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Role of seasonal migrations of limnophilic bird species in bringing influenza A (H5N1) virus into Lower-Volga region. – Zavialov E.V., Matrosov A.N., Tabachishin V.G., Kutyrev I.V., Popov N.V., Yakushev N.N., Mosolova E.Yu., Khomutova T.Yu., Khrustov I.A. – The geographical links of birds of the limnophilic complex in the Saratov region and adjacent territories have been analyzed. Basic ecologo-epidemiological and seasonal features of the bird influenza A (H5N1) virus circulation are summarized. The domination of limnophilic bird species in the nesting and post-nesting periods in left-bank districts of the Saratov region has been established. An increase of the role of near migrants in bringing the bird influenza A (H5N1) virus to the territory of the northern Lower-Volga region is noted. A high probability of formation of secondary centers of the bird influenza A (H5N1) in the Saratov Trans-Volga region is substantiated.
Key words: birds, influenza A virus, epizootia, migratory paths, Saratov region.
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Ecological analysis of cestodes (Cestoda) of murine rodents in the Samarskaya Luka. – Kirillova N.Ju., Kirillov þ.þ. – 14 cestode species in 9 micromammalian species were registered in the course of our 2000 – 2004 survey of the helminthofauna of murine rodents in the Samarskaya Luka. The specific variety of the cestodes of separate rodent species in several areas of the survey is analyzed. The influence of some cestode biology features and the ecology of their hosts on the tape-worm invasion in murine rodents is considered.
Key words: cestodes, muride rodents, Samarskaya Luka, Samara region.
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Cenopopulation dynamics of trees and bushes of the forest-steppe complex of Volga Height. – Kudriavtsev A.Yu. – Data on the structure and dynamics of the forest-steppe complex ecosystems are given. A succession resulting in formation of a Padus avium Mill. forest is considered as an example. Changes during succession of the density and vitality level of five tree and shrub species predominated at various stages of succession are described.
Key words: forest-steppe complex, succession, population, density, vitality level.
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Testate amoebae community structure in the Naskaftym sphagnum bog (Middle-Volga Region). – Mazei Yu.A., Bubnova O.A. – The community structure of testate amoebae from the sphagnum bog Naskaftym in the Middle-Volga region was investigated. 39 testate amoebae species were identified. There are three community types within the bog. In the most wet biotopes Phryganella hemisphaerica, Arcella arenaria, Centropyxis aculeata, Difflugia parva, and Difflugia pristis predominate, in the driest biotopes Arcella arenaria, Assulina muscorum, and Archerella flavum prevail, and in the intermediate conditions a species complex consisted of Nebela tincta major with several subdominant species (Arcella arenaria, Centropyxis aculeata, and Phryganella hemisphaerica) is formed. In the driest conditions the community is characterized by the lowest species richness and diversity. The Naskaftym sphagnum bog is a young boggy ecosystem at the earlier lake-to-bog successional stage. Peculiarities of the testate amoebae species composition are represented by the lack of such specific sphagnobiont genera as Hyalosphenia, Archerella, and Heleopera as well as predomination of eurybionts (Arcella arenaria, Phryganella hemisphaerica, Assulina muscorum) and detritophilous species specific to lake sediments (Centropyxis spp., Difflugia spp.).
Key words: testate amoebae, community structure, sphagnum bogs, Penza region, Russia.
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On helminths of common spadefoot toad – Pelobates fuscus (the eastern form) in flood-lands of some rivers in Middle and Lower-Volga region. – Ruchin A.B., Chikhlyaev I.V., Lukiyanov S.V., Ryzhov M.K. – Our 1998 – 2002, 2004 – 2006 surveys of the helminthofauna of common spadefoot toad (the eastern form) are reported. The helminthofauna of this species is mainly formed by the larval forms of trematodes. The adult forms of helminths are represented by both trematodes and nematodes. Those species of nematodes whose development is associated with land are most widely-distributed, which reflects the terraneous life mode of the host in the conditions of dry biotops.
Key words: Pelobates fuscus, Nematoda, Trematoda.
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Railway embankment flora in the southern Volga Height. – Skvortsova I.V., Berezutski M.A. – 574 species of vascular plants have been found on railway embankments in the southern part of the Volga Height (within the Saratov region). The role of the Asteraceae and Rosaceae families in the taxonomic spectrum of the flora under survey is increased while that of Cyperaceae is reduced in comparison with the regional flora. An increased contribution of species with a short life cycle and wood species is characteristic of the biomorphological spectrum. Of the ecocenotic species groups, weed, steppe and forest-edge plants predominate. Populations of some protected plants (Chartolepis intermedia, Astragalus cornutus, Glycyrrhiza glabra, Iris halophila, Stipa pennata, Adonis wolgensis, Dodartia orientalis etc.) have been revealed on the enbankments.
Key words: vascular plants, railway embankment, Volga Height, Saratov region.
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Snout beetle acarofauna (Coleoptera, Curculionoidea). – Ermilov S.G., Mokrousov M.V., Dmitrieva I.N. – Data on the fauna of acariform mites (Acariformes) using snout beetles as carriers are reported for the first time in Russia. 18 species, 14 genera, 6 families, and 3 suborders have been revealed. Representatives of genus Scwiebea were the most mass species of mites on snout beetles.
Key words: acarofauna, mites, snout beetles, phoresy.
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Dynamics of ecologo-toxicological influence of hydrogen sulfide on animals under EHF electromagnetic radiation. – Rogacheva S.M., Denisova S.A., Shantrokha A.V., Somov A.Yu., Kuznetsov P.E. – The ecologo-toxicological influence of hydrogen sulfide upon animals under the action of electromagnetic radiation was studied. The lethal doze of irradiated gas for laboratory rats was found to increase by 1.7 – 1.9 times. The toxicity reduction of hydrogen sulfide is influenced by the parameters of radiation. The maximum effect was rendered by radiation with frequencies of 167 and 303 GHz and energy flux densities of 6 and 240 μW/cm2, respectively.
Key words: laboratory animals, hydrogen sulfide, electromagnetic radiation, lethal concentration.
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