EFFECT OF TEMPERATURE ON THE LIFE-CYCLE OF ANAX JUNIUS (ODONATA: AESHNIDAE) IN CANADA

1971 ◽  
Vol 103 (12) ◽  
pp. 1671-1683 ◽  
Author(s):  
Robert Trottier
Keyword(s):  
Life Cycle ◽  
Laboratory Experiments ◽  
Field Studies ◽  
Migration Pattern ◽  
Effect Of Temperature ◽  
Threshold Temperature ◽  
Degree Days ◽  
Rate Of Development ◽  
Resident Population ◽  
Anax Junius

AbstractThe effect of temperature on the rate of development of Anax junius Drury was studied. Monthly larval samples were carried out for 2 years and laboratory experiments were conducted at constant temperatures. Field studies, at a eutrophic pond near Toronto, showed that in Canada populations of A. junius are not only maintained by migrants each year but also by residents. Two distinct populations were found, a summer (non-resident) population which developed from oviposition to emergence in approximately 3 months, from June to September, and an overwintering (resident) population which overwintered as half-grown larvae and developed in approximately 11 months from mid-July of one calendar year to the end of June of the next year. The former population was larger and comprised approximately 48% males and the latter was smaller and comprised approximately 41% males. A threshold temperature of development of 8.7° ± 0.1 °C was determined in the laboratory for the development of final-instar larvae of the summer population. The rate of development of final-instar larvae, reared at constant temperature, was similar to that of the entire summer aquatic stages which developed in fluctuating temperature. An average of 1332 degree-days ± 1% was required for development from the onset of oviposition to the onset of emergence of the summer population; whereas 20.5% more degree-days were required for the development of the overwintering population, employing the threshold temperature of 8.7 °C as determined for the summer population.It is recommended that correlation between degree-day totals and duration of larval development be used in further studies as a means for understanding the migration pattern and also the climatic limit of distribution for A. junius.

THE EFFECT OF TEMPERATURE, MOISTURE AND NITROGEN ON THE RATE OF DEVELOPMENT OF SPRING WHEAT AS MEASURED BY DEGREE DAYS

1983 ◽  
Vol 63 (4) ◽  
pp. 833-846 ◽  
Author(s):  
H. R. DAVIDSON ◽  
C. A. CAMPBELL
Keyword(s):  
Spring Wheat ◽  
Standard Error ◽  
Time Scale ◽  
Field Experiments ◽  
Effect Of Temperature ◽  
Degree Days ◽  
Rate Of Development ◽  
Degree Day ◽  
Developmental Parameters ◽  
Growth Room

A phenological index based on meteorological parameters that accurately describes the development of wheat is urgently needed by agricultural researchers. In this study, a biometeorological time scale was proposed. It was developed from data obtained in a growth chamber study in which the effect of temperature, N fertility and soil moisture on spring wheat (Triticum aestivum L.) development were assessed. The model was then proofed using data from two field experiments. A normalized time scale was derived relating phenological development to percent SD, defined as ((number of days to a selected phenological stage)/(number of days to soft dough)) × 100. The degree day equation was modified to incorporate this time scale as:[Formula: see text]where K1 is a rate constant having units % SD∙°C−1∙day−1; bo is a base temperature below which no development occurs with units °C; and Tm is the mean daily temperature between growth stages S1 and S2. This equation was used to derive values for the developmental parameters. In the growth room K = 0.0875 (standard error 0.0045) and bo = 4.6 (standard error 0.99). Under fie d conditions K1 = 0.0935 (standard error 0.0123) and bo = 2.4 (standard error 2.213). The growth room and field parameters were not significantly different at the 5% probability level. Temperature was the only environmental parameter which influenced the rate of development under the conditions of this experiment. The number of days to the various developmental stages was inversely and linearly related to mean daily temperature over the 15–25 °C range. The degree day equation was shown to be a good index of development. Under fie d conditions the number of degree days to progress a crop to the flowering stage was 703 (standard error 9.4) and to the soft dough stage 1086 (standard error 15.4). The small variability in the values of the developmental parameters obtained in the growth room and field experiments were attributed to errors in the determination of phenological dates, and differences between temperature in the crop microclimate and measured temperatures from the standard meteorological site. A further modification to the degree day equation was postulated to account for the influence of daylength on wheat development.Key words: Temperature and development, moisture and development, degree days, development of wheat

