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1.
The paper treats the taxonomy of the genus Systenostrema Hazard & Oldacre, 1975, starting with an ultrastructural investigation of two new species, parasitic in larvae of the dragonflies Aeshna grandis and Libellula quadrimaculata, collected in Sweden. The two species are identical in pathology and presporal stages, but differ in the shape of spores and sporophorous vesicles, the fine structure of the spores, and numerical characters. The new species, which are named S. alba and S. candida, are compared to the octosporoblastic microsporidia parasitic in Odonata. An emended diagnosis of the genus Systenostrema is given, together with a taxonomic summary. The new combinations S. trichostegiae for Thelohania trichostegiae Baudoin, 1969 and Amblyospora capillata for T. capillata Larsson, 1983 are established.  相似文献   

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InCallithrix, Saguinus, Aotus, andCallicebus other group members than the mother participate in infant care. Differences among these species are obvious in respect to the time of being off any caregiver, and in respect to the carrying position (Aotus andCallicebus). Alloparental care, a basic behaviour pattern in these species, has evolved from the parking behaviour of the prosimians. The infants are «parked» at other group members.  相似文献   

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Eleven species ofIchneumonidae were identified as parasites of lepidopterous pests of lucerne. All of the parasitized Lepidoptera are new host records for theseIchneumonidae andDiadegma variegata Szépl. is a species of parasite new to Romania.  相似文献   

4.
Notes on the taxonomy and distribution of various species of Labiatae of Mexico, and Central and South America, are presented, as part of a continuing series of supplements to the authors’ earlier monographs. Eight new species are described in the generaHyptis, Salvia, Satureja, andScutellaria. Two new combinations are made, one each inHarlanlewisia andSatureja. A key and revision are given for the six species ofLepechinia sect.Parviflorae.  相似文献   

5.
Fifty brackish supra-littoral pools bordering the Waddenzee were studied. The structure of plant communities (Potamogeton pectinatus L., Ranunculus baudotii Godr. and Zannichellia pedunculata Rchb.) is discussed in relation to water level fluctuations, chlorinity and water transparency. Chlorinity tolerances of the macrophytes (7 species) are discussed. The macrofauna was studied semi-quantitatively. The aquatic Coleoptera had the greatest diversity (24 species). A distinct relationship between the number of Coleoptera species and the percentage of macrophyte coverage was found. The distribution patterns of the most frequent species with respect to chlorinity categories are shown in histograms. The number of aquatic Heteroptera species is also discussed in relation to chlorinity and vegetation coverage. Less important macrofaunal groups (the Crustacea, Mollusca and Odonata) occurred in low species numbers.  相似文献   

6.
Of the many types of freshwater bodies across Iceland (e.g., lakes, springs, rivers, and ponds), greater effort has been invested in researching the freshwater Crustacea (Cladocera, Copepoda) of more permanent, larger, and deeper water bodies than on smaller or more ephemeral sites. To address this, we described the fauna of 12 shallow freshwater bodies distributed from the coast to the central highlands of Iceland. We identified 16 species in 11 genera belonging to six families of Cladocera, and 12 species in eight genera belonging to four families of Copepoda. Five of the species we identified (Alona werestschagini, Cyclops vicinus, Daphnia cristata, Diacyclops abyssicola, and Heterocope borealis) represent new distribution records for Iceland, increasing the number of species now known from this region to 34 Cladocera and 38 Copepoda taxa. Additionally, we discuss the taxonomy of some species with doubtful taxonomical status. Six crustacean taxocenes are described, each characterized by the dominance of different taxa, with bottom sediment characteristics best explaining species assemblage structure. We evaluated the relationships between Icelandic Cladocera and Copepoda faunas and those of the adjacent Svalbard, Faroe, and Shetland Islands, Greenland, and the mainland Norway. The taxonomic composition of the Icelandic fauna is dominated by widely distributed Holarctic, and secondarily Palaearctic and Nearctic species, and is more similar to the faunas of the major North Atlantic islands (64.2–71.8 % similarity) than it is to that of continental Norway.  相似文献   

7.
Phytophthora plurivora and other Phytophthora species are known to be serious pathogens of forest trees. Little is known, however, about the presence of P. plurivora in Polish oak forests and their role in oak decline. The aims of this study were to identify P. plurivora in healthy and declining Quercus robur stands in southern Poland and to demonstrate the relationship between different site factors and the occurrence of P. plurivora. In addition, the virulence of P. plurivora and other Phytophthora species was evaluated through inoculations using 2-year-old oak seedlings. Rhizosphere soil was investigated from 39 oak stands representing different healthy tree statuses. The morphology and DNA sequences of the internal transcribed spacer regions (ITS) of the ribosomal DNA and the mitochondrial cox1 gene were used for identifications. P. plurivora, an oak fine root pathogen, was isolated from rhizosphere soil samples in 6 out of 39 stands. Additionally, Phytophthora cambivora, Phytophthora polonica and Phytophthora rosacearum-like were also obtained from several stands. The results showed a significant association between the presence of P. plurivora and the health status of oak trees. Similar relationships were also observed for all identified Phytophthora species. In addition, there was evidence for a connection between the presence of all identified Phytophthora species and some site conditions. Phytophthora spp. occurred more frequently in declining stands and in silt loam and sandy loam soils with pH?≥?3.66. P. plurivora and P. cambivora were the only species capable of killing whole plants, producing extensive necrosis on seedling stems.  相似文献   

