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1.
N P Mezenev 《Parazitologiia》1990,24(1):28-36
6000 adult punkies were collected from man and animals over a period of 15 years in the Taimyr and Evenki Autonomous Okrugs of Krasnoyarsk Territory. Four species Culicoides chiopterus, C. pulicaris, C. fascipennis, C. alatavicus are reported from tundra and forest-tundra of Taimyr (68 degrees 00'-73 degrees 13' N). Punkies of the above species are small in number and do not occur all over the region. In northern and middle taiga of Evenkia (60 degrees 20'-65 degrees 45' N) punkies are very abundant and occur everywhere. 7 species C. obsoletus, C. chiopterus, C. punctatus, C. pulicaris, C. grisescens, C. fascipennis, C. helveticus are reported from this region. A relative abundance of punkies in the complex of bloodsucking Diptera during a summer period in different landscape zones is shown. Their seasonal and daily activity is shown and maximum levels of attacking man, reindeer and dog are given. 相似文献
2.
We studied the ecological conditions forming on the solifluction areas often occurring in cryolithic zone of Central Evenkia.
A significant change of microenvironment was registered on some solifluction “microecosystems” that differ sharply form the
control ones in plantation. The ecological conditions formed in these areas result in the change of species composition of
vegetation and its diversity. However, we revealed no significant differences of separate ecological groups depending on hydrothermal
and trophic conditions. 相似文献
3.
Within- and among-population diversity of Gmelin larch Larix gmelinii (Rupr.) Rupr. from Evenkia was inferred from data on 17 genes determining allozyme diversity of ten enzymes. More than 50% of the genes proved to be polymorphic. On average, each tree was heterozygous at 9.2% genes. Heterozygosity expected from the Hardy-Weinberg proportions was higher, 12.5%. A deficit of heterozygous genotypes was observed in all populations under study and attributed to inbreeding. With Wright's F statistics, average individual inbreeding was estimated at 26.6% relative to the population (F(IS)) and at 27.8% relative to the species (F(IT)). The greatest deficit of heterozygosity was observed for the youngest population. Within-population variation accounted for more than 98% of the total variation, while the contribution of among-population variation was 1.66%. Genetic distance between populations varied from 0.0025 to 0.0042, averaging 0.0035. 相似文献
4.
Molecular identification techniques are used where morphological characters are not useful for distinguishing species that resemble each other closely. The example studied here is the Adoxophyes species complex, in which A. orana (Fischer von R?sslerstamm) is officially the only known Korean species in the genus Adoxophyes (Lepidoptera: Tortricidae). However there have been suspicions that at least two types of A. orana exist in Korea based on the distribution and range of the host, with A. orana attacking apples and peaches, and another Adoxophyes sp. attacking tea and pears. The latter is presumed to be A. honmai (Yasuda), but the two have remained confused because of their extreme morphological similarity, despite several Asian studies of pheromonal and morphological characteristics. To confirm the occurrence of an Adoxophyes species other than A. orana in Korea, we compared 940 bp of the mitochondrial cytochrome oxidase I (COI) gene from 16 samples of Adoxophyes and found that there is a second Adoxophyes species different from A. orana. Comparison of the different sequences to that of Japanese A. honmai confirmed that they belong to the latter. From the sequence difference between the two Korean species, we were able to develop new PCR primer sets that distinguish them. This molecular identification technique with no enzyme digestion or sequencing step is a convenient and rapid way of differentiating between species that are hard to distinguish morphologically. 相似文献
5.
The impact of solifluction (soil-sliding) on soil and vegetation cover as well as their restoration during the period after
the disturbance was analyzed in the continuous permafrost region of Central Siberia (Central Evenkia). The role of vegetation
invading after a disturbance is demonstrated for accumulation of biogenic elements and soil development. 相似文献
6.
P. M. Marsh 《BioControl》1977,22(4):365-372
A brief discussion is given on the taxonomy, nomenclature, distribution, and hosts of severalAphidius species attacking the pea aphid,Acyrthosiphon pisum (Harris), in North America.Aphidius pisivorus Smith,A. smithi S. & S. R., andA. ervi Hal. are considered distinct species attacking the pea aphid;A. nigripes Ashm. is shown not to be a parasite of the pea aphid;A. pulcher Baker is placed in synonymy withA. nigripes. Distinguishing characters for each species are illustrated. 相似文献
7.
