Thermoregulation in Small Flies (Syrphus Sp.): Basking and Shivering

1975 ◽  
Vol 62 (3) ◽  
pp. 599-610
Author(s):  
BERND HEINRICH ◽  
CURT PANTLE
Keyword(s):  
Air Temperature ◽  
Beat Frequency ◽  
Vibration Frequencies ◽  
Wing Beat ◽  
Hovering Flight ◽  
Warm Up ◽  
Ambient Temperatures ◽  
Thoracic Temperature ◽  
Flight Muscles ◽  
Vibration Rate

1. Flies of the genus Syrphus aggregated at specific sites in the field (‘lecks’). Flies at leeks were always capable of ‘instant’ take-of, even at ambient temperatures of 10 °C or less. 2. The flies regulated their thoracic temperature by a combination of basking and shivering. During hovering flight in sunshine thoracic temperature rose 12–14 °C above the ambient temperature. 3. The flies engaged in frequent brief chases while at the lecks. 4. At an air temperature > 18 °C the flies at the leck remained in hovering flight most of the time. 5. The vibration frequencies of the thorax during shivering and flight ranged from about 100 to 200 Hz at 10–27 °C, though at a given temperature and spike frequency the vibration rate during warm-up was higher than the wing-beat frequency (assumed to be the same as thoracic vibration frequency) during flight. 6. During shivering, but not in flight, there is a tendency for the indirect flight muscles to be activated in synchrony.

Activation of the Fibrillar Muscles in the Bumblebee During Warm-Up, Stabilization of Thoracic Temperature and Flight

1973 ◽  
Vol 58 (3) ◽  
pp. 677-688
Author(s):  
BERND HEINRICH ◽  
ANN E. KAMMER
Keyword(s):  
Heat Production ◽  
Action Potentials ◽  
Spike Frequency ◽  
Warm Up ◽  
Ambient Temperatures ◽  
Heating And Cooling ◽  
Thoracic Temperature ◽  
Flight Muscles ◽  
Frequency Of Action Potentials ◽  
Physical Laws

1. Extracellular action potentials and thoracic temperatures (TTh) were simultaneously recorded from the fibrillar flight muscles of Bombus vosnesenskii queens during preflight warm-up, during stabilization of TTh in stationary bees, and during fixed flight. 2. In most stationary bees during warm-up and during the stabilization of TTh the rate of heat production, as calculated from thoracic temperature and passive rates of cooling, is directly related to the frequency of action potentials in the muscles. 3. The rate of heat production increases throughout warm-up primarily because of a greater spike frequency at higher TTh. 4. In stationary bees during the stabilization of TTh at different ambient temperatures (TA) the fibrillar muscles are activated by any in a continuous range of spike frequencies, rather than only by on-off responses. 5. Regulation of TTh in stationary bees may involve not only changes in the rate of heat production but also variations of heat transfer from the thorax to the abdomen. 6. During fixed flight the fibrillar muscles are usually activated at greater rates at the initiation of flight than later in flight, but the spike frequency and thus heat production are not varied in response to differences in TA and heating and cooling rates. 7. During fixed flight TTh is not regulated at specific set-points; TTh appears to vary passively in accordance with the physical laws of heating and cooling. 8. Differences in the TTh of bees in free and in fixed flight are discussed with regard to mechanisms of thermoregulation.

scholarly journals Relationship of Wing Beat Frequency and Temperature During Take-Off Flight in Temperate-Zone Beetles

1989 ◽  
Vol 145 (1) ◽  
pp. 321-338 ◽  
Author(s):  
J. J. OERTLI
Keyword(s):  
Temperature Sensitivity ◽  
Beat Frequency ◽  
Temperate Zone ◽  
Wing Beat ◽  
Large Variability ◽  
Ambient Temperatures ◽  
Wing Beat Frequency ◽  
Thoracic Temperature ◽  
Before And After ◽  
Q10 Values

In 24 species of temperate-zone beetles thoracic temperatures (Tth), and wing beat frequency (n) were measured over a range of ambient temperatures (Ta) during take-off flight. The sensitivity of wing beat frequency to thoracic temperature varied greatly in different species: Q10 values ranged from 0.8 to 1.3. The wing beat frequency of beetles with higher average n was more sensitive to thoracic temperature. It is suggested that the temperature sensitivity of wing beat frequency results from temperature-dependent changes in the resonant properties of the beetle flight system rather than from changes in the temperature sensitivity of the muscle or nervous system. There was large variability in thermoregulatory precision. Beetles with higher n tended to thermoregulate more precisely than beetles with lower n. Measurements of thoracic temperature before and after flight indicated endothermic heat production during pre-flight activity, but not during the brief take-off flights.

