Adult survival and reproduction in an arctic mite, Ameronothrus lineatus (Acari, Oribatida): effects of temperature and winter cold

2003 ◽  
Vol 81 (9) ◽  
pp. 1579-1588 ◽  
Author(s):  
Guldborg Søvik ◽  
Hans Petter Leinaas

Survival and reproduction of an arctic population of Ameronothrus lineatus were studied at four constant temperatures (5, 10, 15, and 21 °C). By simulating winters in the laboratory, an adult population was followed through 3 "years". Increasing temperatures reduced adult longevity. Females survived longer than males. A temperature of 15 °C was the most favourable for reproduction, with highest larviposition rate and reproductive output. Lifetime reproductive output was also high at 10 °C, while lower numbers of larvae at 21 °C indicated the beginning of heat stress. Comparison with field data showed that the reproductive performance at 15 °C corresponded to reproduction in a natural population experiencing a mean temperature of 8–9 °C, suggesting a positive effect of daily temperature fluctuations. A simulated winter with freezing temperatures increased male survival and positively affected all aspects of reproduction the following laboratory summer.

Forests ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 432 ◽  
Author(s):  
Melody A. Keena ◽  
Paul M. Moore ◽  
Gregg Bradford

Anoplophora chinensis (Forster) is an invasive species that can damage many tree species in orchard, urban, and forested habitats. Adult survival, reproduction, and egg hatch of A. chinensis from Italy and China are evaluated at eight constant temperatures (5, 10, 15, 20, 25, 30, 35, and 40 °C) under laboratory conditions. The estimated Tmax for longevity was 42 and 33 °C for females and 42 and 39 °C for males from China and Italy, respectively. The estimated Tmax, Tmin, and optimum temperature for fecundity were 35, 9, and 29 °C, respectively. Females laid eggs at 15–30 °C and eggs hatched at 15–35 °C. Days to first oviposition increased exponentially from 13 days at 30 °C to >300 days near 10 °C. The estimated Tmin for egg hatch was 13 °C, the Tmax at 38 °C, and the optimum 29 °C. Percentage hatch was estimated to be highest at 26 °C and have a Tmax of 31 °C and Tmin of 10 °C. These results indicate that summer temperatures over a wide range of latitudes should support beetle survival and reproduction, but at temperatures ≥35 °C, oviposition ceases, and adult survivorship declines. In addition, females may survive into the fall, but lay fewer eggs that may not hatch. These responses of A. chinensis to temperature can be used for developing phenological models to predict the timing of stages for management or eradication efforts.


Energies ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3961
Author(s):  
Hussein Al-Hazmi ◽  
Xi Lu ◽  
Dominika Grubba ◽  
Joanna Majtacz ◽  
Przemysław Kowal ◽  
...  

The short-term effects of temperature on deammonification sludge were evaluated in a laboratory-scale sequencing batch reactor (SBR). Mathematical modeling was used for further evaluations of different intermittent aeration strategies for achieving high and stable deammonification performance at decreasing temperatures. As for the biomass cultivated at high temperatures (e.g., 30 °C), a higher temperature dependency (the adjusted Arrhenius coefficient θ for 11–17 °C = 1.71 vs. θ for 17–30 °C = 1.12) on the specific anammox growth rates was found at lower temperatures (11–17 °C) in comparison with higher temperatures (17–30 °C). Further evaluations of recovering the nitrogen removal efficiency at decreasing temperatures with the mathematical model by modifying the intermittent aeration strategies (aeration frequency (F) and the ratio (R) between non-aerated (non-aer) phase and aerated (aer) phase durations) indicated that intermittent aeration with a prolonged non-aerated phase (e.g., R ≥ 4 regardless of F value) would help to maintain high and stable deammonification performance (~80%) at decreasing temperatures (14–22 °C). Extending the non-aerated phases (increasing R) and reducing the frequency (F) of off/on phase changes have a positive effect on increasing energy savings, leading to increasing interest in this method.


