Influence of odour plume structure on upwind flight of mosquitoes towards hosts

1999 ◽  
Vol 202 (12) ◽  
pp. 1639-1648 ◽  
Author(s):  
M. Geier ◽  
O.J. Bosch ◽  
J. Boeckh
Keyword(s):  
Carbon Dioxide ◽  
Lactic Acid ◽  
Human Skin ◽  
Activation Effect ◽  
Upwind Flight ◽  
Response Characteristics ◽  
Plume Structure ◽  
Odour Plume ◽  
Initial Activation ◽  
Odour Plumes

Both the concentration and the fine-scale plume structure of host odours influence the upwind flight of female mosquitoes Aedes aegypti (L.) (Diptera: Culicidae) in a wind tunnel. The attractive effects of carbon dioxide, human skin odour and l-(+)-lactic acid were tested in homogeneous, turbulent and filamentous odour plumes. With carbon dioxide, the percentage of upwind-flying mosquitoes increased with the increasing fluctuations in concentration that occur in turbulent and filamentous plumes. In homogeneous plumes, an initial activation effect was observed, but sustained upwind flights were less frequent than in the other plumes. The opposite was found with plumes of human skin odour: the highest number of mosquitoes flew upwind in the homogeneous plume, whereas in turbulent or filamentous plumes their numbers were significantly lower. Regardless of plume type, the percentage of upwind-flying mosquitoes increased with increasing concentrations of carbon dioxide and of skin odour. With l-(+)-lactic acid, the dose-response characteristics were not consistent, and the relative effects of different plume types upon upwind flights differed within different ranges of concentration. Even maximum reactions to this compound were modest compared with those to carbon dioxide or to skin odour. Our findings demonstrate (1) that mosquitoes are able to orient upwind under continuous odour stimulation and (2) that upwind flight is dependent upon plume structure in different ways for different host odour components.

Field responses of tsetse flies (Diptera: Glossinidae) to odours of men, lactic acid and carbon dioxide

1979 ◽  
Vol 69 (3) ◽  
pp. 459-467 ◽  
Author(s):  
G. A. Vale
Keyword(s):  
Carbon Dioxide ◽  
Lactic Acid ◽  
Human Skin ◽  
Glossina Morsitans Morsitans ◽  
The Body ◽  
Tsetse Flies ◽  
Glossina Morsitans ◽  
Human Breath ◽  
Odour Source ◽  
Body Odour

AbstractThe numbers of Glossina morsitans morsitans Westw. and G. pallidipes Aust. attracted to odour at a distance were studied by catches in Zimbabwe-Rhodesia from an electrocuting net near a stationary odour source. Also, the numbers of flies attracted to an ox and the proportion of flies engorging on it when it was sprayed with L-lactic acid were assessed from the numbers of fed and unfed flies caught by a pair of nets around the penned bait. The body odour of men depressed by up to four-fifths the numbers attracted to ox odour from a distance. Lactic acid, which was shown to occur on human skin, produced a similar effect, and when sprayed on an ox it reduced by about half the proportion of attracted flies that engorged. Human breath was mildly attractive, due largely or entirely to its content of carbon dioxide.

Nanocellular and needle-like structures in poly(l-lactic acid) using spherulite templates and supercritical carbon dioxide

RSC Advances ◽  
2015 ◽  
Vol 5 (46) ◽  
pp. 36320-36324 ◽  
Author(s):  
Junsong Li ◽  
Guangjian He ◽  
Xia Liao ◽  
Hao Xu ◽  
Qi Yang ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Lactic Acid ◽  
Supercritical Carbon Dioxide ◽  
Supercritical Carbon

The random nanocells and the radial needle-like cells are formed in the interlamellar amorphous regions of spherulites in PLLA.

