Abstract: Objective To investigate the species composition, population density, and seasonal fluctuation of mosquitoes in human settlements and surrounding environments in Guizhou province, China, and to provide a basis for risk assessment of mosquito-borne diseases and scientific and effective vector control.Methods Mosquito surveillance data from 78 provincial vector surveillance sites in Guizhou province from 2017 to 2021 were collected to analyze mosquito species composition and compare mosquito population density and seasonal fluctuations in different years, regions, and habitats. SPSS 24.0 software was used to perform analysis of variance on the Breteau index (BI) and density of mosquitoes in different habitats for risk assessment.Results A total of 131 476 female mosquitoes were captured from 2017 to 2021, with a density of 5.82 mosquitoes/light·night. Culex pipiens quinquefasciatus accounted for the highest proportion with 43.34% of the total catches, followed by Anopheles sinensis with 20.68%. Cx. pipiens quinquefasciatus was the dominant mosquito species in most cities/prefectures. Zunyi had the highest composition ratio of Cx. pipiens quinquefasciatus with a total of 17 409 catches (61.32%). There was a statistical difference in mosquito density in different areas (F=5.276, P<0.001). From 2017 to 2021, the highest densities of mosquitoes were all in livestock sheds, and Cx. pipiens quinquefasciatus was the dominant mosquito species in all habitats. The density of mosquitoes was statistically different in different habitats (F=114.368, P<0.001). Adult mosquito density by light trapping increased gradually from May, peaked during June to August, and decreased rapidly from September. BI showed two obvious peaks in June and August, respectively. The BI began to rise rapidly in May, and gradually declined in September and October. The BI was greater than 5 for each year. The areas of level-1 risk included Anshun, Guiyang, and Qiandongnan Miao and Dong Autonomous Prefecture. The BI values in Anshun in 2019 and Guiyang in 2021 were both greater than 10, indicating a level-2 risk.Conclusions Cx. pipiens quinquefasciatus and An. sinensis are the dominant mosquito species in human settlements and surrounding environments in Guizhou province. The mosquito density is high in rural habitats, especially in livestock sheds, which are major mosquito breeding sites, and mosquito control should be strengthened in such environments. The peaks of mosquito activity in Guizhou province are in June and August, which may by closely related to the unique climate and rainfall conditions of Guizhou province. Mosquito control should be done before the peak breeding season of mosquitoes to reduce the density of mosquitoes and the risk of mosquito-borne virus transmission.

Key words: Mosquito, Population density, Seasonal fluctuation, Breteau index method

摘要： 目的 了解贵州省人居及周边环境蚊虫的种类构成、种群密度和季节消长规律,为蚊媒传染病的风险评估和病媒生物的科学有效防控提供依据。方法 收集整理2017－2021年贵州省78个病媒生物省级监测点的蚊虫数据,分析蚊虫的种类构成,比较不同年份、不同地区、不同生境蚊虫密度差异及季节消长规律。利用SPSS 24.0软件对不同生境布雷图指数（BI）和蚊密度进行方差分析,评估风险等级。结果 2017－2021年共捕获雌蚊131 476只,蚊密度平均为5.82只/（灯·夜）,其中致倦库蚊占比最高,达43.34%,其次是中华按蚊,占20.68%；大多数市（州）的优势蚊种均为致倦库蚊,其中致倦库蚊构成比最高的地区为遵义市,共捕获17 409只,占捕获总数的61.32%,不同地区蚊虫密度差异有统计学意义（F=5.276,P<0.001）；2017－2021年蚊密度最高的生境均为牲畜棚,各生境优势蚊种均为致倦库蚊,不同生境蚊密度差异有统计学意义（F=114.368,P<0.001）；灯诱法监测的成蚊密度5月开始逐渐上升,蚊密度高峰出现在每年的6－8月,蚊密度9月开始迅速下降；BI季节消长呈现较明显的双峰分布,分别为6和8月,BI 5月开始迅速上升,9、10月逐渐下降；不同年份BI均>5,风险等级为1级的地区有安顺和贵阳市及黔东南苗族侗族自治州,2019年安顺市和2021年贵阳市BI均>10,风险等级为2级。结论 贵州省人居及周边环境中致倦库蚊和中华按蚊为优势蚊种；农村环境蚊密度较高,特别是牲畜棚,它是蚊虫的重要孳生地,要特别加强该类环境蚊虫的防制。总体来看,贵州省的蚊虫活动高峰呈双峰型,分别为6和8月,出现双峰的原因可能与贵州省的独特气候和降雨情况息息相关。因此可在蚊虫繁殖高峰来临之前做好防治工作,降低蚊虫密度以及蚊媒病毒传播的风险。

关键词: 蚊类, 种群密度, 季节消长, 布雷图指数法