Relationships between body mass, motor output and flight variables during free flight of juvenile and mature adult locusts, Schistocerca gregaria

2000 ◽  
Vol 203 (18) ◽  
pp. 2723-2735 ◽  
Author(s):  
H. Fischer ◽  
W. Kutsch
Keyword(s):  
Body Mass ◽  
Schistocerca Gregaria ◽  
Flight Speed ◽  
Free Flight ◽  
Wingbeat Frequency ◽  
Motor Patterns ◽  
Mature Adult ◽  
Body Angle ◽  
Flight System ◽  
Functional Relationships

Little information is available about how the adult locust flight system manages to match the aerodynamic demands that result from an increase in body mass during postmoult maturation. In Schistocerca gregaria of both sexes, flight variables, including flight speed, ascent angle and body angle, were investigated under closed-loop conditions (i.e. during free flight) as a function of adult maturation. Motor patterns were examined by telemetric electromyography in juvenile and adult mature animals of both sexes. Functional relationships between particular flight variables were investigated by additional loading of the animals and by reductions in wing area. The results indicate that an increase in flight speed as the flight system matures enables it to match the aerodynamic demands resulting from increases in body mass. Furthermore, the data suggest that this postmoult increase in flight speed is not simply a consequence of the increase in wingbeat frequency observed during maturation. The instantaneous body angle during flight is controlled mainly by aerodynamic output from the wings. In addition, the mean body angle decreases during maturation in both sexes, and this may play an important part in the directional control of the resultant flight force vector.

Tegula function during free locust flight in relation to motor pattern, flight speed and aerodynamic output

1999 ◽  
Vol 202 (6) ◽  
pp. 711-721 ◽  
Author(s):  
H. Fischer ◽  
E. Ebert
Keyword(s):  
Schistocerca Gregaria ◽  
Motor Pattern ◽  
Flight Speed ◽  
Adaptive Behaviour ◽  
Proprioceptive Information ◽  
Free Flight ◽  
Wingbeat Frequency ◽  
Motor Patterns ◽  
Flight System ◽  
Flight Parameters

Tegulae are complex proprioceptors at the wing base of locusts. Deafferentation of the tegulae causes a lack of specific phasic information related to the wing downstroke and the timing of the upstroke. Employing telemetry during free flight of the locust Schistocerca gregaria, we investigated the consequences of tegula ablation on free flight parameters including motor patterns (wingbeat frequency and the relationship between the activation of flight muscle antagonists), free flight speed and aerodynamic output. We investigated the role of the tegula pairs of both wings on the motor pattern generated in free-flying locusts. We show that the tegula organs are not essential for generating the motor patterns necessary for free flight. However, they are required for increasing the motor output to give additional effective lifting power during adaptive behaviour. We also investigated long-term changes in the free flight parameters after tegula ablation. The recovery of the adult flight system revealed in the present study suggests that there is adaptation to the loss of proprioceptive information; this argues for a full functional and behavioural recovery of the flight system of the locust under closed-loop conditions.

scholarly journals Kinematics Measurement and Power Requirements of Fruitflies at Various Flight Speeds

Energies ◽  
2020 ◽  
Vol 13 (16) ◽  
pp. 4271
Author(s):  
Hao Jie Zhu ◽  
Mao Sun
Keyword(s):  
The Body ◽  
Flight Speed ◽  
Specific Power ◽  
Flight Performance ◽  
Wingbeat Frequency ◽  
Body Angle ◽  
Flying Insects ◽  
Speed Range ◽  
Full Speed ◽  
Stroke Amplitude

Energy expenditure is a critical characteristic in evaluating the flight performance of flying insects. To investigate how the energy cost of small-sized insects varies with flight speed, we measured the detailed wing and body kinematics in the full speed range of fruitflies and computed the aerodynamic forces and power requirements of the flies. As flight speed increases, the body angle decreases and the stroke plane angle increases; the wingbeat frequency only changes slightly; the geometrical angle of attack in the middle upstroke increases; the stroke amplitude first decreases and then increases. The mechanical power of the fruitflies at all flight speeds is dominated by aerodynamic power (inertial power is very small), and the magnitude of aerodynamic power in upstroke increases significantly at high flight speeds due to the increase of the drag and the flapping velocity of the wing. The specific power (power required for flight divided by insect weigh) changes little when the advance ratio is below about 0.45 and afterwards increases sharply. That is, the specific power varies with flight speed according to a J-shaped curve, unlike those of aircrafts, birds and large-sized insects which vary with flight speed according to a U-shaped curve.

