAGONFLY WINGS. D.j.S.
Some structural characters and morphometric variables-size, body shape and proportions, wing shap... more Some structural characters and morphometric variables-size, body shape and proportions, wing shape and structure-that appear in insects to be linked with flight performance, are discussed and evaluated, and methods are described for deriving these from fossil material. Some wing design categories associated with particular flight techniques and capabilities are identified. Their use in reconstructing the flight performance of extinct insects is illustrated with reference to Carboniferous palaeodictyopteroids and Mesozoic palaeontinoid Hemiptera.
Representatives of six butterfly species, flying freely in the field or in simulated field condit... more Representatives of six butterfly species, flying freely in the field or in simulated field conditions, were filmed with a high-speed cin6 camera and subjected to kinematic and morphometric analysis. This is the first detailed investigation on an insect performing the varied patterns of 'natural' flight. Kinematic parameters in representative sequences of selected flight modes were calculated and compared, and wing shapes were characterized using aspect ratio and non-dimensional moment parameters. The analyses and field observations of these and other butterflies suggest possible correlations between flight performance and wing shape. The behaviour of individual species conforms reasonably well with crude predictions based on aspect ratio, wing loading and wing inertia.
Insect wings are mounted on hinges, restricting the extent to which their bases can be supinated ... more Insect wings are mounted on hinges, restricting the extent to which their bases can be supinated for the upstroke. The forewings of many insects therefore include devices that allow the distal part of the wing to twist relative to the base under aerodynamic loading in the upstroke, but restrict such twisting in the downstroke where the effect would be detrimental. In the broad forewings of butterflies, this asymmetric resistance to aerodynamic twisting seems to be a consequence of the curved section of the leading edge. The wing can be modelled as a cantilevered, thin cambered plate. Torsional tests on the forewings of four butterfly species and on a paper wing of curved section confirm the effect. Differences between the results for the four species appear to fit their morphological and kinematic differences. The nature of the mechanism is outlined.
Uploads
Papers by Robin Wootton