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1.
粘虫的迁飞发生区及其分布的数学模型   总被引:1,自引:0,他引:1  
邬祥光 《生态学报》1981,1(4):327-334
粘虫(Mythimna separata Walker)的年周期远距离迁飞,早已为我国多数昆虫学者所证实(林昌善等、1963、1964;马世骏;1963;陈永林等,1963;李光博等,1964;陈瑞鹿等;1965;李绵春等,1965)。作者亦曾于1962年全国昆虫学会及1963年广东省植保学会上提出数据,同意此观点。并作出全国粘虫迁飞发生区地图,综合粘虫的水平迁飞及垂直迁飞为害实况,绘出福建南部,广东中、南部,广西中、南部,云南南部为第一次发生区,2—3月幼虫为害小麦。山东南部,河南中、南部,陕西东、南角西至贵州、四川、云南的平坝地  相似文献   

2.
Adontorhina cyclia BERRY, 1947 is widely distributed on the continental borderland of southern California. It is a faunal element in every major habitat type including two of the outer deep basins, Santa Cruz Basin and San Nicolas Basin. On the mainland shelf it is discontinuously distributed from Point Conception to the US/Mexican Border. The depth distribution of Adontorhina reflects the fact that it inhabits both topographic highs and some of the deep basins of the borderland. Its depth range is from 11.6 to 1,886.0 meters. While Adontorhina is able to inhabit a wide range of sediment types, from 1.5 to 8.1 mean phi, it was primarily collected from locations where sediments ranged from 3 to 5 mean phi. A diverse array of macrofaunal taxa is associated with Adontorhina. The numerically dominant taxa varied from habitat to habitat.  相似文献   

3.
Gargett, V. 1982. Synchronous hatching and the Cain and Abel struggle in the Black Eagle. Ostrich 53:147-150.

An experiment was conducted to cause two Black Eagle Aquila verrreauxii chicks to hatch synchronously. There was ample food on the nest and the female offered it to both chicks, but the smaller chick, from the smaller second-laid egg, died. The greater reach of the chick from the first-laid egg enabled it to obtain more of the food offered, so that it gained weight. Its greater mass then enabled it to prevent its sibling from taking food. Both chicks showed aggression, but that of the heavier chick was more effective.  相似文献   

4.
Sordaria fimicola, which does not appear to have been isolated from maize before, was isolated from stalks in the field throughout the growing season. The fungus occurred at low frequencies and was confined largely to the nodes. Although it was repeatedly isolated from maize stalks it appears to be an opportunistic inhabitant. In a greenhouse study it could not be re-isolated from maize seedling roots although a reduction in dry weight accumulation, root length and plant height was recorded.  相似文献   

5.
The land! don't you feel it? Doesn't it make you want to go out and lift dead Indians tenderly from their graves, to steal from them—as if it must be clinging even to their corpses—some authenticity.  相似文献   

6.
A new species, Tropaeolum sparrei Ståhl (Tropaeolaceae), is described from submontane cloud forest habitat in western Ecuador. It differs from T. papillosum Hughes (the species it resembles most) by having thinner, tomentose stems, smaller, glabrous or subglabrous leaves with the petiole inserted relatively closer to the lower leaf margin, and flowers with uniformly coloured and straight calyx spurs. In leaf shape it is also similar to T. repandum Heilborn, from which it differs in its larger flowers with entirely black petals and blue anthers.  相似文献   

7.
A new species ofChromobacterium was isolated from open ocean waters. While it possessed somewhat different flagellar characteristics than some described species it demonstrated enough affinities to establish it in the genusChromobacterium. Under optimum conditions this organism had an unusually short generation time as well as an unusually rapid transition from the lag phase of growth to the death phase. It is suggested that this characteristic is one of the major reasons that organisms of this type have not, in the past, been successfully transferred from isolation plates inoculated with samples of sea water. The proposed name isChromobacterium marinum.  相似文献   

8.
Vibrational spectra of proteins potentially give insight into biologically significant molecular motion and the proportions of different types of secondary structure. Vibrational spectra can be calculated either from normal modes obtained by diagonalizing the mass-weighted Hessian or from the time autocorrelation function derived from molecular dynamics trajectories. The Hessian matrix is calculated from force fields because it is not practical to calculate the Hessian from quantum mechanics for large molecules. As an alternative to molecular dynamics the spectral response can be calculated from a time autocorrelation derived from numerical solution of the harmonic equations of motion, resulting in calculations at least 4 times faster. Because the calculation also scales linearly with number of atoms, N, it is faster than normal-mode calculations that scale as N 3 for proteins with more then 4,700 atoms. Using this method it is practical to perform all-atom calculations for large biological systems, for example viral capsids, with the order of 105 atoms.  相似文献   

