昆虫对极端高低温胁迫的响应研究

温度是影响昆虫地理分布和扩散的重要因素之一,温度胁迫耐受性研究是昆虫生态学研究的热点之一.温度胁迫是指生物对正常生存温度之外的温度反应,包括低温胁迫和高温胁迫,它是预测害虫发生分布区、建立物候学模型、以及引入天敌的重要依据,根据昆虫温度胁迫耐受性的分化模式可预测种群的起源、分布和动态规律.本文概述了温度胁迫下昆虫的生态可塑性反应,分析了高低温交叉胁迫对昆虫抗性的影响,探讨了温度胁迫对昆虫适应性影响的内在机制,并结合国内外研究现状分析了高低温胁迫对烟粉虱Bemisia tabaci的影响,认为应从生理生化和分子生物学水平研究低温胁迫对昆虫耐受性的影响.     

Adaptations to cold in Canadian arctic insects

The survival of insects that inhabit Canadian arctic regions depends on a number of factors which have important ecological, behavioral, physiological, and biochemical components. The ability to withstand low winter temperatures is one of the most conspicuous adaptations of northern insects and the one most closely studied in the laboratory. Most species studied so far conform to one or other of the two major overwintering strategies, namely, frost susceptibility, the ability to avoid freezing by supercooling to a considerable degree, or frost tolerance, the survival of actual ice formation within the body. The Arctic beetle, Pytho americanus Kirby, is frost tolerant in both larval and adult stages, a situation which would be congruous with its northern distribution and allow it to spread its life cycle over a number of growing seasons. The main biochemical correlates during the cold-hardening process in this species are increasing glycerol and decreasing glycogen concentrations. In addition to its normally assumed roles in cryoprotection there is evidence to suggest that glycerol may further serve to minimize dehydration in the overwintering insect by increasing the level of bound water. P. americanus larvae and adults have narrow supercooling ranges and maintain their supercooling points in the region of ?4 to ?8 °C. It is hypothesized that these elevated supercooling points are a result of the presence in the hemolymph of nucleating agents which ensure ice formation at high subzero temperatures.Low temperature tolerance strategies of some other arctic and alpine species have been examined and compared with those of relatives from more southerly latitudes. P. americanus has been collected in the Canadian Rockies at elevations of over 6000′, and its frost-tolerant attributes are identical to those of the population collected in the Arctic. A closely related species, P. deplanatus, from the Rockies, however, although it too exhibits frost tolerance in the larval stage, differs markedly from P. americanus in its ability to depress its supercooling range to ?54 °C. It appears that P. deplanatus does not have the ability to synthesize ice-nucleating agents and, therefore, can overwinter in a supercooled condition. Two congeneric species of willow leaf gall sawflies (Pontania spp.), one from Tuktoyaktuk, N.W.T., and the other from southern Vancouver Island have also been compared and contrasted. Pontania sp. on Salix glauca (Tuk., ca. 70 °N) is frost tolerant in its larval stage, has relatively high supercooling points (ca. ?9.0 °C), but does not accumulate glycerol. Pontania sp. from Salix lasiandra (Victoria, ca. 48 °N) has almost identical overwintering properties, indicating the close phylogenetic affinities of cold tolerance in this genus rather than independent adaptation to widely different climatic conditions. Some of the lowest supercooling points ever recorded are from willow stem gall forming insects. Rhabdophaga sp. (Cecidomyiidae) forms potato galls on the stems of Salix lanata in the Inuvik area, N.W.T. After low temperature acclimation, supercooling points down to ?66 °C have been recorded from individual larvae. This is a record, and it indicates that we may be dealing with a system in which most water is in a metabolically bound state. Glycerol levels reach 20% of the fresh body weight during this period. Diastrophus kincaidii Cynipidae) forms stem galls on Thimble Berry (Rubus parviflorus) on southern Vancouver Island. Both of the forementioned species overwinter as larvae in their galls and are, therefore, exposed to ambient air temperatures. A more benign winter climate on Vancouver Island is reflected in the fact that D. kincaidii has supercooling points only in the ?30 to ?33 °C range at the peak of low temperature acclimation, and glycerol levels just below 4% of fresh body weight. Both species are frost susceptible and depend on their supercooling abilities to survive low winter temperatures.     

