Cold-hardiness of Lacanobia atlantica (Lepidoptera: Noctuidae), and a comparison with three other insect species that overwinter in the same habitat

1993 ◽  
Vol 71 (9) ◽  
pp. 1710-1714 ◽  
Author(s):  
W. J. Turnock
Keyword(s):  
Cold Hardiness ◽  
Cold Injury ◽  
Delia Radicum ◽  
Upper And Lower Bounds ◽  
Supercooling Point ◽  
Response Curves ◽  
The Mean ◽  
Response To Temperature ◽  
Lepidoptera Noctuidae ◽  
Athrycia Cinerea

The pupae of Lacanobia atlantica (Grt.) overwinter in the soil and are susceptible to freezing. Cold injury and death occur at temperatures above the supercooling point (SCP) of −26.4 °C, and below ca. −12.6 °C. Mortality increases as temperature decreases and as exposure lengthens. These results are compared with those for Mamestra configurata Wlk., Delia radicum (L.), and Athrycia cinerea Coq., which have similar overwintering habits. Their mean SCPs (−27.3 to −20.3 °C) differ less than do the values representing the highest temperature at which cold injury occurs (≈−12.6 to ≈4 °C). Response curves of three of the species were similar for changes in temperature and duration of exposure, and similarly in a plot of the time to 50% survival (LT50) against temperature. They differed only in their relative cold-hardiness. In contrast, A. cinerea was less sensitive to changes in temperature and duration of exposure. A single parameter (e.g., the mean SCP) is not adequate to describe the cold-hardiness of these species because they vary not only in the upper and lower bounds of their cold-injury zones but also in their response to temperature and duration of exposure within this zone.

A comparison of the cold hardiness of populations of Delia radicum (L.) (Diptera: Anthomyiidae) from southern England and the Canadian Prairies

1990 ◽  
Vol 68 (5) ◽  
pp. 830-835 ◽  
Author(s):  
W. J. Turnock ◽  
P. M. Reader ◽  
G. K. Bracken
Keyword(s):  
Low Temperature ◽  
Cold Hardiness ◽  
Cold Injury ◽  
Delia Radicum ◽  
Supercooling Point ◽  
Canadian Prairies ◽  
Canadian Population ◽  
English Population ◽  
Cold Hardy ◽  
The Relationship

The Canadian population of Delia radicum is more cold hardy than the English population in that the supercooling point is slightly lower and overwintering pupae are less sensitive to lower temperatures and longer exposure times. However, the Canadian population is slightly less cold hardy at higher temperatures within the cold injury zone. Female D. radicum were more susceptible to cold-induced mortality than males among the Canadian population, but this sex difference was not significant in the English population. The proportion of malformed adults and the rate of postdiapause development were not related to cold injury in either population. The bounds of the cold injury zone for species or populations of freezing susceptible, diapausing insects plus the sensitivity of the species to cold injury within this zone can provide an ecologically sound method of describing cold hardiness. Sensitivity, measured by the slope of a regression describing the relationship between survival and the duration of exposure at a low temperature, can also be used to calculate the rate at which cold injury occurs at any temperature within the cold injury zone. This slope may reflect the overwintering conditions of a species or population because Canadian populations of both D. radicum and Mamestra configurata (Noctuidae) have similar coefficients, but these are very different from the coefficient of the English population of D. radicum. The supercooling point did not provide a useful indication of the susceptibility of these cold-hardy diapausing insects to cold injury.

INTERPOPULATION DIFFERENCES IN THE COLDHARDINESS OF DELIA RADICUM (DIPTERA: ANTHOMYIIDAE)

1998 ◽  
Vol 130 (2) ◽  
pp. 119-129 ◽  
Author(s):  
W.J. Turnock ◽  
G. Boivin ◽  
R.A. Ring
Keyword(s):  
British Columbia ◽  
North America ◽  
Cold Injury ◽  
Delia Radicum ◽  
Regression Equations ◽  
Founder Populations ◽  
The Mean ◽  
Cabbage Root Maggot ◽  
Lower Temperature ◽  
Root Maggot

