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1.
Summary The oriental species of the genera Olabidocarpus Lawrence, 1948, Dentocarpus Dusbabek & Cruz, 1966, Labidocarpellus Fain, 1976 and Pteropiella Fain, 1970 are revised. The species are redescribed and depicted except for a few which have been fully described recently. The total number of species known from these genera in this region is now 17. Labidocarpellus papuanus Fain, 1975 is replaced in the genus Pteropiella. The subgenus Dentocarpus (Paradentocarpus) Fain, 1976 is placed in synonymy with Labidocarpellus and the three species described in this subgenus (D. (P.) abyssinicus Fain, 1976, D. (P.) phyllodermae Fain, 1976, and D. (P.) kimberleyensis Fain & Lukoschus, 1981) are transferred to Labidocarpellus. Labidocarpellus notopteris Fain, 1976 and L. novaeguineae Fain, 1976 are now transferred to Dentocarpus. Olabidocarpus peropteryx Fain, 1972 and O. guyanensis Fain, 1972 are transferred to Labidocarpellus. A key is given to all the genera of Chirodiscidae parasitic on bats. ac]19820102  相似文献   

2.
From 1966 to 1976, samples of Phorodon humuli were collected annually from five commerical hop gardens in Kent and from other hop gardens where problems in control occurred. A susceptible stock was obtained from wild hop growing in northern England in 1969. The samples were cultured in isolation on potted hops and bioassayed against insecticides in common use. The level of resistance to demeton-S-methyl was c. 10X in 1966 after 10 yr use, and more than doubled from 1968–1974 apparently due to the spread of a more resistant type; there was a further increase to c. 50X in 1975–1976. There was also resistance of C. 20–30X to omethoate, 2–7X to methidathion and 4–8X to methomyl. Assays and field results show an increased resistance to methidathion and less certainly to methomyl after 5 yr use. There was no clear change in response to endosulfan. The LC50's estimated from a single dose and a mean probit slope were found to agree satisfactorily with the LC50's calculated from serial doses and so should be adequate for monitoring trends in resistance.  相似文献   

3.
Aim To document changes in the floristic composition and vegetation structure of Carnac Island during a period of 40 years. This paper presents a synthesis of all available floristic and vegetational information. Location Carnac Island is 8 km offshore from Fremantle, south‐west Western Australia. Methods Comparison of lists of plant species for 1951, 1958/9, 1966/7, 1975/6 and 1995–6. Comparison of vegetation, based on structural and floristic elements, for 1951, 1965, 1972, 1984 and 1995. Results Floristic composition (both native and exotic species) changed most dramatically in the period 1975/6–1995/6, with a 37% reduction in number of plant species. The number of annual and perennial native species present in 1995/6 was most similar to that in 1951. The most remarkable change in the flora has been the increase in annual exotic species since 1951. Immigration and extinction rates were greatest in the periods 1951–58/9 and 1958/9–1966/7, respectively. Vegetation structure has also altered, involving a reduction in height of dominant species from 3–4 m to 1 m as Acacia rostellifera and Olearia axillaris have declined in distribution. The weed species Mesembryanthemum crystallinum (first recorded 1975) and Malva parviflora (1958) now dominate the vegetation of half the island. Main conclusions Five factors are considered to have contributed to botanical change: nesting seabird populations, eradication of the rabbit in 1969, drought, increased saltload from occasional cyclones in summer or autumn, and competition from increasing dominance of several weed species. Several of these factors have operated in opposing ways with respect to plant species richness and vegetation cover. Experimental studies are required to determine the strength of these interactions. Two weed species, Zantedeschia aethiopica (first recorded 1966) and Lycium ferocissimum (1992) have the potential to dominate the vegetation of the island.  相似文献   