Flight Energetics and Heat Exchange of Gypsy Moths in Relation to Air Temperature

1980 ◽  
Vol 88 (1) ◽  
pp. 133-146
Author(s):  
TIMOTHY M. CASEY
Keyword(s):  
Air Temperature ◽  
Heat Production ◽  
Beat Frequency ◽  
Warm Up ◽  
Heating And Cooling ◽  
Thoracic Temperature ◽  
Air Temperatures ◽  
Respiratory Heat Loss ◽  
Flight Morphology ◽  
Gypsy Moths

Gypsy moths elevate thoracic temperature (Tth) during flight by endogenous heat production but do not regulate it. Thoracic temperature of moths in free, near-hovering flights exceeded air temperature by approximately 6–7 °C at all Tα's between 17 and 32 °C. Mean rates of mass specific oxygen consumption varied between 40 and 47 ml O2 (g·h)−1 and were not correlated with air temperature. Wing-beat frequency increased from 27 to 33 (s)−1 between air temperatures of 18 and 35 °C. Thoracic heating and cooling constants are similar in live and dead moths, and removal of thoracic scales increases heating constants by about 12%. Preflight warm-up occurs at low Tα's but the moths are capable of immediate, controlled flight at Tα's above 22 °C. Relatively low levels of heat production by the flight muscles are a consequence of low power requirements associated with the flight morphology of gypsy moths. Calculated rates of thoracic and respiratory heat loss of free-flying moths are slightly lower than values of heat production.

Thermoregulation of African and European Honeybees during Foraging, Attack, and Hive Exits and Returns

1979 ◽  
Vol 80 (1) ◽  
pp. 217-229 ◽  
Author(s):  
HEINRICH BERND
Keyword(s):  
Metabolic Rate ◽  
Ambient Temperature ◽  
Heat Loss ◽  
Warm Up ◽  
Ambient Temperatures ◽  
Thoracic Temperature

1. While foraging, attacking, or leaving or returning to their hives, both the African and European honeybees maintained their thoracic temperature at 30 °C or above, independent of ambient temperature from 7 to 23 °C (in shade). 2. Thoracic temperatures were not significantly different between African and European bees. 3. Thoracic temperatures were significantly different during different activities. Average thoracic temperatures (at ambient temperatures of 8–23 °C) were lowest (30 °C) in bees turning to the hive. They were 31–32 °C during foraging, and 36–38 °C in bees leaving the hive, and in those attacking. The bees thus warm up above their temperature in the hive (32 °C) before leaving the colony. 4. In the laboratory the bees (European) did not maintain the minimum thoracic temperature for continuous flight (27 °C) at 10 °C. When forced to remain in continuous flight for at least 2 min, thoracic temperature averaged 15 °C above ambient temperature from 15 to 25 °C, and was regulated only at high ambient temperatures (30–40 °C). 5. At ambient temperatures > 25 °C, the bees heated up during return to the hive, attack and foraging above the thoracic temperatures they regulated at low ambient temperatures to near the temperatures they regulated during continuous flight. 6. In both African and European bees, attack behaviour and high thoracic temperature are correlated. 7. The data suggest that the bees regulate thoracic temperature by both behavioural and physiological means. It can be inferred that the African bees have a higher metabolic rate than the European, but their smaller size, which facilitates more rapid heat loss, results in similar thoracic temperatures.

scholarly journals Kinematics of wings from Caudipteryx to modern birds

2021 ◽  
pp. 095440622110487
Author(s):  
Yaser Saffar Talori ◽  
Jing-Shan Zhao ◽  
Jingmai K O'Connor
Keyword(s):  
Surface Area ◽  
Morphological Changes ◽  
Beat Frequency ◽  
Wing Beat ◽  
Wing Morphology ◽  
Wing Area ◽  
Evolutionary Changes ◽  
Flight Muscles ◽  
Air Speed ◽  
Fossil Data

