scholarly journals The Influence of Temperature on the Rate of Development of Insects, With Special Reference·to the Eggs of Gryllulus Commodus Walker

1952 ◽  
Vol 5 (1) ◽  
pp. 96 ◽  
Author(s):  
TO Browning

Eggs of the cricket Gryllulus commodus Walked (Gryllidae, Orthoptera) were incubated at nine constant temperatures; the mean duration of the incubation period and its variance have been determined at each temperature.

1990 ◽  
Vol 25 (2) ◽  
pp. 277-283
Author(s):  
G. C. Rock ◽  
R. E. Stinner

Effects of constant temperatures of 10, 15, 20, 25, 30 and 35°C on the preoviposition period and the effects of a constant 25°C on oviposition, fecundity, and longevity of the redbanded leafroller, Argyrotaenia velutinana (Walker), and the tufted apple bud moth, Platynota idaeusalis (Walker), were investigated. Oviposition did not occur at 35°C for either species and only the redbanded leafroller oviposited at 10°C. The threshold for oviposition for RBLR was calculated to be 8.7°C with 29.4 DD necessary for oviposition, while the oviposition threshold for TABM was calculated to be 10.5°C with 33.5 DD needed for oviposition. The mean oviposition periods for the two species did not differ; however, tufted apple bud moth longevity was significantly greater at 25°C. Fecundity was greater for the tufted apple bud moth (301 eggs/female) than for the redbanded leafroller (221 eggs/female).


The law of Neumann assumes that when an atom enters into chemical combination it retains the same capacity for heat as when in the uncombined or elemental state. This generalisation is, however, based on the values observed for the mean specific heats of elements and their compounds between 0° and 100° C. Attention was directed in Part II. of this investigation to the great differences found in the influence of temperature on the specific heats of various metals, such as aluminium on the one hand, and silver or platinum on the other. The experiments now about to be described were undertaken with the object of ascertaining to what extent these differences persist in the compounds of such elements.


1966 ◽  
Vol 44 (3) ◽  
pp. 237-246 ◽  
Author(s):  
E. W. B. Ward

A study was made of the influence of temperature on growth and oxygen uptake by Sclerotinia borealis Bub. and Vleug. Growth was measured as the increase in diameter of colonies on agar media and oxygen uptake, by conventional manometric procedures with cells removed from shake cultures incubated at 0 °C.The results indicated that the fungus is highly psychrophilic with an optimum temperature for growth at 0 °C, a maximum at approximately 15 °C, and a minimum below −5 °C. Cultures grown at 0 °C ceased to grow when transferred to temperatures above 15 °C but, within limits, resumed growth again after a lag when returned to 0 °C. The length of the lag period was proportional to both the degree and the duration of the temperature elevation.The optimum temperature for oxygen uptake was 25 °C, the rate remaining linear at this temperature during a 6-hour incubation period. The rate at 25 °C declined slowly over a period of 4 days but the rate at 1 °C declined to a similar degree. The Q10for oxygen uptake was very low, the rate at 25 °C being only double that at 1 °C.


1991 ◽  
Vol 62 (2) ◽  
pp. 48-50 ◽  
Author(s):  
J. S. Van den Berg

Clinically normal horses (n = 8) with ages ranging from 5 to 8 years, were starved for 12 h and their plasma ammonia concentrations were measured. The mean fasting plasma ammonia concentration was 17,8±3,8 µmol l-1. After dosing ammonium chloride at a dose rate of 0,02 g kg-1, there was a significant increase in plasma ammonia concentration, with a maximum rise after 20 min (P 0,05). To investigate the influence of temperature on plasma ammonia concentrations of stored samples, 8 plasma samples were stored at -20°C and 4°C respectively. The plasma ammonia concentrations were measured after 6, 12 and 24 h in each of the stored samples. Plasma ammonia concentrations increased significantly after 12 and 24 h when stored at 4°C (P 0,05). When plasma was stored at 20°C there was no significant increase from baseline concentrations during 24h (P 0,05).


1993 ◽  
Vol 22 ◽  
Author(s):  
Ionizete Garcia da Silva ◽  
Ennio Luz

Estudou-se a influência da temperatura no ciclo evolutivo de Triatoma maculata (Erichson) (Hemiptera, Reduviidae), tendo em vista uma criação em grande escala, em laboratório, para serem testados no xenodiagnóstico e, ainda, fornecer informações que subsidiem investigações sobre esta espécie. Apresentam-se os resultados do ciclo evolutivo obtidos a 25±0,5°C e 30°C±1,0°C , com umidade relativa de 70+5% e fotoperíodo de 12 horas, que foram de 223,5 e 222,3 dias, para machos e fêmeas, respectivamente, a 24°C e 30°C, a duração média foi de 168,7 e 167,2 dias, respectivamente, para machos e fêmeas. Abstract The influence of temperature on the biology of Triatoma maculata (Erichson) (Hemiptera, Reduviidae), was studied in order to obtain a larger number of Triatominae reared in laboratory. to use in xenodignosis. The experiments were performed in two climatized chambers at 25±0.5°C and 30°C±1.0°C , 70+5% of relative humidity and fotoperiod of 12 hours. The mean duration of the evolutive cycle for males and females was 223.5 and 222.3 days, at 25°C, and 168.7, and 167.2 days, at 30°C. Résumé L’influence de la temperature dans la biologie de Triatoma maculata (Erichson) (Hemiptera, Reduviidae), a été étudié. pour obtenir un grand numéro de Triatominae, élevé on laboratoire et utilizé le xenodiagnostique. Les épreuves ont étés faites dans deux chambres climatiques à 25±0,5°C et 30°C±1,0°C humidité relatif était 70±5% et le photopériode de 12 heurs. En moyenne, la durée du cycle évolutif a été pour les mâles et les femelles de 223,5 et de 222,3 jours à 25°C. et 168,7 et de 167,2 jours, à 30°C.


1969 ◽  
Vol 26 (9) ◽  
pp. 2503-2510 ◽  
Author(s):  
James E. Stewart ◽  
John W. Cornick ◽  
B. M. Zwicker

The mean time to death for lobsters (Homarus americanus) infected with Gaffkya homari and kept at constant temperatures was 2 days at 20 C, 12 days at 15 C, 28 days at 10 C, 65 days at 7 C, 84 days at 5 C, and 172 days at 3 C. The lobsters were unable to mobilize at any of these temperatures systemic defenses adequate to eliminate the pathogen. No deaths that could be attributed to infection with G. homari occurred during the 250-day trial at 1 C; the pathogen, however, was not eliminated at this temperature but remained in the lobsters at low levels with virulence unchanged and gave rise to a fatal infection when the temperature was increased. Further studies showed that infected lobsters were adversely affected by a relatively rapid increase of 10 degrees C but not by a 5-degree C increase; a relatively rapid decrease of 15 degrees C but not 10 degrees C was adverse. Infected lobsters at 15 C were most sensitive to a 5-degree C decrease around the 12th day of the infection.


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