scholarly journals The Influence of Starvation on the Thermal Death-Point on Insects

1934 ◽  
Vol 11 (1) ◽  
pp. 48-53
Author(s):  
MELLANBY KENNETH
Keyword(s):  
High Temperatures ◽  
Moist Air ◽  
Dry Air ◽  
Pediculus Humanus ◽  
Thermal Death ◽  
Thermal Death Point ◽  
Food Reserves

Experiments are described in which newly hatched larval lice (Pediculus humanus corporis) and adult C. fatigans were exposed to high temperatures. The humidity was controlled, and the exposures lasted for either 1 or 24 hours. Larval lice, whether fed or unfed, withstood 46.5° C. for 1 hour, while the Culex were much less resistant--they only withstood a temperature of 39° C. The humidity of the air did not affect these results. When exposed for 24 hours, larval lice which had fed withstood 38° C. in moist air. They only withstood 33° C. in dry air, as they were killed by desiccation at higher temperatures. Mosquitoes (C. fatigans) which had gorged gave similar results. They survived 37° C. for 24 hours in moist air, and only 32° C. in dry. Unfed lice or mosquitoes behaved differently, as they could not withstand such high temperatures for periods of 24 hours. This was because they had small food reserves, and at high temperatures their rate of metabolism was so increased that they died of starvation.

The Influence of Atmospheric Humidity on the Thermal Death Point of a Number of Insects

1932 ◽  
Vol 9 (2) ◽  
pp. 222-231
Author(s):  
MELLANBY KENNETH
Keyword(s):  
High Temperature ◽  
Low Temperatures ◽  
Causes Of Death ◽  
Moist Air ◽  
Atmospheric Humidity ◽  
Dry Air ◽  
Hot Air ◽  
Thermal Death ◽  
Thermal Death Point ◽  
Large Meal

An account is given of a technique suitable for exposing small insects to high temperature and air of controlled humidity. Data of survival points obtained from a number of species are given, for 1-hour and 24-hour experiments. In the 1-hour experiments, the humidity of the air had no effect on the death point, except in the case of large meal-worms, which died at 1° C. higher in dry air than in moist. The temperature which any species can stand for 1 hour is sharply defined, but there is a range of 7° C. between the species of insects worked with. In 24-hour experiments, in moist air, all the species died between 36 and 39.5° C. Their death was presumably caused by the heat. In dry air, those insects not able to conserve their water died at low temperatures--22° C. in the case of flea larvae: this was attributed to desiccation. There seem to be two main causes of death of insects when they are killed at high temperatures: (1) When the temperature is over 40° C., they die from the effects of the heat. (2) Below 36° C. all the insects experimented with were able to survive at least 24 hours in moist air, but in dry air insects unable to conserve their water may die of desiccation. In hot air, over 40° C., certain large insects are better able to survive in dry air, as they keep their bodies cool by evaporating water. I am grateful to Mr H. S. Leeson for the supply of X. cheopis, and to Dr R. P. Hobson for the Lucilia adults. And I am indebted to Dr P. A. Buxton and Dr V. B. Wigglesworth, who made many helpful suggestions when the work was in progress and who read through the typescript.

Effects of Temperature and Humidity on the Metabolism of the Fasting Bed-Bug (Cimex lectularius), Hemiptera

Parasitology ◽  
1932 ◽  
Vol 24 (3) ◽  
pp. 419-428 ◽  
Author(s):  
Kenneth Mellanby
Keyword(s):  
Dry Matter ◽  
Moist Air ◽  
Bed Bugs ◽  
Bed Bug ◽  
Dry Air ◽  
Loss Of Weight ◽  
Cent Relative Humidity ◽  
Effects Of Temperature ◽  
Rate Of Evaporation ◽  
Food Reserves

A method is described by which individual bed-bugs, weighing only 5 mg., can be accurately weighed, and their rate of loss of weight measured during starvation.Fasting bed-bugs were kept for various periods at five temperatures, ranging from 8° C. to 37° C., and at four humidities—0, 30, 60 and 90 per cent. relative humidity—at each temperature. Analysis after the experiments showed that the same amounts of food reserves were used up at each humidity for one temperature, and, as more water was evaporated from those kept in dry air than from those in moist, the proportion of dry matter rose most rapidly in dry air. Protein was the main food reserve used.Although the rate of loss of water was greatest in dry air, the rate of loss was relatively greater in moist air when the saturation deficiencies are compared. It appears that the insects conserve their water in dry air, but their surface area being so great in comparison with their volume, they cannot prevent all evaporation. This evaporation is at a rate nearly proportional to the saturation deficiency of the air.In moist air water appears to be evaporated freely. It is suggested that the spiracles are kept closed more in dry air and less in moist, which accounts for the fact that the rate of evaporation is proportionately greatest in moist air.A comparison is made between the results obtained with Cimex and Rhodnius.