I. M. Danilin 《Contemporary Problems of Ecology》2009,2(1):55-65
The author considers specific features of the postfire formation of a larch (Larix gmelinii) phytocenosis in Central Evenkia, the north of Central Siberia. Morphological parameters of trees, structure, height, growth, and biological productivity of the tree stand, shrub layer, live ground cover, and accumulation of detritus after progressive pyrogene succession are analyzed and discussed. 相似文献
8.
L S Nekrasova 《Parazitologiia》1983,17(1):80-83
20 species of blood-sucking mosquitoes were recorded from the northern taiga of Ural (the northern part of the Sverdlovsk region): 15 species of the genus Aedes, 2 species of Culex, 2 species of Culiseta and 1 species of Anopheles. Larvae of Aedes occur in masse in small temporary water bodies. In summer after rains larvae of Culiseta and Culex as well as some species of Aedes appear. In May overhibernated Culiseta alaskaensis, C. bergrothi and An. maculipennis begin the flight of mosquitoes. The peak of the number and specific variety of attacking mosquitoes was recorded in July; in August their activity started to decrease. Aedes communis and A. punctor are mass species, A. excrucians, A. hexodontus and C. bergrothi are rather abundant, the other species are small in number or rare. 相似文献
9.
M.J. G. HOPKINS 《Biological journal of the Linnean Society. Linnean Society of London》1983,19(4):329-338
Earlier studies of the interrelationships between bruchid beetles and their host plants have suggested that the typical pattern tends to be that one bruchid species attacks only a few host species, and that most host species are attacked by only one bruchid species, or at most very few. However, the bruchids attacking Parkia in Amazonian Brazil do not conform to this pattern. The bruchid diversity on Parkia was found to be higher than on any other legume genus yet studied. It is not yet possible to assess whether Parkia is particularly unusual in this regard, or whether such high levels of diversity are typical in Amazonian forests. The number of bruchid taxa attacking any one Parkia species is related to the number of co-occurring closely-related Parkia species. In either taxonomically or geographically isolated host species the bruchid diversity is much reduced. 相似文献
10.
21 species of bloodsuckling midges were recorded from the Kishert region of the Perm district. During the period of investigation the group obsoletus was most abundant, then the group pulicaris and fascipennis. There was noted a poor adaptation of midges to different biotopes and high ecological plasticity of mass species. Specific composition of midges attacking man and domestic animals is more diverse as compared to species attacking birds. Food specialisation is more distinct in ornithophilous species. 相似文献
11.
Julia K. Parrish 《Ethology : formerly Zeitschrift fur Tierpsychologie》1993,95(3):233-246
Four piscine predator species were observed repeatedly attacking large (> 100,000) schools of flat-iron herring, Harengula thrissina. The predators could be categorized into two groups. Stalking predators (two species) were slow-moving, predominantly solitary hunters attacking from positions beneath the school. Attacks were directed at individual prey and the sequence of events was orient-approach-strike. Although the stalking species were seen most often and were responsible for the majority of the attacks, capture success was low. The remaining two species were fast-moving, pelagic hunters regularly occurring in groups of up to 8 individuals. These predators were extremely proficient at capturing prey, either by orienting on individuals (stragglers) or accelerating into the school and ramming their prey (impact attacks). Group size was positively associated with capture success, but not significantly so. Because stalking predators orient towards individual prey, they may suffer from the effect of confusion when attacking schooling prey. Use of the impact strategy, by comparison, may allow predators to overcome the confusion effect either by attacking prey already separated from the school, or by orienting towards aggregated prey rather than particular individuals. 相似文献
12.
The effect of group was studied on cattle being attacked by horse flies of three genera. The method of simultaneous registrations of attacking horse flies in herds of 8 to 100 animals and on single cows was used. It has been shown that the effect of group reveals itself only when animals in the herd reach a certain minimum number, the effect rate depending on peculiarities of attacking of a given species of bloodsuckers, such as a part of responding individuals, distance of an attack, duration of contact with an object. These parameters tend to change with increasing number of animals in the herd. Therefore differences in the intensity of attacks on herds with different cattle stock cannot be explained proceeding only from differences in the occupied areas. The number of attacking horse flies decreases from the periphery of the herd to its centre and is not the same in different parts of the periphery. The effectiveness of attacking, ie the part of sucking individuals of a given species (genus) from the number of horse flies attacking for a definite period of time, is the highest in a large herd and increases in its ranges from the periphery to the centre. This dependence leads to a more even distribution of sucking individuals as compared to attacking ones. 相似文献
13.