4.
Dixon  L. K.  Nelson  B. A.  Priest  R. L. 《Genetica》1984,52(1):63-68
Mice of the genus Peromyscus all have 48 chromosomes. Yet the appearance of the 48 chromosomes is highly variable from species to species (Hsu & Arrighi, 1966, 1968, 1971; Pathak et al., 1973) and even in different populations of the same species (Sparkes & Arakaki, 1966; Ohno et al., 1966; Hsu & Arrighi, 1968; Arakaki et al. 1970; Te & Dawson, 1971; Bradshaw & Hsu, 1972; Murray & Kitchin, 1976). The evolutionary significance of this variation and the mechanisms for its initiation and maintenance have been of interest for quite a few years. However, it was not until the sophisticated chromosome banding techniques became available that mammalian cytogeneticists were able to begin to study the chromosome variation of Peromyscus in some detail. The use of C-banding led Hsu & Arrighi (1971) to the finding that the short arms of chromosomes in three different species of Peromyscus contained constitutive heterochromatin. These results suggested that the variations in the number of acrocentric chromosomes in Peromyscus might be a result of different amounts of heterochromatin. Later studies (Duffey, 1972; Waterbury, 1972; and Pathak et al., 1973) were also consistent with this hypothesis.However, it was soon discovered that not all chromosomal differences among Peromyscus populations are due to heterochromatin changes. Studies by Arighi et al. (1976) and Murray & Kitchin (1976) showed that some chromosomal differences between species and subspecies of Peromyscus are due to pericentric inversions. Thus, it appears that both inversions and the addition of heterochromatin are involved in the evolution of the karyotype of Peromyscus.The purpose of our study was to investigate the chromosomes of Peromyscus maniculatus in different populations in Colorado (U.S.A.) and to test for relationships involving an altitudinal gradient. In the first part of this study, orcein stained chromosomes from three subspecies of mice sampled at nine different altitudes were examined for karyotype variability. In the second part of the study, karyotypes of two subspecies (P. m. rufinus and P. m. luteus), representing high and low altitude populations were examined with Q banding to determine the mechanisms responsible for chromosomal differences.  相似文献   

5.
Management practices over the past 100 years, especially fire exclusion and suppression, in Yosemite Valley, Yosemite National Park, CA resulted in forest stands with basal areas in excess of 110 m2 ha-1. Accelerated attack by several species of bark beetles (Scolytidae) followed a severe drought in 1976–77. Pinus ponderosa, already under attack by root rot (Heterobasidion annosus) was affected severely, and mortality exceeded 70%. Calocedrus decurrens did not suffer comparable mortality and has replaced P. ponderosa as the dominant species. Size class distributions as well as comparisons of relative density and relative basal area from 1961, 1976 and 1983–85 also demonstrate a major change in forest composition. This change is most pronounced on alluvial landforms.  相似文献   

6.
Abstract. This paper describes the vegetation change in an 18-year experiment designed to test a range of control of Pteridium aquilinum (Pteridium) and heathland restoration treatments; cutting, asulam application and Calluna vulgar is seeding, in a range of combinations at Cavenham Heath in Breckland, UK between 1978 and 1996. Vegetation change was recorded in two Phases; in Phase I (1978-1986) species biomass was sampled and in Phase II (1986-1996) cover was measured. Initially, Calluna establishment was good in some treatments, especially where Calluna seed was added and Pteridium was controlled. Other plots developed either a grass-heath flora dominated by Agrostis capillaris, Deschampsia flexuosa, Dicranum scoparium, Festuca ovina and Rumex acetosella or were dominated by clonal species such as Calamagrostis epigejos or Carex arenaria. An unconstrained ordination showed significant vegetation change through time and that several treatments influenced the vegetation, especially those involving asulam application. When variation partitioning with constrained ordination was used a different explanation emerged. In Phase I the most important factors were the management treatments applied, elapsed time and spatial factors, with little overlap. In Phase II, elapsed time became irrelevant because the variation time explained overlapped that which could be explained by other variables. The most important of these were management treatments, spatial effects, weather, the amount of bare ground caused by disturbance and Pteridium litter cover (an index of Pteridium recovery). The implications of these results in interpreting vegetation change are discussed.  相似文献   