Adaptations of crop-raiding baboons in Kenya

A field study of baboon behavior as it relates to crop-raiding was conducted on the Kenya Coast. The results proved useful for quantifying the distribution, movement, and other factors of their behavior. Such variables as troop organization, crop season, and the behavior of the farmers influence raiding behavior. Apparently diversionary activities of crop-raiding baboons result from troop distribution along habitat margins between farms and forest and from baboon vigilance behavior.     

Notes on Cladocera and Copepoda from high altitude lakes in the Mount Everest Region (Nepal)

The paper deals with Cladocera and Copepoda species from eight high altitude lakes in the Khumbu area. In all lakes, an endemic known diaptomid of the palearctic genus Arctodiaptomus is found. The dark and large Daphnia tibetana occurs in five of the lakes sampled, characterized by the persistence of the spine in adults (parthenogenetic and ephippial females, males). Apparently, this is an unknown feature of this species. The literature on the diagnostic traits of the different morphs described is reviewed. In addition, a transparent and smaller-sized Daphnia species occurs in two lakes. This is a D. longispina characterized by the absence in adults of the carapace spine (var. aspina Weretschagin, 1911). The presence of these two species is discussed in relation to water transparency, colour, and vertical distribution. Two hypotheses on the evolution of cuticular pigmentation in Daphnia are examined. In addition to these mostly dominant species, a macrothricid also typical of high altitude lakes in the Alps was found (Macrothrix hirsuticornis) together with two cosmopolitan Chydoridae.     

Metabolic rate and oxidative stress in insects exposed to low temperature thermal fluctuations

Fluctuating temperatures are a predominant feature of the natural environment but their effects on ectotherm physiology are not well-understood. The warm periods of fluctuating thermal regimes (FTRs) provide opportunities for repair leading to increased survival, but there are also indications of negative effects of warm exposure. In this study, we examined respiration and oxidative stress in adult Alphitobius diaperinus exposed to FTRs and to constant low temperatures. We hypothesized that cold exposure will cause oxidative stress and that FTRs would reduce the amount of chill injuries, via activation of the antioxidant system. We measured V˙CO2, activities of super oxide dismutase (SOD), amounts of total (GSHt) and oxidized glutathione (GSSG) during cold and warm periods of FTRs. Increased severity of cold exposure caused a decrease in the glutathione pool. SOD levels increased during the recovery period in the more severe FTR. The antioxidant response was sufficient to counter the reactive oxygen species production, as the GSH:GSSG ratio increased. We conclude that cold stress causes oxidative damage in these beetles, and that a warm recovery period activates the antioxidant system allowing repair of cold-induced damage, leading to the increased survival previously noted in beetles exposed to fluctuating versus constant temperatures.     

Hematocrit and hemoglobin levels in some peruvian rodents from high and low altitude

Hematocrit levels in highland (3900–4500 m) AKODON (4 species) showed no change following a month at sea level, but showed a reduction of about 50 ml/1 after an additional 1–2 months. Feral MUS established at 4500 m had more cells(570 vs.470 ml/l) than those from sea level; about half this advantage was lost after a week at sea level. Highland species or races showed no consistent advantage in erythrocyte level over lowland species. The lowland PHYLLOTIS DARWINII LIMATUS actually had a higher hematocrit than any of the highland PHYLLOTIS. Mean cell hemoglobin concentrations ranged from 28 to 33 g/100 ml in rodents, and to 42 g/100 ml in the alpaca.Mean cell volumes ranged from 44 to 65 3 in rodents, and were 25–263 for the alpaca and vicna. The cell hemoglobin mass varied from 13 to 18 g in rodents and was 11.5g in the alpaca and vicuña. None of these values for rodents appear remarkable.

