TEMPERATURE-DEPENDENT DEVELOPMENT OF EGGS AND LARVAE OF WINTHEMIA FUMIFERANAE TOTH. (DIPTERA: TACHINIDAE), A LARVAL–PUPAL PARASITOID OF THE SPRUCE BUDWORM (LEPIDOPTERA: TORTRICIDAE)

1990 ◽  
Vol 122 (2) ◽  
pp. 329-341 ◽  
Author(s):  
Christian Hébert ◽  
Conrad Cloutier

AbstractRelationships between temperature and development rates of eggs and larvae of Winthemia fumiferanae Toth. were experimentally determined, using the spruce budworm as host. Hatching of parasitoid eggs was triggered by host pupation. The median time required to complete egg development at different temperatures was estimated from distributions of percentage development success of the parasitoid over time between egg deposition and host pupation. For parasitoid eggs that had sufficient time to hatch, detachment from the host before pupation was the most important cause of mortality at 15 °C or higher, but was negligible below this temperature. A curvilinear model describing egg development rate as a function of temperature was used to simulate the development of W. fumiferanae eggs in the field. The relationship between larval development rate and temperature also was modelled, and the variability described. Simulations initiated by host pupation-driven egg hatching, and terminated with prepupal drop to the ground, are presented and discussed with respect to the appropriateness of using host pupation as an indicator of parasitoid egg hatching in the field.

1982 ◽  
Vol 114 (8) ◽  
pp. 657-666 ◽  
Author(s):  
Mark W. Houseweart ◽  
Susan G. Southard ◽  
Daniel T. Jennings

AbstractSpruce budworm egg deposition spanned 27 days during both 1979 and 1980. The egg deposition curve is essentially a normal bell-shaped distribution with a slight skew to the right. Spruce budworm eggs are most acceptable to T. minutum Riley for successful parasitism during the earlier stages of host–egg development. Parasitism rates at two different temperatures (21 °C and 27 °C) were significantly greater for 1- to 3-day-old eggs than for 6- to 8-day-old spruce budworm eggs. Major reduction in host–egg acceptability occurred after the fifth day at 21 °C and after the 4th day at 27 °C.


Author(s):  
Natalie E. van Dis ◽  
Maurijn van der Zee ◽  
Roelof A. Hut ◽  
Bregje Wertheim ◽  
Marcel E. Visser

Climate change is rapidly altering the environment and many species will need to genetically adapt their seasonal timing to keep up with these changes. Insect development rate is largely influenced by temperature, but we know little about the mechanisms underlying temperature sensitivity of development. Here we investigate seasonal timing of egg hatching in the winter moth, one of the few species which has been found to genetically adapt to climate change, likely through selection on temperature sensitivity of egg development rate. To study when during development winter moth embryos are most sensitive to changes in ambient temperature, we gave eggs an increase or decrease in temperature at different moments during their development. We measured their developmental progression and timing of egg hatching, and used fluorescence microscopy to construct a timeline of embryonic development for the winter moth. We found that egg development rate responded more strongly to temperature once embryos were in the fully extended germband stage. This is the phylotypic stage at which all insect embryos have developed a rudimentary nervous system. Furthermore, at this stage timing of ecdysone signaling determines developmental progression, which could act as an environment dependent gateway. Intriguingly, this may suggest that, from the phylotypic stage onward, insect embryos can start to integrate internal and environmental stimuli to actively regulate important developmental processes. As we found evidence that there is genetic variation for temperature sensitivity of egg development rate in our study population, such regulation could be a target of selection imposed by climate change.


1997 ◽  
Vol 54 (1) ◽  
pp. 190-197 ◽  
Author(s):  
P Hamel ◽  
P Magnan ◽  
P East ◽  
M Lapointe ◽  
P Laurendeau

We performed laboratory incubations of white sucker (Catostomus commersoni) eggs to determine (i) the incubation time to organogenesis, eyed egg, hatching, and swim-up phases at eight different temperatures (8.5-21.2°C), and (ii) the best model to describe the relationship between these incubation times and temperature. Seven models (degree-day, power-law, B e lehrádek's equation, quadratic equation, first- and second-order exponentials, and a thermodynamic model) all gave comparable and highly significant fits to our data (R2 > 0.90). We thus compared the in situ and predicted incubation times by (i) the degree-day model, because of its simplicity, and (ii) the thermodynamic model, because of its theoretical foundation. The degree-day model was at least as accurate as the thermodynamic model (overall mean difference between predicted and observed incubation times of 1.4 ± 1.0 and 1.2 ± 1.2 days for the thermodynamic and degree-day models, respectively). Given its high accuracy and simplicity of use, we conclude that the degree-day model should be used to predict the incubation times of white sucker. We also observed a synchronization of hatching in situ that suggested an influence of photoperiod in addition to that of water temperature.