1989 ◽  
Vol 67 (6) ◽  
pp. 1599-1602 ◽  
Author(s):  
Vital Boulé ◽  
Gerard J. Fitzgerald

Female threespine sticklebacks (Gasterosteus aculeatus) spend only 9–15 days on the spawning grounds, an intertidal salt marsh at Isle Verte, Quebec, during a 2-month breeding season. Individuals average only one spawning. However, in the laboratory they lay clutches of several hundred eggs every 3–5 days for several months. We designed laboratory experiments to determine (i) whether daily temperature fluctuations similar to those encountered in the marsh affect reproduction (number of clutches, number of eggs per clutch, and size of eggs) and (ii) whether the amplitude of the fluctuations encountered by the fish affects reproduction. We compared the reproduction of females held in fluctuating temperatures with that of females kept at 20 °C. Fish kept under fluctuating conditions produced more eggs per clutch but had longer interspawning intervals than those at 20 °C. Total seasonal egg production and egg size did not differ between the two groups. Fish in fluctuating temperatures survived longer and were in better condition than those at 20 °C. We conclude that the amplitude of the fluctuations is less important than mean temperature in determining reproductive performance. Fluctuating temperatures on the spawning grounds are not responsible for the short residency there.


1995 ◽  
Vol 32 (1) ◽  
pp. 8-14 ◽  
Author(s):  
Akio NIBE ◽  
Takashige SUGIMOTO ◽  
Hiroshi TAKAHASHI ◽  
Mikio ONOZATO

2009 ◽  
Vol 52 (1) ◽  
pp. 51-64 ◽  
Author(s):  
A. Köck ◽  
B. Fürst-Waltl ◽  
R. Baumung

Abstract. In this study records of 58 925 litters of Austrian Large White and 17 846 litters of Austrian Landrace pigs were analysed. Regression models were used to determine the effects of litter, dam and sire inbreeding on total number of born, born alive and weaned piglets in Large White and Landrace. In both populations, litter and dam inbreeding showed a negative effect on all traits. Sire inbreeding had no effect in Large White, whereas a significant positive effect was observed in Landrace. On average, inbred sires with an inbreeding coefficient of 10 % had 0.45 more piglets born total and 0.43 more piglets born alive in comparison to non-inbred sires. In a further analysis the total inbreeding coefficients of the animals were divided into two parts: »new« and »old« inbreeding. »New« inbreeding was defined as the period of the first five generations. It was shown that the observed inbreeding effects were not only caused by recent inbreeding. Reproductive performance was also affected by »old« inbreeding. Finally partial inbreeding coefficients of four important ancestors in each population were calculated to investigate if inbreeding effects are similar among these ancestors. The results revealed a varation of inbreeding effects among the four ancestors. Alleles contibuting to inbreeding depression were descendent from specific ancestors.


2002 ◽  
Vol 45 (1) ◽  
pp. 53-58 ◽  
Author(s):  
Antônio Ricardo Panizzi ◽  
Shirlei Regina Cardoso ◽  
Viviane Ribeiro Chocorosqui

Lanceleaf crotalaria, Crotalaria lanceolata E. Mey (Leguminosae) was found hosting the small green stink bug, Piezodorus guildinii (Westwood), in Paraná State, Brazil. In the laboratory, nymphs showed less mortality when fed on immature pods of crotalaria (64%) than when fed on immature pods of soybean, Glycine max (L.) Merrill (88%). From 2nd stadium to adult, nymphs required less time to complete development on crotalaria (mean of females and males = 18.4 days) than on soybean (21.5 days). Fresh body weight at adult emergence was greater on crotalaria (mean of females and males = 51.4 mg) than on soybean (42.2 mg). Adult P. guildinii tended to live longer on crotalaria than on soybean. Mean adult longevity was 34.6 days on crotalaria, and 28.8 days on soybean. However, the reproductive performance of females, although similar on both foods, tended to be greater on soybean. These results indicated that P. guildinii was able to develop and reproduce on the wild host lanceleaf crotalaria. Compared to soybean, this weed plant was more suitable for nymph development, and equally suitable for adult reproduction.