This study seeks to better quantify the parameters that drove the evolution of flight from non-volant winged dinosaurs to modern birds. In order to explore this issue, we used fossil data to model the feathered forelimbs of Caudipteryx, the most basal non-volant maniraptoran dinosaur with elongated pennaceous feathers that could be described as forming proto-wings. In order to quantify the limiting flight factors, we created three hypothetical wing profiles for Caudipteryx with incrementally larger wingspans. We compared them with what revealed through fossils in wing morphology. These four models were analyzed under varying air speed, wing beat amplitude, and wing beat frequency to determine lift, thrust potential, and metabolic requirements. We tested these models using theoretical equations in order to mathematically describe the evolutionary changes observed during the evolution of modern birds from a winged terrestrial theropod like Caudipteryx. Caudipteryx could not fly, but this research indicates that with a large enough wing span, Caudipteryx-like animal could have flown. The results of these analyses mathematically confirm that during the evolution of energetically efficient powered flight in derived maniraptorans, body weight had to decrease and wing area/wing profile needed to increase together with the flapping angle and surface area for the attachment of the flight muscles. This study quantifies the morphological changes that we observe in the pennaraptoran fossil record in the overall decrease in body size in paravians, the increased wing surface area in Archaeopteryx relative to Caudipteryx, and changes observed in the morphology of the thoracic girdle, namely, the orientation of the glenoid and the enlargement of the sternum.

Carbohydrate Use in the Flight Muscles of Manduca Sexta During Pre-Flight Warm-Up

1987 ◽  
Vol 133 (1) ◽  
pp. 317-327 ◽  
Author(s):  
BARBARA JOOS
Keyword(s):  
Manduca Sexta ◽  
Glycogen Content ◽  
Agricultural Experiment Station ◽  
Warm Up ◽  
Total Cost ◽  
Ambient Temperatures ◽  
Budget Analysis ◽  
Rutgers University ◽  
Agricultural Experiment ◽  
Flight Muscles

Although fat is the principal fuel for flight in moths and butterflies, some use of carbohydrate fuels during activity would be predicted on energetic and biochemical grounds, particularly in nectivores. The present study evaluates the use of carbohydrate fuels during pre-flight warm-up in the endothermic sphinx moth Manduca sexta (L.). Carbohydrate content of moths was measured at intermediate points during the pre-flight warm-up cycle and at take-off. Muscle glycogen content declined during the initial phases of warm-up, whereas glucose and trehalose concentrations were unchanged. Abdominal carbohydrates were not mobilized during warm-up. Energy budget analysis suggests that glycogen oxidation supplies about 39% of the energy needed for the initial phase of warm-up and about 6% of the total cost of warm-up. Glycogen use during warm-up may be correlated with the capacity for endothermic warm-up at low ambient temperatures. Carbohydrates appear to be more important as fuels for activity in some lepidopterans than has been previously reported for other members of this diverse Order. Note: Present address: Department of Entomology and Economic Zoology, New Jersey Agricultural Experiment Station, Cook College, Rutgers University, New Brunswick, NJ 08903, USA.

An Analysis of Pre-Flight Warm-Up in the Sphinx Moth, Manduca Sexta

1971 ◽  
Vol 55 (1) ◽  
pp. 223-239 ◽  
Author(s):  
BERND HEINRICH ◽  
GEORGE A. BARTHOLOMEW
Keyword(s):  
Ambient Temperature ◽  
Manduca Sexta ◽  
Heat Production ◽  
Blood Circulation ◽  
Cardiac Activity ◽  
Warm Up ◽  
Ambient Temperatures ◽  
Thoracic Temperature ◽  
Wing Vibration ◽  
Rate Of Increase