DEVELOPMENT OF THE CARROT RUST FLY, PSILA ROSAE (DIPTERA: PSILIDAE), RELATIVE TO TEMPERATURE IN THE LABORATORY

1981 ◽  
Vol 113 (7) ◽  
pp. 569-574 ◽  
Author(s):  
A. B. Stevenson
Keyword(s):  
Effect Of Temperature ◽  
Thermal Constant ◽  
Degree Days ◽  
Psila Rosae ◽  
Egg Hatch ◽  
Rate Of Development ◽  
Threshold Temperatures ◽  
Thermal Constants ◽  
The Relationship

AbstractThe effect of temperature on development of the carrot rust fly, Psila rosae (F.), was determined at constant temperatures in the laboratory. The relationship between rate of development and temperature was essentially linear from 10° to 17.5°C but began to diverge from linearity between 17.5° and 20°C. Estimated threshold temperatures (t) and thermal constants (K) for development of overwintered pupae were 2.3°C and 319 degree-days (dd) for first emergence and 1.8°C and 368 dd for 50% emergence. For laboratory-reared stages, t and K values were 4.1°C and 102 dd for egg hatch, 2.0°C and 642 dd for development from egg to mature larvae, and 3.0°C and 107 dd for pupation. Development in the laboratory from egg (less than 24 h old) to adult was completed in 59, 70, and 81 days at 20°, 17.5°, and 15°C respectively; no threshold or thermal constant was estimated because few or no individuals completed development to adult at 12.5° or 10°C within expected times, presumably because diapause was induced at these temperatures.

Effect of temperature on the life cycle of Heterodera schachtii infecting oilseed rape (Brassica napus L.)

Nematology ◽  
2012 ◽  
Vol 14 (7) ◽  
pp. 855-867 ◽  
Author(s):  
Stephen Kakaire ◽  
Ivan G. Grove ◽  
Patrick P.J. Haydock
Keyword(s):  
Life Cycle ◽  
Brassica Napus ◽  
Oilseed Rape ◽  
Second Generation ◽  
Cultivar Differences ◽  
Effect Of Temperature ◽  
Optimum Temperature ◽  
Degree Days ◽  
Temperature Range ◽  
The Uk

Oilseed rape (OSR; Brassica napus L.) is a crop of increasing world importance and suffers yield loss when infected with Heterodera schachtii. The in vitro hatch, in planta root invasion and development of a field population of H. schachtii were investigated in six thermostatically-controlled water baths at temperatures of 5.0, 10.1, 20.5, 27.8, 32.2 and 37.5°C in a glasshouse. The UK winter OSR cvs Flash and Castille were used. Temperature was shown to have a major influence on the development of H. schachtii in OSR. The highest cumulative percentage hatch of second-stage juveniles (J2) observed over an 8-week incubation period occurred between 20.5 and 27.8°C in leachates of both OSR cultivars, indicating that this is the optimum temperature range for hatching of this population. Cumulative hatch was lowest at 37.5 and 5.0°C. Root invasion was inhibited at 5.0 and 37.5°C, whilst the highest number of J2 invaded the roots between 20.5 and 32.2°C, indicating that this is the optimum temperature range for root invasion. The life cycle took between 21 days at 20.5°C and 42 days at 5.0°C from the inoculated J2 to the J2 of the second generation, with the associated accumulated heat units (AHU) of 424 and 203 degree-days with a base temperature (Tb) of 5.0°C. The optimum temperature range (To) for development was between 20.5 and 27.8°C and the maximum (Tm) was 37.5°C. As temperature increased, the AHU required to complete the life cycle increased from 203 degree-days at 5.0°C to 1406 at 37.5°C. Leachates from both OSR cultivars stimulated more J2 to hatch than the distilled water controls. No significant cultivar differences were observed for J2 hatching, root invasion and duration of the life cycle at the different temperatures but significantly more cysts of the second generation (g root)−1 were observed in cv. Flash than cv. Castille at 27.8 and 32.2°C, suggesting that the latter cultivar is a poorer host of H. schachtii than cv. Flash. This is the first report of the effect of temperature on H. schachtii development on current winter OSR cultivars in the UK and provides insight into the potential effects of climate change on the nematode-host interaction.

