关键词: 蚊类, 种群密度, 季节消长, 布雷图指数法

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