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Zusammenfassung Die HÄmatokrit-Werte von 4 Arten Hochland-AKODON (3900–4500 m) zeigten nach einem Monat Aufenthalt der Tiere auf Meereshöhe keine VerÄnderung; nach 2–3 Monaten waren die Werte 50 ml/l niedriger als der Vorwert. Wilde MUS in 4500 m Höhe hatten 570 ml und wilde MUS auf Meereshöhe 470 ml Erythrozyten/1 Blut. Wurden die Tiere aus der Höhe ins Tal gebracht, verschwand die HÄlfte des Unterschiedes innerhalb einer Woche. Die Erythrozyten-Werte von Hochland-Arten und -Rassen zeigten keine übereinstimmende überlegenheit über die von Tiefland-Arten. Tiefland PHYLLOTIS DARWINII LIMATUS hatten sogar einen höheren HÄmatokrit als Hochland PHYLLOTIS. In Hochland-Nagern betrug der mittlere Zell-HÄmoglobingehalt 28 bis 33 g/100 ml, in Alpaca bis 42 g/100 ml. Das mittlere Zellvolumen war bei Nagern 44–653 und beim Alpaca und Vivuna 25–263. Die Menge HÄmoglobin pro Zelle betrug 13–18g bei Nagern und 11-5g beim Alpaca und Vicuna. Die Werte bei Nagern im Hochland sind in keiner Weise bemerkenswert.

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Résumé Les valeurs hématocrites de 4 sortes d'AKODON de hautes terres (3000 – 4500 m) ne montraient pas de changement après un mois de séjour des animaux au niveau de la mer; après 2–3 mois, les valeurs étaient 50 ml/l plus basses que la valeur précédante. A 4500 m d'altitude les MUS sauvages avaient 570 ml érythrocytes/l sang et au niveau de la mer 470 ml. Les animaux transportés de l'altitude dans la vallée, la moitié de la différence disparut au bout d'une semaine.Les valeurs d'erythrocytes de sortes et rasses de hautes terres ne montraient point de supériorité concordante aux sortes de basses terres. PHYLLOTIS DARWINI LIMATUS de basses terres avaient mÊme un hématocrit plus haut que le PHYLLOTIS de hautes terres. Le contenu moyen de l'hémoglobine cellulaire des rongeurs de hautes terres était de 28 à 33/100 ml,chez Alpaca jusqu'à 429/100 ml. Aux rongeurs, la volume cellulaire moyenne,était 44–653et Alpaca et Vicuna avaient 25–263. Les rongeurs avaient une quantité d'hémoglobine par cellule de 13–18g, les Alpaca et Vicuna avaient 11,5g. Les valeurs aux rongeurs ne sont remarquable en aucun égard.

     

Seasonal changes of blood values in Rufous-collared sparrows from high and low altitude

Haematocrit, red blood cell (RBC) count, haemoglobin (Hb) concentration, and plasma solids concentration, were measured in populations ofZonotrichia capensis captured during different seasons of the year at altitudes ranging from sea level up to 3500 m. Winter blood values of birds from high and low altitude proved not to be significantly different. Similar results were obtained during summertime, with the exception of cell Hb content and concentration, which were about 10% higher in low-altitude birds. Seasonal changes in RBC size and number appear to be better correlated with the prevailing summer and winter conditions than with the particular altitudinal distribution of the examined populations.     

Hematocrit and hemoglobin levels in some chilean rodents from high and low altitude