The effect of temperature on rate of egg and larval development in populations of Argia vivida Hagen (Odonata: Coenagrionidae) from habitats with different thermal regimes

1985 ◽  
Vol 63 (11) ◽  
pp. 2578-2582 ◽  
Author(s):  
Mark Leggott ◽  
Gordon Pritchard
Keyword(s):  
British Columbia ◽  
Life Cycle ◽  
Larval Development ◽  
Growth Rates ◽  
Development Time ◽  
Effect Of Temperature ◽  
Degree Days ◽  
Isolated Populations ◽  
Thermal Regimes ◽  
Geothermal Regime

The hypothesis was tested that isolated populations of Argia vivida living in habitats with different thermal regimes would show similar rates of egg and larval development when reared at any constant temperature. Eggs from three populations developed and hatched normally over the temperature range 12.5–32.5 °C, but development rates at 15 and 20 °C were faster in a population from a habitat with daily and annual fluctuations in temperature (Deep Creek, Idaho) than in a population from a more stable geothermal regime (Banff, Alberta), which were in turn faster than in a population from a geothermal site with damped annual fluctuations (Albert Canyon, British Columbia). However, differences between slope or intercept values for the regressions of development time on temperature from the three sites were not statistically significant. Growth rates for Deep Creek larvae were also generally higher than for Banff larvae at all temperatures in all instars, but few of these differences were statistically significant. An estimate of 2600 degree-days above 11.25 °C for completion of egg and larval development leads to prediction of a 1-year life cycle at Banff, a 2- or 3-year life cycle at Deep Creek, and a 3-year life cycle at Albert Canyon.

EFFECT OF TEMPERATURE ON OVIPOSITION AND EGG DEVELOPMENT IN THE SPOTTED TENTIFORM LEAFMINER, PHYLLONORYCTER BLANCARDELLA (LEPIDOPTERA: GRACILLARIIDAE)

1986 ◽  
Vol 118 (8) ◽  
pp. 781-787 ◽  
Author(s):  
R.M. Trimble
Keyword(s):  
Regression Analysis ◽  
Linear Regression ◽  
Linear Regression Analysis ◽  
Effect Of Temperature ◽  
Threshold Temperature ◽  
Thermal Constant ◽  
Degree Days ◽  
Egg Development ◽  
Temperature Calculation ◽  
Phyllonorycter Blancardella

AbstractThe threshold temperature (t0) for both oviposition and egg development and the thermal constant (K) for egg development were determined using linear regression analysis for an Ontario population of the spotted tentiform leafminer, Phyllonorycter blancardella (Fabr.). Fecundity was highly variable, ranging from 1 to 152 eggs, and was not significantly affected by temperature. Calculation of the daily oviposition rates for the first 4 days of the experiment and for the period from the beginning of the experiment until the day on which the last egg was laid resulted in estimates of the oviposition threshold of 9.1 and 8.9°C, respectively. The threshold temperature for egg development was estimated as 2.5°C and the thermal constant for egg development as 172.5 degree-days.

The effect of temperature on rates of development of larval Protostrongylus spp. (Nematoda: Metastrongyloidea) from bighorn sheep, Ovis canadensis canadensis, in the snail Vallonia pulchella

1985 ◽  
Vol 63 (6) ◽  
pp. 1445-1448 ◽  
Author(s):  
J. Samson ◽  
J. C. Holmes
Keyword(s):  
Bighorn Sheep ◽  
Ovis Canadensis ◽  
Effect Of Temperature ◽  
Thermal Constant ◽  
Temperature Threshold ◽  
Degree Days ◽  
Rate Of Development ◽  
Slow Development ◽  
Third Stage ◽  
Stage Development