9.
Bacillus thuringiensis is a nonhuman pathogen bacterium that is used as a fungal and insect biocontrol agent. Because of its environmental interaction, it possesses several extracellular enzymes that are able to degrade chitin and chitosan, two of the most important polymers because of their application in numerous fields. However, in recent years, it has been observed that oligosaccharides from the enzymatic degradation of chitosan have important benefits for human health. Comparison and exploration of the production of chito-oligosaccharides from different sources of chitosan will improve the process parameters and expand the biotechnology based in these molecules. This study shows the production of chito-oligosaccharides from three different sources of colloidal chitosan and conducts a qualitative–quantitative comparison between them, using the extracellular enzyme of B. thuringiensis. We found that in the three substrates, it is possible to get a mixture of chito-oligosaccharides from dimer to hexamer in a concentration range from 0.72 to 8.09?mg?·?g?1 of original substrate. The best substrate to obtain these molecules was commercial chitosan as it has the highest production yields.  相似文献   

10.
Changes in phosphate metabolism were explored in discs from tobacco (Nicotiana tabacum) leaves of three contrasting types: green leaves which were fully expanded and attached to the plant, leaves which had yellowed following excision and dark starvation, and leaves which had yellowed while attached to the plant. 2,4-Dinitrophenol at 10−5m stimulated the respiration rate of discs from green and yellow-detached leaves only slightly, but markedly stimulated that of discs from yellow-attached leaves. Following a 10-minute uptake period the incorporation of 32P-orthophosphate into phosphate esters and lipids of discs from yellow-detached leaves was resistant to 2,4-dinitrophenol, whereas in discs from green and yellow-attached leaves it was inhibited by 2,4-dinitrophenol. Incorporation into a salt-soluble fraction containing unidentified nucleotide material showed converse behavior in that it was stimulated by 2,4-dinitrophenol in discs from green and yellow-attached leaves; in discs from yellow-detached leaves it was resistant to 2,4-dinitrophenol. In discs from yellow-detached and yellow-attached leaves there was a shift in the labeling pattern of phosphate esters toward increased label in hexose phosphates at the expense of adenine nucleotides, 3-phosphoglycerate, and phosphoenolpyruvate. It is concluded that incorporation into phosphate esters in discs from yellow-detached leaves is by substrate level phosphorylation coupled to enhanced aerobic glycolysis. In discs from yellow-attached leaves, on the other hand, incorporation depends on oxidation phosphorylation, and it is suggested that the shift in labeling pattern is caused by senescence-induced changes in activity of glycolytic enzymes.  相似文献   

11.
Three new oribatid mite species of the genus Pergalumna (Galumnidae) are described from growing mosses on rocks near a water stream in India. Pergalumna paraclericata sp. n. is very similar morphologically to Carinogalumna clericata (Berlese, 1914), however, it differs from the latter by the structure of lamellar lines and number of notogastral porose areas. Pergalumna minipora sp. n. is very similar morphologically to Pergalumna bifissurata Hammer, 1972, however, it differs from the latter by the body size and the presence of prodorsal ridges and a median pore. Pergalumna paracattienica sp. n. is very similar morphologically to Pergalumna cattienica Ermilov & Anichkin, 2011, however, it differs from the latter by the number of notogastral porose areas and the body integument on the ventral plate.  相似文献   

12.
The species of Metailurus major has a large geographical extension and is known from localities spread out from West Europe to China. In Greece it is known from the Late Miocene locality of Halmyropotamos in Euboea, while some authors mention it also in Pikermi and Samos in faunal lists only. Two specimens from Pikermi prove its existence in this classical locality.  相似文献   

13.
A rare species, Diaphanosoma celebensis (Stingelin, 1900) is redescribed from type material and material from the South of Vietnam. In comparative morphological aspect it is close to D. volzi, but it is relatively less specialized. D. celebensis is known from single locations in Indonesia, Sri Lanka, Vietnam. It probably also occurs in Malaysia. The size frequency and sex structure of a population from Vietnam is described.  相似文献   

14.

