Temperature, Size and Egg Production in the Cabbage Butterfly, Pieris Rapae L.

1982 ◽  
Vol 30 (2) ◽  
pp. 223 ◽  
Author(s):  
RE Jones ◽  
JR Hart ◽  
GD Bull

Larvae reared at low temperatures produce larger pupae and adults than those reared at high temperatures, and pupal weight is linearly related to lifetime egg production; mean egg production in a group reared at 29-3l�C may be twice that of another reared at 17.5-19�C. The number of eggs visible with a dissecting microscope in the ovaries of young females is not proportional to their lifetime production. Once size is taken into account, there is no additional effect of temperature or larval diet on total egg production. The timing of egg production throughout an adult's life is unaffected by its size or by the conditions in which it was reared. but there are marked differences between Australian and Canadian (Vancouver) individuals. The size of eggs is inversely correlated with both the age and the size of the mother. In any particular set of rearing conditions, males tend to be larger than females, and the sexes show an equal and high degree of variation in size.

1998 ◽  
Vol 201 (4) ◽  
pp. 503-513 ◽  
Author(s):  
W J Heitler ◽  
D H Edwards

The effects of temperature on transmission through the voltage-sensitive giant motor synapse (GMS) were investigated in crayfish both experimentally and in computer simulation. The GMS is part of the fast reflex escape pathway of the crayfish and mediates activation from the lateral giant (LG) command neurone to the motor giant (MoG) flexor motoneurone. The investigation was motivated by an apparent mismatch between the temperature sensitivity of the activation time constant of the GMS, with a Q10 reported to be close to 11, and that of the active membrane properties of LG and MoG, which are thought to have Q10 values close to 3. Our initial hypothesis was that at cold temperatures the very slow activation of the GMS conductance would reduce the effectiveness of transmission compared with higher temperatures. However, the reverse was found to be the case. Effective transmission through the GMS was reliable at low temperatures, but failed at an upper temperature limit that varied between 12 degrees C and 25 degrees C in isolated nerve cord preparations. The upper limit was extended above 30 degrees C in semi-intact preparations where the GMS was less disturbed by dissection. The results of experiments and simulations both indicate that transmission becomes more reliable at low temperatures because the longer-duration presynaptic spikes are able to drive more current through the GMS into the MoG, which is more excitable at low temperatures. Conversely, effective transmission is difficult at high temperatures because the transfer of charge through the GMS is reduced and because the input resistance of MoG is lowered as its current threshold is increased. The effect of the high Q10 of the GMS activation is to help preserve effective transmission through the synapse at high temperatures and so extend the temperature range for effective operation of the escape circuit.


Parasitology ◽  
1941 ◽  
Vol 33 (2) ◽  
pp. 243-249 ◽  
Author(s):  
H. S. Leeson

The hatching of the eggs of Pediculus humanus corporis De Geer is influenced by temperature.High temperatures accelerate and low temperatures delay development.The lowest constant temperature at which eggs will hatch is 24° and the highest 37°.At 24° eggs begin to hatch on the seventeenth day and continue hatching until the twenty-first. At 37° eggs hatch on the sixth and seventh days. The temperature at which eggs hatch in the shortest time is 35° and the time 5 days. At these extremes many eggs are killed so that the percentages of successful hatches are very low. Eggs are killed by 2 days' exposure to 39°.Temperatures at which the maximum number of eggs hatch he between 29 and 32°. In this range of “favourable” temperatures, up to 97% of successful hatches may be recorded. The incubation period is from 7 to 11 days. This is a convenient range of temperatures for laboratory purposes and gives largest numbers in a reasonably short time.Newly deposited eggs will not hatch if kept for 14 days at 23° or for shorter periods at lower temperatures, until at 8° exposure for 7 days is sufficient to ensure that all eggs are dead.If partially developed eggs are exposed to temperatures of 15° or lower, development ceases. If they are restored to a favourable temperature within 7 days, development is resumed and some of the eggs will hatch.Older eggs which have almost reached hatching point at a “favourable” temperature hatch if transferred to temperatures as low as 18°. They do not hatch at 15° or lower if kept at such temperatures for at least 9 days.


1991 ◽  
Vol 69 (5) ◽  
pp. 1261-1264 ◽  
Author(s):  
S. Zervos ◽  
S. C. Johnson ◽  
J. M. Webster

Larvae of Galleria mellonella were kept at temperatures of 5, 10, 15, 20, 25, and 30 °C, and exposed to six levels of inocula (5, 10, 25, 50, 100, and 500 infective juveniles/larva) of Heterorhabditis heliothidis and Steinernema glaseri. Temperature and inoculum level significantly affected time to first emergence, duration of emergence, and yield of juveniles. All parameters except emergence of H. heliothidis showed significant interactions between temperature and inoculum level. No juveniles emerged at 5 or 10 °C and development time was most rapid at 25 °C. No juvenile H. heliothidis emerged at 30 °C or with 500 infective juveniles/host, but duration of emergence was shortest at high temperatures with large inocula; yield per host and yield per inoculum were greatest at 20 °C with small inocula. Yields of S. glaseri were half those of H. heliothidis; duration of emergence was shortest at low temperatures; yield per host was greatest at 20 and 25 °C from large inocula; and yield per inoculum level was greatest when the numbers inoculated were small (5–50/host).


