中国云南洱海周边小兽体表恙螨多样性

摘要

本文运用shnnon-wiener,系统聚类分析方法(SPSS 13.O软件)和Levins niche等对云南大理洱海周边3 303头小兽体表寄生恙螨的物种多样性、群落结构、相似性、分布和生态位进行研究.调查点位于我国11大鼠疫自然疫源地之一,此地也是我国恙虫病和流行性出血热的流行地区.选择的洱海周边3个不同方位恰好处于东部无量山、南部哀老山和西部苍山,由于洱海的天然隔离使这3个方位形成了同地域(经度、纬度、海拔和动物地理区划相同)异生境的地理景观.从洱海的3个方位共计诱捕小兽3 303头,分类鉴定为4目,7科,15属,21种.从小兽体表共计检获56 895头恙螨.分类鉴定为3亚科,13属,109种.恙螨的丰富度、分布和物种多样性随着宿主和生境的不同而存在着显著的差异.恙螨只有幼虫寄生,强烈受到环境(温度、降雨量和生境)的影响.恙螨的宿主特异性很低,恙螨的群落相似性大小与宿主小兽之间的近缘性高低呈现较低的关联度.结果提示,大部分的宿主小兽和恙螨之间协同进化程度不高;恙螨的这些特征从流行病学的角度来看,恙螨作为医学媒介生物在宿主之间传播疾病的潜能较大.%The aim of the present study was to study the species diversity,community structure,simolanty,distribution and niche of chigger mites on the body surface of 3 303 sinail mammals in the surrounding areas ol Erhai Lake in Dali,Yunnan by using Shannon-Wiener,hierarchical cluster analysis (SPSS 13.0) and Levins'niche.The investigated site was located in the wild rodent-type plague focus,one of 11 known plague foci in China and also an important focus of both tsutsugamushi disease and epidemic hemorrhagic fever (EHF),where stand alongside three cordilleras surrounding the Erhai Lake, namely Eastern Wuliang Mountain, Southern Ailao Mountain and Western Cangshan Mountain.The three confined oriented areas with different landscapes are within the same zone with similar longitude,latitude,altitude and zoological location,which forms an inartificial barrier's isolation by Erhai Lake.A total of 3 303 small mammal hosts were captured from the three differently oriented areas belonging to 7 families,15 genem and 21 species in 4 orders (Rodentia,Insectivora,Seandentia and Carnivora),56 895 individuals of chigger mites collected from the body surface of the small mammal hosts were identified as 3 subfamilies,13 genera and 109 species.The abundance,distribution and diversity of chigger mites vary among different populations ot host species and habitats.Chigger mites spent a considerable time off hosts (only the larvae are ectoparasites) and so are strongly affected by the off-host environment (temperature,precipitation and habitat).Host-specificity of chigger mites is very low,the similarity of chigger mite communities is not highly consistent with the affinity of small mammal hosts in taxonomv and this implies that the co-evolution between sinail mammals and chigger mites has not reached a high degree,and the above ecological characteristics of chigger mites might strengthen the chigger mites'potential ability of transmitting some mites born diseases among different small mammal hosts.