内蒙古自治区东部草原鼠体寄生恙螨调查

An investigation of chigger mites on rodents in the grasslands of eastern Inner Mongolia Autonomous Region,China

目的 调查内蒙古自治区(内蒙古)东部草原地区鼠体表寄生恙螨的种类构成及时空分布规律。方法 2021年5、7、9月在内蒙古东部锡林郭勒盟、呼伦贝尔市、通辽市牧区草原选择8个调查点,用鼠夹法和鼠笼法捕鼠,采集鼠体表寄生恙螨并制作标本,进行形态学分类鉴定。计算各调查点、月份和鼠种的体表携带恙螨率和恙螨指数,利用χ2检验分析差异性。结果 自672只鼠体标本捡获恙螨1 232只,隶属2科3属3种,分别为椭盾纤恙螨、鼠兔多毛恙螨和粗棒囊棒恙螨,椭盾纤恙螨占97.02%,为当地优势螨种。其寄生宿主以布氏田鼠、长爪沙鼠和黑线仓鼠为主。恙螨主要分布在呼伦贝尔市新巴尔虎右旗和锡林郭勒盟东乌珠穆沁旗2个调查点,5、7、9月均有恙螨分布且呈升高趋势。结论 内蒙古东部草原鼠体恙螨种类较少,优势恙螨种类分布广、时间长、宿主多样。

Objective To investigate the species composition and spatiotemporal distribution of chigger mites parasitized on the body surface of rodents in the grasslands of eastern Inner Mongolia Autonomous Region(Inner Mongolia), China. Methods The snap trap and cage trap methods were used to capture rodents in eight survey sites distributed in Xilin-Gol League, Hulun-Buir, and Tongliao of eastern Inner Mongolia in May, July, and September, 2021.Parasitic chiggers were collected from the body surface of the rodents. Then the specimens were made for morphological identification. The infestation rate(IR) and index of chigger mites(IC) were calculated for each survey site, month, and rodent species, and the statistical differences were analyzed using Chi-square test. Results A total of 1 232 chigger mites were collected from the bodies of 672 rodents, which belonged to three species of three genera of two families,namely, Leptotrombidium oblongatum, Multisetosa ochotonae, and Ascoschoengastia crassiclava. L. oblongatum was the dominant species, accounting for 97.02%. Their main hosts included Lasiopodomys brandtii, Meriones unguiculatus, and Cricetulus barabensis. These chigger mites were mainly distributed in two survey sites, i.e., New Barag Right Banner in Hulun-Buir and East Ujimqin Banner in Xilin-Gol League. They were active in May, July, and September, and showed an increasing trend with month. Conclusion There are few species of chigger mites on rodents in the grasslands of eastern Inner Mongolia. The dominant chigger species has a wide distribution, a long time of infestation, and diverse hosts.