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

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.

2020 ◽  
Author(s):  
Lei Qin ◽  
Qiang Sun ◽  
Jiani Shao ◽  
Yang Chen ◽  
Xiaomei Zhang ◽  
...  

Abstract Background: The effects of temperature and humidity on the epidemic growth of coronavirus disease 2019 (COVID-19)remains unclear.Methods: Daily scatter plots between the epidemic growth rate (GR) and average temperature (AT) or average relative humidity (ARH) were presented with curve fitting through the “loess” method. The heterogeneity across days and provinces were calculated to assess the necessity of using a longitudinal model. Fixed effect models with polynomial terms were developed to quantify the relationship between variations in the GR and AT or ARH.Results: An increased AT dramatically reduced the GR when the AT was lower than −5°C, the GR was moderately reduced when the AT ranged from −5°C to 15°C, and the GR increased when the AT exceeded 15°C. An increasedARH increased theGR when the ARH was lower than 72% and reduced theGR when the ARH exceeded 72%.Conclusions: High temperatures and low humidity may reduce the GR of the COVID-19 epidemic. The temperature and humidity curves were not linearly associated with the COVID-19 GR.


1947 ◽  
Vol 24 (1-2) ◽  
pp. 79-94
Author(s):  
L. E. S. EASTHAM ◽  
F. SEGROVE

1. The effects of temperature and humidity on the duration of each instar of the life cycle of Calandra granaria Linn. have been examined. The insects were reared at temperatures ranging from 15 to 30° C. and at atmospheric humidities ranging from 40 to 80% R.H. 2. A method is described for assessing the effect of temperature as an independent factor. 3. The temperatures employed fall within the ‘vital zone’. Extrapolation indicates the threshold temperature to be approximately 11° C. for the egg and larval instars though somewhat lower for the pupa. 30° C. is below the optimum temperature. 4. The durations of the egg and pupal stages are not affected by atmospheric humidity. 5. The duration of all larval instars is affected by moisture. It is suggested that this is largely due to atmospheric humidity and that food water is of little significance. 6. Shortage of moisture acts as an obstacle to development. Evidence is presented which indicates that drier atmospheres tend to desiccate the insect and that desiccation is responsible for retarded growth and development. 7. Since much earlier work on temperature and moisture has been done on fasting insects and, therefore, on insects deficient in one of the most important environmental factors, we suggest that our results, incomplete as they are, indicate the need for new approaches to be made. More complete data on feeding insects under controlled conditions of food, temperature and moisture are required, from which can be drawn up more complete balance sheets of development involving measurements of food utilization and respiratory rates.


Weed Science ◽  
1976 ◽  
Vol 24 (1) ◽  
pp. 115-119 ◽  
Author(s):  
H. P. Wilson ◽  
F. B. Stewart ◽  
T. E. Hines

Effects of temperature on response of transplanted tomatoes (Lycopersicon esculentumMill. ‘Campbell 17′) to trifluralin (α,α,α-trifluoro-2,6-dinitro-N,N-dipropyl-p-toluidine), nitralin [4-(methylsulfonyl)-2,6-dinitro-N,N-dipropylaniline], profluralin [N-(cyclopropylmethyl)-α,α,α-trifluoro-2,6-dinitro-N-propyl-p-toluidine], and isopropalin (2,6-dinitro-N,N-dipropylcumidine) were investigated in field studies. Trifluralin and nitralin caused greater reductions in growth and yields of tomatoes transplanted early in April than to tomatoes transplanted around May 1. Responses to profluralin were similar but total yields of early transplanted tomatoes were not reduced although initial yields were below those of tomatoes treated with isopropalin. In controlled environment chamber studies, percent phosphorus of plant tops was reduced by trifluralin at low temperatures but was not influenced by trifluralin at high temperatures. Tomoto responses to phosphorus as reflected by plant fresh weight, dry weight and phosphorus content (mg/plant) were reduced by trifluralin at low and high temperatures.


