Abstract:

Objective: To investigate mosquito species composition and density fluctuation in a stable state of urbanization of Wuxi, Jiangsu Province, China, so as to provide a scientific basis for early warning of mosquito-borne infectious diseases. Methods: From March to November of 2012 to 2021, mosquitoes were monitored by lamp trapping in five habitats of urban residential areas, parks, hospitals, rural houses and livestock sheds in Wuxi. The species, densities, and seasonal fluctuations of mosquitoes in different environments were analyzed. An analysis of variance was performed on the similarity and diversity indices of mosquitoes in different years and habitats for annual trends. A linear regression analysis was used to analyze the relationship between mosquito density and the minimum mean temperature in the 5 days before monitoring (T_min⁵), followed by testing with analysis of variance. Results: A total of 3 777 mosquito lamp traps were placed, capturing 27 158 female mosquitoes, with an average density of 0.60 mosquitoes/lamp·h. The dominant species were Culex pipiens pallens/quinquefasciatus and Cx. tritaeniorhynchus. The mosquito density decreased from 1.18 mosquitoes/lamp·h in 2012 to 0.13 mosquitoes/lamp·h in 2021. The seasonal fluctuation of the overall average mosquito density showed a bimodal pattern. The mosquito diversity index of livestock sheds was highest at 0.97, which was statistically higher than that of other habitats (all P < 0.05), followed by rural houses, urban residential areas, parks, and hospitals. There was no statistical difference in the diversity index of different habitats in different years (F=1.328, P=0.253). The similarity index was high between residential areas, parks, hospitals, and rural house but not livestock sheds. In all the years except 2012, mosquito density was linearly correlated with T_min⁵ (all P < 0.05). Conclusions: The species composition of mosquito in different environments in Wuxi is different. The densities of dominant mosquito species in all the habitats showed a generally decreasing trend year by year. The density and diversity of mosquitoes in livestock sheds were highest, which should be a focus of mosquito control. The fluctuation of mosquito density was statistically correlated with temperature, and T_min⁵ can be used as a potential risk indicator for mosquito density surveillance and early warning.

Key words: Mosquito, Density fluctuation, Composition ratio, Diversity, Similarity

摘要：

目的: 了解江苏省无锡市城镇化进程稳定状态下的蚊虫种类组成及密度消长等特征，为蚊媒传染病流行风险预警提供科学依据。方法: 2012－2021年每年的3－11月，应用诱蚊灯法在无锡市居民区、公园、医院、农户、牲畜棚5种生境进行蚊虫调查。对不同环境蚊虫的种类、密度和季节消长规律进行分析；对不同年份、生境的蚊虫相似性、多样性等指数进行方差分析，了解年度变化趋势；使用线性回归分析蚊密度与监测前5日最低均温（T_min⁵）的关系，使用方差分析对结果进行检验。结果: 共放置诱蚊灯3 777灯次，捕获雌蚊27 158只，总蚊密度为0.60只/（灯·h），其中优势蚊种为淡色/致倦库蚊和三带喙库蚊。蚊密度从2012年的1.18只/（灯·h）降至2021年的0.13只/（灯·h），蚊虫总平均密度季节消长呈双峰型。牲畜棚蚊虫多样性指数最高，为0.97，高于其余各生境（均P < 0.05），其余生境从高到低依次为农户、居民区、公园、医院，不同年份各生境多样性指数差异无统计学意义（F=1.328，P=0.253）。除牲畜棚外，居民区、公园、医院、农户之间的相似性指数均较高。除2012年外，其余各年份蚊密度与T_min⁵呈线性相关（均P < 0.05）。结论: 无锡市不同环境中蚊虫种类组成不同，总体上各生境优势蚊种密度呈逐年下降趋势，牲畜棚蚊虫密度最大、多样性指数最高，应重点防制。蚊密度消长与气温显著相关，T_min⁵可作为蚊密度监测预警潜在风险指标。

关键词: 蚊虫, 密度消长, 构成比, 多样性, 相似性