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.

Investigation and analysis of chigger mites on Apodemus chevrieri in Yunnan Province

Objective To investigate and analyze the infestation status of chigger mites on a single rodent species,Apodemus chevrieri.Methods The field investigation was done in 25 counties of Yunnan Province.Food bait was placed in mouse traps to prey on A.chevrieri.The parasitic chigger mites on the body surface of the animals were collected,and then mounted on slides with Hoyer＇s medium,classified,and identified under a microscope.Some conventional statistical methods were used in the analysis of chigger mites on the rat （A.chevrieri）,including constituent ratio,rate of mite infestation,mean abundance,mean intensity,species richness and Shannon-Wiener＇s index.The spatial distribution indices were used to determine the spatial pattern of the dominate chigger mites among different individuals of the host （A.chevrieri）.Preston＇s lognormal model was used to describe the species-abundance distribution of chigger mite communities on A.chevrieri.Based on the species-abundance distribution,the total species number of chigger mites was estimated.Results From the body surface of 1 620 individual rats （A.chevrieri）,8 038 individuals of chigger mite were collected,which were identified to comprise 88 species in 11 genera of 3 subfamilies （including 7 unidentified species）.The overall rate of mite infestation and mean abundance of chigger mites from all the rats were 28.83% and 4.93 （mites/per examined rat） respectively.A linear correlation existed between rate of mite infestation and mean abundance with the correlation coefficient r =0.87.Of the collected 88 species of chigger mites,five species were determined as the dominant species.The constituent ratio of the main dominant species of chigger mites,Leptotrombidium scutellare,reached 27.05%.All the dominant species of chigger mites showed an aggregated distribution among different individuals of A.chevrieri.The species-abundance distribution of chigger mite communities was successfully fitted to Preston＇s lognormal model （R2=0.89）.The total number of chigger mite species was approximately estimated as 110 species,and therefore about 22 species were missed in the sampling process.Conclusions As a single rodent species,A.chevrieri has a great potential to harbor abundant chigger mites with high species diversity in Yunnan Province of China.L.scutellare is the main mite species on A.chevrieri.A large host sample is recommended in the future field investigation in order to find more mite species.