The physiology of pre-flight warm-up in Manduca sexta was analysed with regard to rate of heat production, regional partitioning of heat between thorax and abdomen, and the control of blood circulation. 1. When moths which have come to equilibrium with ambient temperature undergo pre-flight warm-up, the thoracic temperature increases linearly until flight temperature (37-39 °C) is approached. 2. The rate of increase in thoracic temperature during warm-up increases directly with ambient temperature from about 2 °C/min at 15 °C to about 7.6 °C/min at 30 °C. 3. The temperature of the abdomen remains near ambient throughout the period of warm-up, but during the initial part of post-flight cooling while thoracic temperature declines sharply abdominal temperatures rise appreciably. 4. During warm-up the rate of wing vibration increases linearly with thoracic temperature. At a thoracic temperature of 15 °C the rate is about 8/sec and at 35 °C it is about 25/sec. 5. When resting animals are held by the legs they at once begin to beat their wings through a wide angle. These wing beats at any given thoracic temperature are slower than the wing vibrations characteristic of normal warm-up, but they cause thoracic temperature to increase at almost the normal rate. 6. The removal of thoracic scales causes a decrease in rate of warm-up, but in still air this does not prevent the moths from reaching flight temperature. 7. During cooling the rate of decrease in thoracic temperature is greater in live animals than in freshly killed ones. At any given difference between thoracic and ambient temperatures cooling rates are directly related to thoracic temperature. 8. In resting moths heart pulsations are usually variable with regard to rate, amplitude, rhythm, and sometimes direction, but the records of cardiac activity simultaneously obtained from thorax and abdomen show close correspondence. 9. During warm-up the records of changes in impedance from electrodes in the abdomen indicate that pulsations of the abdominal heart are either absent, greatly reduced, or at a frequency different from that simultaneously recorded from the thorax. 10. The calculated rate of heat production during warm-up is linearly related to thoracic temperature. 11. Our data are consistent with the assumption that heat produced in the thorax during warm-up is sequestered there by reduction in blood circulation between thorax and abdomen. 12. Rates of warm-up in insects are close to the values predicted on the basis of body weight from data on heterothermic birds and animals.

Functional aspects of flight in belostomatid bugs (Heteroptera)

1966 ◽  
Vol 164 (994) ◽  
pp. 21-39 ◽  
Keyword(s):  
Motor Neurons ◽  
Spike Activity ◽  
Muscle Activity ◽  
Beat Frequency ◽  
Motor Units ◽  
Nerve Trunk ◽  
The Other ◽  
Wing Beat ◽  
Wing Beat Frequency ◽  
Flight Muscles

1. There are four pairs of fibrillar muscles in the mesothorax of the Belostomatidae. The dorsal longitudinal muscles provide power for the downstroke and automatic pronation of the wings. The dorso-ventral muscles provide upstroke power and automatic supination. The oblique dorsal muscles act mainly as wing supinators; they are also important in the wing unlocking process. The fourth pair of fibrillar flight muscles are basalars which act indirectly via an insertion on the pre-episterna; their action is that of an accessory wing depressor and pronator. The only direct flight muscles in the mesothorax are the tonic wing-folding muscles which insert on the third axillary sclerites. There are no fibrillar flight muscles in the metathorax. 2. The pterothorax contains a fused meso- and metathoracic ganglion. The most anterior nerve trunk from this ganglion provides the motor supply to the dorsal longitudinal and oblique dorsal muscles. There are no recurrent nerves between pro- and pterothoracic ganglia, yet some of the motor neurons of the dorsal longitudinal and oblique dorsal muscles are located anterior to the pterothoracic ganglion. This is not true of the motor neurons of any of the other pterothoracic muscles. There are at least three motor units in each oblique dorsal muscle and five or more in each dorsal longitudinal muscle. The anterior nerve trunk of the pterothoracic ganglion also supplies a sensory nerve to the wings and a small nerve which sup­plies the mesothoracic scolopophorous organ which probably monitors the flight rhythm. The second nerve trunk of the pterothoracic ganglion supplies all of the other mesothoracic muscles and sends one nerve to the mesothoracic legs. 3. Wing-beat frequency for a specimen of L. maximus 105 mm long and weighing 23·4 g was 21-25/s at 23-24°C. For Hydrocyrius 57 mm long and weighing 2·9 g wing beat was 30/s. For L. uhleri typical values are 42 mm long, 1·7 g weight and wing-beat frequency of 38/s. 4. The fibrillar muscles all display strong spike activity coincident with wing opening. The wings may be held open indefinitely without flight and fibrillar muscle activity then subsides to a lower level within a few seconds. Once open, the wings may be held open in the absence of any muscle activity. When flight is initiated directly from closed wings a phasic burst of spikes is recorded initially from the fibrillar muscles but this subsides quickly to a lower level characteristic of steady flight. When flight is initiated from open wings and these muscles are already active electrically there is no change in pattern of spike activity signalling start of flight. In steady flight the pattern of spike activity is irregular and bears no temporal rela­tionship to the regular wing beat. The activity of motor units from each muscle of a pair or from different fibrillar muscles also show random temporal relationships.