1953 ◽  
Vol 31 (4) ◽  
pp. 392-403 ◽  
Author(s):  
M. G. Maw ◽  
H. C. Coppel

Phryxe pecosensis (Tns.) is a native parasite attacking several species of lepidopterous larvae. It has been reared consistently from collections of the spruce budworm made in British Columbia. The time required from egg deposition to the beginning of the formation of the puparium was 7 to 11 days, the female taking the longer period. The puparium was usually completed within a 24-hr. period and the adult emerged 9 to 11 days later. The life history and habits of the insect are described and the salient characters of the immature stages and the internal reproductive systems of the adults are illustrated and described.


1978 ◽  
Vol 35 (10) ◽  
pp. 1322-1329 ◽  
Author(s):  
John M. Cooley ◽  
Charles K. Minns

Available literature data on the relationship between freshwater copepod egg development time and temperature were summarized and fitted where possible to Bělehrádek's temperature function[Formula: see text]where D is development time, T is temperature, a, b, and α are fitted constants. In the calanoids, and to a lesser extent cyclopoids, a and α were predictably related as were α and in situ egg hatching temperature (TH) when b was assumed to be constant for all copepods. This information was used to describe a simple procedure whereby a curve relating egg development and temperature could be constructed by only knowing TH and applying it to Bělehrádek's temperature function. Key words: Calanoidea, Cyclopoidea, zooplankton, temperature, production assessment


2021 ◽  
Author(s):  
Natalie E. van Dis ◽  
Maurijn van der Zee ◽  
Roelof A. Hut ◽  
Bregje Wertheim ◽  
Marcel E. Visser

Climate change is rapidly altering the environment and many species will need to genetically adapt their seasonal timing to keep up with these changes. Insect development rate is largely influenced by temperature, but we know little about the mechanisms underlying temperature sensitivity of development. Here we investigate seasonal timing of egg hatching in the winter moth, one of the few species which has been found to genetically adapt to climate change, likely through selection on temperature sensitivity of egg development rate. To study when during development winter moth embryos are most sensitive to changes in ambient temperature, we gave eggs an increase or decrease in temperature at different moments during their development. We measured their developmental progression and timing of egg hatching, and used fluorescence microscopy to construct a timeline of embryonic development for the winter moth. We found that egg development rate responded more strongly to temperature once embryos were in the fully extended germband stage. This is the phylotypic stage at which all insect embryos have developed a rudimentary nervous system. Furthermore, at this stage timing of ecdysone signaling determines developmental progression, which could act as an environment dependent gateway. Intriguingly, this may suggest that, from the phylotypic stage onward, insect embryos can start to integrate internal and environmental stimuli to actively regulate important developmental processes. As we found evidence that there is genetic variation for temperature sensitivity of egg development rate in our study population, such regulation could be a target of selection imposed by climate change.


Author(s):  
D. T. Gauld ◽  
J. E. G. Raymont

The respiratory rates of three species of planktonic copepods, Acartia clausi, Centropages hamatus and Temora longicornis, were measured at four different temperatures.The relationship between respiratory rate and temperature was found to be similar to that previously found for Calanus, although the slope of the curves differed in the different species.The observations on Centropages at 13 and 170 C. can be divided into two groups and it is suggested that the differences are due to the use of copepods from two different generations.The relationship between the respiratory rates and lengths of Acartia and Centropages agreed very well with that previously found for other species. That for Temora was rather different: the difference is probably due to the distinct difference in the shape of the body of Temora from those of the other species.The application of these measurements to estimates of the food requirements of the copepods is discussed.


Sensors ◽  
2021 ◽  
Vol 21 (12) ◽  
pp. 4237
Author(s):  
Hoon Ko ◽  
Kwangcheol Rim ◽  
Isabel Praça

The biggest problem with conventional anomaly signal detection using features was that it was difficult to use it in real time and it requires processing of network signals. Furthermore, analyzing network signals in real-time required vast amounts of processing for each signal, as each protocol contained various pieces of information. This paper suggests anomaly detection by analyzing the relationship among each feature to the anomaly detection model. The model analyzes the anomaly of network signals based on anomaly feature detection. The selected feature for anomaly detection does not require constant network signal updates and real-time processing of these signals. When the selected features are found in the received signal, the signal is registered as a potential anomaly signal and is then steadily monitored until it is determined as either an anomaly or normal signal. In terms of the results, it determined the anomaly with 99.7% (0.997) accuracy in f(4)(S0) and in case f(4)(REJ) received 11,233 signals with a normal or 171anomaly judgment accuracy of 98.7% (0.987).


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