The rate of development of Protostrongylus stilesi and (or) Protostrongylus rushi in the intermediate host Vallonia pulchella was related linearly to temperature between 10 and 30 °C. The temperature threshold was 8 °C and the thermal constant was 305 degree-days. Infected snails kept at 10 °C for several days and then transferred to 25 °C produced third-stage larvae faster than expected. Rates of development of Protostrongylus spp. applied to field conditions indicated that most of the first- to third-stage development occurs during the summer, very slow development takes place in the autumn or the spring, and none occurs over the winter. These data reinforce the hypothesis formulated by D. A. Boag and W. D. Wishart that snails on the bighorn sheep wintering grounds are responsible for transmission of the lungworms to sheep in autumn.

Selection at the Dieldrin Resistance Locus in Overwintering Populations of Lucilia-Cuprina (Wiedemann)

1990 ◽  
Vol 38 (5) ◽  
pp. 493 ◽  
Author(s):  
JA Mckenzie
Keyword(s):  
Life Cycle ◽  
Adult Stage ◽  
Late Summer ◽  
Field Studies ◽  
Lucilia Cuprina ◽  
Resistance Locus ◽  
Rate Of Development ◽  
F2 Generation

Development was arrested in wandering L. cuprina larvae placed in the ground at Heidelberg, Victoria during May and June. During this overwintering period individuals resistant to the insecticide dieldrin were more severely selected against than at other times of the year. Over the 3 years of the study (1986-1988) the proportions of overwintering larvae that reached the adult stage of the life cycle were low (range 2.8-6.0%) compared to those at other times (52.8-80.0%). The rate of development was greatest during the late summer months. In laboratory controls the developmental times from egg to adult (13.0-14.0 days) and the proportions reaching the adult stage (78.0-96.0%) were consistent throughout the experiment. The larvae used in the experiment were of the F2 generation of an original cross between pure-breeding strains that were resistant (Rdl/Rdl) or susceptible (+ /+) to dieldrin. The frequency of the Rdl allele in adults emerging from the overwintering population was significantly lower (0.09-0.15) than at other times (0.44-0.52) when the result were similar to laboratory controls (0.43-0.53). Samples of pre-pupae placed in the ground in May 1988 were removed at 30-day intervals. A consistent decline in the proportion reaching the adult stage and in the Rdl frequency of these populations was observed with increasing time in the ground. Laboratory trials, in which pre-pupae were held at 8�C for periods of up to 11 weeks, showed similar trends to those observed in the field studies.

scholarly journals Theoretical Effect of Temperature on Threshold in the Hodgkin-Huxley Nerve Model

1966 ◽  
Vol 49 (5) ◽  
pp. 989-1005 ◽  
Author(s):  
Richard Fitzhugh
Keyword(s):  
Relaxation Time ◽  
Relaxation Times ◽  
Giant Axon ◽  
Temperature Curve ◽  
Effect Of Temperature ◽  
Threshold Temperature ◽  
Ionic Conductances ◽  
And Shifts ◽  
The Right ◽  
Increasing Temperature

In the squid giant axon, Sjodin and Mullins (1958), using 1 msec duration pulses, found a decrease of threshold with increasing temperature, while Guttman (1962), using 100 msec pulses, found an increase. Both results are qualitatively predicted by the Hodgkin-Huxley model. The threshold vs. temperature curve varies so much with the assumptions made regarding the temperature-dependence of the membrane ionic conductances that quantitative comparison between theory and experiment is not yet possible. For very short pulses, increasing temperature has two effects. (1) At lower temperatures the decrease of relaxation time of Na activation (m) relative to the electrical (RC) relaxation time favors excitation and decreases threshold. (2) For higher temperatures, effect (1) saturates, but the decreasing relaxation times of Na inactivation (h) and K activation (n) factor accommodation and increased threshold. The result is a U-shaped threshold temperature curve. R. Guttman has obtained such U-shaped curves for 50 µsec pulses. Assuming higher ionic conductances decreases the electrical relaxation time and shifts the curve to the right along the temperature axis. Making the conductances increase with temperature flattens the curve. Using very long pulses favors effect (2) over (1) and makes threshold increase monotonically with temperature.

