Preparation for Flight by Hawk-Moths

1962 ◽  
Vol 39 (4) ◽  
pp. 579-588
Author(s):  
D. A. DORSETT
Keyword(s):  
Ambient Temperature ◽  
Flight Muscle ◽  
Beat Frequency ◽  
The Other ◽  
Wing Beat ◽  
Wing Loading ◽  
Warming Period ◽  
The Family ◽  
Fine Control ◽  
Wing Stroke

1. Moths belonging to the family Sphingidae are not capable of controlled flight until the temperature of the flight muscle has been raised by a preliminary period of vibrating the wings. 2. The flight-temperature of forty-five specimens of Deilephila nerii varied between 34 and 45° C., but individuals always flew at the same temperature. 3. The temperature inside the thorax rose at a mean rate of 4.2° C./min. 4. Alteration of the ambient temperature affects the duration of the warming period but not the flight-temperature. 5. The flight-temperature shows a positive correlation with the wing loading. In Deilephila and two other genera of similar dimensions, an increase of 50 mg. in the wing loading corresponds to a rise of 5.75° C. in the flight-temperature. 6. A method of measuring the rise in wing-beat frequency during the warming period is described. The thoracic temperature increases linearly with the frequency. 7. It is concluded that the frequency of the wing beat is determined principally by the wing loading, whilst variations in the other parameters of the wing stroke provide the ‘fine control’ of flight regulation required during flight and whilst hovering.

scholarly journals GENETIC VARIABILITY OF FLIGHT METABOLISM IN DROSOPHILA MELANOGASTER. I. CHARACTERIZATION OF POWER OUTPUT DURING TETHERED FLIGHT

Genetics ◽  
1981 ◽  
Vol 98 (3) ◽  
pp. 549-564
Author(s):  
James W Curtsinger ◽  
Cathy C Laurie-Ahlberg
Keyword(s):  
Drosophila Melanogaster ◽  
Power Output ◽  
Beat Frequency ◽  
Wing Beat ◽  
Tethered Flight ◽  
Flight Metabolism ◽  
Flight Parameters ◽  
Wing Stroke ◽  
Stroke Amplitude

ABSTRACT The mechanical power imparted to the wings during tethered flight of Drosophila melanogaster is estimated from wing-beat frequency, wing-stroke amplitude and various aspects of wing morphology by applying the steady-state aerodynamics model of insect flight developed by Weis-Fogh (1972, 1973). Wing-beat frequency, the major determinant of power output, is highly correlated with the rate of oxygen consumption. Estimates of power generated during flight should closely reflect rates of ATP production in the flight muscles, since flies do not acquire an oxygen debt or accumulate ATP during flight. In an experiment using 21 chromosome 2 substitution lines, lines were a significant source of variation for all flight parameters measured. Broadsense heritabilities ranged from 0.16 for wing-stroke amplitude to 0.44 for inertial power. The variation among lines is not explained by variation in total body size (i.e., live weight). Line differences in flight parameters are robust with respect to age, ambient temperature and duration of flight. These results indicate that characterization of the power output during tethered flight will provide a sensitive experimental system for detecting the physiological effects of variation in the structure or quantity of the enzymes involved in flight metabolism.

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 Myosin light chain-2 mutation affects flight, wing beat frequency, and indirect flight muscle contraction kinetics in Drosophila.

1992 ◽  
Vol 119 (6) ◽  
pp. 1523-1539 ◽  
Author(s):  
J Warmke ◽  
M Yamakawa ◽  
J Molloy ◽  
S Falkenthal ◽  
D Maughan
Keyword(s):  
Myosin Light Chain ◽  
Flight Muscle ◽  
Beat Frequency ◽  
Indirect Flight Muscle ◽  
Wing Beat ◽  
Wild Type ◽  
Wing Beat Frequency ◽  
Myosin Light Chain 2 ◽  
Kinetics Of ◽  
Contraction Kinetics

We have used a combination of classical genetic, molecular genetic, histological, biochemical, and biophysical techniques to identify and characterize a null mutation of the myosin light chain-2 (MLC-2) locus of Drosophila melanogaster. Mlc2E38 is a null mutation of the MLC-2 gene resulting from a nonsense mutation at the tenth codon position. Mlc2E38 confers dominant flightless behavior that is associated with reduced wing beat frequency. Mlc2E38 heterozygotes exhibit a 50% reduction of MLC-2 mRNA concentration in adult thoracic musculature, which results in a commensurate reduction of MLC-2 protein in the indirect flight muscles. Indirect flight muscle myofibrils from Mlc2E38 heterozygotes are aberrant, exhibiting myofilaments in disarray at the periphery. Calcium-activated Triton X-100-treated single fiber segments exhibit slower contraction kinetics than wild type. Introduction of a transformed copy of the wild type MLC-2 gene rescues the dominant flightless behavior of Mlc2E38 heterozygotes. Wing beat frequency and single fiber contraction kinetics of a representative rescued line are not significantly different from those of wild type. Together, these results indicate that wild type MLC-2 stoichiometry is required for normal indirect flight muscle assembly and function. Furthermore, these results suggest that the reduced wing beat frequency and possibly the flightless behavior conferred by Mlc2E38 is due in part to slower contraction kinetics of sarcomeric regions devoid or partly deficient in MLC-2.

