...Rudolf J. Schilder; Hannah Stewart ABSTRACT We previously demonstrated the existence of a naturally occurring metabolic disease phenotype in Libellula pulchella dragonflies that shows high similarity to vertebrate obesity and type II diabetes, and is caused by a protozoan gut parasite. To further...

...Csaba Hefler; Huihe Qiu; Wei Shyy ABSTRACT We investigated the characteristics of interwing aerodynamic interactions across the span of the high aspect ratio, flexible wings of dragonflies under tethered and free-flying conditions. This revealed that the effects of the interactions on the hindwings...

... this hypothesis in dragonflies by measuring the oxygen sensitivity of flight metabolic rates and behavior during hovering for 11 species of dragonflies that ranged in mass by an order of magnitude. We measured flight times and flight metabolic rates in seven oxygen concentrations ranging from 30% to 2.5...

... repeatable measurements of the reconstructed wing deformations. Using an Eastern pondhawk ( Erythimus simplicicollis ) dragonfly for demonstration, we quantify and visualize the wing twist and camber in both the chord-wise and span-wise directions, and discuss the implications of the results. In particular...

... of these processes for the control of locomotor forces in the behaving animal. e-mail: [email protected] 21 5 2007 © The Company of Biologists Limited 2008 2008 wing–wing interaction wake capture clap-and-fling LEV destruction phase-shifted stroking dragonfly fruit fly...

...Rudolf J. Schilder; James H. Marden SUMMARY In previous work, we found that dragonflies infected with gregarine gut parasites have reduced muscle power output, loss of lipid oxidation in their flight muscles, and a suite of symptoms similar to mammalian metabolic syndrome. Here, we test...

...Ji Kang Wang; Mao Sun SUMMARY The aerodynamics and forewing-hindwing interaction of a model dragonfly in forward flight are studied, using the method of numerically solving the Navier-Stokes equations. Available morphological and stroke-kinematic parameters of dragonfly ( Aeshna juncea ) are used...

...Will J. Maybury; Fritz-Olaf Lehmann SUMMARY Insects flying with two pairs of wings must contend with the forewing wake passing over the beating hindwing. Some four-winged insects, such as dragonflies, move each wing independently and therefore may alter the relative timing between the fore...

...Adrian L. R. Thomas; Graham K. Taylor; Robert B. Srygley; Robert L. Nudds; Richard J. Bomphrey SUMMARY Here we show, by qualitative free- and tethered-flight flow visualization,that dragonflies fly by using unsteady aerodynamic mechanisms to generate high-lift, leading-edge vortices. In normal free...

...Richard O. Prum; Jeff A. Cole; Rodolfo H. Torres SUMMARY For nearly 80 years, the non-iridescent, blue, integumentary structural colours of dragonflies and damselflies (Odonata) have been attributed to incoherent Tyndall or Rayleigh scattering. We investigated the production of the integumentary...

...Mao Sun; Shi Long Lan SUMMARY Aerodynamic force generation and mechanical power requirements of a dragonfly ( Aeschna juncea ) in hovering flight are studied. The method of numerically solving the Navier–Stokes equations in moving overset grids is used. When the midstroke angles of attack...

... systems and non-biological systems is proportional to motor mass 1.0 . Here we trace the mechanisms that cause dragonflies to achieve a change from muscle mass 0.67 scaling of maximum force output by single flight muscles to mass 1.0 scaling of dynamic force output by the intact dragonfly flight motor...

...Hao Wang; Lijiang Zeng; Hao Liu; Chunyong Yin SUMMARY A robust technique for determining the wing kinematics, body position and attitude of a free-flight dragonfly is described. The new method is based on a projected comb-fringe technique combined with the natural landmarks on a dragonfly, allowing...

...James H. Marden; Gail H. Fitzhugh; Mahasweta Girgenrath; Melisande R. Wolf; Stefan Girgenrath SUMMARY The flight muscles of Libellula pulchella dragonflies contain a mixture of six alternatively spliced transcripts of a single troponin T (TnT) gene. Here, we examine how intraspecific variation...

...Antonia B. Kesel ABSTRACT During gliding, dragonfly wings can be interpreted as acting as ultra-light aerofoils which, for static reasons, have a well-defined cross-sectional corrugation. This corrugation forms profile valleys in which rotating vortices develop. The cross-sectional configuration...

... the sensitivity of flight initiation and metabolism to atmospheric oxygen level in the libellulid dragonfly Erythemis ( Mesothemis ) simplicicollis using flow-through res.pirometric measurements of the rate of CO 2 emission . Flight initiations were unimpaired in atmospheric oxygen levels as low as 10 %. However...

...Gail H. Fitzhugh; James H. Marden ABSTRACT Maximum lift production and the thermal sensitivity of lift production increase dramatically during adult maturation of Libellula pulchella dragonflies. Here, we report that the mechanistic basis for this transition appears to involve a developmental...

...J. M. Wakeling; C. P. Ellington ABSTRACT The free gliding flight of the dragonfly Sympetrum sanguineum was filmed in a large flight enclosure. Reconstruction of the glide paths showed the flights to involve accelerations. Where the acceleration could be considered constant, the lift and drag forces...

...J. M. Wakeling; C. P. Ellington ABSTRACT The free flapping flight of the dragonfly Sympetrum sanguineum and the damselfly Calopteryx splendens was filmed in a large flight enclosure at 3000 frames s −1 . The wingtip kinematics are described for these flights. Despite the two species being similar...

...J. M. Wakeling; C. P. Ellington ABSTRACT A mean lift coefficient quasi-steady analysis has been applied to the free flight of the dragonfly Sympetrum sanguineum and the damselfly Calopteryx splendens . The analysis accommodated the yaw and accelerations involved in free flight. For any given...