Observations on the Thermal Death Points of the Blow-fly at different relative Humidities

1928 ◽  
Vol 18 (4) ◽  
pp. 397-403 ◽  
Author(s):  
Mary V. F. Beattie
Keyword(s):  
Relative Humidity ◽  
Blow Fly ◽  
Dry Air ◽  
Optimum Point ◽  
Thermal Death ◽  
Thermal Death Point

In summarising, the following points are to be noted:—1. The thermal death point of the blow-fly was definitely influenced by the factor of humidity.2. Saturated and dry air had the effect of lowering the thermal death point.3. Relative humidities from 60 per cent. to 80 per cent. were more favourable, while relative humidity of 70 per cent. actually was found to be an optimum point.4. From the weighings it may be concluded that death in saturated air was due to the inability of the flies to regulate their heat by evaporation.

THERMAL TOLERANCE IN MACROCENTRUS ANCYLIVORUS ROH. (HYMENOPTERA: BRACONIDAE)

1954 ◽  
Vol 32 (1) ◽  
pp. 30-38 ◽  
Author(s):  
D. P. Pielou ◽  
R. F. Glasser
Keyword(s):  
High Temperatures ◽  
Thermal Tolerance ◽  
Direct Action ◽  
Oriental Fruit Moth ◽  
Moist Air ◽  
Lethal Effects ◽  
Old Adults ◽  
Dry Air ◽  
Sucrose Solutions ◽  
Higher Temperature

The lethal effects of high temperatures were investigated on Macrocentrus ancy-livorus Roh., a parasite of the oriental fruit moth. Day-old adults were exposed to uniform high temperatures for fixed periods ranging from 15 min. to 8 hr. in different tests. Temperatures investigated ranged from 30° to 45 °C. The insects had been reared under uniform and rigidly specified conditions at constant temperatures. After exposure all the test insects were removed, put in bottles, and provided with 10% sucrose solutions as food. Mortality was recorded 24 hr. later. Sexes were kept separate. Tests at all temperatures and exposure times were carried out both in dry and in moist air. At temperatures up to 34 °C. mortality was light even at the 8-hr. exposure. At 44 °C. almost 100% mortality was recorded at the 1/2-hr. exposure. Between these limits mortality increased with higher temperature or lengthened exposure time; it was generally greater in dry air than in moist. Females were more resistant than males. Thermograph records from the peach growing areas of the Niagara peninsula showed that only in exceptionally hot summers could conditions cause appreciable death from the direct action of temperature alone.

scholarly journals Studies on temperature regulation. I. The Pulmonata and Oligochaeta

1944 ◽  
Vol 132 (868) ◽  
pp. 239-252 ◽  
Keyword(s):  
Body Temperature ◽  
Temperature Regulation ◽  
Helix Pomatia ◽  
Ground Level ◽  
The Body ◽  
Saturation Point ◽  
Dry Air ◽  
Thermal Death ◽  
Thermal Death Point ◽  
Binding Power

The slug, Arion ater , at all times, and the snail, Helix pomatia , when fully extended, maintain a body temperature well below that of the surrounding air unless it is fully saturated, and slightly, if at all, above that of the wet-bulb thermometer. By withdrawal into the microclimate of the shell the snail can appreciably reduce loss of water by evaporation; and in such circumstances its body temperature tallies more nearly with that of the surrounding atmosphere. After the formation of the epiphragm the body temperature of H. pomatia is identical with that of the atmosphere outside and varies accordingly. Since the slime of the slug loses water in air unless the R. H. is very near saturation point the water­-binding power of the mucus is not an effective check to loss of water by evaporation. The body temperature of an earthworm after relatively short periods of exposure to fairly dry air diverges increasingly from the wet-bulb reading. This appears to be due to rapid desicca­tion of the surface. Since the upper thermal death-point of the earthworm is relatively low, this means that earthworms are not adapted to long survival at ground level in sunlight. To this extent their equipment for maintaining body temperature below the danger point accords both with their habits, and with what views may plausibly be entertained about their ancestry.

scholarly journals The Temperature and Humidity Relations of the cockroach

1936 ◽  
Vol 13 (1) ◽  
pp. 28-34
Author(s):  
DONALD L. GUNN ◽  
F. B. NOTLEY
Keyword(s):  
Body Temperature ◽  
The Body ◽  
Moist Air ◽  
Dry Air ◽  
Thermal Death ◽  
Temperature And Humidity ◽  
Ecological Importance

1. The thermal death-points of three species of cockroaches in dry and in moist air have been determined for 1-day and 1-hour exposures. 2. Moist air is more favourable than dry in the longer exposures, because in dry air death occurs from desiccation when the temperature itself is not fatal. 3. Dry air is more favourable than moist in the shorter exposures, owing to the fact that the evaporation of water lowers the body temperature. 4. Bearing in mind the thermotactic behaviour of these animals, these observations would seem to have little ecological importance.

scholarly journals The Effects of Temperature and Humidity on the Cheese Skipper, Piophila Casei (L.)

