scholarly journals Climatic Variation of Supercooling Point in the Linden Bug Pyrrhocoris apterus (Heteroptera: Pyrrhocoridae)

Insects ◽  
2018 ◽  
Vol 9 (4) ◽  
pp. 144 ◽  
Author(s):  
Tomáš Ditrich ◽  
Václav Janda ◽  
Hana Vaněčková ◽  
David Doležel

Cold tolerance is often one of the key components of insect fitness, but the association between climatic conditions and supercooling capacity is poorly understood. We tested 16 lines originating from geographically different populations of the linden bug Pyrrhocoris apterus for their cold tolerance, determined as the supercooling point (SCP). The supercooling point was generally well explained by the climatic conditions of the population’s origin, as the best predictor—winter minimum temperature—explained 85% of the average SCP variation between populations. The supercooling capacity of P. apterus is strongly correlated with climatic conditions, which support the usage of SCP as an appropriate metric of cold tolerance in this species.

2020 ◽  
Vol 13 (1) ◽  
Author(s):  
Lisa Tippelt ◽  
Doreen Werner ◽  
Helge Kampen

Abstract Background Aedes albopictus, a vector of numerous viruses and filarial worms, has already established in 20 countries in Europe, mainly colonising subtropical regions. Continuing adaptation to climatic conditions in temperate areas would probably result in a spread to more northern European countries, producing an increasing risk of mosquito-borne pathogen transmission over a much greater area. Based on previous studies showing that Ae. albopictus is able to overwinter in Germany, this study aims to determine more exactly its ecological limits of enduring low temperatures. Methods Non-diapausing and experimentally induced diapausing eggs of three different Ae. albopictus strains (tropical, subtropical and temperate origins) were exposed to four different regimes with constant temperatures and three different regimes with fluctuating temperatures in a course of a day for a minimum of 2 and a maximum of 30 days. The hatching rate of larvae after cold exposure of the eggs was taken as a measure of cold tolerance. Results The experiments showed that the tropical Ae. albopictus strain had a lower cold tolerance than the subtropical and the temperate strains. The eggs of all used strains were able to survive constant temperatures as low as −5 °C for an exposure period of 30 days, while constant temperatures as low as −10 °C were endured for 2 days by the tropical strain and for 10 and 20 days by the subtropical and temperate strains, respectively. At fluctuating temperatures, both the subtropical and the temperate strains exhibited hatching under all temperature regimes, even with a minimum temperature of −10 °C, whereas the tropical strain ceased hatching after an exposure period of 30 days under the temperature regime with a minimum temperature of −10 °C. The analyses showed that the temperature played the major role in interpreting the hatching rates of the eggs. The condition, whether the eggs were diapausing or not, had no significant influence, although results indicated a slightly higher cold tolerance of diapausing eggs at −10 °C. Conclusions It must be expected that subtropical and temperate strains of Ae. albopictus are able to withstand common central European winters and are able to establish in considerable parts of the continent.


1991 ◽  
Vol 69 (12) ◽  
pp. 3028-3037 ◽  
Author(s):  
Olga Kukal ◽  
Matthew P. Ayres ◽  
J. Mark Scriber

A steep decline in the diversity of swallowtail butterfly species at high latitudes could be due to limited cold tolerance of overwintering pupae. If this is so, species with unusually northerly distributions should be unusually cold tolerant. We compared the northerly distributed Papilio canadensis with its southern relative, P. glaucus. Pupae were exposed for 2–5 months to four acclimatization treatments: outdoors in Alaska, outdoors in Michigan, constant 5 °C, and constant −25 °C. Field temperatures encountered by pupae in Alaska were lower than in Michigan. The supercooling point of P. glaucus pupae was unaffected by acclimatization (mean ± SE= −23.5 ± 0.52 °C). The supercooling point of P. canadensis pupae did not differ from that of P. glaucus pupae, except following acclimatization in Alaska, when it dropped to −27.0 ± 0.55 °C. Survival of pupae in Michigan was high for all populations (70–90%); in Alaska, survival of P. canadensis was just as high, but survival of P. glaucus dropped to 14%. Freezing was usually fatal in both species, but death was not immediate. No pupae survived 6 weeks at −25 °C. Trehalose was the most conspicuous metabolite revealed by nuclear magnetic resonance spectroscopy of live pupae and hemolymph. Labelled glucose was metabolized differently by the two species, which may underly the difference in acclimation potential and cold tolerance. The results support the hypothesis that winter temperatures limit swallowtail distributions.