scholarly journals Embodied linearity of speed control in Drosophila melanogaster

2012 ◽  
Vol 9 (77) ◽  
pp. 3260-3267 ◽  
Author(s):  
V. Medici ◽  
S. N. Fry
Keyword(s):  
Control Strategy ◽  
High Speed ◽  
Hierarchical Control ◽  
Speed Control ◽  
Micro Air Vehicles ◽  
The Body ◽  
Flight Speed ◽  
Free Flight ◽  
Body Angle ◽  
Visual Speed

Fruitflies regulate flight speed by adjusting their body angle. To understand how low-level posture control serves an overall linear visual speed control strategy, we visually induced free-flight acceleration responses in a wind tunnel and measured the body kinematics using high-speed videography. Subsequently, we reverse engineered the transfer function mapping body pitch angle onto flight speed. A linear model is able to reproduce the behavioural data with good accuracy. Our results show that linearity in speed control is realized already at the level of body posture-mediated speed control and is therefore embodied at the level of the complex aerodynamic mechanisms of body and wings. Together with previous results, this study reveals the existence of a linear hierarchical control strategy, which can provide relevant control principles for biomimetic implementations, such as autonomous flying micro air vehicles.

scholarly journals ONTOGENETIC SCALING OF JUMP PERFORMANCE IN THE AFRICAN DESERT LOCUST (SCHISTOCERCA GREGARIA)

1993 ◽  
Vol 177 (1) ◽  
pp. 81-111 ◽  
Author(s):  
S. L. Katz ◽  
J. M. Gosline
Keyword(s):  
Body Size ◽  
Body Mass ◽  
Power Output ◽  
Schistocerca Gregaria ◽  
Flight Speed ◽  
Desert Locust ◽  
Jump Performance ◽  
Characteristic Distance ◽  
Jumping Performance ◽  
Similarity Model

Ontogenetic growth was used as a model for the effect of body size on jumping performance of the African desert locust (Schistocerca gregaria). Using models that generated relationships between morphology and body size proposed by McMahon and the relationships between morphology and performance described by Hill, we generated testable predictions of how jumping performance measures may change as a function of body mass. Data were collected over an ontogenetic sequence that ranged from 1-day-old first instars to 45-day-old adults. Performance was quantified using a high- sensitivity, three-dimensional force plate. Performance parameters quantified included the force, acceleration, take-off velocity, kinetic energy and power output. With the exception of power output, each measure of performance scaled to body mass in a manner consistent with the predictions of the elastic similarity model. Power output scaled to body mass in a manner consistent with the predictions of the constant stress similarity model. As we noted previously for the scaling of flexural stiffness of the metathoracic tibiae, the elastic similarity model is approximated by the performance of the locust in spite of the morphological design that deviates from that model's predictions. These results indicate that the jump has separate functions in the flightless juvenile instars and in the flying adult stage of the life history. Juvenile locusts produce take-off velocities of between 0.9 and 1.2 m s-1 that are relatively scale-independent. The take-off velocity in juveniles produces a distance of ballistic travel that averages between 20 and 30 cm. In adults, the take-off velocity is also relatively scale-independent at a level approximately twice as high as in juveniles (i.e. 2.5 m s-1). This velocity is coincident with the minimum flight speed reported by Weis-Fogh and a minimum flight speed that we have estimated using actuator disc theory. We suggest that, in juveniles, the jump is designed to achieve a characteristic distance travelled and in adults the jump is designed to achieve a minimum velocity necessary to fly.

scholarly journals Biomechanics of Flight in Neotropical Butterflies: Morphometrics and Kinematics

1990 ◽  
Vol 150 (1) ◽  
pp. 37-53 ◽  
Author(s):  
ROBERT DUDLEY
Keyword(s):  
Body Mass ◽  
Flight Speed ◽  
Morphological Parameters ◽  
Wing Loading ◽  
Body Angle ◽  
Positive Allometry ◽  
Wing Kinematics ◽  
Positional Angle ◽  
Comparable Magnitude ◽  
Stroke Amplitude

