Balashov Iu S, Bochkov A V, Vashchenok V S, Grigor'eva L A, Staniukovich M K, Tret'iakov K A
Parazitologiia. 2007 Sep-Oct;41(5):329-47.
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.
该论文报道了在伊尔门 - 沃尔霍夫低地（诺夫哥罗德地区）南部泰加林和库尔戈洛夫斯基保护区（列宁格勒地区）对啮齿动物和食虫动物体外寄生虫进行的为期八年的调查结果。共捕获了12种小型哺乳动物，其中包括3种优势物种——棕背䶄（2722只标本）、普通鼩鼱（1658只标本）和林姬鼠（367只标本）。棕背䶄的寄生虫群落包括34种螨、蜱和昆虫，普通鼩鼱的群落有25种，林姬鼠的群落包含28种。研究表明，体外寄生虫群落的分类多样性基于寄生类型的多样性和宿主身体的生态位。永久性体外寄生虫有2种虱和14种蜱螨亚纲螨类。临时性寄生虫包括13种跳蚤、10种革螨、3种硬蜱和1种恙螨。在泰加林生态系统中存在小型哺乳动物临时性寄生虫的共同库。不同鼩鼱和啮齿动物物种作为宿主的重要性取决于潜在宿主的种群密度以及许多其他因素。不同小型哺乳动物物种寄生虫群落的物种多样性取决于宿主体内可能的生态位数量。体外寄生虫对这些生态位的实际占据通常低于潜在占据。临时性寄生虫的物种组成、出现情况和丰度会随季节变化。由于种群高峰期的季节性错开，临时性寄生虫物种间的种间竞争可能会减少。体外寄生虫生态位的多样化使得在一个宿主上同时取食的寄生虫个体比寄生单一物种或几种具有相似生态位的物种时更多。还研究了寄生虫在宿主上的分布。仅在硬蜱幼虫中发现了聚集分布，跳蚤的分布接近泊松分布。偏离聚集分布可能是多种独立因素的结果，包括小型哺乳动物为众多寄生虫提供食物的能力有限。在大多数宿主上，每种蜱、螨和跳蚤物种同时寄生的个体不超过1 - 3只。体外寄生虫的过度侵染可能会受到哺乳动物宿主自我净化有效反应的限制。