Turbulent plumes of heat, moist heat, and carbon dioxide elicit upwind anemotaxis in tsetse flies Glossina morsitans morsitans Westwood (Diptera: Glossinidae)

2002 ◽  
Vol 80 (7) ◽  
pp. 1149-1155 ◽  
Author(s):  
W G Evans ◽  
R H Gooding
Keyword(s):  
Carbon Dioxide ◽  
Wind Tunnel ◽  
Relative Humidity ◽  
Glossina Morsitans Morsitans ◽  
Tsetse Flies ◽  
Glossina Morsitans ◽  
Low Velocity ◽  
Upwind Flight ◽  
Moist Heat ◽  
Heated Air

The roles and interactions of turbulent plumes of heat, moist heat, and carbon dioxide in mediating upwind flight of adult tsetse flies (Glossina morsitans morsitans Westwood) were investigated using a wind tunnel in a constant-environment chamber. Heat fluctuations in the plume that were detected by a thermocouple and displayed as oscilloscope traces allowed direct visualization of the structures of the plumes. Significantly more flies flew upwind when exposed to plumes of (i) carbon dioxide (0.0051% above background) and air (58% relative humidity) compared with air alone; (ii) carbon dioxide and heated air (35% relative humidity and temperature fluctuating up to 0.09°C above background) compared with carbon dioxide and air; and (iii) carbon dioxide and moist (82% relative humidity) heated air (temperature fluctuating up to 0.05°C above background) compared with carbon dioxide and heated air. However, there were no significant differences in upwind flight of flies exposed to plumes of (i) air compared with humidified air (65% relative humidity); (ii) carbon dioxide and heated air compared with heated air alone; and (iii) carbon dioxide and moist heated air compared with moist heated air alone. Recorded temperature fluctuations in heat plumes transported downwind from a tethered steer in a pasture showed patterns similar to those produced in the wind-tunnel plumes. These results suggest that host emissions of carbon dioxide alone and combined heat and moisture carried downwind by low-velocity winds elicit upwind anemotaxis in tsetse flies, which distinguish these emissions from a background of lower atmospheric levels.

Enzymatic synthesis of L-lactic acid from carbon dioxide and ethanol with an inherent cofactor regeneration cycle

2010 ◽  
Vol 108 (2) ◽  
pp. 465-469 ◽  
Author(s):  
Xiaodong Tong ◽  
Bilal El-Zahab ◽  
Xueyan Zhao ◽  
Youyan Liu ◽  
Ping Wang
Keyword(s):  
Carbon Dioxide ◽  
Lactic Acid ◽  
Enzymatic Synthesis ◽  
Cofactor Regeneration ◽  
Regeneration Cycle

scholarly journals Lactic Acid Formation and Carbon Dioxide Fixation

Nature ◽  
1957 ◽  
Vol 180 (4594) ◽  
pp. 1053-1053 ◽  
Author(s):  
D. A. BARBER
Keyword(s):  
Carbon Dioxide ◽  
Lactic Acid ◽  
Carbon Dioxide Fixation ◽  
Acid Formation

scholarly journals The Active Transport of Oxygen and Carbon Dioxide into the Swim-Bladder of Fish

1966 ◽  
Vol 49 (6) ◽  
pp. 1209-1220 ◽  
Author(s):  
H.J. KUHN ◽  
E. MARTI
Keyword(s):  
Carbon Dioxide ◽  
Lactic Acid ◽  
Active Transport ◽  
Bladder Pressure ◽  
Swim Bladder ◽  
Rete Mirabile ◽  
Partial Pressures ◽  
Gas Gland ◽  
Counter Current ◽  
Good Agreement

The active transport of oxygen and carbon dioxide into the swim-bladder of fish is discussed. The rete mirabile is a capillary network which is involved in the gas secretion into the bladder. The rete is regarded as a counter-current multiplier. Lactic acid which is produced in the gas gland generates in the rete single concentrating effects for oxygen and carbon dioxide; i.e., for equal partial pressures the concentrations of the gases in the afferent rete capillaries are higher than those in the efferent ones. The single concentrating effects were calculated from measurements of sea robin blood (Root, 1931). The multiplication of these effects within the rete for different rete lengths and different transport rates was numerically evaluated. The calculated O2 and CO2 pressures in the bladder are in good agreement with the experimental results of Scholander and van Dam (1953). The descent velocities at equilibrium between bladder pressure and hydrostatic pressure are discussed for fishes with different rete lengths.

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