云南省16县(市)大绒鼠体表寄生恙螨调查

Investigation of Chigger Mites on the Rat Eothenomys miletus in Yunnan

目的了解云南省大绒鼠体表寄生恙螨的种类、空间分布情况、优势种及其种间关系。方法选取2000～2004年云南省16县(市)现场用鼠笼加食饵诱捕大绒鼠,收集耳壳及耳窝部所有恙螨,进行分类和鉴定。恙螨种间关系与种群的空间分布格局分别用协调系数(V)和聚块指数(m*/m)判定。结果捕获大绒鼠1157只。收集恙螨37613只,隶属3亚科9属80种。大绒鼠总带螨率(68.2%)和总螨指数(32.5)较高,其中小板纤恙螨、中华纤恙螨、西盟合轮恙螨、绒鼠纤恙螨、枪棒爬虫恙螨、寒冬纤恙螨6种恙螨为优势种,在不同大绒鼠个体之间呈聚集型分布;优势恙螨之间存在正协调和负协调关系。结论大绒鼠体表恙螨种类繁多、数量大、物种多样性高,主要恙螨在大绒鼠体表的寄生有聚集性。

Objective To understand the species, species distribution, the dominant species and their interspecies interaction of chigger mites on Eothenomys miletus（a dominant species of rats） in Yunnan. Method The rats were captured with mouse traps in 16 counties （or cities） during 2000-2004. All mites on the surface of two auricles of the hosts were collected and identified. The patch index （m^＊/m） and the coefficient of association （V） were adopted to judge the spatial distribution patterns and interspecies interaction of the dominant chigger mite species among different individuals of the rats （E. miletus）. Results 1157 individuals of E. miletus were captured from 16 counties （citys）. 37613 chigger mites （belonging to 3 subfamily, 9 genus and 80 species） were collected from the auricles （body surface） of 1157 rat hosts with a high “overall mite infestation rate” （68.2%） and “overall mite index” （32.5）. Six species of mites were found dominant on E. miletus： Leptotrombidium scutellare, Leptotrombidium sinicum, Helenicula simena, Leptotrombidium eothenomydis, Herpetacarus hastoclavus and Leptotrombidium hiemalis. The distribution of the chigger mites among different individuals of E.miletus showed an aggregation pattern. Both positive and negative association existed between each two dominant species of chigger mites. Conclusion The species composition of chigger mites on Eothenomys miletus is complex with abundant individuals, which reflects a high species diversity of the mites. The main species of chigger mites tend to an aggregation on the body surface of E. miletus.