scholarly journals MITOCHONDRIA IN THE FLIGHT MUSCLES OF INSECTS

1956 ◽  
Vol 39 (4) ◽  
pp. 497-512 ◽  
Author(s):  
Leo Levenbook ◽  
Carroll M. Williams
Keyword(s):  
Cytochrome C ◽  
Flight Muscle ◽  
Beat Frequency ◽  
Adult Life ◽  
Adult Emergence ◽  
Dry Weight ◽  
Phormia Regina ◽  
Wing Beat ◽  
Wing Beat Frequency ◽  
Wet Weight

1. In the present study a correlation has been sought between aging, flight muscle mitochrondria (sarcosomes), cytochrome c, and flight ability in the blowfly, Phormia regina. 2. During the 1st week of adult life, individual sarcosomes increase in mass from 2.7 x 10–7 µg. dry weight at the time of emergence, to 8.5 x 10–7 µg. by the 7th day. During this period of growth, the number of sarcosomes per fly (6.7 x 108) remains constant. When mature, the sarcosomes account for 32.6 per cent of the total muscle dry weight, or close to 40 per cent on a wet weight basis. 3. It appears probable that the high content of flight muscle cytochromes is entirely localized in the sarcosomes. The cytochromes continue to be synthesized and increase in titer within the sarcosomes for 7 days after adult emergence. 4. As determined spectroscopically, the various cytochrome components at all times maintain a constant ratio both to one another and to the sarcosomal dry weight. This suggests the possibility that the cytochrome system may be synthesized as a single entity. 5. The wing-beat frequency of Drosophila funebris and Phormia varies with the age of these flies, being lowest at the time of emergence and maximum after the 6th day. 6. The relations between wing-beat frequency, respiration during flight, and sarcosomal cytochrome c content are discussed. On the basis of some likely assumptions it is calculated that the cytrochrome c turnover number is over 5,000, and that the cytochrome c turns over once for every two wing-beat cycles.

Oxygen Consumption of Moths During Rest, Pre-Flight Warm-Up, and Flight In Relation to Body Size and Wing Morphology

1978 ◽  
Vol 76 (1) ◽  
pp. 11-25 ◽  
Author(s):  
GEORGE A. BARTHOLOMEW ◽  
TIMOTHY M. CASEY
Keyword(s):  
Oxygen Consumption ◽  
Aspect Ratio ◽  
Body Mass ◽  
Beat Frequency ◽  
Wing Beat ◽  
Wing Loading ◽  
Warm Up ◽  
Pooled Data ◽  
Wing Beat Frequency ◽  
Tightly Coupled

Morphometrics and oxygen consumption were studied in about 35 sphingids, 50 saturniids, and 20 other heterothermic moths belonging to various families. For the pooled data of all species the regression of oxygen consumption on mass in grams is described by the following equations: at rest, cm3/h = 0.402 g0.775; during hovering flight, cm3/h = 59.430.818; during warm-up, cm3 = 1.186 g0.898. Similar equations are presented for the families Saturniidae and Sphingidae. In sphingids and saturniids thoracic mass, wing length, and wing area increased with body mass, whereas wing loading and aspect ratio were independent of body mass. The sphingids had higher wing loading, aspect ratio, and wing beat frequency during flight than the saturniids. Wing beat frequency was more tightly coupled to morphological parameters in sphingids than in saturniids. The allometry of resting and active aerobic metabolism in heterothermic moths is compared with that of reptiles, mammals and birds. The scaling of oxygen consumption during flight in the moths is almost identical to that of bats and birds.

The Supply of Oxygen to the Active Flight Muscles of some Large Beetles

1966 ◽  
Vol 45 (2) ◽  
pp. 285-304 ◽  
Author(s):  
P. L. MILLER
Keyword(s):  
Beat Frequency ◽  
Wing Beat ◽  
Volume Changes ◽  
Tracheal System ◽  
Air Sacs ◽  
Tethered Flight ◽  
Flight Muscles ◽  
Wing Stroke ◽  
Stroke Amplitude ◽  
Comparable Size

1. Measurements of the wing-beat frequency, wing-stroke amplitude and stroke plane and of abdominal ventilation have been made during the tethered flight of twenty-six species of beetles belonging to five families, mainly in Uganda. 2. Abdominal ventilation is weak or absent in all species of Cerambycidae, Elateridae and Anthribidae examined in flight. The tracheal system in these families is characterized by the complete absence of air sacs, and in larger species by the presence of four giant trunks running through the metathorax between spiracles 2 and 3 and forming the primary supply to the flight muscles. 3. Abdominal ventilation is strong during the flight of all species over 0.6 g. in weight of the Scarabaeidae and Buprestidae which were examined. Their tracheal systems contain an abundance of air sacs while giant trunks are absent. 4. Measurements of the thoracic volume changes which accompany each wing beat show that the amount of air which can be pumped in this way increases in larger Cerambycidae per second per gram as compared with small species. Large Cerambycidae pump more per gram than Scarabaeidae of comparable size. 5. During the flight of the cerambycid Petrognatha the thoracic pump exchanges 540 µl. air/sec./g. Its action is mainly on the compressible secondary tracheae. In a wind speed of 5 m./sec. 1050µl. air/sec./g. are driven through the four giant trunks, entering through spiracle 2 and leaving from spiracle 3. The trunks are stout-walled and probably unaffected by the thoracic pump.

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