7.
Summary The floristic composition of the Rivers Tees and Skerne in 1963–1966 was compared in detail with that recorded by a previous worker in 1929–1933. In spite of the long time interval during which considerable changes have taken place in the rivers there was only one marked change in the flora. This is the apparent invasion of Enteromorpha intestinalis. Other changes were very few and did not involve common species.  相似文献   

8.
The community of elaterid larvae of three sites (field and two fallows), representing different stages of secondary succession, were studied using soil sampling from 1986 to 1993. All three sites were abandoned arable land: a field cultivated until 1991, a fallow I abandoned in 1986, and a fallow II abandoned about 1976. The fallow II was used as a meadow after abandonment and was regularly mown until 1985, when cultivation stopped. Six species of Elateridae larvae were found at all three study sites. In the field, Agriotes obscurus, Athous niger, Athous subsuscus, Dalopius marginatus and Athous vittatus were found, A. niger and A. obscurus being the most abundant species. During cultivation, larval densities were very low, however, larval abundance increased up to 8.8 ± 8.3 ind. m-2 when cultivation stopped. Only small A. obscurus larvae were found during cultivation, whereas larval size increased after abandonment. In fallow I A. obscurus, A. niger, A. subsuscus, D. marginatus, and Agrypnus murinus were found and the average annual abundance fluctuated between 0.8 ± 1.4 to 40.8 ± 10.9 ind. m-2 with A. obscurus being the most abundant species. Fallow II supported the highest densities of wireworms from all plots studied (71.2±35.2 to 280.0±24.8 ind. m-2). A. obscurus, A. niger, A. subsuscus and D. marginatus were found in fallow II. The abundance of all larval Elateridae as well as the dominant species A. obscurus decreased during the study period, while simultaneously the occurrence of small sized A. obscurus larvae decreased. The frequency of cultivation and time elapsed since last cultivation appeared to be the most important factors affecting elaterid occurrence in the field and fallow I. In fallow II, the decrease in abundance correlates with the accumulation of a dense litter layer, which may correspond with soil surface structure, plant community changes or predator pressure.  相似文献   

9.
For many years the biosystematic status of several species in the Rhipicephalus sanguineus group has been confused, with the result that they have often been misidentified. Over the years some 18 of these species have been synonymised with R. sanguineus (Latreille, 1806) itself. More recently four new species in the group have been described: R. guilhoni Morel & Vassiliades, 1963; R. moucheti Morel, 1964; R. bergeoni Morel & Balis, 1976; and R. camicasi Morel, Mouchet & Rodhain, 1976.The literature on this group is critically reviewed and the main systematic problems analysed. R. sulcatus Neumann, 1908 and R. turanicus Pomerantsev, 1936 are two species that were confused both morphologically and ecologically. This has resulted in erroneous conclusions regarding their host relationships and distributions. Integrated biological, morphological and ecological studies on these two species have been conducted. Cross-breeding experiments have proved that both are distinct taxonomic entities. Interbreedings between African and Cypriot strains of R. turanicus demonstrated marked heterosis.A scanning electron microscope was used to determine the main diagnostic morphological differences between the larvae, nymphae and adults of R. sulcatus and R. turanicus, and the morphological similarities between African and Cypriot strains of R. turanicus. Rhipicephalus sulcatus occurs widely in the Afrotropical region in wetter ecological habitats and most frequently parasitises hares, dogs and jackals. R. turanicus occurs more-or-less throughout the Afrotropical region in a wide range of climatic biotopes, as well as in parts of southern Europe, Arabia and Asia, and is most abundant in the late rainy/early dry seasons. It occurs on a wide range of domesticated and wildlife hosts, including ground-feeding birds.  相似文献   