1987 ◽  
Vol 35 (1) ◽  
pp. 43 ◽  
Author(s):  
GG White

Rates of survival and development of the immature stages of Tribolium castaneum (Herbst) (Coleoptera : Tenebrionidae) were determined in wheat grain at constant temperatures from 20 to 37.5�C and constant relative humidities from 25 to 65%. The rates for eggs and pupae were similar to those previously published for T. castaneum in flour, but larval development was slower and mortality greater, except at low temperature and high humidity. The effect of temperature and humidity on rates of fertility and oviposition in young adults were also determined in wheat grain. The patterns of effects of temperature and humidity on oviposition were similar to those previously published for T. castaneum in flour, but the maximum observed oviposition rate was lower. Fertility was significantly reduced when densities of adults were greater than one pair per 250 g. Mathematical functions were fitted to data from the present and previous studies on age-specific survival and fecundity of adults; population growth rate statistics were calculated from life-table parameters defined by these functions. Under optimal conditions within the range of the present study (35�C, 65% RH), the innate capacity for increase rm was 0.84 per week. The limits for population increase, where rm is zero, were largely determined by.the limits for larval survival, which were approximately 35% RH, and 20-22�C at the lower limit and 40�C at the upper limit.


1934 ◽  
Vol 11 (1) ◽  
pp. 48-53
Author(s):  
MELLANBY KENNETH

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.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Gigi Y. Lau ◽  
Georgina K. Cox ◽  
John D. Stieglitz ◽  
Daniel D. Benetti ◽  
Martin Grosell

Abstract Maintaining energy balance over a wide range of temperatures is critical for an active pelagic fish species such as the mahi-mahi (Coryphaena hippurus), which can experience rapid changes in temperature during vertical migrations. Due to the profound effect of temperature on mitochondrial function, this study was designed to investigate the effects of temperature on mitochondrial respiration in permeabilized heart and red skeletal muscle (RM) fibres isolated from mahi-mahi. As RM is thought to be more anatomically isolated from rapid ambient temperature changes compared to the myocardium, it was hypothesized that heart mitochondria would be more tolerant of temperature changes through a greater ability to match respiratory capacity to an increase in temperature and to maintain coupling, when compared to RM mitochondria. Results show that heart fibres were more temperature sensitive and increased respiration rate with temperature increases to a greater degree than RM. Respiratory coupling ratios at the three assay temperatures (20, 26, and 30 °C), revealed that heart mitochondria were less coupled at a lower temperature (26 °C) compared to RM mitochondria (30 °C). In response to an in vitro acute temperature challenge, both tissues showed irreversible effects, where both heart and RM increased uncoupling whether the assay temperature was acutely changed from 20 to 30 °C or 30 to 20 °C. The findings from this study indicate that mahi-mahi heart mitochondria were more temperature sensitive compared to those from RM.


Author(s):  
Azizmohammad Gharanjik ◽  
Ardeshir Karami Mohammadi

In this paper, the molecular gas lubrication model was used to analyze the nonlinear dynamic behavior of two-lobe non-circular gas-lubricated micro-bearings. The effects of temperature rise are taken into account. At high temperatures, in addition to gas rarefaction, its viscosity and friction will also change, and slip across boundaries will occur. The rarefaction of the lubricating gas film caused by the microscale effect at high temperatures was considered. The effects of temperature and rotation speed (with and without rarefaction effect) on the dynamic behavior of the non-circular micro gas bearing were studied. The nonlinear equation governing the gas behavior is discretized using the finite-element method and then solved simultaneously with the dynamic equations of rotor motion using the fourth-order Runge–Kutta method. Center orbit diagrams, phase portraits, Poincare maps, power spectrum, and bifurcation diagrams are used to investigate the dynamic behavior of two-lobe non-circular gas-lubricated micro-bearings. Some results show that with increasing temperature, the rotor behavior changes from T-periodic to quasi-periodic. It was also observed that at high temperatures, with increasing rotational speed, the behavior of the system changes from T-periodic to quasi-periodic, but if the gas is rarefied, this change occurs at a slower speed.


Author(s):  
Pingchuan Li ◽  
Xianguo Tuo ◽  
Mingzhe Liu ◽  
Jun Ren ◽  
Qibiao Wang ◽  
...  

This paper reported the experimental results of ion current under different temperatures and relative humidity using long range alpha detector (LRAD). An approximation relation between the measuring values, temperatures and relative humidity has been obtained using the linear multiple regression method. The experimental results have shown that the measuring values decrease with the increase of temperature and humidity. The influence of humidity on results outweighs that of temperatures. And both temperature and humidity are obviously negative correlated with measured values. Further experiments will be performed to confirm the coupling effects of temperature and humidity and reported later.


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