Hematocrit levels were measured on a series of Chilean mammals including PHYLLOTIS DARWINI RUPESTRIS, AKODON ANDINUS, AKODON BERLEPSCHII, LAGIDIUM VISCACIA and CHINCHILLA BOLIVIANA from high altitude; and PHYLLOTIS D. DARWINI, AKODON (ABROTHRIX) LONGIPILIS, ORYZOMYS LONGICAUDATUS, NOTIOMYS MEGALONYX, ABROCOMA BENNETTI, OCTODON DEGU, CHINCHILLA VELLIGERA and ORYCTOLAGUS CUNICULUS from near sea level. Translocation of 3 highland species to sea level for 2 months did not reduce their hematocrits. The offspring of two highland species showed no reduction in hematocrit after birth and rearing in the laboratory at sea level.Hematocrit levels by species ranged from 380 to 540 ml/l but showed no correlation with the altitude of origin. The hematocrit in more vigorous species at both high and low altitudes was about 20% higher than in less vigorous species.The erythrocyte hemoglobin concentrations ranged from 295–316 g/l for 4 highland species (plus P. D. DARWINI). Lower values (256–278 g/l) were found in 3 lowland species; and higher values were found in the larger LAGIDIUM (330 g/l) and guanaco, LAMA GUANICOE (423 g/l) from high altitudes.

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Zusammenfassung Der HÄmatokrit wurde in einer Anzahl SÄugetiere in Chile bestimmt: PHYLLOTIS DARWINI RUPESTRIS, AKODON ANDINUS, AKODON BERLEPSCHII, LAGIDIUM VISCACIA und CHINCHILLA BOLIVIANA aus dem Hochland und PHYLLOTIS D. DARWINI, AKODON (ABROTHRIX) LONGIPILIS, ORYZOMYS LONGICAUDATUS, NOTIOMYS MEGALONYX, ABROCOMA BENETTI, OCTODON DEGU, CHIN-Chilla VELLIGERA und ORYCTOLAGUS CUNICULUS aus dem Tiefland. Die überführung von 3 Hochland-Arten auf Meereshöhe führte innerhalb von 2 Monaten zu keiner Änderung der HÄmatokrit-Werte. Die Nachkommen von 2 Hochland-Arten wiesen keine Verminderung der HÄmatokrit-Werte beim Vergleich mit denen der Eltern auf,weder nach der Geburt noch wÄhrend der Aufzucht im Laboratorium auf Meereshöhe. Die HÄmatokrit-Werte aller Arten lagen im Bereich von 380 bis 540 ml/l; es bestand keine Beziehung zur Höhe auf der die Tiere lebten. Der HÄmatokrit der lebensvolleren Arten des Hoch- und Tieflandes war 20% höher als der der weniger lebensvollen Arten.Der Erythrozyten-HÄmoglobin-Gehalt lag bei 4 Hochland Arten (einschliesslich P.D. DARWINI)zwischen 295und 316 g/l. Bei 3 Tiefland-Arten wurden niedrigere Werte gefunden (256–278 g/l);höhere Werte zeigten Lagidium (330 g/l) und Lama Guanicoe (423 g/l) aus dem Hochland.

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Résumé L'hématocrit a été determiné pour un certain nombre de mammifères du Chili: PHYLLOTIS DARWINI RUPESTRIS, AKODON ANDINUS, AKODON BERLEPSCHII, LAGIDIUM VISCACIA, et CHINCHILLA BOLIVIANA des hautes terres et PHYLLOTIS D. DARWINI, AKODOR ABROTHRIX) LONGIPILIS, ORYZOMYS LONGICAUDATUS, NOTIOMYS MEGALONYX, ABROCOMA BENETTI, OCTODON DEGU, CHINCHILLA VELLIGERA et ORYCTOLAGUS CUNICULUS des basses terres. Le transport de 3 sortes de hautes terres au niveau de la mer ne venait à aucun changement des valeurs d'hématocrit en deux mois.En comparant les valeurs des hématocrites des descendants de 2 espèces de hautes terres avec ceux de leur parents, ils ne montraient aucune diminuation, ni après la naissance, ni pendant l'élevage au laboratoire au niveau de la mer. Les valeurs Je l'hématocrit de toutes les espèces variaient entre 380 et 540 ml/l sans correlation avec l'hauteur, où les animaux vivaient. L'hématocrit des espèces plus vigoureuses de hautes terres et de basses terres était 20% plus haut que celui des espèces moins vigoureuses. Le contenu d'érythrocytes et de l'hémoglobine variait pour 4 espèces de hautes terres (y compris P. D. Darwini)entre 295 et 316 g/l. Pour 3 espèces de basses-terres on a trouvé des valeurs plus basses(256–278 g/l); des valeurs plus élevées montraient LAGIDIUM (330 g/l) et LAMA GUANICOE (423 g/l) de hautes terres.