Heritage ◽  
2019 ◽  
Vol 2 (1) ◽  
pp. 279-305 ◽  
Author(s):  
George Alexandrakis ◽  
Constantine Manasakis ◽  
Nikolaos A. Kampanis

The demand for a new concept of heritage, in which monuments and landscapes are considered active factors in creating a sense of history, is esteemed not only from a scientific and academic perspective, but as well as part of a more sensitive and efficient strategy to link cultural heritage and tourism, by bringing an integrative perspective to the forefront. Implementing such strategies is strictly correlated with the ability to support decision-makers and to increase people’s awareness towards a more comprehensive approach to heritage preservation. In the present work, a robust socioeconomic impact model is presented. Moreover, this work attempts to create an initial link between the economic impacts and natural hazards induced by the changes in the climatic conditions that cultural heritage sites face. The model’s novel socioeconomic impact analysis is the direct and indirect revenues related to the tourism use of a site, on which local economies are strongly correlated. The analysis indicated that cultural heritage sites provide a range of both market and non-market benefits to society. These benefits provide opportunities for policy interventions for the conservation of the cultural heritage sites and their promotion, but also to their protection against the impacts of climate change and natural disasters.


1992 ◽  
Vol 72 (1) ◽  
pp. 83-91 ◽  
Author(s):  
H. J. Hope ◽  
R. Maamari ◽  
S. Séguin ◽  
R. I. Hamilton ◽  
L. M. Dwyer ◽  
...  

One important reason for limited progress in selecting corn (Zea mays L.) with superior cold tolerance during germination and early growth is the unpredictable occurrence of cold, wet test springs. Breeders need an efficient laboratory test paralleling field emergence under such climatic conditions. Laboratory screening data from 30 corn hybrids with under 2400 corn heat unit ratings were compared to field emergence data in Atlantic Canada to evaluate the usefulness of a laboratory test as an indicator of cold tolerance. Hybrids were ranked by mean percent emergence using 1985–1989 field data collected from seven locations in the Atlantic region. From daily observations on seed germinated in a germinator at 11 °C, mean times to 50% root and coleoptile initiation, and 1-cm coleoptile were calculated using probit analyses. Field emergence ranked from 1 (highest percent) to 30 was compared to ranking of time to 50% 1-cm coleoptile in the laboratory (one represented most rapid growth). Of the top 15 hybrids (by 1-cm coleoptile), 11 fell in the top half of the hybrids ranked by field emergence. Removal of hybrids with low numbers of field observations, all made during the unusually warm spring of 1989, improved the comparison. These results indicate that time to 50% production of a 1-cm coleoptile is a useful screening parameter to select corn hybrids with superior cold tolerance during germination and early growth.Key words: Corn, maize, low temperature tolerance, emergence


10.12737/6540 ◽  
2014 ◽  
Vol 9 (3) ◽  
pp. 117-119
Author(s):  
Гасанов ◽  
Alibulat Gasanov ◽  
Абакарова ◽  
Muslimat Abakarova

Grey mountain Caucasian bees are of great interest for the selection, as a valuable gene pool of different populations of this race is supported by high mountains and inaccessible gorges of Dagestan, while serving as an isolated mountainous natural breeding areas. The studies were conducted in three different climatic conditions of the republic: the plains, foothills and mountainous areas. In the area of natural dispersal of gray mountain Caucasian bees in Dagestan released several local populations and different backgrounds. Characteristics of the main morphological features of honey bees are the length of proboscis, wing and width of the third tergite and others. These features bees vary, depending on the habitat population. Numerous studies of Dagestan honeybees showed, that the longest proboscis inherent in bees of mountain zone (6.85 ± 0.03 mm). The plain bees have a smaller proboscis (up to 6.71 ± 0.01 mm), and in the foothills bees the proboscis occupies an intermediate position (from 6.69 ± 0.01 to 6.83 ± 0.01 mm). Two other peculiarities (wing length and the third tergite) are subject to variation, depending on the altitude above sea level.