AbstractThe cabbage root maggot, Delia radicum (L.), was introduced to North America in the mid-1800s, likely from northwestern Europe, and probably reached Quebec and British Columbia before 1885 and Manitoba by 1922. The mean temperature of crystallization (Tc) for overwintering pupae was −22.8 ± 1.2 °C for the St-Jean-sur-Richelieu, Quebec, population and −23.8 ± 0.7 °C for the Vancouver, British Columbia, population. The mean Tc for these two populations and for Winnipeg, Manitoba (−24.4 °C), Ascot, England (−22.8 °C), Tallinn, Estonia (−25.2 °C), and St. Petersburg, Russia (ca. −20 °C), did not show any relation to mean January temperatures. These locations represent both temperate oceanic and temperate continental climates and a range of mean January temperatures from +4.6 to −17.7 °C. Survival of puparia from St-Jean-sur-Richelieu exposed to nonfreezing temperatures decreased as temperature decreased and exposure time lengthened. The parameters for the regression equations describing this relationship were similar to those describing the Winnipeg population, and both were more coldhardy than the Ascot population. The upper limit of the cold injury zone (ULCIZ) for the St-Jean-sur-Richelieu population was −12.7 °C and the lower limit of this zone (LLCIZ) was −27.6 °C. Coldhardy populations from temperate continental climates (St-Jean-sur-Richelieu, Winnipeg) showed a rate of decrease in survival with increased cold stress (lower temperature, longer exposure) within the cold injury zone which was much slower than in the less coldhardy population (Ascot). Thus, some individuals from the coldhardy populations would be physiologically capable of surviving exposure to temperatures below Tc, whereas in the Ascot population nonfreezing injury would kill all the overwintering puparia at a temperature (−19.6 °C) well above Tc (−22.8 °C). The observed survival of puparia from Vancouver, following various nonfreezing exposures, resembled more closely the calculated survival for these exposures when the equations describing the Ascot population were used than when the equations for Winnipeg or St-Jean-sur-Richelieu were used. The Ascot and Vancouver populations, both from temperate oceanic climates, are less coldhardy than the populations from St-Jean-sur-Richelieu and Winnipeg (temperate continental climates). The founder populations of D. radicum in North America, which probably originated in the temperate oceanic climates of northwestern Europe, have adapted to the colder temperate continental climates by increasing their ability to survive longer exposures to all temperatures within the cold injury zone and not by lowering Tc. Therefore, selection for coldhardiness in D. radicum must have operated on structures, processes, or physiological-biochemical mechanisms that help the organism to avoid or repair nonfreezing cold injury but not on those that determine Tc.

scholarly journals Enzyme Activity, Cold Hardiness, and Supercooling Point in Developmental Stages of Acrosternum arabicum (Hemiptera: Pentatomidae)

2016 ◽  
Vol 16 (1) ◽  
Author(s):  
Mozhgan Mohammadzadeh ◽  
Hamzeh Izadi
Keyword(s):  
Cold Hardiness ◽  
Developmental Stages ◽  
Instar Nymph ◽  
Amylolytic Activity ◽  
Supercooling Point ◽  
Optimal Activity ◽  
Adult Females ◽  
First Instar ◽  
The Mean ◽  
Optimal Ph

Abstract Several species of pentatomid bugs feed on pistachio fruits in Iran. Acrosternum arabicum Wagner (Hemiptera: Pentatomidae) is one of the most important pests of pistachio in Rafsanjan, Iran. This study was carried out to investigate the carbohydrase activities, supercooling points, and cold hardiness profiles of different developmental stages of A. arabicum under laboratory conditions. The midgut amylolytic of A. arabicum showed an optimal pH at 7.0. The highest amylolytic activity was found in the female adults (35.41 ± 0.90 nmol/min/gut). The mean amylolytic activity measured in first instar nymph was 6.75 ± 0.54 nmol/min/gut. Midgut α- and β-glucosidase showed an optimal activity at pH 5 and 7, respectively. These activities increased from first (83 ± 5 and 54 ± 5 nmol/min, respectively) to fifth (881 ± 17 and 237 ± 14 nmol/min, respectively) instar nymphs. The enzyme activities increased in the adults. Midgut α- and β-galactosidase showed an optimal activity at pH 5. α- and β-galactosidase activities were low in the first instar nymphs (73 ± 5 and 21 ± 3 nmol/min, respectively). The level of α- and β-galactosidase activities in the female adults (533 ± 18 and 246 ± 6 nmol/min, respectively) was higher than the nymphs. The lowest super cooling points (−19 and −18.2 °C, respectively) and the highest cold hardiness (22 and 18% following 24 h exposure at − 20 °C, respectively) were recorded for the eggs and adult females.

OVARIAN ASCORBIC ACID DEPLETION TEST FOR LUTEINIZING HORMONE

1967 ◽  
Vol 56 (4) ◽  
pp. 619-625 ◽  
Author(s):  
Hans Jacob Koed ◽  
Christian Hamburger
Keyword(s):  
Ascorbic Acid ◽  
Luteinizing Hormone ◽  
Dose Response ◽  
Response Curve ◽  
Dose Response Curve ◽  
Human Origin ◽  
Response Curves ◽  
Significant Difference ◽  
The Mean ◽  
Different Levels

ABSTRACT Comparison of the dose-response curves for LH of ovine origin (NIH-LH-S8) and of human origin (IRP-HMG-2) using the OAAD test showed a small, though statistically significant difference, the dose-response curve for LH of human origin being a little flatter. Two standard curves for ovine LH obtained with 14 months' interval, were parallel but at different levels of ovarian ascorbic acid. When the mean ascorbic acid depletions were calculated as percentages of the control levels, the two curves for NIH-LH-S8 were identical. The use of standards of human origin in the OAAD test for LH activity of human preparations is recommended.

