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41.
Ten species of Lepadella Bory de St. Vincent, 1826, including one new species and one new form, are documented from North-Eastern India. Two of these species are new records from this country and six are new reports from N.E. region. Comments are also made on the status and distribution of various Indian taxa. 相似文献
42.
Are galling insects better protected against parasitoids than exposed feeders?: a test using tenthredinid sawflies 总被引:1,自引:0,他引:1
ABSTRACT.
- 1 Data mostly from the published literature were used to assess the effect of galling on the number of parasitoid species per host species in the phylogeny of nematine sawflies from free external feeders (colonial and solitary) to leaf gallers and shoot gallers.
- 2 The strongest effects of galling were the total elimination of the species-rich cocoon-attacking guild of parasitoids, and eonymphal parasitoids, from the parasitoid community on shoot gallers, all of which are in the genus Euura.
- 3 All tachinid larval parasitoids were also eliminated by the galling habit.
- 4 The cumulative effects of these exclusions resulted in a decline in mean number of parasitoid species per host species from almost sixteen species on external colonial feeders to 4.0 species on shoot gallers.
- 5 General patterns in per cent parasitism by non-tachinid and tachinid larval parasitoids, eonymphal and cocoon parasitoids, on exposed feeders to shoot gallers, showed declines in non-tachinid attack and elimination of tachinid, eonymphal and cocoon parasitoids. But leaf gallers tended to be attacked more than exposed feeders by non-tachinid larval parasitoids.
- 6 The galling habit had a long-term impact by reducing the number of parasitoid species attacking nematine sawfly gallers and per cent mortality inflicted, so that natural enemies may have been important as a selective factor in the evolution of galling nematine sawflies.
43.
EDMUND L. SEYD 《Biological journal of the Linnean Society. Linnean Society of London》1988,34(4):349-362
A faunal list of oribatid mites collected from the summit of the Cheviot, Northumberland, is given, together with notes on the taxonomy and distribution of several of the species. Special attention is paid to the Arctic-alpine and European-alpine species and the list provides further support for the view that the upland areas of Britain are characterized by a common group of oribatid species. It is suggested that these species may be cold hardy or cold tolerant with relatively high supercooling points, enabling them to survive the winter at these higher altitudes. 相似文献
44.
David Waugh 《Zoo biology》1988,7(3):269-280
Different types of training in zoo biology, captive breeding, and conservation are discussed and the availability of a variety of programs documented. Emphasis is given to the need for more training in general, and especially for less-developed countries where zoos have much potential yet to be realized. The aims, structure, content, and impact of the Jersey Wildlife Preservation Trust's International Training Program are examined. 相似文献
45.
The serum of the channel catfish (Ictalurus punctatus) was examined for heme- and hemoglobin-binding proteins. Electrophoretic mobility retardation assays failed to detect a hemoglobin-binding material similar to mammalian haptoglobin; however, a heme-binding component (not previously described) was identified in catfish seru. The heme-binding component was purified by gel filtration chromatography; electrophoretic analyses suggested it to be composed of two polypeptide subunits of molecular masses about 115 and 98 kDa. This composition is inconsistent with hemopexin, the known heme-binding serum protein of mammals. Although it was not fully saturated with heme, the catfish component contained detectable heme in normal sera. When complexed by the binding material, heme was used as an iron source by isolates of the bacterial Gram-negative genusAeromonas; the capacity of other bacteria to use the complex was not tested. The physiological function of the catfish heme-binding serum protein is presently not clear. 相似文献
46.
The described fossil testudinids from the Miocene of Africa are reviewed. Geochelone stromeri sp. nov . is described from Lower Pliocene (Langebaanweg) and Miocene (Namib) specimens. Kinixys erosa , an extant species, is reported from Songhor Hill. Chersina sp. is reported from Arrisdrift. Impregnochelys pachytectis gen. et sp. nov . is described from Rusinga Island, Kenya, and is unique in having the anterior shell opening orientated ventrally and in having struts on the internal surface of the neurals, but shares with Kinixys a unique epiplastron shape, a high number of axillary scutes and unique orientation of the head of the femur. 相似文献
47.
J. A. McComb 《Plant Cell, Tissue and Organ Culture》1985,4(2):151-158
The number of plants in the gazetted rare species Stylidium coroniforme was increased through micropropagation. A method was first developed using the common species S. brunonianum. It was found that for both species, rapid propagation could be obtained by excising shoots from sterile seedlings and inducing shoot proliferation on Murashige and Skoog medium supplemented with 1 M BAP. Rooting was achieved using 1 M IBA and over 100 plants of each species were successfully established in soil. Leaf pieces could also be used to initiate cultures. In media with 20–25 M BAP and 1–5 M IBA, leaf pieces of S. brunonianum, S. piliferum, S. caricifolium and S. crassifolium produced adventitious buds, thus providing another method of micropropagation. 相似文献
48.
Ben J. G. Flik 《Aquatic Ecology》1985,19(2):117-122
Production versus light response curves were made of natural phytoplankton assemblages during the year in an incubator at 8 different light intensities ranging from 60 to 1500 Einstein.m–2.sec–1. The shape of these curves is analyzed in relation to the sensitivity for photo-inhibition. At the end of the month of April, there is a sudden shift in this sensitivity at higher light intensities. The algal assemblage becomes less sensitive for photo-inhibition. The influence of light-adaptation, temperature, nutrient limitation and species composition is discussed. 相似文献
49.
Interference by DDT and cyclodiene types of insecticides with chloroplast-associated reactions 总被引:1,自引:0,他引:1
The effects of DDT, some of its analogs, and selected cyclodiene insecticides on isolated spinach (Spinacea oleracea L.) thylakoids were identified, characterized, and compared to responses induced by selected herbicides. Except for endrin, the insecticides inhibited light-induced electron transport, altered chlorophyll fluorescence transients, and competitively displaced [14C]atrazine [2-chloro-4-(ethylamino)-6-(isopropylamino)-s-triazine], a known photosystem II inhibitor, from the membranes. The insecticides appeared to act at, or near B, the secondary electron acceptor of photo-system II. Binding of DDT and dieldrin was estimated at 900 and 2200 molecules, respectively, per photosynthetic unit (490 chlorophyll molecules). The insecticides also inhibited valinomycin-induced swelling of the thylakoid membrane. Whereas inhibition of electron transport can be attributed to interaction by the insecticides with a proteinaceous component of the thylakoid membrane, interference with the action of valinomycin may involve interaction with lipoidal constituents of the membrane. 相似文献
50.