10.
ABSTRACT

The Dipteran family Streblidae are ectoparasites of bats. These flies are viviparous and have an intrauterine larval life phase, a free-living sessile puparium phase and the adult obligate parasite. Here we describe the external morphology of the puparium of Aspidoptera phyllostomatis (Perty, 1833), Megistopoda aranea (Coquillett, 1899), M. proxima (Séguy, 1826), Noctiliostrebla morena Alcantara et al., 2019, Paradyschiria parvula Falcoz, 1931, Strebla consocia Wenzel, 1966, Trichobius joblingi Wenzel, 1966 and T. longipes (Rudow, 1871) and provide an identification key. We also describe the method we developed for collecting the puparia, which was done between April 2015 and August 2016. The characters that most differentiated the species were spiracles and ornaments.  相似文献   

11.
Therodamas tamarae n.sp. is described based on females removed from branchial filaments of Plagioscion squamosissimus (Teleostei, Sciaenidae) caught in a lake near the Araguaia River, State of Goiás, Brazil. The new species shares with Therodamas elongatus (Thatcher, 1986) the same host, a similar reaction from the host to the presence of the parasites, and the same general shape of body; in addition, the two species are from the Amazon basin. On the other hand, it resembles T. fluviatilis Paggi, 1976 in the structure of legs 1 to 4. An identification key for Therodamas species, as well as comments on the distribution of the species, are included.  相似文献   

12.
Capsule?Of 26 species of wintering waterbirds, 18 showed an increase in numbers, five showed a decrease and two showed no change.

Aim?To assess long-term trends in the numbers and distribution of the 26 most abundant wintering waterbird species in the Czech Republic.

Methods?We used International Waterbird Census data from between 48 and 639 wetland sites which had been counted annually in the Czech Republic from 1966 to 2008. From these data long-term changes in numbers and distributions were determined. Log-linear Poisson regression analysis was used to estimate missing data using trim software. The distribution of each species was described as the ratio of the number of sites occupied by that species to the total number of sites investigated.

Results?Increasing trends were found for 18 species, five species were found to be declining, one species was stable and two species were found with uncertain trends. Wintering distributions (the ratio of sites occupied by a given species to the total number of sites counted) increased in 16 species and decreased in two species, broadly correlated with the species changes in numbers.

Conclusion?In most species changes in numbers as well as changes in distribution followed the Western Palearctic population trends. Those species which increased were mainly piscivores and included geese, ducks and gulls. Scarcer species also exhibited an increase in numbers. The changes in numbers (both positive and negative) were more frequent among species associated with running water, whereas species which showed uncertain trends were more frequently recorded on standing water, which is more affected by variable weather conditions.  相似文献   

13.
Edward B. Reed 《Hydrobiologia》1986,139(2):127-133
Weekly mean lenghts of adult female Acanthocyclops robustus ranged between 1.14 and 1.41 mm in a Colorado alpine lake during the summer of 1966. The smallest animals occurred in late September and the largest in mid-August, corresponding to development in warm and cool water, respectively. The males also declined in mean length during the course of the summer and were about 70% of the length of the females on any date. About 75% of the females possessed a 3.4.4.4 spine formula; 8%, 2.3.3.3 and 17% an anomalous formula. Eight-one percent of the males had a 3.4.4.4 formula; 7%, 2.3.3.3 and 12% were anomalous. Morphological variation, and breeding experiments performed by Price (1958) suggest that A. robustus and A. vernalis as defined by Kiefer (1976) are likely species complexes, rather than just two species.  相似文献   

14.
Background: Grasslands have only a few dominants and most of the diversity consists of subdominants. Because dominants differ widely in phenology and resource use, dominants may control the recruitment and establishment of other species.

Aims: To explore the relationship between the identity of the dominant species and successional vegetation changes in grassland communities.

