Abstract:

Objective To determine the situation of Simuliids infected with mermithid nematode parasites and its infection rate of seasonal dynamic changes in Qingyan, Guizhou province. Methods From March 2013 to February 2014, larval blackflies were collected in Qingyan stream each month. The infection rates of mermithid nematodes were investigated and the seasonal changes were analyzed. Results There are Simulium (Wilhelmia) xingyiense Chen and Zhang, 1998 and Simulium (Simulium) wuzhishanense Chen, 2003 in Qingyan stream. Except 2013 October, the number of S. (S.) xingyiense larvae was collected more than S. (S.) wuzhishanense every month. Two kinds of Simuliids were the hosts of the mermithid. The green mermithid nematode infected S. (S.) xingyiense. But the white mermithid nematode infected S. (S.) wuzhishanense. The mermith infected 4.70% of 12 649 larvae of S. (S.) xingyiense, ranging from 1.26% to 21.57%. The mermith infected 20.84% of 3 694 larvae of S. (S.) wuzhishanense, ranging from 1.33% to 43.05%. The peak incidences in S. (S.) xingyiense occurred during the autumn. The peak incidences in S. (S.) xingyiense occurred during the winter. The parasitic rate of S. (S.) wuzhishanense is higher than S. (S.) xingyiense. Conclusion The infection rate of mermithid nematodes in simuliids changed with seasonal variations.

Key words: Simuliidae, Mermithid nematode, Infection rate, Season

摘要：

目的 了解贵州省青岩镇蚋类自然感染索科线虫状况及其感染率的季节性变化。方法 2013年3月至2014年2月,每月上旬在青岩古镇旁溪流中定点采集蚋类幼虫,调查线虫感染率,并分析季节性变化。结果 青岩地区主要存在兴义维蚋和五指山蚋2个蚋种。除2013年10月外,各月采集的兴义维蚋幼虫数量均高于五指山蚋。2种蚋均可被索科线虫感染,兴义维蚋感染青绿色索科线虫,五指山蚋感染白色索科线虫。全年共获取兴义维蚋幼虫12649条,平均寄生感染率为4.70%(595/12649),每月寄生感染率为1.26%~21.57%;五指山蚋幼虫3694条,平均寄生感染率为20.84%(770/3694),每月寄生感染率为1.33%~43.05%。兴义维蚋感染索科线虫高峰主要在秋季,而五指山蚋感染高峰在冬季;五指山蚋的索科线虫寄生率高于兴义维蚋。结论 贵州省青岩镇蚋类感染索科线虫的感染率随季节变化。

关键词: 蚋, 索科线虫, 感染率, 季节性动态变化