Wing and body kinematics of free cruising flight are described for 37 species of Panamanian butterflies ranging over two orders of magnitude in body mass. Butterflies exhibit considerable diversity in body and wing shape, but morphological design is, in general, isometric. Wing loading and mean body diameter show positive allometry. The cruising flight of butterflies is characterized by low wingbeat frequencies (here averaging 11 Hz), stroke amplitudes averaging 103°, and forward speeds in excess of 1m s−1. Body angles during flight are close to horizontal, and stroke plane angles are correspondingly high. Advance ratios are typically greater than 0.9, indicating that the forward and flapping velocity vectors are of comparable magnitude. Flight speed scales with morphological parameters in general accordance with predictions based on isometric design. Interspecifically, no consistent correlation exists between wing kinematics and absolute flight speed. However, maximum positional angle and stroke amplitude tend to increase while body angle decreases with increased relative flight speed.

Recovery of the flight system following ablation of the tegulae in immature adult locusts

1996 ◽  
Vol 199 (6) ◽  
pp. 1395-1403 ◽  
Author(s):  
C Gee ◽  
R Robertson
Keyword(s):  
Locusta Migratoria ◽  
Motor Pattern ◽  
Recovery Period ◽  
Wingbeat Frequency ◽  
Mature Adult ◽  
Flight System ◽  
Mature Adults ◽  
Locust Flight ◽  
Adult Locust ◽  
The Individual

The capacity of the flight system to recover from ablation of the tegulae was studied in immature adult Locusta migratoria and compared with recovery in mature adults. We ablated the hindwing tegulae or all tegulae in adult locusts either 1 day after the imaginal moult (immature locusts) or 2 weeks after the imaginal moult (mature locusts). We monitored recovery throughout the recovery period by using a stroboscope to measure the wingbeat frequency of tethered locusts. In addition, we measured other parameters of the flight motor pattern using electromyographic electrodes implanted into recovered locusts. Both methods of monitoring recovery yielded the same results. There was no reduction, during adult maturation, in the capacity of the locust flight system to recover from the loss of these proprioceptors. Plasticity of the locust flight system was therefore maintained in the mature adult locust. This suggests that the flight system is not fixed and simply implemented when the locust reaches adulthood, but that the circuitry can be remodelled throughout the animal's life to produce behaviour adapted to the needs and constraints of the individual.

scholarly journals FLIGHT PHYSIOLOGY OF NEOTROPICAL BUTTERFLIES: ALLOMETRY OF AIRSPEEDS DURING NATURAL FREE FLIGHT

1994 ◽  
Vol 191 (1) ◽  
pp. 125-139 ◽  
Author(s):  
R Dudley ◽  
R Srygley
Keyword(s):  
Body Mass ◽  
Wing Length ◽  
Correlation Coefficients ◽  
Flight Speed ◽  
Morphological Data ◽  
Free Flight ◽  
Wing Loading ◽  
Natural Conditions ◽  
Wing Area ◽  
Wing Aspect Ratio

Airspeed measurements during natural free flight were made on a total of 270 neotropical butterflies representing 62 species. Morphological data were obtained from the same individuals for which airspeeds had been determined. Flight speed was positively correlated with body mass, thoracic mass and wing loading. Controlling for body mass, higher wing loadings were correlated with increased flight speed. Flight speed and wing aspect ratio were negatively correlated. No consistent correlations were found between airspeed and wing length, wing area or body length. Released butterflies and butterflies encountered in natural free flight did not differ substantially in flight speed allometry. The observed scaling of flight speeds was similar to that derived for a much smaller sample of butterflies flying in an insectary, although absolute values of flight speed were approximately three times higher in natural flight and correlation coefficients of allometric regressions were typically lower. These results suggest that butterfly airspeeds under natural conditions can reasonably be predicted from morphological measurements, and that studying flight in enclosed spaces preserves the allometry of flight speeds.

scholarly journals Hovering performance of Anna's hummingbirds ( Calypte anna ) in ground effect

2014 ◽  
Vol 11 (98) ◽  
pp. 20140505 ◽  
Author(s):  
Erica J. Kim ◽  
Marta Wolf ◽  
Victor Manuel Ortega-Jimenez ◽  
Stanley H. Cheng ◽  
Robert Dudley
Keyword(s):  
Wing Length ◽  
Ground Effect ◽  
The Body ◽  
Plane Angle ◽  
Metabolic Power ◽  
Wingbeat Frequency ◽  
Body Angle ◽  
Induced Flow ◽  
Induced Velocity ◽  
Calypte Anna