Parasitology ◽  
1995 ◽  
Vol 111 (5) ◽  
pp. 539-545 ◽  
Author(s):  
B. H. Noden ◽  
M. D. Kent ◽  
J. C. Beier

SUMMARYThe effect of temperature on early Plasmodium falciparum development was examined in Anopheles stephensi. The rates of both ookinete development and bloodmeal digestion were lengthened as temperatures decreased from 27 to 21 °. However, low temperatures (21–27 °) did not significantly influence infection rates or densities of either ookinetes or oocysts. In contrast, high temperatures (30 and 32 °) significantly impacted parasite densities and infection rates by interfering with developmental processes occurring between parasite fertilization and ookinete formation, especially during zygote and early ookinete maturation. This study demonstrates clearly that temperature affects the sporogonic development of P. falciparum in anophelines by altering the kinetics of ookinete maturation. These studies not only confirm the ookinete as the key development stage affecting the probability of vector infectivity, they provide new insights into the epidemiology of P. falciparum infections.


Spurious kinks in estimated palaeogeotherms may result from small errors in the calibration of the geothermometers and geobarometers. New data indicate that the equilibrium solubility of alumina in enstatite is even less than shown by recent studies, and that the slopes (d T /d P ) of the isopleths of equal alumina content are steeper than hitherto believed. Consequently, pressures of equilibration estimated from current formulations of the orthopyroxene-garnet geobarometer will be too high at high temperatures (> 1200 °C) and too low at low temperatures.


2021 ◽  
Author(s):  
Haifeng Li ◽  
Xinyu ZHang ◽  
Yi Wu ◽  
Feng ZHang ◽  
CHunlin Li

Abstract Personality has been observed in a variety of animal taxa with important implications in ecology and evolution. Exploring the influence of environmental temperature during early life on personality could help to understand the ontogeny of this phenotypic trait in animals. In this study, we reared newborn mosquitofish Gambusia affinis at high (30°C) and low (25°C) water temperatures and measured their shyness and exploration upon sexual maturity. We tested the repeatability of each behavioral trait; the correlation between them; and the effects of rearing temperature, sex, and body length on the behaviors. When growing up at low temperatures, female fish exhibited repeatability in shyness and exploration, and males exhibited marginal repeatability in shyness. However, neither of the 2 behaviors were repeatable when the fish were reared at high temperatures. There was a negative correlation between shyness and exploration, indicating that the 2 behaviors comprise a behavioral syndrome in this species. Mosquitofish reared at high temperatures were more explorative than those reared at low temperatures, while there was no difference in shyness between the 2 treatments. Body length and sex had no significant effects on the average values of the 2 behaviors. The results indicate that environmental temperature during early life could shape the personality of mosquitofish and modify the average of the behavioral traits. These findings might provide insights to understand the ontogeny of animal personality and how changes in environmental temperature influence animal dispersal by shaping their personality.


1997 ◽  
Vol 127 (4) ◽  
pp. 609-620 ◽  
Author(s):  
H.-J. Hirche ◽  
U. Meyer ◽  
B. Niehoff

Agronomy ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 288
Author(s):  
Jorge Gavara ◽  
Ana Piedra-Buena ◽  
Estrella Hernandez-Suarez ◽  
Manuel Gamez ◽  
Tomas Cabello ◽  
...  

Phthorimaea operculella is one of the most important pests causing damage to stored potatoes. In this work, the effect of temperature (at 10, 20 and 30 °C) on the predation of pest eggs by Blattisocius tarsalis was studied in the laboratory. In addition, the effect of three predatory release rates on two pest densities was studied under microcosm conditions. The results showed that B. tarsalis maintains its predatory capacity at low temperatures (10 °C), obtaining an efficiency of 49.66 ± 5.06% compared to the control. In turn, at 20 °C, a maximum efficacy of 78.17 ± 4.77% was achieved, very similar to that presented at 30 °C (75.57 ± 4.34%). Under microcosm conditions and at low pest density (10 eggs/container), the mortality due to the mite was 96.97 ± 3.03%, 81.82 ± 8.84%, and 84.85 ± 8.30%, respectively, for the three predatory release rates (5, 10 or 20 mites/container). At the high infestation level, the pest control ranged from 61.54 ± 9.21% to 92.31 ± 2.74%, depending on the predatory release rate. The results obtained show that B. tarsalis could be a relevant control agent against P. operculella under non-refrigerated potato storage conditions, as well as in the first stages of their storage under refrigerated conditions.


2004 ◽  
Vol 811 ◽  
Author(s):  
Nobuhiro Kin ◽  
Koichiro Honda

ABSTRACTTo develop higher density FRAM requires reducing cell size. Therefore, the size effects resulting from device processing and the material's physical properties must be measured. Therefore, analyzing the electric characteristics of a single bit cell capacitor has become important. Two known characteristics of ferroelectric material are that the Vc increases at low temperatures, and the Pr falls at high temperatures. To further evaluate the impact of temperature on ferroelectrics, we constructed a new evaluation system based on a scanning probe microscope, that can measure the electric characteristics of a single bit cell capacitor. This system can be used in the temperature range from −120 degrees to 300 degrees C. We accomplished this by circulating liquid nitrogen around a SPM stage and by using an electrical heater. We measured the electrical properties of ferroelectric microcapacitors by using a sample with IrOx/PZT/Pt structure. Our measurements revealed that 2Pr really increases at low temperatures, and Pr decreases at high temperatures. That is, we have shown that Vc increases 30% at low temperatures and Pr decreases 10% also in an actual FRAM single bit cell capacitor.


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