Abstract:

Objective To investigate the mosquito species composition and activity rhythm in the lower reaches of Ertix River on the Sino?Kazakhstan border and their relationship with the habitat. Methods The species, density, seasonal rhythm, and circadian rhythm of mosquitoes in different habitats were investigated by human?baited net traps. Biting cycles were determined through biting indices. Results Eight species of four genera of mosquitoes were found in the lower reaches of Ertix River on the Sino?Kazakhstan border. Aedes vexans was the predominant species, with a proportion between 82.22% and 96.09% among all captured mosquitoes in different habitats. The seasonal activity of Ae. vexans started in mid?April, ended in early September, and reached the peak between mid?June and late July. The circadian rhythm of activity was in a double?peak pattern, with the morning peak appearing at 1-2 h after sunrise and the evening peak at 1 h after sunset; the evening peak was higher than the morning peak. The biting circadian rhythm was dawn type; biting activity started around sunset and ended after sunrise. The biting circadian rhythm was also double?peaked; the morning peak appeared at 1 h before sunrise, and the evening peak appeared at 1 h after sunset. The species diversity index ranged from 0.1912 to 0.7227, indicating that mosquito species were not abundant in the lower reaches of Ertix River on the Sino?Kazakhstan border. The habitat had significant impacts on the species distribution and number of mosquitoes. The numbers of Ae. vexans, Anopheles messeae, and Culex modestus in riparian forest were significantly higher than those in saline regions. Biting of Ae. vexans was the severest in riparian forest. However, seasonal activity, circadian activity, and biting cycle were similar for Ae. vexans in different habitats. Conclusion The habitat has a significant impact on the population size of Ae. vexans. In integrated prevention and control of Ae. vexans, special focus should be placed on microhabitats where mosquitoes propagate.

Key words: Mosquito, Species distribution, Activity rhythm, Habitat, The lower reaches of Ertix River on the Sino?Kazakhstan border

摘要：

目的 查清额尔齐斯河下游中哈边境地区蚊虫种类组成和活动节律, 探讨生境对种类分布和活动节律的影响。方法 通过人帐诱法调查蚊虫种类、密度、季节活动节律和昼夜活动节律, 通过刺叮指数法调查刺叮周环。结果 额尔齐斯河下游中哈边境地区蚊虫有4属8种, 刺扰伊蚊为优势种, 在不同生境刺扰伊蚊占捕获蚊虫总数的82.22%～96.09%。该蚊从4月中旬出现, 9月上旬活动消失, 6月中旬至7月下旬为活动高峰。昼夜活动为双峰型, 晨峰在日出后1～2 h, 昏峰在日落后1 h, 昏峰高于晨峰。昼夜刺叮活动为黄昏型, 吸血活动从日落前后开始, 日出后逐渐停止, 出现晨峰和昏峰2个高峰, 晨峰在日出前1 h, 昏峰出现在日落后1 h。额尔齐斯河下游中哈边境蚊虫种类不丰富, 多样性指数低(0.1912～0.7227)。生境对蚊虫种类分布和数量影响大。刺扰伊蚊的数量和刺叮危害在河岸林生境中最为严重。刺扰伊蚊、米赛按蚊和凶小库蚊在河岸林中的数量显著高于盐渍化荒地。但在不同生境, 刺扰伊蚊季节活动、昼夜活动和刺叮周环节律相似。结论 生境对刺扰伊蚊种群数量影响大, 在刺扰伊蚊综合防制中, 应注重适宜蚊虫孳生和栖息的小生境处理。

关键词: 蚊虫, 种类分布, 活动节律, 生境, 额尔齐斯河下游中哈边境