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The genus Dolichovespula consists provisionally of 18 species. Aerial nest site characteristics have been established for seven species but most of these species show flexibility in their choice of nest sites and two species often nest in shallow subterranean situations. Colony length is usually just over 3 months to approximately 4 months, but at lower latitudes may extend to more than 5 months. Mature colony size is usually approximately 1000 cells with more large cells than small cells. Parasitized colonies have a shorter colony cycle and smaller colonies. During the production of the sexual brood the larva/worker ratio reaches its lowest value of approximately 2.5 larvae per worker. Colonies often have upper mixed combs of small and large cells. Total adult production is usually less than 2000 adults. Colonies of D. arenaria and D. norwegica may specialize in mainly producing males or queens. Variations in mature colony size and production of queens is probably a consequence of the number of workers present, particularly early in the colony cycle.  相似文献   

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The genus Nonnapsylla Wagner, 1938 (Craneopsyllinae) includes only 1 species, Nonnapsylla rothschildi Wagner, 1938 . Two subspecies are recognized by the shape of the dorsal margin of the helmet, apical shape of the spines in helmet and genal combs, length of first and fourth segments of the maxillary palpus, and shape of the hilla of the spermatheca. The validity of the characters used to separate the 2 subspecies of Nonnapsylla rothschildi Wagner, 1938 is discussed based on information from the literature, as well as from direct observation of type specimens and specimens collected in northwestern Argentina. We conclude that Nonnapsylla rothschildi wagneri Johnson, 1957 should be considered as a synonym of the nominal subspecies. We also extend the southern limits of the distribution of the species and report its presence in Argentina.  相似文献   

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Genetic relationships among 15 South West European populations of Polyommatus coridon were evaluated by the electrophoretic study of 16 gene-enzyme systems. Nei's indexes I and D and other statistics demonstrated that two different species are involved, identifiable as Polyommatus coridon (six populations from Southern France and Italy) and Polyommatus caelestissimus (nine populations from Spain), respectively. The Spanish complex is characterized by a different genetic balance, involving much higher degree of interdemic differentiation. It also differs from populations from France and Italy on one alternative locus showing complete fixation. Species-level distinction is independent of haploid chromosome numbers that vary from 87 to 88 in both groups. An evaluation of selective pressures as operated by climatic factors was attempted. The Pleistocene radiation of this group and consequent patterns of the gene flow were reconstructed using spatial autocorrelation analysis.  相似文献   

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Background and Aims

Floral variation, pollination biology and mating patterns were investigated in sunbird-pollinated Babiana (Iridaceae) species endemic to the Western Cape of South Africa. The group includes several taxa with specialized bird perches and it has been proposed that these function to promote cross-pollination.

Methods

Pollinator observations were conducted in 12 populations of five taxa (B. ringens subspp. ringens, australis, B. hirsuta, B. avicularis, B. carminea) and geographic variation in morphological traits investigated in the widespread B. ringens. Experimental pollinations were used to determine the compatibility status, facility for autonomous self-pollination and intensity of pollen limitation in six populations of four taxa. Allozyme markers were employed to investigate mating patterns in four populations of three species.

Key Results

Sunbirds were the primary pollinators of the five Babiana taxa investigated. Correlated geographical variation in perch size, flower size and stigma–anther separation was evident among B. ringens populations. Experimental pollinations demonstrated that B. ringens and B. avicularis were self-compatible with variation in levels of autonomous self-pollination and weak or no pollen limitation of seed set. In contrast, B. hirsuta was self-incompatible and chronically pollen limited. Estimates of outcrossing rate indicated mixed mating with substantial self-fertilization in all species investigated.

Conclusions

Despite the possession of specialized bird perches in B. ringens and B. avicularis, these structures do not prevent considerable selfing from occurring, probably as a result of autonomous self-pollination. In eastern populations of B. ringens, smaller flowers and reduced herkogamy appear to be associated with a shift to predominant selfing. Relaxed selection on perch function due to increased selfing may explain the increased incidence of apical flowers in some populations.  相似文献   