Aerodynamic performance and energetic savings for flight in ground effect are theoretically maximized during hovering, but have never been directly measured for flying animals. We evaluated flight kinematics, metabolic rates and induced flow velocities for Anna's hummingbirds hovering at heights (relative to wing length R = 5.5 cm) of 0.7 R , 0.9 R , 1.1 R , 1.7 R , 2.2 R and 8 R above a solid surface. Flight at heights less than or equal to 1.1 R resulted in significant reductions in the body angle, tail angle, anatomical stroke plane angle, wake-induced velocity, and mechanical and metabolic power expenditures when compared with flight at the control height of 8 R . By contrast, stroke plane angle relative to horizontal, wingbeat amplitude and wingbeat frequency were unexpectedly independent of height from ground. Qualitative smoke visualizations suggest that each wing generates a vortex ring during both down- and upstroke. These rings expand upon reaching the ground and present a complex turbulent interaction below the bird's body. Nonetheless, hovering near surfaces results in substantial energetic benefits for hummingbirds, and by inference for all volant taxa that either feed at flowers or otherwise fly close to plant or other surfaces.

Scaling bat wingbeat frequency and amplitude

2002 ◽  
Vol 205 (17) ◽  
pp. 2615-2626 ◽  
Author(s):  
R. D. Bullen ◽  
N. L. McKenzie
Keyword(s):  
Lower Half ◽  
Flight Speed ◽  
Simple Relationship ◽  
Wingbeat Frequency ◽  
Wing Area ◽  
High Speeds ◽  
Second Mode ◽  
Speed Range

SUMMARYWingbeat frequency (fw) and amplitude(θw) were measured for 23 species of Australian bat,representing two sub-orders and six families. Maximum values were between 4 and 13 Hz for fw, and between 90 and 150° forθ w, depending on the species. Wingbeat frequency for each species was found to vary only slightly with flight speed over the lower half of the speed range. At high speeds, frequency is almost independent of velocity. Wingbeat frequency (Hz) depends on bat mass (m, kg) and flight speed (V, ms-1) according to the equation: fw=5.54-3.068log10m-2.857log10V. This simple relationship applies to both sub-orders and to all six families of bats studied. For 21 of the 23 species, the empirical values were within 1 Hz of the model values. One species, a small molossid, also had a second mode of flight in which fw was up to 3 Hz lower for all flight speeds.The following relationship predicts wingbeat amplitude to within±15° from flight speed and wing area (SREF,m2) at all flight speeds:θ w=56.92+5.18V+16.06log10SREF. This equation is based on data up to and including speeds that require maximum wingbeat amplitude to be sustained. For most species, the maximum wingbeat amplitude was 140°.

Wingbeat frequency of barn swallows and house martins: a comparison between free flight and wind tunnel experiments

2002 ◽  
Vol 205 (16) ◽  
pp. 2461-2467 ◽  
Author(s):  
Felix Liechti ◽  
Lukas Bruderer
Keyword(s):  
Wind Tunnel ◽  
Single Pulse ◽  
Free Flight ◽  
Wind Tunnel Experiments ◽  
Wingbeat Frequency ◽  
Flight Costs ◽  
Radar Echo ◽  
The Mean ◽  
Barn Swallows ◽  
Air Speed

SUMMARYThe flight paths and wingbeat patterns of 39 barn swallows (Hirundo rustica) and 26 house martins (Delichon urbica) were recorded by tracking radar during the spring migration. Depending mostly on flight angle,hirundines performed anything from continuous flapping flight during climbing to single pulse-like wing beats during descent. Unlike most other passerines,hirundines rarely showed regular flapping and rest phases, allowing them to be distinguished from other bird migrants by radar echo signatures. Effective wingbeat frequency (Feff) was calculated as the mean number of wing beats per second, including non-flapping phases. Under comparable flight conditions, Feff was higher in house martins than in barn swallows. Within species, Feff values were higher during climbing and slow flying than during descent. Of the variance in Feff, 71 % could be explained by climb rate,air speed and species; similar results were obtained in the wind tunnel. Under comparable flight conditions, barn swallows and house martins in free flight had significantly lower values of Feff than individuals in wind tunnel experiments (by 40 % and 32 %, respectively). This difference may at least partly be due to the shorter wings of the juveniles tested in the wind tunnel during autumn. However, it seems unlikely that this can account for all of the large difference. It is suggested that wind tunnel experiments might overestimate birds' flight costs compared with free flight.

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