2013 ◽  
Vol 11 (3) ◽  
pp. 206-211 ◽  
Author(s):  
Clarissa Challam ◽  
Gayle Alisha Kharshing ◽  
Julia S. Yumnam ◽  
Mayank Rai ◽  
Wricha Tyagi

Low temperature is a major constraint for crop productivity. To cope with this challenge, plants have developed several mechanisms to adapt to low temperature. Developing breeding strategies to enhance cold stress tolerance in crops requires an understanding of the mechanisms by which plants perceive and transmit cold stress-related signals to their cellular machinery, thereby activating adaptive responses. Only one quantitative trait locus for tolerance to low-temperature germination, qLTG3-1, has been narrowed down to the gene level in rice. A 71 bp indel that can be used to distinguish between tolerant and susceptible parents has been identified. We tested the 71 bp indel on 65 diverse rice genotypes including those adapted to colder climates of North and Northeastern India to find evidence of the tolerant allele (insertion) and to see whether it is associated with low-temperature germinability in these genotypes. Our results show that 48% of the rice genotypes tested carried the tolerant allele. The insertion was found to be significantly associated with cold tolerance during germination. Moreover, several landraces/improved varieties known for their superior performance in other abiotic stress conditions such as drought and high salinity conditions, and which were previously never exposed to low temperature, carry the beneficial allele for qLTG3-1, suggesting an additional role of this allele in adverse climatic conditions. This study enhances current understanding of the distribution of the tolerant allele qLTG3-1 in rice germplasm, which could help in the identification of suitable donors for potential marker-assisted breeding programmes.


1996 ◽  
Vol 26 (8) ◽  
pp. 1504-1509 ◽  
Author(s):  
Stéphane Riverin ◽  
Réjean Gagnon

Regeneration dynamics have been studied in three open lichen–spruce woodlands located in the black spruce feather-moss forest zone. Black spruces (Piceamariana (Mill.) BSP) belonging to the adult stratum originated from a fire that occurred in 1877. Population history and ecology has been studied on the basis of the establishment period of individuals. The age of black spruces belonging to the regeneration stratum was calculated by using the cross-dating method. The establishment period of the seedlings was determined by the age structure. The black spruces of these open forests belong to two different populations. The adult population originated from the 1877 fire whereas the regeneration population seems to have established itself following another fire that occurred in 1922–1923. Black spruce seedlings of the regeneration stratum are very old (60 years-old on average) in spite of a low height (mean height of 96 cm). Although these open forests are under favourable climatic conditions, they have dynamics similar to lichen–spruce woodlands of the taiga zone. In the last 45 years, no seedlings have settled in these sparse forests.


Author(s):  
Ernesto Chanes Rodríguez-Ramírez ◽  
J. Antonio Vázquez-García ◽  
Othón Alcántara-Ayala ◽  
Isolda Luna-Vega

The distribution of Mexican Magnolia species´ occur under restricted climatic conditions. As many other tree species from the tropical montane cloud forests (TMCF), Magnolia species appear to be sensitive to drought. Through the use of dendrochronological techniques, this study aims to determine the climate influence on the vessel traits of M. vovidesii and M. schiedeana which are endangered tree species that are endemic to the Sierra Madre Oriental in eastern Mexico. Because most of the tree species in TMCFs are sensitive to climate fluctuations, it is necessary to investigate the differences in the climatic adaptability of the vessel architecture of these trees. This could allow us to further understand the potential peril of climate change on TMCFs. We compared vessel frequency, length and diameter in drought and non–drought years in two Mexican Magnolia species. We used tree–rings width and vessel traits to assess the drought effects on Magnolias’ diffuse–porous wood back to the year 1929. We obtained independent chronologies for M. vovidesii with a span of 75 years (1941–2016), while for M. schiedeana we obtained a span of 319 years (1697–2016). We found that temperature and precipitation are strongly associated with differences in tree–ring width (TRW) between drought and non–drought years. Our results showed anatomical differences in vessel trait response between these two Magnolia species to climatic variation. We suggest that our approach of combining dendroclimatic and anatomical techniques is a powerful tool to analyse anatomic wood plasticity to climatic variation in Magnolia species.


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