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This and the following paper are numbers 9 and 10 of a series describing results of the Wisconsin South American Physiological Expedition, 1959–60. These studies received support from NSF (67073, 65005 and Senior postdoctoral fellowship to PRM) and PHS-NIH (H-4458), supplementary help from the Rockefeller Foundation, and logistic assistance from ONR (NONR-224700).     

Fertility at low and high altitude in central Nepal

Abstract

Data are reported on ages of menarche, first marriage and first childbirth, migration, venereal disease, birth control, birth spacing and on completed fertility rate in populations of Central Nepal living at low (8,500 feet) and high altitude (12,400 feet). The high‐altitude population reported a significantly lower completed fertility rate which could be partly accounted for by later age at marriage and first childbirth and increased birth spacing. Longer post‐partum ammenorhea and breast feeding did not account for the increased average pregnancy gap.     

Fertility at low and high altitude in Central Nepal

Since the 1930s, a number of different studies have tended to show that fertility is lower at high altitude. The present investigation attempts to provide some answers to this question by examining completed fertility rate (CFR) in Highland and Lowland villages in Central Nepal and relating rate differences to age at menarche, age at 1st childbirth, age at 1st marriage, incidence of venereal disease, birth control (vasectomy or hysterectomy), length of postpartum amenorrhea, and breastfeeding. Data was obtained by direct questioning, and under-reporting of births thus cannot be excluded. Fertility histories were taken from post-menopausal women over the age of 45 years. Results indicate no significant difference in reported menarcheal ages between highlanders and lowlanders. Age at 1st marriage and 1st childbirth were both significantly later in highlanders. CFR was significantly lower in highlanders. It would appear that the reduced fertility rate at high altitude can be partly attributable to later age at marriage and later 1st childbirth. Other factors, e.g., husband absenteeism and remarriage have also been suggested as possible contributors to the observed difference. This paper presents the results of a multiple regression analysis using 9 dependent variables: ages of marriage, 1st childbirth and menarch, the average gap between pregnancies, the average amount of time the husband was away, the number of marriages, presence or absence of venereal disease at some time, whether birth control was practiced and altitude status. Average pregnancy gap, age at 1st childbirth and presence or absence of venereal disease were the only variables that independently made a significcant contribution to CFR variance. The increase in pregnancy gap may be related to longer periods of breastfeeding in high altitude women and there would be a concomitant delay in recommencement of menstruation. In testing the hypothesis, no difference is found in reported duration of breastfeeding or in postpartum amenorrhea. The age at marriage and age at 1st childbirth accounted for over 16% of the explained variance in CFR. Some of the observed difference in CFR can be explained by the difference in marital age but not by the interval between marriage and 1st childbirth, as it was very similar in both groups. The lower CFR among the high altitude population could be due to lowering of biological fecundity at high altitude, or simply a matter of choice. The difference might reflect human reproductive hormone differences between high and low altitude populations. Further research will be needed to determine whether or not differences in CFR can be explained by variation in these factors.     

Evolution of semelparity in Mount Kenya lobelias

Summary Two closely related long-lived rosette plants in the genusLobelia occur on alpine Mount Kenya.Lobelia telekii grows in drier sites and is semelparous (dies after first reproduction).Lobelia keniensis grows in wetter sites and is iteroparous (flowers repeatedly). I used long-term data to evaluate two related models of the evolution of semelparity (reproductive effort and demographic), and found evidence to support only one. Eight years of population data indicate that a simple mathematical model accurately describes the demographic conditions that have favoured the evolution of semelparity. In drier sites,Lobelia individuals flower so infrequently and suffer such high mortality between reproductive episodes that the probability of future reproduction is outweighed by the greater fecundity associated with semelparity.     

