【作者】 左小华；

【导师】 郭宪国；

【作者基本信息】 大理学院 ， 病原生物学， 2011， 硕士

【摘要】 目的：(1)对比研究小型哺乳动物(小兽)体表寄生蚤虱昆虫(蚤类与吸虱)的宿主选择范围、营养生态位宽度、生态位重叠和生态位分离的异同,综合评判不同蚤种和不同虱种的宿主特异性高低和生态分化情况；(2)预测代表性小兽体表蚤虱昆虫感染率。材料与方法：(1)原始数据资料来源于1997～2009年13年间对云南省境内23个县(市)的现场抽样调查；(2)运用构成比(Cr)、物种丰富度(S)、Levins生态位宽度指数,结合对应分析,综合分析主要蚤虱昆虫的宿主特异性；运用Pianka生态位重叠指数,结合聚类分析,进行生态位重叠群划分；(3)选择褐家鼠体表蚤虱昆虫为研究对象,运用流行病模型,预测蚤虱昆虫的感染率。结果：(1)共捕获小兽15082头,分类鉴定为5目(啮齿目、食虫目、攀鼩目、兔形目、食肉目)10科35属65种。从捕获的小兽体表共采集到蚤12264只,经分类鉴定,隶属于6科26属51种(包括待定1种)；共采集吸虱38885只,经分类鉴定隶属5科7属31种；(2)大部分蚤种比吸虱的宿主范围、生态位宽度和生态位重叠值较大。基于主要蚤虱昆虫生态位重叠指数的系统聚类表明,12种吸虱在λ=15.0的位置被分成8个生态位重叠群,但蚤只被分成4个生态位叠群；(3)吸虱和其宿主存在“一对一”的稳定寄生关系(种特异性、属特异性和科特异性均较高),但蚤类的宿主特异性明显低于吸虱；(4)褐家鼠体表蚤虱昆虫实测感染率和预测感染率之间存在较高的线性相关,拟合优度较高。结论：(1)吸虱昆虫是一类宿主特异性很高的体表寄生虫。在宿主选择上,吸虱昆虫存在明显的生态位分离。特定吸虱种类与特定小兽宿主之间往往存在“一对一”的稳定对应寄生关系,吸虱昆虫与小兽宿主之间的协同进化程度较高。(2)与吸虱昆虫相比较,蚤类昆虫的宿主特异性较低且因具体蚤种的不同而存在较大差异。在宿主选择上,不同蚤种之间大多存在程度不同的生态位重叠,生态位分离不明显。蚤类昆虫与小兽宿主之间虽然存在一定的协同进化关系,但整体协同进化程度明显低于吸虱昆虫。(3)宿主选择范围较窄、与小兽宿主间协同进化程度很高的吸虱昆虫高度特化,宿主特异性很高,其在不同宿主动物间传播疾病的媒介潜能明显下降。宿主选择范围较宽、与小兽宿主间协同进化程度较低的蚤类昆虫,宿主特异性较低,其在不同宿主动物间传播疾病的媒介潜能较高。这是蚤类能够在不同动物宿主之间(如：鼠-鼠之间)以及在动物宿主和人之间(鼠-人之间)传播诸如鼠疫和鼠源性斑疹伤寒(地方性斑疹伤寒)等人兽共患病的基本原因。(4)褐家鼠体表蚤虱昆虫的感染率可以通过平均多度M来对所研究的蚤虱昆虫感染率进行预测。更多还原

【Abstract】 Objectives:(1) To comparatively study the ectoparasitic fleas and sucking lice on small mammals in Yunnan Province, which covered the host range, niche breadth and niche overlap; (2) To predict the prevalence of ectoparasitic fleas and sucking lice on some typical hosts by a certain epidemiological model.Materials and Methods:(1) The original data came from the field investigation in 23 locations of Yunnan Province from 1997 to 2009; (2) The constituent ratio (Cr), species richness (S), Levins’niche breadth and correspondence analysis were used to measure the host specificity. Based on Pianka’s niche overlap of the dominant insect species, hierarchical cluster analysis was used to classify the niche overlapping groups, which reflect the host resource utilizations by corresponding ectoparasitic insects, fleas or sucking lice; (3) Taylor’s power law indicating aggregation patterns, which based on mean abundance and variance of abundance, was used to predict the prevalence of both categories of insects, fleas and sucking lice, on a species of rat host, Rattus norvegicus.Results:(1) A total of 15 082 individuals of small mammals were captured and identified as five orders (Rodentia, Insectivora, Scandentia, Lagomorpha and Carnivora),10 families,35 genera and 65 species. From the body surface of small mammalian hosts,12 264 individuals of fleas were collected, which represents 6 families,26 genera and 51 species, and 38 885 individuals of sucking lice representing 5 families,7 genera and 31 species; (2) Most species of fleas have the high values of host range, niche breadth and niche overlap in comparison with sucking lice. Based on niche overlap, sucking louse species’resource utilization were sorted into 8 niche overlapping groups atλ= 15, whereas fleas were sorted into 4 groups; (3) Most species of sucking lice usually showed a higher host specificity at different taxonomic levels (species level, genus level and family level), and a certain species of sucking louse usually choose one or few small mammalian species as their dominant hosts, whereas fleas have a lower host specificity; (4) A highly linear correlation existed between the observed prevalence and predicted prevalence, a modeling efficiency of predicted prevalence against observed prevalence was successfully obtained with a high fitting goodness.Conclusions:(1) Ectoparasitic sucking lice have a higher degree of host specificity, and a prominent niche separation exists in the host selection of sucking lice. Sucking lice have a higher level of coevolution with their small mammal hosts since a certain species of sucking louse usually choose one or few small mammalian species as their dominant hosts; (2) In comparison with sucking lice, fleas have a lower degree of host specificity that varies among parasite species. Although most species of fleas exist niche overlap in the host selection of fleas, fleas have a lower level of coevolution with their small mammal hosts than sucking lice; (3) Vector-borne Diseases transmission between different hosts could be reduced by narrow host range, high degree of coevolution between sucking lice and their small mammalian host, and high host specificity, whereas viceversa increased vector-borne diseases transmission. This is the basic factor of fleas as vectors of zoonoses diseases (plague and endemic typhus, etc.) transmission between different animal hosts, and animal host to human host; (4) The prevalence of both fleas and sucking lice on Rattus norvegicus can be expected by an epidemiological model based on their mean abundance.更多还原