Structure of populations and ecological nishes of ectoparasites in the parasite communities of small forest mammals. P. 329-347.
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.
Morpho-cytogenetic characteristic of the mosquito Anopheles artemievi (Diptera: Culicidae), a malaria vector from the complex maculipennis. P. 348-363.
Detailed morphological analysis of all stages of the mosquito Anopheles artemievi Gordeev et al., 2005 is carried out. Characteristic traits that allow discriminating of An. artemievi and An. messeae Falleroni, 1926 in the area of joint occurrence of these two species are provided. Cytogenetic description of the polytene chromosomes from the nurse cells of ovaries is given. Differences of An. artemievi from previously studied species of the complex maculipennis by the structre of the polytene chromosomes from the nurse cells of ovaries are shown.
Species composition and ecological peculiarities of the mosquito genera Aedes and Anopheles (Diptera: Culicidae) in the Novgorod Region. P. 364-371.
Five mosquito species form the genera Aedes and Anopheles are found in the Novgorod Region as a result of eight-year investigation (1997—2004). The species Ae. rossicus is for the first time recorded in the Novgorod Region.
Investigation of the sensory organs on antennae of the horseflies Hybomitra bimaculata and Tabanus bovinus (Diptera: Tabanidae) by scanning electron microscope. P. 372-380.
Sensory organs on the antennae of the horseflies Hybomitra bimaculata Macq. and Tabanus bovinus Loew are represented by the same morphological types of sensilla. Never differences in the topographical distribution of the sensilla on antennae have been also found, which can be explained by the similarity of ecological and behavioural adaptations of these insects. First and second antennal segments are found to be supplied with tactile hairs and proprioceptors. Other antennal segments bear sensory organs of several morphological types. Short thin olfactory hairs are most numerous among them. They are present on all segments of the antennal flagellum and belong to two morphological types different by the hair length. In the upper parts of the antennal segments from third to seventh several sensilla trichoidea are present, which probably serve as tactile and taste receptors.
Component communities of parasites in the grayling Thymallus thymallus (L.) (Salmoniformes, Thymallidae) and the minnow Phoxinus phoxinus (L.) (Cypriniformes, Cyprinidae) from the Pechora River. P. 381-391.
Component communities of parasites of Thymallus thymallus and Phoxinus phoxinus are described. The communities differ in the number of species and in the number of dominate species, which is one in P. phoxinus and usually two in T. thymallus. In the first case the dominate species is allogenic, while in the second case dominate species are autogenic. Values of the species diversity indexes are also different for these communities. The differences between parasite communities of T. thymallus and P. phoxinus underline positions of these hosts in hydrobiocenose. Species specialists take first place in the parasite communities both of the hosts, that is characteristic for the parasite communities of the fishes from the boreal submountain faunistic complex. Parasite communities in both of the hosts consist of three groups of species discriminated by the ratio of their biomasses, that suggests forming of the groups by a coordination of the species biomasses.
Helminth fauna of the common shrew Sorex araneus L. (Soricidae) from Samarskaya Luka. P. 392-398.
Ecological analysis of the helminth fauna of common shrew Sorex araneus L. from Samarskaya Luka (Samara Region) has been carried out. Twenty-three helminth species are found including 3 species of trematodes, 8 cestodes, 10 nematodes, and 2 acanthocephales. Dependence of the structure of helminth fauna on the host age is revealed.
Relictolepis gen. n. — a new cestode genus (Cyclophyllidea: Hymenolepididae) from rodents of the Russian Far East the description of R. feodorovi sp. n. P. 399-405.
A new cestode genus and species Relictolepis feodorovi gen. et sp. n. having armed scolex is described ex Clethrionomis rufocanus Sundevall, 1846 (Rodentia, Microtinae) from the Russian Far East.
Cronicle. P. 406-407.
Summary is absent.