An aerial netting study of insects migrating at high altitude over England

Day and night sampling of windborne arthropods at a height of 200 m above ground was undertaken at Cardington, Bedfordshire, UK, during July 1999, 2000 and 2002, using a net supported by a tethered balloon. The results from this study are compared with those from the classic aerial sampling programmes carried out by Hardy, Freeman and colleagues over the UK and North Sea in the 1930s. In the present study, aerial netting was undertaken at night as well as daytime, and so the diel periodicity of migration could be investigated, and comparisons made with the results from Lewis and Taylor's extensive survey of flight periodicity near ground level. In some taxa with day-time emigration, quite large populations could continue in high-altitude flight after dark, perhaps to a previously underrated extent, and this would greatly increase their potential migratory range. Any trend towards increases in night temperatures, associated with global warming, would facilitate movements of this type in the UK. Observations on the windborne migration of a variety of species, particularly those of economic significance or of radar-detectable size, are briefly discussed.     

Colonization of artificial substrates by benthos in a second-order high altitude river in Kenya

An investigation on the colonization of artificial substrate baskets by benthos was carried out in the Naro Moru River, a second-order high altitude river in Kenya, from November, 1986 to October, 1987. Simuliidae dominated the colonizing benthos. The mean (±95% CL) maximum colonization time was achieved after 9.63±1.57 days. The highest mean diversity (H) occurred after 6 days of exposure whilst the highest mean H_maximum, evenness (J) and species richness (s) were achieved after 10, 8 and 10 days respectively.The benthos arrival rate (AR) declined exponentially with time. The changes in benthos departure rate (DR) with time was insignificant. Equilibrial state (AR:DR=1.0) was not achieved in the present study.     

Neuropsychological acclimatization to high altitude

Subjects acclimatized to high altitudes manifest improved manual dexterity as well as trunkal and distal limb co-orbination over un-acclimatized subjects. There is no change in reaction time. Improved attentiveness may contribute to the improved performance, as well as the ability to adapt behaviorally to the numerous physiological consequences of hypoxia. From an ecological and perhaps evolutionary standpoint it matters little whether the adjustment to hypoxia involves intrinsic changes in tissue metabolism (physiological), or results from learning compensatory strategies at altitude (behavioral).     

Thoracic adaptation to high altitude

Growth in the thoracic region and its adaptation to higher altitude was investigated in boys between 5 to 18 years of Rajput origin at two altitudes, i. e. Rampur Bushahr (800 m above sea level) and Kinnaur (3,000 m above sea level). Both places are located in Himachal Pradesh. The sample includes 405 individuals From Bushahr and 676 individuals from Kinnaur. The results of this study reveal that as the higher altitudes are attained the vital capacity also increases relatively more, and these differences become more pronounced after adolescence, indicating longer time of apnoea. The population living at higher altitudes is also characterised by a significant greater chest length.     

Adaptations to extreme low light in the fern Trichomanes speciosum

Trichomanes speciosum is a threatened species restricted to sheltered, very humid sites. Uniquely amongst European ferns, differing ecological tolerances of the gametophyte and sporophyte generations are manifested as widely differing distributions. The perennial, vegetatively propagating gametophyte persists in drier, colder, darker habitats than the sporophyte. In sites where the gametophyte grows, light availability was found to be < 1 μmol m² s¹ for approx. 85% of daylight hours, rarely or (in some sites) never rising above 10 μmol m² s¹. Much of the time, light was < 0.01% of full sunlight. Measurements of gas exchange and chlorophyll fluorescence yield show that these plants have optimal photosynthesis at light intensities c . 5–10 μmol m² s¹, the highest light to which they are normally exposed to in their natural environment. The absence of any capacity for reversible nonphotochemical fluorescence quenching means that there is little or no protection of the photosynthetic apparatus from light-induced damage. We conclude that these plants are able to create what are essentially monocultures in their extreme environments only because of a combination of low metabolic rate (at low temperatures) and an ability to make efficient use of what little light is available to them by morphological and physiological means.