云南省部分地区微红纤恙螨的分布及宿主选择

目的探讨云南省部分地区微红纤恙螨的分布和宿主选择情况。方法根据云南省不同地理方位、地形、地貌、气候与生态等特点,于2001-2011年选取23个县(市)为野外调查点,用鼠笼(夹)加食饵诱捕小型哺乳动物(小兽)宿主。选择小兽的双侧耳廓和外耳道采集恙螨幼虫,用Hoyer’S液常规封片后在显微镜下逐一鉴定螨种。统计微红纤恙螨在不同地域、不同景观和不同宿主小兽体表的分布情况。计算微红纤恙螨在不同宿主小兽体表的感染率(P)、平均多度(MA)和感染度(MI)并分析三者间的线性关系,用聚块指数(m*m)测定其在宿主不同个体间的空间分布格局。结果23个县(市)中有4个县(市)采集到微红纤恙螨(共654只,占所有恙螨的0．603%)。96．637%的微红纤恙螨采自坝区地理景观(尤其是较低海拔地区),只有3．363%的微红纤恙螨采自山区景观。宿主大类选择显示,采自啮齿目(鼠类)、食虫目(嗣鼯)和攀鼢目(树鼢)小兽体表的微红纤恙螨分别为96．296%、2．469%和1．235%,而兔形目等小兽体表未采集到。宿主种类选择显示,所捕获的5目12科34属67种小兽中,有7种小兽采集到微红纤恙螨,其中96．788%采自黄胸鼠(P=3．776%,MI=8．792只螨/鼠),其次是板齿鼠。聚块指数显示,微红纤恙螨在大多数宿主小兽不同个体问的分布呈聚集分布格局。结论云南省存在微红纤恙螨,但是数量较少。其主要分布在海拔较低的坝区,寄生多种小兽宿主,宿主特异性低,但主要倾向于寄生在黄胸鼠等家栖小兽体表。     

Analysis of gamasid mites (Acari: Mesostigmata) associated with the Asian house rat, Rattus tanezumi (Rodentia: Muridae) in Yunnan Province, Southwest China

During a survey lasting from 1990 to 2008, we captured 4,113 Asian house rats, Rattus tanezumi Temminck 1844 (Rodentia: Muridae) from 28 counties of Yunnan Province in Southwestern China. From these rats, a total of 19,304 gamasid mites (Acari: Mesostigmata) were collected and identified as comprising 50 different species. The species diversity of gamasid mites from this single rat species is higher than that reported previously from multiple hosts within a given geographical region. Of the 50 mite species, 31 species belonged to ectoparasites and 19 species belonged to free-living mites. The species diversity of the mites from rats trapped outdoors was much higher than from rats trapped indoors. The parameter K from the negative binomial distribution was used to measure the spatial distribution patterns of the dominant mite species and revealed that all the mites had an aggregated distribution among the rat hosts. Most mite species showed a predominantly female-biased population structure with many more females than males.     

Ectoparasitic insects and mites on Yunnan red-backed voles (Eothenomys miletus) from a localized area in southwest China

Ectoparasitic insects and mites on Yunnan red-backed voles (Eothenomys miletus) in Dali prefecture, Yunnan Province, southwest China, were studied between 2003 and 2004. In total, 34,389 individuals of 86 species of ectoparasitic insects (seven species of fleas and five species of sucking lice) and mites (23 species of gamasid mites and 51 species of chigger mites) were collected from 916 individual hosts. The diversity of ectoparasites on this single rodent species in such a small area was much higher than in previous reports, which concerned more host species and greater geographical areas. The majority of the ectoparasites were chigger mites, which accounted for 59.3 % of the parasite species and 87.4 % of the individual parasites. Most voles harbored parasites with an overall prevalence (P) of 82.5 % and mean abundance (MA) of 37.5 parasites per host. The dispersion coefficient (C) and patchiness index (m*/m) were used to study the spatial patterns of the seven dominant parasite species, and all seven had aggregated distributions. The species abundance distribution of the ectoparasites on the vole was fitted by Preston’s lognormal distribution (R ²?=?0.82), and the total expected parasite species was estimated from this plot as 167 species. Yunnan red-backed voles harbor many ectoparasites as revealed by examination of a large host population. Future field investigations should sample large numbers of host individuals to assess ectoparasite populations.     

对云南省齐氏姬鼠体表恙螨的调查分析

目的 以齐氏姬鼠为对象,调查分析单一鼠种体表恙螨的寄生状况. 方法 选取云南省的25个县（市）作为现场调查点,在鼠笼内放置食饵诱捕齐氏姬鼠,收集其体表寄生的恙螨,用霍氏液封片、固定后在显微镜下对恙螨进行分类鉴定.对云南省齐氏姬鼠体表恙螨的构成比、染螨率、平均多度、感染度、物种丰富度指数、Shannon-Wiener多样性指数等指标进行统计分析.应用空间分布型指数测定优势恙螨在同一鼠种（齐氏姬鼠）不同个体之间的空间分布格局.用Preston对数正态模型研究单一鼠种（齐氏姬鼠）体表恙螨群落的种-多度分布情况,并在此基础上对群落内总物种数进行预测. 结果 从所捕获的1 620只齐氏姬鼠体表共采集到恙螨8 038只,分类鉴定出3亚科11属88种（包括7种待定种）,总染螨率为28.83％,平均多度为4.93只螨/鼠,二者之间存在直线正相关,相关系数r=0.87.在所采集的88种恙螨中,有5种优势恙螨,其中小板纤恙螨（Leptotrombidium scutellare）是最主要的优势恙螨,其构成比为27.05％.主要恙螨在齐氏姬鼠不同个体之间呈聚集型分布.齐氏姬鼠体表恙螨群落的种-多度分布服从Preston对数正态分布,理论曲线的拟合优度较高（R2=0.89）.在种-多度分布理论曲线拟合基础上,根据Preston总物种预测方法,初步推测出齐氏姬鼠体表恙螨的总物种数大约为110种,即：在目前的宿主样本数量（1 620只齐氏姬鼠）下,约有22种恙螨未采集到. 结论 云南省齐氏姬鼠体表寄生恙螨种类丰富,物种多样性较高.小板纤恙螨是云南省齐氏姬鼠体表最主要的优势恙螨.大样本研究在恙螨生态研究中十分重要.