云南省19个县(市)印度囊棒恙螨的分布调查

Distribution of Ascoschoengastia indica in 19 counties of Yunnan province

目的探讨云南省印度囊棒恙螨在不同宿主、不同地域及其不同生境的分布情况。方法选择云南省19个县(市)进行现场调查,用鼠笼加食饵诱捕小兽,收集其双侧耳廓和外耳道的恙螨幼虫,用Hoyer's液封片后在显微镜下逐一分类鉴定到种。统计不同恙螨种类、构成比及其在对应寄生宿主的染螨率和螨指数,分析其在不同宿主体表和不同地域、生境的分布情况。结果调查19个县(市)共采集到印度囊棒恙螨1267只,占采集到所有恙螨的1.36%;相对于云南省其它主要恙螨种,印度囊棒恙螨宿主特异性高,仅在7种3224只小兽体表有分布,且94.40%寄生在黄胸鼠体表。从地域分布来看,19个县(市)中6个县(市)有印度囊棒恙螨分布,主要集中在云南省南部和中西部。从生境来看,印度囊棒恙螨喜活动于坝区的房屋周围生境。结论印度囊棒恙螨分布于云南省南部和中西部的坝区房屋周围生境,且集中寄生于黄胸鼠(恙虫病主要宿主动物)体表。

Objective To determine the host selection and distribution of Ascoschoengastia indica on different small mammal hosts in different areas of Yunnan province. Methods A field survey was carried out in 19 counties of Yunnan province. The small mammal hosts were captured with mice cages and traps with baits. The chigger mites on the surface of two auricles were scraped off by a bistoury and then preserved in 70% ethanol. Species of each specimen of the chigger mites was identified using microscopy. Conventional statistical methods were adopted to calculate the constituent ratios of A. indica on different hosts and in different areas, together with its prevalence and mean abundance on different hosts. Results A total of 1267 individuals of A. indica （1.36% of the total chigger mite species） were collected from the body surface of 3224 individual small mammal hosts of 7 species. The host specificity of A. indica was relatively high compared to that of other species of chigger mites, of which 94.40% were collected from the body surface of Rattus tanezumi. Conclusion The A. indica species are mainly distributed in southern and midwestern Yunnan with a high abundance, mostly on the body surface of R. tanezumi, a major reservoir host of tsutsugamushi disease.