A biometric analysis of the morphology of a late Pliocene planktic diatom lineage, Rhizosolenia praebergonii Mukhina indicates that it appeared abruptly in the fossil record in the Indian Ocean at 2.9 Ma after which it remained virtually unchanged. The observed pattern can be explained by “local”; evolution from the ancestral form Rhizosolenia bergonii, Peragallo or by migration from thecentral Pacific Ocean, where it originated gradually, in conjunction with an accelerated rate of evolution. At present time, it is not possible to conclude which one of the two hypotheses is more likely.  相似文献   

15.
Summary A bacterium was isolated from soil which utilizes 2-hydroxypyridine as sole source of carbon and nitrogen. When grown on solid medium with this substrate massive amounts of green rectangular crystals are deposited extracellularly in the colony mass. The pigment producing organism proved to be a hitherto undescribed species to which the name Arthrobacter crystallopoietes was applied. The pigment formed is characterized qualitatively by the following properties: it is an oxidation product of 2-hydroxypyridine probably still containing a six-membered heterocyclic ring; it exists as an anion with an intense blue color in neutral or slightly alkaline solution and as a metal salt in the deposited crystals; it precipitates from acid solution as a red water-insoluble free acid; it can be reversible oxidized and reduced, being colorless in the reduced form; and in solution it is spontaneously oxidized by air, the reaction being very rapid at alkalineph. The ultraviolet, visible and infrared spectra of the blue and red forms are presented. The properties of the pigment show that it is a member of a chemically poorly defined group of compounds termed azaquinones and that it is related to but not identical with pigments produced by the bacterial oxidation of nicotine, nicotinic acid and isonicotinic acid.This investigation was supported in part by grants G9882 and GB736 from the National Science Foundation.  相似文献   

16.
Primula zhui a new species of Primula endemic to the Yunnan Province, China, is described and illustrated. It is morphologically similar to P. intanoensis from Thailand, and P. calyptrata from southeast Yunnan, affiliated to Primula sect. Carolinella (Hemsl.) Pax. However, it is easily distinguished from the Thailand species by its longer corolla tube and distylous flowers, and it differs from the Chinese species by its leaf ovate to ovate‐elliptic blade and distylous flowers.  相似文献   

17.
J. Fraser 《Oecologia》1980,45(3):419-420
Summary Some populations of the isopod Asellus aquaticus from polluted rivers are tolerant to lead. Here it is shown that nontolerant animals from an unpolluted site can be made tolerant by laboratory exposure to low levels of the metal, and it is suggested that naturally occurring tolerance may be achieved by acclimation.  相似文献   

18.
《Geobios》1986,19(5):661-667
A new antilope, Ouzocerus gracilis n.g., n.sp., isdescribed from a late Miocene layer from Northern Greece. It is known from an incomplete skull, jaws and limb bones. A comparison with other spiral horned antilopes shows it has some affinities with Protragelaphus but it is clearly different. Its known geographic area extends from Greece to Iran.  相似文献   

19.
The title of Beth Shapiro’s ‘How to Clone a Mammoth’ contains an implicature: it suggests that it is indeed possible to clone a mammoth, to bring extinct species back from the dead. But in fact Shapiro both denies this is possible, and denies there would be good reason to do it even if it were possible. The de-extinct ‘mammoths’ she speaks of are merely ecological proxies for mammoths—elephants re-engineered for cold-tolerance by the addition to their genomes of a few mammoth genes. Shapiro’s denial that genuine species de-extinction is possible is based on her assumption that resurrected organisms would need to be perfectly indistinguishable from the creatures that died out. In this article I use the example of an extinct New Zealand wattlebird, the huia, to argue—contra Shapiro—that there are compelling reasons to resurrect certain species if it can be done. I then argue—again, contra Shapiro—that synthetically created organisms needn’t be perfectly indistinguishable from their genetic forebears in order for species de-extinction to be successful.  相似文献   

20.
A tall-spined ornithopod dinosaur from the Pinilla de los Moros Formation (Upper Hauterivian-Lower Barremian) of Salas de los Infantes (Burgos, Spain) is described. The material consists of seven associated axial remains, including five middle dorsal vertebrae, a fragmentary neural spine and a dorsal rib, from a single medium-sized individual. This material was previously referred to Iguanodon cf. fittoni. It is characterised by having a high dorsal neurapophysis that is approximately 4.5 times the height of the centrum. The elongation and vertical orientation of the dorsal neural spines allow it to be distinguished from other ornithopods from the Wealden of Europe, including Hypselospinus and Barilium from the Valanginian, and Iguanodon and Mantellisaurus from the Barremian-Aptian. The material is here referred to Iguanodontia indet. because it is so incomplete, but it is potentially a distinct taxon. Among the ornithopods, only Ouranosaurus and the hadrosaurid Hypacrosaurus possess higher dorsal neural spines.  相似文献   

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