Within- and among-population diversity of Gmelin larch Larix gmelinii (Rupr.) Rupr. from Evenkia was inferred from data on 17 genes determining allozyme diversity of ten enzymes. More than 50% of the genes proved to be polymorphic. On average, each tree was heterozygous at 9.2% genes. Heterozygosity expected from the Hardy–Weinberg proportions was higher, 12.5%. A deficit of heterozygous genotypes was observed in all populations under study and attributed to inbreeding. With Wright's F statistics, average individual inbreeding was estimated at 26.6% relative to the population (F
IS) and at 27.8% relative to the species (F
IT). The greatest deficit of heterozygosity was observed for the youngest population II. Within-population variation accounted for more than 98% of the total variation, while the contribution of among-population variation was 1.66%. Genetic distance between populations varied from 0.0025 to 0.0042, averaging 0.0035. 相似文献
14.
Humpback whales interfering when mammal‐eating killer whales attack other species: Mobbing behavior and interspecific altruism?
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Robert L. Pitman Volker B. Deecke Christine M. Gabriele Mridula Srinivasan Nancy Black Judith Denkinger John W. Durban Elizabeth A. Mathews Dena R. Matkin Janet L. Neilson Alisa Schulman‐Janiger Debra Shearwater Peggy Stap Richard Ternullo 《Marine Mammal Science》2017,33(1):7-58
Humpback whales (Megaptera novaeangliae) are known to interfere with attacking killer whales (Orcinus orca). To investigate why, we reviewed accounts of 115 interactions between them. Humpbacks initiated the majority of interactions (57% vs. 43%; n = 72), although the killer whales were almost exclusively mammal‐eating forms (MEKWs, 95%) vs. fish‐eaters (5%; n = 108). When MEKWs approached humpbacks (n = 27), they attacked 85% of the time and targeted only calves. When humpbacks approached killer whales (n = 41), 93% were MEKWs, and ≥87% of them were attacking or feeding on prey at the time. When humpbacks interacted with attacking MEKWs, 11% of the prey were humpbacks and 89% comprised 10 other species, including three cetaceans, six pinnipeds, and one teleost fish. Approaching humpbacks often harassed attacking MEKWs (≥55% of 56 interactions), regardless of the prey species, which we argue was mobbing behavior. Humpback mobbing sometimes allowed MEKW prey, including nonhumpbacks, to escape. We suggest that humpbacks initially responded to vocalizations of attacking MEKWs without knowing the prey species targeted. Although reciprocity or kin selection might explain communal defense of conspecific calves, there was no apparent benefit to humpbacks continuing to interfere when other species were being attacked. Interspecific altruism, even if unintentional, could not be ruled out. 相似文献
15.
During the period 1997–2007, a comprehensive study of the occurrence and distribution of Phytophthora species was conducted on Hainan Island of South China. To date, 14 species of Phytophthora have been recovered and their distribution determined. Phytophthora nicotianae ( =P. parasitica ) is the most important species attacking a wide variety of crops, followed by Phytophthora capsici and Phytophthora citrophthora . In contrast to Phytophthora colocasiae attacking taro leaves throughout the entire island, Phytophthora cyperi was found only once on Digitaria ciliaris in Danzhou. It is of interest to note that Phytophthora heveae, Phytophthora katsurae and Phytophthora insolita are commonly found in forest soil/water of protected mountains without causing any plant diseases. Although Phytophthora species are usually terrestrial or found in fresh water, one isolate of Phytophthora resembling closely the asexual isolates of P. insolita in Hainan was obtained from decaying Rhizophora leaves submerged in seawater. An unidentified Phytophthora species producing non-papillate; internally proliferating sporangia was isolated from the soil in which Ceriops tagel and Bruguiera serangula were growing in a salt water shrimp farm. 相似文献
16.