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Coral species are difficult to discern because of their morphological plasticity, long generation times, and slow rates of mitochondrial DNA evolution. Among Caribbean representatives of the genus Porites are three named species (P. divaricata, P. furcata, and P. porites) with branching colony morphologies whose validity as genetically isolated species has been debated. We present sequence data from the mitochondrial control region, nuclear ITS, and nine single-copy nuclear loci for the Caribbean Porites and a related eastern Pacific species. mtDNA sequences were nearly invariant among the three branching species and their crustose sister P. branneri, and ITS sequences from these four were intermingled. An information theoretic analysis provided no support for upholding the three named Caribbean branching species. Both a clustering analysis and an analysis of molecular variance showed that sequence variation from the three branching forms is partitioned more by geography than by taxonomy. Multi-locus coalescent phylogenetic analysis provided a calibrated estimate for the nuclear DNA substitution rate (0.14 % Ma?1) close to that for other corals. Because no generalities have emerged from genetic investigations of the validity of morphologically defined coral species, the use of single-copy nuclear data is likely to be important in testing problematic species designations.  相似文献   

13.
It can be demonstrated that the Indigo of Commerce in Colonial North America consisted of three species in the genusIndigofera. One of these was a native plant,I. Caroliniana Mill, while the other two were introduced.Indigofera tinctoria L. (French Indigo), an Old World species, andI. Suffruticosa Mill. (Guatemala Indigo), a New World species, were both introduced into South Carolina in the late 17th and early 18th centuries. Their cultivation flourished until the American Revolution. Neither of the introduced species has become naturalized in the Carolinas.  相似文献   

14.
Collections from French Guiana, Amazonian Brazil, and Colombia taken in the last 20 years include new species in the following genera:Duroia, Pagamea, Psychotria, Randia, Retiniphyllum, Rudgea, Sabicea, Sipanea, andSphinctanthus. Twenty-one new species are described and five are illustrated.  相似文献   

15.
A combined taxonomic revision and wood anatomical study ofDicorynia, a South American genus of legumes that is unusual in both its floral and wood anatomy, is presented. Two possible evolutionary pathways leading to the unique 8-to 10-thecate anthers are discussed, and it is concluded that apical proliferation of the thecal primordia is the more likely. Gross and microscopic features of this silica-accumulating wood are given in detail and contrasted with other legume woods especially those containing silica. Economic uses of the trees, especially the wood ofD. guianensis, are discussed particularly in regard to marine construction. It is suggested that the high resistance of this wood to marine borers lies not so much in its silica content as to the presence of some other chemical. Based on the similarity of floral and fruit structures, the number of species is reduced from 7 to 2:D. guianensis in the Guianas andD. paraensis in the Amazonian region. Vegetative variations in the Amazonian population, previously given species rank, are reduced to 5 new varieties ofD. paraensis.  相似文献   

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One new species of Chusquea and three of Swallenochloa are described. Morphological characters, especially of the culm leaves and branching, are pointed out as useful in distinguishing the two genera. A key to the 7 recognized species of Swallenochloa is given, and a discussion of its habitat, the páramo. Comment is made upon the recent evolution of the páramo habitat and therefore of the bamboo adapted to it, and reasons offered for the apparent active speciation which characterizes this bamboo genus.  相似文献   

18.
Two new genera of Chrysobalanaceae are described.Hunga distributed in New Caledonia, the Loyalty Islands and Papua and New Guinea, contains eight species, three new, and five formerly placed in the generaAngelesia, Licania andParinari.Kostermanthus is described to accommodate two species with united filaments formerly placed inParinari andAcioa. Both new genera are quite as distinct as others of the family and have been overlooked by undue emphasis placed on the single character of a bilocular ovary.Licania palawanensis Prance is also described; it is the second species of its genus from Malesia.  相似文献   

19.
Seasonal predatory and scavenger arthropod densities were studied at interior and coastal southern California poultry ranches. Though some seasonal population clumping occurred with some species, the distribution of predators and scavengers was fairly uniform within each ranch. Correlation analyses of key predators in theHisteridae, Staphylinidae, Hydrophylidae andDermaptera with the potential hosts,Musca domestica L.,Tinea fuscipunctella Haworth, andFannia spp. suggested that predator activity was seasonally influenced. Possible periodic avoidance of a particular host's habitat was detected as significant negative correlations. The data tend to support the importance of different species of predators in different seasons and the need for natural enemy complexes rather than single species for biological control.  相似文献   

20.
Insight into colonization of new areas by invasive species and their relationships with aboriginal species is a major challenge in ecology, allowing for prediction of the outcome of biological invasions. In this context, the current expansion of the Barnacle Goose (Branta leucopsis) is of great interest. The seasonal dynamics of Barnacle Goose feeding and the structure of its diet on Kolguev Island during the nesting and postnesting periods (May 27–July 29) have been examined. The diet structures of the invasive Barnacle Goose and the aboriginal species White-fronted goose (Anser albifrons) and Bean goose (A. fabalis) have been compared. The probability of interspecific competition and the ecological advantages in the diet patterns of these species have been estimated. If the Barnacle Goose population on Kolguev Island continues to increase, this may led to a decline in the population of aboriginal species of geese on the island.  相似文献   

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