Methods: The compositional change over 23 years in 1900 permanent plots dominated by four grasses (Andropogon gerardii, Elymus repens, Poa pratensis and Schizachyrium scoparium) was examined within 19 old fields in Minnesota. Fields were abandoned 1–56 years before sampling. Rate of directional change and degree of compositional dissimilarity were determined.

Results: Non-natives, P. pratensis and E. repens, were associated with either no or a slow directional change. Elymus repens was associated with high dissimilarity and P. pratensis with intermediate dissimilarity. Natives, A. gerardii and S. scoparium, were associated with compositional change that followed expectations based on field age. The rate of directional change and degree of dissimilarity between sampling intervals was lower for A. gerardii relative to S. scoparium, the only species to be associated with strong directional change.

Conclusions: Dominance by non-native grass species may impede traditional successional processes and result in a community composition quite dissimilar from native prairies.  相似文献   

15.
Summary

The “Borneo endemic” genus Chinemesa Wygodzinsky, 1966 is recorded from the mainland of Asia for the first time. A new species, Chinemesa chinensis n. sp., is described and illustrated. An updated key to species of Chinemesa is provided. Relationship between Chinemesa and Ocelliemesina Wang, Wang, Cao & Cai, 2015 is discussed, and diagnostic characters of Chinemesa are revised. Distribution of Chinemesa is briefly discussed.  相似文献   

16.
Background: The South Aegean Volcanic Arc (SAVA), one of the most notable geological structures of the Mediterranean Sea, is floristically well known. Nevertheless, the factors that contribute to shaping the plant species richness of the SAVA remain unclear.

Aims: To investigate the factors that affect plant species richness and identify plant diversity hotspots in the SAVA and other central Aegean islands.

Methods: We used stepwise multiple regression to test the relationship between a number of environmental factors and plant species richness in the SAVA, as well as the residuals from the species–area linear regressions of native, Greek and Cycladian endemic taxa as indicators of relative species richness.

Results: The area was confirmed to be the most powerful single explanatory variable of island species richness, while geodiversity, maximum elevation and mean annual precipitation explained a large proportion of variance for almost all the species richness measures. Anafi, Amorgos and Folegandros were found to be endemic plant diversity hotspots.

Conclusions: We have demonstrated that geodiversity is an important factor in shaping plant species diversity in the Cyclades, while mean annual precipitation, human population density and maximum elevation were significant predictors of the Greek endemics present in the Cyclades. Finally, Anafi was found to be a plant diversity hotspot in the South Aegean Sea.  相似文献   

17.
Abstract

The age at first breeding and the influence of age on laying date, clutch size, and egg size of white-fronted terns were studied at the Kaikoura Peninsula, New Zealand, between 1971 and 1976. Of the 134 banded birds recovered breeding at Kaikoura, 63% were marked as nestlings at Kaikoura; the remainder came from colonies within 104 km. The bird is extremely capricious in its choice of nesting locality, and there are indications that it is not consistently philopatric. A small number bred as 3-year-olds, but the majority did not commence breeding until after they were 6 years old. Most pairs (73%) were of partners with an age difference of 1 year or less. Laying date and egg size varied with the age of the parent, but clutch size showed no significant change in relation to age. Mean egg volume did not vary between one-egg and two-egg clutches, but in two-egg clutches the first egg laid was significantly the larger in length, breadth, and volume. Single-egg clutches were the most common, but as the season progressed the proportion of two-egg clutches increased. There was no significant seasonal change in egg size.  相似文献   