2011 ◽  
Vol 50 (No. 4) ◽  
pp. 155-162
Author(s):  
V. Matoušek ◽  
A. Čermáková ◽  
N. Kernerová ◽  
P. Králová

The objective of the paper was to evaluate the results of reproductive performance of sows in some elite breeding herds of the Large White breed included in experimental herds for the production of hyperprolific lines of dam breeds. The set consisted of 98 sows with the known genotypes of ESR, FSHâ and PRLR genes. The dendrogram shows that on the basis of their genetic outfit the sows can be divided into two clusters. The first cluster can be described as a cluster with marked dominance of HPL sows and the second cluster with marked dominance of the sows of basic herd. The first cluster consisted of individuals in which the preferred genotype AA of PRLR gene was not detected. As for FSHâ gene, the beneficial genotype BB was found out in 74.10% of sows. In ESR gene the beneficial genotype DD was recorded only in 11.10% of individuals. On average for the lifetime performance they delivered by 2.08 piglets more in all born piglets and by 1.96 piglets more in live-born piglets per litter. Differences in the reproductive traits between HPL sows and the sows of basic herd in the first cluster were statistically highly significant. On the contrary, genotype AA of PRLR gene was identified in all sows of the second cluster, 61.36% of animals possessed beneficial genotype BB of FSHâ gene. As for ESR gene, beneficial genotype DD was identified within the whole cluster in 31.82% of sows. In lifetime performance the HPL sows had on average by 1.10 individuals more in all born piglets and by 1.01 more in live-born piglets (statistically significantly higher values). The unambiguous expression of a positive effect of preferred genotypes of selected candidate genes failed to be confirmed by the results of statistical analyses testing the associations of candidate genes for pig reproduction with selected parameters of breeding value and prolificacy of sows.  


2009 ◽  
Vol 59 (1) ◽  
pp. 127-144 ◽  
Author(s):  
Lia Hemerik ◽  
Chris Klok ◽  
Maja Roodbergen

AbstractMany populations of wader species have shown a strong decline in number in Western-Europe in recent years. The use of simple population models such as matrix models can contribute to conserve these populations by identifying the most profitable management measures. Parameterization of such models is often hampered by the availability of demographic data (survival and reproduction). In particular, data on survival in the pre-adult (immature) stage of wader species that remain in wintering areas outside Europe are notoriously difficult to obtain, and are therefore virtually absent in the literature. To diagnose population decline in the wader species; Black-tailed Godwit, Curlew, Lapwing, Oystercatcher, and Redshank, we extended an existing modelling framework in which incomplete demographic data can be analysed, developed for species with a pre-adult stage of one year. The framework is based on a Leslie matrix model with three parameters: yearly reproduction (number of fledglings per pair), yearly pre-adult (immature) and yearly adult (mature) survival. The yearly population growth rate of these populations and the relative sensitivity of this rate to changes in survival and reproduction parameters (the elasticity) were calculated numerically and, if possible, analytically. The results showed a decrease in dependence on reproduction and an increase in pre-adult survival of the population growth rate with an increase in the duration of the pre-adult stage. In general, adult survival had the highest elasticity, but elasticity of pre-adult survival increased with time to first reproduction, a result not reported earlier. Model results showed that adult survival and reproduction estimates reported for populations of Redshank and Curlew were too low to maintain viable populations. Based on the elasticity patterns and the scope for increase in actual demographic parameters we inferred that conservation of the Redshank and both Curlew populations should focus on reproduction. For one Oystercatcher and the Black-tailed Godwit populations we suggested a focus on both reproduction and pre-adult survival. For the second Oystercatcher population pre-adult survival seemed the most promising target for conservation. And for the Lapwing populations all demographic parameters should be considered.


2016 ◽  
Vol 87 (11) ◽  
pp. 1334-1339 ◽  
Author(s):  
Kerstin Wegner ◽  
Christian Lambertz ◽  
Gürbüz Das ◽  
Gerald Reiner ◽  
Matthias Gauly

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