SET-VALUED PERFORMANCE APPROXIMATIONS FOR THE QUEUE GIVEN PARTIAL INFORMATION

2020 ◽  
pp. 1-23
Author(s):  
Yan Chen ◽  
Ward Whitt
Keyword(s):  
Steady State ◽  
Decay Rate ◽  
Waiting Time ◽  
Partial Information ◽  
Upper And Lower Bounds ◽  
Interarrival Time ◽  
Limited Information ◽  
Wide Range ◽  
The Mean ◽  
Third Moment

In order to understand queueing performance given only partial information about the model, we propose determining intervals of likely values of performance measures given that limited information. We illustrate this approach for the mean steady-state waiting time in the $GI/GI/K$ queue. We start by specifying the first two moments of the interarrival-time and service-time distributions, and then consider additional information about these underlying distributions, in particular, a third moment and a Laplace transform value. As a theoretical basis, we apply extremal models yielding tight upper and lower bounds on the asymptotic decay rate of the steady-state waiting-time tail probability. We illustrate by constructing the theoretically justified intervals of values for the decay rate and the associated heuristically determined interval of values for the mean waiting times. Without extra information, the extremal models involve two-point distributions, which yield a wide range for the mean. Adding constraints on the third moment and a transform value produces three-point extremal distributions, which significantly reduce the range, producing practical levels of accuracy.

Study on the physiology of diapause, cold hardiness and supercooling point of overwintering pupae of the pistachio fruit hull borer, Arimania comaroffi

2012 ◽  
Vol 58 (7) ◽  
pp. 897-902 ◽  
Author(s):  
Marjan Bemani ◽  
Hamzeh Izadi ◽  
Kamran Mahdian ◽  
Abbas Khani ◽  
Mohammad Amin samih
Keyword(s):  
Cold Hardiness ◽  
Supercooling Point

DDC Lubrication: A New Concept in Tribology

1992 ◽  
Vol 114 (1) ◽  
pp. 181-185 ◽  
Author(s):  
K. To̸nder
Keyword(s):  
Film Thickness ◽  
Reynolds Equation ◽  
Gap Function ◽  
Upper And Lower Bounds ◽  
Roughness Effects ◽  
Cavity Depth ◽  
Roughness Amplitude ◽  
Previously Treated ◽  
The Mean ◽  
Expansion Scheme

A new lubrication concept is presented, Deep Disconnected Cavities. It differs from the lubrication of microcavities, previously treated by other authors, by the deepness of the cavities. The validity of Reynolds’ equation and nonturbulent conditions are assumed. By a Taylor expansion scheme, it is shown that the roughness effects are expressible in terms of roughness factors modifying the Reynolds equation, similar to those proposed by Patir and Cheng (1978). Unlike those established for ordinary roughness, the DDC factors are independent of local film thickness and roughness amplitude (cavity depth), and may therefore be used to modify standard hydro-dynamic parameters. By a different mathematical approach, involving upper and lower bounds on the various hydrodynamic quantities, it is found that Reynolds’ equation and all the other hydrodynamic expressions may be written just as for smooth surfaces, with the following modifications: 1. The film thickness should be expressed by the minimum gap function, and not by the mean gap function. 2. There are, in general, three effective viscosities, lower than the physical one, two of which are associated with the x and y directions respectively and appear in the modified Reynolds equation as well as in the flow terms. The third one appears only in the expression for shear stress.

SURVIVAL OF PUPAE OF MAMESTRA CONFIGURATA (LEPIDOPTERA: NOCTUIDAE) AND TWO OF ITS PARASITES IN UNTILLED AND TILLED SOIL

1984 ◽  
Vol 116 (2) ◽  
pp. 257-267 ◽  
Author(s):  
W. J. Turnock ◽  
R.J. Bilodeau
Keyword(s):  
Soil Type ◽  
Brassica Campestris ◽  
Total Mortality ◽  
Pupal Stage ◽  
Mamestra Configurata ◽  
Overwintering Mortality ◽  
Lepidoptera Noctuidae ◽  
Athrycia Cinerea