scholarly journals ENDOTHERMY IN THE SOLITARY BEE ANTHOPHORA PLUMIPES: INDEPENDENT MEASURES OF THERMOREGULATORY ABILITY, COSTS OF WARM-UP AND THE ROLE OF BODY SIZE

1993 ◽  
Vol 174 (1) ◽  
pp. 299-320 ◽  
Author(s):  
G. N. Stone
Keyword(s):  
Ambient Temperature ◽  
Heat Loss ◽  
Body Mass ◽  
Thermal Power ◽  
Thermal Conditions ◽  
Energetic Cost ◽  
Solitary Bee ◽  
Warm Up ◽  
Ambient Temperatures ◽  
Thoracic Temperature

1. This study examines variation in thoracic temperatures, rates of pre-flight warm-up and heat loss in the solitary bee Anthophora plumipes (Hymenoptera; Anthophoridae). 2. Thoracic temperatures were measured both during free flight in the field and during tethered flight in the laboratory, over a range of ambient temperatures. These two techniques give independent measures of thermoregulatory ability. In terms of the gradient of thoracic temperature on ambient temperature, thermoregulation by A. plumipes is more effective before flight than during flight. 3. Warm-up rates and body temperatures correlate positively with body mass, while mass-specific rates of heat loss correlate negatively with body mass. Larger bees are significantly more likely to achieve flight temperatures at low ambient temperatures. 4. Simultaneous measurement of thoracic and abdominal temperatures shows that A. plumipes is capable of regulating heat flow between thorax and abdomen. Accelerated thoracic cooling is only demonstrated at high ambient temperatures. 5. Anthophora plumipes is able to fly at low ambient temperatures by tolerating thoracic temperatures as low as 25 sC, reducing the metabolic expense of endothermic activity. 6. Rates of heat generation and loss are used to calculate the thermal power generated by A. plumipes and the total energetic cost of warm-up under different thermal conditions. The power generated increases with thoracic temperature excess and ambient temperature. The total cost of warm-up correlates negatively with ambient temperature.

Proline powers pre-flight warm-up in the african fruit beetle pachnoda sinuata

1998 ◽  
Vol 201 (10) ◽  
pp. 1651-1657 ◽  
Author(s):  
L Auerswald ◽  
P Schneider ◽  
G Gäde
Keyword(s):  
Narrow Range ◽  
Wingbeat Frequency ◽  
Glycogen Level ◽  
Warm Up ◽  
Ambient Temperatures ◽  
Tethered Flight ◽  
Rate Of Oxygen Consumption ◽  
Flight Muscles ◽  
Carbohydrate Levels ◽  
Linear Manner

We investigated thoracic temperatures (Tth) during different activities of the endothermic fruit beetle Pachnoda sinuata and analysed which energy substrates are used for the pre-flight warm-up of its flight muscles. Pachnoda sinuata elevates its Tth prior to take-off either by basking in the sun or by warming endothermically to a narrow range around 34 degreesC. During lift-generating tethered flight at low ambient temperatures (Ta=25 degreesC), Tth of P. sinuata decreases steadily until it reaches 28 degreesC, which is not sufficiently high to sustain flight. Tth remains stable during lift-generating tethered flight at high Ta (31 degreesC). Wingbeat frequency (fw) is dependent on Tth: when Tth declines, fw decreases in a linear manner. The proline concentrations in the haemolymph and flight muscles decrease during warm-up. In contrast, the carbohydrate levels in the haemolymph and flight muscles are not affected by the warm-up process, while the glycogen level of the flight muscles declines significantly during the first 10 s of lift-generating tethered flight. This suggests that the energy for endothermic warm-up is produced solely by the oxidation of proline. Measurements of the respiratory quotient (RQ) confirmed that P. sinuata uses a combination of carbohydrates and proline to power its flight. At rest and during lift-generating tethered flight, the RQ is approximately 0.9. During warm-up, the RQ is significantly lower at 0.82, which is close to the theoretical value of 0.8 for the partial oxidation of proline. The rate of oxygen consumption during endothermic warm-up is 45 % of that during lift-generating tethered flight

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