[Ultrafine structure of salivary glands of the chicken mite Dermanyssus gallinae (Acarina, Gamasina, Dermanyssidae)].

Using the method of transmission electron microscopy, structure of salivary glands of the chicken mite Dermanyssus gallinae (De Geer, 1778) is studied. Structure of the glands and of their ducts is described. The cellular composition, ultrastructural characteristics of secretion, and peculiarities of its release from cells are revealed.

[Structure of populations and ecological nishes of ectoparasites in the parasite communities of small forest mammals].

The paper reports the results of eight-year investigations on the ectoparasites of rodents and insectivores carried out in southern taiga of the Ilmen-Volkhov lowland (Novgorod Region) and Kurgolovsky reserve (Leningrad Region). Twelve species of small mammals were captured including three dominate species--bank vole Clethrionomys glareolus (2722 specimens), common shrew Sorex araneus (1658 specimens), and wood mouse Apodemus uralensis (367 specimens). Parasite community of the bank vole comprises 34 species of mites, ticks, and insects, the community of common shrew comprises 25 species, and the community of A. uralensis includes 28 species. Taxonomic diversity of the ectoparasite communities was shown to be based on the diversity of types of parasitism and ecological nishes of the host body. Permanent ectoparasites are found to be represented by 2 species of lie and 14 species of acariform mites. The group of temporary parasites includes 13 species of fleas, 10 species of gamasid mites. 3 ixodid species and 1 Trombiculidae. There is a common pool of temporary parasites of small mammals in the ecological system of taiga. Significance of different shrew and rodent species as hosts were found to be dependent on the population density in possible hosts and many other factors. Species diversity in the parasite communities of different small mammal species is dependent on the number of possible ecological nishes in the host body. Actual infill of these nishes by ectoparasites is usually lesser than potential one. Species composition of temporary parasites, their occurrence and abundance changes according to season. Interspecific competition in the temporary parasite species can decrease because of the seasonal disjunction of their population peaks. Diversification of the ecological niches of ectoparasites allow simultaneous feeding of more parasite individuals on one host, than in the case of parasitising of single species or several species with similar ecological nishes. The distribution of parasites on their hosts was also studied. The aggregative distribution has been found in ixodid larvae only, and the distribution of fleas was close to the Poisson distribution. Deviations from the aggregative distribution can be an effect of several independent factors, including limited ability of small mammals for providing numerous parasites with food. On the most part of hosts simultaneous parasitizing of no more than 1-3 individuals of each tick, mite, and flea species was registered. Excessive infestation by ectoparasites may probably be limited by effective reactions of self-purification in the mammal hosts.

[New species of mites of the genus Ptilonyssus (Gamasina: Rhinonyssidae) isolated from Passeriformes (Aves: Passeriformes) from Russia and neighboring countries]. / Novye vidy kleshchei roda Ptilonyssus (Gamasina: Rhinonyssidae) iz vorob'inykh (Aves: Passeriformes) Rossii i sopredel'nykh stran.

Eight new species of the genus Ptilonyssus (Berl. et Troues.) (Gamasina: Rhinonyssidae) from nasal cavities of the passeriformes from territory of the former USSR are described: P. ammomani sp. n. from Ammomanus deserti (Alaudidae) collected in Turkmenistan; P. spini sp. n. from Spinus spinus (Fringillidae) of Kaliningrad district (Russia); P. ripariae sp. n. from Riparia riparia (Hirundinidae) and P. acanthopneustes sp. n. from Phylloscopus borealis (Sylviidae) collected in Tjumen district (Russia); P. pyrrhulinus sp. n. from Pyrrhula pyrrhula (Fringillidae) and P. anthi sp. n. from Anthus trivialis (Motacillidae) of Rjazan district; P. sylviicola sp. n. from Sylviae communis (Sylviidae) collected in Tatarstan; P. cyanosylviae sp. n. from Cyanosylvia svecica (Turdidae) collected from Novosibirsk district.

[Comparative study of the sensory system in gamasid mites Rhinonyssus rhinolethrum, Rh. subrhinolethrum and Ptilonyssus motacillae (Mesostigmata: Gamasina: Rhinonyssidae), parasites in the nasal cavity of birds]. / Sravnitel'noe issledovanie sensornoi sistemy gamazovykh kleshchei Rhinoyssus rhinolethrum, Rh. subrhinolethrum i Ptilonyssus motacillae (Mesostigmata: Gamasina: Rhinonyssidae), parazitov nosovoi polosti ptits.

Sensillae of the tarsal receptor complex, palpal organ, and body chaetom were examined by means of scanning electron microscopy in three endoparasitic gamasid mites: Rhinonyssus rhinolethrum, Rh. subrhinolethrum and Ptilonyssus motacillae, the parasites of Anser albifrons, Anas crecca, and Motacilla alba, respectively. In the tarsal sensory complex, the scale of reduction of the olfactory sensilla reflects the adaptation of gamasid mites to cavernous parasitism. The topography of this sensilla is specific at generic and species taxonomic levels. In the palpal sensory organ, the number and scale of reduction of two main sensilla types depend on peculiarities of places of blood-sucking.

[Structure of subepidermal tissue of gamasid mites (electron microscopy data)]. / Stroenie subépidermal'noi tkani gamazovykh kleshchei po dannym élektronnoi mikroskopii.

Fine structure of the subepidermal tissue was investigated in the adult predatory mite Hypoaspis miles (Gamasina: Laelapidae) and bloodsucking mite Dermanyssus gallinae (Gamasinae: Dermanyssidae) of both sexes. This tissue is analogous to the fat body of other arthropodes. The subepidermal tissue of females consists of two types of cells: cells containing a synthetic apparatus and secretory granules; cells containing storage substances. In the subepidermal tissue of H. miles, cells being similar to hemocytes were also observed. As the males of both species have only one cell type in this tissue--the storage one and the females have the secretory cells, it is suggested that the subepidermal tissue of females could probably take part in the vitellogenesis.

[New species of the Rhinonyssid mites (Gamasina: Rhinonyssidae) from birds of Russia and neighboring countries]. / Novye vidy kleshchei-rinonissid (Gamasina: Rhinonyssidae) ptits Rossii i sopredel'nykh stran.

Four new species of the nasal mite family Rhinonyssidae collected in different regions of the former USSR are described: Neonyssus (Otocorinyssus) alaudae sp. n. from Alauda arvensis L. (Alaudidae, Passeriformes) from Turkmenistan; Rhinonyssus clangulae sp. n. from Clangula hyemalis (L.) (Anatidae, Anseriformes) from Yakutia; R. marilae sp. n. from Aythya marilae L. (Anatidae, Anseriformes) from the Russian Far East; Locustellonyssus sibiricus sp. n. from Locustella certhiola (Pall.) (Sylviidae, Passeriformes) from Siberia.