18.
1. Measurements of total phosphorus (TP) concentrations since 1975 and a 50‐year time series of phytoplankton biovolume and species composition from Lake Mondsee (Austria) were combined with palaeolimnological information on diatom composition and reconstructed TP‐levels to describe the response of phytoplankton communities to changing nutrient conditions. 2. Four phases were identified in the long‐term record. Phase I was the pre‐eutrophication period characterised by TP‐levels of about 6 μg L?1 and diatom dominance. Phase II began in 1966 with an increase in TP concentration followed by the invasion of Planktothrix rubescens in 1968, characterising mesotrophic conditions. Phase III, from 1976 to 1979, had the highest annual mean TP concentrations (up to 36 μg L?1) and phytoplankton biovolumes (3.57 mm3 L?1), although reductions in external nutrient loading started in 1974. Phases II and III saw an expansion of species characteristic of higher nutrient levels as reflected in the diatom stratigraphy. Oligotrophication (phase IV) began in 1980 when annual average TP concentration, Secchi depth and algal biovolume began to decline, accompanied by increasing concentrations of soluble reactive silica. 3. The period from 1981 to 1986 was characterised by asynchronous trends. Annual mean and maximum total phytoplankton biovolume initially continued to increase after TP concentration began to decline. Reductions in phytoplankton biovolume were delayed by about 5 years. Several phytoplankton species differed in the timing of their responses to changing nutrient conditions. For example, while P. rubescens declined concomitantly with the decline in TP concentration, other species indicative of higher phosphorus concentrations, such as Tabellaria flocculosa var. asterionelloides, tended to increase further. 4. These data therefore do not support the hypotheses that a reduction in TP concentration is accompanied by (i) an immediate decline in total phytoplankton biovolume and (ii) persistence of the species composition characterising the phytoplankton community before nutrient reduction.  相似文献   

19.
Background: The effect of the anticipated climate change on the stability of vegetation and the factors underlying this stability are not well understood.

Aims: Our objective was to quantify long-term vegetation changes in a range of habitats in northern Europe by exploring species co-occurrences and their links to diversity and productivity gradients.

Methods: We re-sampled vegetation in 16 arctic, mountain and mire sites 20 to 90 years after the original inventories. A site-specific change in species assemblages (stability) was quantified using species co-occurrences. Using a randomisation test we tested whether the changes observed were significantly greater than those expected by chance. Relationships between patterns in vegetation stability and time between surveys, numbers of plots, or species diversity and proxies for productivity, were tested using regression analysis.

Results: At most sites the changes in species co-occurrences of vascular plants and bryophytes were greater than those expected by chance. The changes observed were found to be unrelated to gradients in productivity or diversity.

Conclusions: Changes in species co-occurrences are not strongly linked to diversity or productivity gradients in vegetation, suggesting that other gradients or site-specific factors (e.g. land use or species interactions) may be more important in controlling recent compositional shifts in vegetation in northern Europe.  相似文献   

20.
The fauna of the genus Sphaerophoria Le Peletier et Serville, 1828 of Siberia and adjacent territories is analyzed on the basis of examination of the material deposited at the Siberian Zoological Museum, Institute of Systematics and Ecology of Animals, Russian Academy of Sciences, Siberian Branch (Novosibirsk), and at the Zoological Institute, RAS (St. Petersburg). The following new synonymies are established: Sphaerophoria interrupta (Fabricius, 1805) = Sph. altaica Violovitsh, 1976, syn. n.; Sphaerophoria macrogaster (Thomson, 1869) = Sph. krocha Violovitsh, 1976, syn. n.; Sphaerophoria rueppellii (Wiedemann, 1830) = Sph. montivaga Violovitsh, 1985, syn. n.; Sphaerophoria macrogaster (Thomson, 1869) = Sph. nana Violovitsh, 1976, syn. n.; Sphaerophoria chongjini Bańkowska, 1964 = Sph. tinae Violovitsh, 1976, syn. n. Sphaerophoria kamtshatica Violovitsh and Sph. sachalinica Violovitsh are regarded as nomina nuda. Sphaerophoria bankowskae Goeldlin, 1989; Sph. laurae Goeldlin, 1989; Sph. potentillae Clausssen, 1984 and Sph. turkmenica Bańkowska, 1964 are found in Russia for the first time. A number of species is also reported for different territories of Siberia for the first time.  相似文献   

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