scholarly journals Determining the critical period for weed control in high-yielding cotton using common sunflower as a mimic weed

2019 ◽  
Vol 33 (6) ◽  
pp. 800-807 ◽  
Author(s):  
Graham W. Charles ◽  
Brian M. Sindel ◽  
Annette L. Cowie ◽  
Oliver G. G. Knox
Keyword(s):  
Weed Control ◽  
Critical Period ◽  
Yield Loss ◽  
Field Studies ◽  
Growing Degree Days ◽  
Degree Days ◽  
Weed Density ◽  
High Level ◽  
The Cost ◽  
Planting Season

AbstractField studies were conducted over six seasons to determine the critical period for weed control (CPWC) in high-yielding cotton, using common sunflower as a mimic weed. Common sunflower was planted with or after cotton emergence at densities of 1, 2, 5, 10, 20, and 50 plants m−2. Common sunflower was added and removed at approximately 0, 150, 300, 450, 600, 750, and 900 growing degree days (GDD) after planting. Season-long interference resulted in no harvestable cotton at densities of five or more common sunflower plants m−2. High levels of intraspecific and interspecific competition occurred at the highest weed densities, with increases in weed biomass and reductions in crop yield not proportional to the changes in weed density. Using a 5% yield-loss threshold, the CPWC extended from 43 to 615 GDD, and 20 to 1,512 GDD for one and 50 common sunflower plants m−2, respectively. These results highlight the high level of weed control required in high-yielding cotton to ensure crop losses do not exceed the cost of control.

scholarly journals Interactions Between Chill-Hours and Degree-Days Affect Carpogenic Germination in Monilinia vaccinii-corymbosi

2001 ◽  
Vol 91 (1) ◽  
pp. 77-83 ◽  
Author(s):  
H. Scherm ◽  
A. T. Savelle ◽  
P. L. Pusey
Keyword(s):  
Laboratory Experiments ◽  
Field Experiments ◽  
Degree Days ◽  
Carpogenic Germination ◽  
Conditioning Period ◽  
Low Degree ◽  
Heating Degree Days ◽  
Relationship Of ◽  
High Degree ◽  
The Relationship

The relationship of cumulative chill-hours (hours with a mean temperature <7.2°C) and heating degree-days (base 7.2°C) to carpogenic germination of pseudosclerotia of Monilinia vaccinii-corymbosi, which causes mummy berry disease of blueberry, was investigated. In two laboratory experiments, pseudosclerotia collected from rabbiteye blueberry in Georgia were conditioned at 5 to 6°C for 26 to 1,378 h prior to placement in conditions favorable for germination and apothecium development. The number of chill-hours accumulated during the conditioning period affected the subsequent proportion of pseudosclerotia that germinated and produced apothecia, with the greatest incidence of carpogenic germination occurring after intermediate levels of chilling (≈700 chill-hours). The minimum chilling requirement for germination and apothecium production was considerably lower than that reported previously for pseudo-sclerotia from highbush blueberry in northern production regions. The rate of carpogenic germination was strongly affected by interactions between the accumulation of chill-hours and degree-days during the conditioning and germination periods; pseudosclerotia exposed to prolonged chilling periods, once transferred to suitable conditions, germinated and produced apothecia more rapidly (after fewer degree-days had accumulated) than those exposed to shorter chilling periods. Thus, pseudosclerotia of M. vaccinii-corymbosi are adapted to germinate carpogenically following cold winters (high chill-hours, low degree-days) as well as warm winters (low chill-hours, high degree-days). Results were validated in a combined field-laboratory experiment in which pseudosclerotia that had received various levels of natural chilling were allowed to germinate in controlled conditions in the laboratory, and in two field experiments in which pseudosclerotia were exposed to natural chilling and germination conditions. A simple model describing the timing of apothecium emergence in relation to cumulative chill-hours and degree-days was developed based on the experiments. The model should be useful for better timing of field scouting programs for apothecia to aid in management of primary infection by M. vaccinii-corymbosi.

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