AbstractThe survival of Mamestra configurata Wlk. was determined from autumn and spring samples in 1973/74, 1980/81, and 1981/82 taken from unfilled and tilled portions of 12 fields of canola (Brassica campestris L. and B. napus L.). Survival from the pre-pupal stage in the autumn to post-diapause pupae in the spring varied from 2.9 to 56.5% in unfilled soil and from 0 to 25.4% in tilled soil. In untilled soil, the variations among fields in total mortality of M. configurata were related to parasitism by Banchus flavescens and to overwintering mortality. In tilled soil, overwintering mortality accounted for most of the variability in total mortality among fields. The percentage of mortality from injury to pupae, and their disappearance following tillage, greatly increased but this type of mortality did not account for much of the variability in total mortality. The disappearance of pupae following tillage was attributed to predation. In both untilled and tilled soils, the amount of overwintering mortality was related to the depth of accumulated snow, and mortality was lower in untilled soil because the stubble trapped more snow. The survival of M. configurata was not related to soil type, the type of tillage equipment, or the frequency of tillage. The number of adults emerging from untilled and tilled soil in one field were 2.58 and 0.27/m2 for M. configurata, 5.22 and 2.85/m2 for the parasite B. flavescens, and 4.46 and 3.60/m2 for the parasite Athrycia cinerea, indicating that the survival of the parasites was less affected by tillage than that of their host.Tillage may reduce the frequency and severity of outbreaks of M. configurata not only by increasing mortality but also by differentially affecting the survival of its main parasites.

scholarly journals Woody species do not differ in dormancy progression: differences in time to budbreak due to forcing and cold hardiness

2021 ◽  
Author(s):  
Al Kovaleski
Keyword(s):  
Maximum Rate ◽  
Path Length ◽  
Cold Hardiness ◽  
Woody Species ◽  
Two Dimensions ◽  
Spring Phenology ◽  
Wide Range ◽  
The Difference ◽  
Response To Temperature ◽  
Phenological Phases

AbstractBudbreak is one of the most observed and studied phenological phases in perennial plants. Two dimensions of exposure to temperature are generally used to model budbreak: accumulation of time spent at low temperatures (chilling); and accumulation of heat units (forcing). These two effects have a well-established negative correlation: the more chilling, the less forcing required for budbreak. Furthermore, temperate plant species are assumed to vary in amount of chilling required to complete endodormancy and begin the transition to breaking bud. Still, prediction of budbreak remains a challenge. The present work demonstrates across a wide range of species how bud cold hardiness must be accounted for to study dormancy and accurately predict time to budbreak. Cold hardiness defines the path length to budbreak, meaning the difference between the cold hardiness buds attain during the winter, and the cold hardiness at which deacclimated buds are predicted to open. This distance varies among species and throughout winter within a species. Increases in rate of cold hardiness loss (deacclimation) measured throughout winter show that chilling controls deacclimation potential – the proportion of the maximum rate response attained at high chill accumulation – which has a sigmoid relationship to chilling accumulation. For forcing, rates of deacclimation increase non-linearly in response to temperature. Comparisons of deacclimation potential show a dormancy progresses similarly for all species. This observation suggests that comparisons of physiologic and genetic control of dormancy requires an understanding of cold hardiness dynamics and the necessity for an update of the framework for studying dormancy and its effects on spring phenology.

scholarly journals Preferred temperature and thermal breadth of birds wintering in peninsular Spain – the limited effect of temperature on species distribution

2016 ◽  
Author(s):  
Luis M. Carrascal ◽  
Sara Villén-Pérez ◽  
David Palomino
Keyword(s):  
Species Abundance ◽  
Bird Species ◽  
Effect Of Temperature ◽  
Response Curves ◽  
Large Variability ◽  
Preferred Temperature ◽  
Mean Temperature ◽  
The Mean ◽  
Thermal Preferences ◽  
Peninsular Spain

Background. Availability of environmental energy, as measured by temperature, is expected to limit the abundance and distribution of endotherms wintering at temperate latitudes. A prediction of this hypothesis is that birds should attain their highest abundances in warmer areas. However, there may be a spatial mismatch between species preferred habitats and species preferred temperatures, so some species might end-up wintering in sub-optimal thermal environments. Methods. We model the influence of minimum winter temperature on the relative abundance of 106 terrestrial bird species wintering in peninsular Spain, at 10x10 Km2 resolution, using 95%-quantile regressions. We analyze general trends across species on the shape of the response curves, the environmental preferred temperature (at which the species abundance is maximized), the mean temperature in the area of distribution and the thermal breadth (area under the abundance-temperature curve). Results. There is a large interspecific variability on the thermal preferences and specialization of species. Despite this large variability, there is a preponderance of positive relationships between species abundance and temperature, and on average species attain their maximum abundances in areas 1.9 ºC warmer than the average temperature available in peninsular Spain. The mean temperature in the area of distribution is lower than the thermal preferences of the species, although both parameters are highly correlated. Discussion. Most species prefer the warmest environments to overwinter, which suggests that temperature imposes important restrictions to birds wintering in the Iberian Peninsula. However, most individuals overwinter in locations colder than the species thermal preferences, probably reflecting a limitation of environments combining habitat and thermal preferences. Beyond these general trends, there is a high inter-specific variation in the versatility of species using the available thermal space .

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