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The goal of this review is to highlight what little is known,and point to the bulk of what is yet to be learned, about thenatural history of placozoans in the field—in order tostimulate a broader search for placozoans and a fuller explorationof their distribution, diversity, and all other aspects of theirenigmatic lives. The documented geographic distribution of placozoanslies mostly in the nearshore, warm, marine waters of the tropicsand subtropics. Although placozoans have long been viewed asbenthic organisms, they can be more readily collected from thewater column, well above the sea bottom. The full life-historyof placozoans is unknown, including the nature of this abundantpelagic phase and all details of sexual reproduction and development.We note observations on the biota associated with placozoansin field collections, in particular the other regular membersof the microcommunity in which placozoans occur on our collectingplates and on some factors influencing this assemblage. Amongthe animals found are some potential predators against whichplacozoans appear to be defended, although the mechanisms arestill to be examined. Also yet to be uncovered is the full breadthof diversity in this phylum, certainly underrepresented by itssingle named species. We report here greatly expanded distributionsfor known haplotypes and fresh specimens that include a newhaplotype, and we review the evidence that many more almostcertainly await discovery. We also describe some methods forcollecting and handling these small, fragile animals.  相似文献   

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Abstract. The taxonomy and biology of the supposedly lestobiotic ant genus Paedalgus is reviewed. Ten species are recognized, from Sri Lanka and the Afro tropical region, of which six are described here as new: distinctus, octatus, pisinnus, rarus, robertsoni and saritus. The genus is defined and an identification key to species is provided. Evidence for and against a lestobiotic lifeway is discussed and what is known of the biology of the species is reviewed.  相似文献   

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Taxonomic identification and classifications of insect pest genera Chrysodeixis and Ctenoplusia of the subfamily Plusiinae is very compulsory due to their phytophagous nature and potential to damage the cash as well as cereal crops. Taxonomy plays a key role in proper not only in identification and classification of the pest but also in designing a successful managing strategy. In current study, specimens of Chrysodeixis and Ctenoplusia genera were collected from different geographical areas of south Punjab, Pakistan and their diagnostic features were examined following taxanomic keys. The data of temperature, relative humidity and rainfall were also recorded during the study period. Genitalia was extracted by dissecting of the abdomen and inspected under Stereo microscope. The results revealed two new species, Chryodeixis maxus and Ctenoplusia oleraceaus, from south Punjab region in addition to previously reported species: Chrysodeixis furihatai. Suitable management of the voracious insect pest at appropriate time may help in sustaining the agriculture in Pakistan.  相似文献   

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This paper provides an overview of the family Bathyclupeidae of the world fauna; the geographic and bathymetric distribution of species is updated. It is concluded that the family includes nine species that are grouped into two genera—Bathyclupea Alcock and Neobathyclupea gen. nov. The new genus differs from the type one by the development of black pigment in the orobranchial cavity, smooth ventral branch of preoperculum, developed last pair of pleural ribs, and the number of rays in the vertical fins.  相似文献   

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The taxonomy and distribution of the genus Quillaja (Quillajaceae) is examined and two species, Q. brasiliensis and Q. saponaria, are recognised and keyed out. Quillaja bra‐ siliensis is distributed in southern Brazil, northern Uruguay, northeastern Argentina and eastern Paraguay. The presence of Q. brasiliensis in Peru, indicated in some sources, is not confirmed with herbarium specimens. Quillaja saponaria is distributed in central Chile, besides one doubtful collection from Andean Bolivia. The mention of its presence in Peru is likewise unjustified. A distribution map of the species is provided and two names are lectotypified here. Se examina la taxonomía y distribución del género Quillaja (Quillajaceae), donde dos especies, Q. brasiliensis y Q. saponaria, se reconocen y diferencian mediante una clave. Quillaja brasiliensis se distribuye en el sur de Brasil, norte de Uruguay, noreste de Argentina y este de Paraguay. La presencia de Q. brasiliensis en Perú, indicada en algunas fuentes, no se ve respaldada por ejemplares de herbario. Quillaja saponaria se distrbuye en Chile central, más una colección dudosa proveniente de los Andes de Bolivia. La mención de Q. saponaria para Perú tampoco se justifica. Se presenta un mapa de distribución de las especies y se lectotipifican dos nombres. (© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)  相似文献   

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The closely related neotropical melastomean genera Pterogastra and Schwackaea are revised, the species illustrated, and their distribution mapped. Schwackaea is maintained as a monotypic genus because it is readily distinguished from all other melastomes by its 8-winged capsule. This weedy little plant occurs from Mexico throughout Central America, chiefly on the Pacific slope, to northern Colombia and on Cocos Island and grows in natural or man-made savannas from sealevel to 2000 m altitude. Two species are recognized in Pterogastra and one new combination, P. divaricata spp. glabra , is made. Pterogastra is characterized by distinctly 4- or 5-winged capsules, unlike those of Schwackaea or any other New World melastome. The more widespread species occurs in Colombia, Venezuela, Guyana, Ecuador, and Peru at altitudes between sealevel and 2600 m in natural or disturbed grasslands. The second species is endemic in southwestern Venezuela and is confined to natural savannas at low altitudes.  相似文献   

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