目的 了解北京市朝阳区三带喙库蚊的分布和季节消长规律。方法 参考《病媒生物密度监测方法 蚊虫》(GB/T 23797-2009),于2014年8-9月采用CO₂诱蚊灯捕获成蚊;分布调查按地域选取调查点,包括公园(绿地)和居民区2种环境类型;2014年5-10月,于固定地点进行季节消长调查,每旬监测1次。结果 在二环至三环、三环至四环、四环至五环和五环以外调查点捕获三带喙库蚊的比例分别为1/2、3/3、4/8和3/6,不同环路间差异无统计学意义(P=0.570);捕获到三带喙库蚊有水体的公园(或绿地)占76.92%(10/13),居民区占16.67%(1/6),两者的阳性率差异有统计学意义(P=0.020);二环至三环、三环至四环、四环至五环和五环外调查点三带喙库蚊密度分别为0.09、0.16、0.31和4.97只/(灯·h);调查点三带喙库蚊密度的平均数(m)为1.56,方差(S²)为24.03,S²/m=15.42,朝阳区三带喙库蚊种群空间格局呈成群分布型;7月中下旬开始捕获三带喙库蚊,此后占捕获蚊种的构成比先增高后降低,9月出现密度高峰。结论 随着水生态恢复与涵养,北京市朝阳区的三带喙库蚊呈现由郊区向城区渗透的迹象,在城区成群分布,需警惕流行性乙型脑炎传播风险,加强防控工作。

Objective To understand distribution and seasonality of Culex tritaeniorhynchus in Chaoyang district, Beijing. Methods According to the Surveillance Methods for Vector Density-Mosquito (GB/T 23797-2009), mosquitoes were collected by the CO₂ traps. To determine the spatial distribution, the two types of sampling sites including park (or green spaces) with waters and human populated area were chosen in different geographical locations, and mosquitoes were trapped from August to September. To find out the seasonality, the mosquitoes were trapped per ten days from May to October in the same place. Results The proportions of sampling sites with Cx. tritaeniorhynchus between 2^nd Ring Road and 3^rd Ring Road, 3^rd Ring Road and 4^th Ring Road, 4^th Ring Road and 5^th Ring Road, outside 5^th Ring Road were 1/2, 3/3, 4/8 and 3/6 respectively, and there were no statistically different in different area subdivided by ring road (P=0.570); the proportions of sampling sites with Cx. tritaeniorhynchus of parks (or green spaces) with waters and human populated areas were 76.92% (10/13) and 16.67% (1/6) respectively, and were statistically different (P=0.020); the Cx. tritaeniorhynchus densities between 2^nd Ring Road and 3^rd Ring Road, 3^rd Ring Road and 4^th Ring Road, 4^th Ring Road and 5^th Ring Road, outside 5^th Ring Road were 0.09, 0.16, 0.31 and 4.97 mosquitoes per trap-hour respectively; the mean (m) and variance (S²) of densities of Cx. tritaeniorhynchus were 1.56 and 24.03, S²/m=15.42>1, which suggested that Cx. tritaeniorhynchus clumped distributed; the first appearance of Cx. tritaeniorhynchus was in the last twenty days of July, then its constituent ratio showed a trend from rise to decline and the peak period of its density was in September. Conclusion Culex tritaeniorhynchus tends to spread from suburb to city with the improvement of water conversation, and clumped distributed in urban area of Chaoyang district. Vigilance is needed to the epidemic risk of Japanese encephalitis, and public health department should strengthen the prevention and control measures.