ROSEMARIJE BUITENHUIS JEFFREY A. HARVEY LOUISE E. M. VET GUY BOIVIN JACQUES BRODEUR 《Ecological Entomology》2017,42(3):325-335
1. In primary parasitoids, significant differences in life history and reproductive traits are observed among parasitoids attacking different stages of the same host species. Much less is known about hyperparasitoids, which attack different stages of primary parasitoids. 2. Parasitoids exploit hosts in two different ways. Koinobionts attack hosts that continue feeding and growing during parasitism, whereas idiobionts paralyse hosts before oviposition or attack non‐growing host stages, e.g. eggs or pupae. 3. Koino‐/idiobiosis in primary parasitoids are often associated with different expression of life history trade‐offs, e.g. endo‐ versus ectoparasitism, high versus low fecundity and short versus long life span. 4. In the present study, life history parameters of two koinobiont endoparasitic species (Alloxysta victrix; Syrphophagus aphidivorus), and two idiobiont ectoparasitic species (Asaphes suspensus; Dendrocerus carpenteri) of aphid hyperparasitoids were compared. These hyperparasitoids attack either the parasitoid larva in the aphid before it is killed and mummified by the primary parasitoid or the parasitoid prepupa or pupa in the dead aphid mummy. 5. There was considerable variation in reproductive success and longevity in the four species. The idiobiont A. suspensus produced the most progeny by far and had the longest lifespan. In contrast, the koinobiont A. victrix had the lowest fecundity. Other developments and life history parameters in the different species were variable. 6. The present results reveal that there was significant overlap in life history and reproductive traits among hyperparasitoid koinobionts and idiobionts, even when attacking the same host species, suggesting that selection for expression of these traits is largely association specific. 相似文献
17.
Most insect populations are exploited by a complex of different parasitoid species, providing ample opportunities for competitive interactions among the latter. Despite this, resource-mediated competition (i.e., exploitative competition) among insect parasitoids remains poorly documented in natural systems. Here we propose a novel way to infer the presence of competitive interactions from covariance patterns in parasitism levels, and illustrate the use of this approach on a relatively well-defined and simple host–parasitoid system. The parasitism levels caused by three parasitoid species on a shared host showed a highly consistent negative covariance among samples. With the levels of parasitism by one species increasing, the levels of parasitism attributable to the two others decreased. Importantly, negative covariance between parasitism levels by different species appeared at high abundance, but not at low abundance of the phenologically earlier parasitoid species. This as well as several other lines of evidence indicates the importance of competitive interactions in this system. Feeding biology and phenology of the parasitoids suggest that competition in this parasitoid assemblage is primarily resource-mediated rather than occurring through direct interference. The species attacking earlier stages of the host are competitively superior to those attacking their host later in the season. Better dispersal ability and use of alternative host species by the inferior species could contribute to the coexistence of these competing parasitoids. 相似文献
18.
MARC DE MEYER 《Systematic Entomology》1996,21(1):15-26
Abstract. The fruit fly genus Ceratitis (Diptera: Tephritidae) comprises several important pest species attacking a wide range of unrelated fruits. In this paper the subgenus Ceratitis ( Pardalaspis ) Bezzi is revised. Ten species are recognized of which five are described as new: C.(P.)hamata sp.n., C.(P.)munroi sp.n., C.(P.)serrata sp.n., C.(P.)semipunctata sp.n. and C.(P.)zairensis sp.n. A key to both sexes is provided. All species are restricted to the Afrotropical Region and distributional and known host plant data are given. 相似文献
19.
Mechanism of bleomycin action: in vitro studies 总被引:6,自引:0,他引:6
The cytotoxic activity of bleomucin results from DNA cleavage, which is also accomplished by reaction mixtures containing Fe(II), drug and O2. Bleomycin forms a complex with Fe(II) and O2 in the presence or absence of DNA. The species attacking DNA forms rapidly from this complex. The nature of the attacking species and of the primary lesion(s) to DNA are not yet known, but two major insults to DNA have been characterized. They are the release of free bases from their glycosidic linkages and, at other residues, the cleavage of the polymer backbone at the deoxyribose C3-C4 bond. 相似文献
20.
Exploitation of the Host's Chemical Communication in a Parasitoid Searching for Concealed Host Larvae 总被引:2,自引:0,他引:2
Thomas S. Hoffmeister & Phillip Gienapp 《Ethology : formerly Zeitschrift fur Tierpsychologie》1999,105(3):223-232
We found empirical evidence for the exploitation of the host's chemical communication in a parasitic wasp foraging for a concealed host. Female Halticoptera laevigata wasps (Hym., Pteromalidae) searched longer and probed more frequently on honeysuckle fruit that carried fresh marking pheromone or harbored a first instar larva of its host, the tephritid fruit fly, Myoleja lucida . They further increased their searching efforts on fruits that provided both host-related cues. While the exploitation of host marking pheromones for host location had previously been shown in two parasitoid species attacking the eggs of their tephritid hosts, this is the first evidence for the exploitation of a host's marking pheromone in a parasitoid attacking the larvae of an herbivorous host. Taking into account the time interval between application of host marking pheromones and parasitoid attack plus the fact that these pheromones are generally water soluble and thus might be washed off by rains, we discuss the reliability-detectability problem for the exploitation of those cues for host location in parasitoids attacking a larval host. 相似文献