1935 ◽  
Vol 12 (4) ◽  
pp. 384-388
Author(s):  
JOHN SMART
Keyword(s):  
High Temperatures ◽  
Effect Of Temperature ◽  
Secondary Effect ◽  
Short Series ◽  
Thermal Death ◽  
Temperature And Humidity ◽  
Series Of Experiments ◽  
Thermal Death Point ◽  
Effects Of Temperature ◽  
Lower Temperature

The paper gives the results of a short series of experiments carried out to determine the thermal death-point under conditions of controlled humidity of the larva and pupa of the Cheese Skipper, Piophila casei (L.). The larva is remarkable for the high temperatures it can withstand, namely 52° C., for 1 hour's exposure and 45° C. for an exposure of 24 hours. The death of the pupa at a much lower temperature is shown to be due to a secondary effect of temperature on its physiology.

scholarly journals The effect of atmospheric humidity on the metabolism of the fasting mealworm ( Tenebrio molitor L., Coleoptera)

1932 ◽  
Vol 111 (772) ◽  
pp. 376-390 ◽  
Keyword(s):  
Relative Humidity ◽  
Dry Matter ◽  
Total Water ◽  
Moist Air ◽  
Atmospheric Humidity ◽  
Dry Air ◽  
Two Temperatures ◽  
The Difference ◽  
Food Reserves ◽  
Metabolic Water

Previous work has shown that fasting mealworms will live at room tempera­ture for two hundred days, and even at 30°C. they usually live for over a month. During the first two days of starvation the mealworms are restless, and they pass a certain amount of excrement. After this they lie quite still, and pass extremely little excreta. The loss in weight of starving mealworms is different in dry and moist air at one temperature, or in air with the same relative humidity at two temperatures. At 23° C. the mealworms evidently regulate their metabolism, because while they lose weight at different rates in air of various relative humidities, yet they keep the ratio of dry matter to water in their bodies constant (Buxton, 1930). In carrying this work further, I have attempted to find whether the rate at which fasting mealworms evaporate water is proportional at any temperature to the saturation deficiency of the air. Now the fasting mealworm not only evaporates water present in its body at the start of the experiment, but also considerable quantities of water produced by the metabolism of food reserves during starvation. We can estimate the amount of water present in the mealworms at the start of starvation, and can find how much is left at the end of the experiment; the difference represents part of the total water evaporated. But this method does not indicate any metabolic water which is produced and also evaporated during starvation. If one wishes to know the total water evaporated, it can be collected in a stream of air, or else the loss of food reserves must be estimated and the metabolic water produced calculated from these results. I preferred to use the second method, as it is not easy to measure the actual amount of water given off by insects except into dry air.

scholarly journals Post-Plasma Catalysis for Trichloroethylene Abatement with Ce-Doped Birnessite Downstream DC Corona Discharge Reactor

Catalysts ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 946
Author(s):  
Grêce Abdallah ◽  
Jean-Marc Giraudon ◽  
Rim Bitar ◽  
Nathalie De Geyter ◽  
Rino Morent ◽  
...  
Keyword(s):  
Corona Discharge ◽  
Active Oxygen Species ◽  
Surface Acidity ◽  
Good Stability ◽  
Ozone Decomposition ◽  
Moist Air ◽  
Plasma Catalysis ◽  
Dry Air ◽  
Water Tolerance ◽  
By Products

Trichloroethylene (TCE) removal was investigated in a post-plasma catalysis (PPC) configuration in nearly dry air (RH = 0.7%) and moist air (RH = 15%), using, for non-thermal plasma (NTP), a 10-pin-to-plate negative DC corona discharge and, for PPC, Ce0.01Mn as a catalyst, calcined at 400 °C (Ce0.01Mn-400) or treated with nitric acid (Ce0.01Mn-AT). One of the key points was to take advantage of the ozone emitted from NTP as a potential source of active oxygen species for further oxidation, at a very low temperature (100 °C), of untreated TCE and of potential gaseous hazardous by-products from the NTP. The plasma-assisted Ce0.01Mn-AT catalyst presented the best CO2 yield in dry air, with minimization of the formation of gaseous chlorinated by-products. This result was attributed to the high level of oxygen vacancies with a higher amount of Mn3+, improved specific surface area and strong surface acidity. These features also allow the promotion of ozone decomposition efficiency. Both catalysts exhibited good stability towards chlorine. Ce0.01Mn-AT tested in moist air (RH = 15%) showed good stability as a function of time, indicating good water tolerance also.

Transport properties of real moist air, dry air, steam, and water

2021 ◽  
pp. 1-9
Author(s):  
Sebastian Herrmann ◽  
Hans-Joachim Kretzschmar ◽  
Vikrant C. Aute ◽  
Donald P. Gatley ◽  
Eckhard Vogel
Keyword(s):  
Transport Properties ◽  
Moist Air ◽  
Dry Air
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