云南省盈江县边境地区按蚊孳生地幼蚊种类构成分析

Composition of anopheline larvae in the China-Myanmar border region in Yingjiang County of Yunnan Province

目的了解云南省盈江县边境地区按蚊孳生地幼蚊种类构成。方法选择盈江县那邦镇卡牙河和平原镇户缺坝为调查点开展按蚊孳生地调查。于2016年6-10月在每个调查点选择缓流、积水、水潭、小型沼泽、水田等孳生地每月开展1次幼蚊构成调查。记录各孳生地水体p H值和面积值,以及Ⅰ龄、Ⅱ龄、Ⅲ龄、Ⅳ龄幼蚊以及蛹的数量。Ⅲ龄后期和Ⅳ龄幼蚊通过形态学鉴定蚊种,蛹饲养至羽化后进行形态学鉴定。采用密度(density,Ds)、种类丰富性指数(species richness index,N)、Simpson多样性指数(Simpson diversity index,D)、Shannon多样性指数(Shannon diversity index,H)、Berger-Parker优势指数(Berger-Parker dominance index,d)、Shannon均衡性指数(Shannon evenness index,E)等6个指标分析按蚊幼蚊种类构成,采用Morisita-Horn相似性指数(Morisita-Horn similarity index,C)分析两乡(镇)幼蚊种类构成相似性。采用SPSS 13.0统计学软件进行统计分析。结果在那邦镇共采集幼蚊标本313份(按蚊268份、库蚊45份),平原镇共采集幼蚊标本81份(按蚊55份、库蚊26份)。那邦镇的主要按蚊幼蚊为中华按蚊(183只,占68.28%)、带足按蚊(33只,占12.31%)和微小按蚊(25只,占9.33%);平原镇则为中华按蚊(27只,占49.09%)、带足按蚊(24只,占43.64%)和迷走按蚊(2只,占3.64%)。盈江县按蚊幼蚊Ds为0.33只/勺,D、H、d、E分别为0.54、1.16、0.65、0.50。那邦镇N、H和d值较大,E接近0.5,但D略低。两乡(镇)C为0.82(接近1)。那邦镇各月份的Ds、N和H均高于平原镇。积水中的按蚊幼蚊种类丰富,N较大,d较小;D和H均最高;E最接近0.5。那邦镇大型水体(面积>100 m2)种类更为丰富,多样性D和H均较高,d略低,E更接近0.5。偏酸性水体(p H值<7)的媒介构成较为复杂。结论云南边境地区面积较大、偏酸性的积水中按蚊种类多、结构复杂,乡镇间媒介种类构成的相似性较大。

Objective To understand the species composition of anopheline larvae in the China-Myanmar border region in Yingjiang County, Yunnan Province of China. Methods The Kayahe Village in Nabang Town and Huqueba Village in Pingyuan Town were selected for determining the breeding-place of anophelines. The composition of anopheline larvae was investigated once a month from June to October, 2016, in potential habitats of s lack water,puddle, pond, moor, and paddy. The values of p H and area, and the numbers of first-, second-, third-, and fourth-instar larvae as well as pupae of mosquitoes were recorded in each habitat. The species of late third-instar and fourthinstar anopheline mosquito larvae were identified under microscope using commonly accepted guidelines. Pupae were morphologically identified after the emergence. Species composition of anopheline larvae was analyzed using six indices, including density（Ds）, Simpson diversity index（D）, Shannon diversity index（H）, Berger-Parker dominance index（d）, and Shannon evenness index（ E）. The Morisita-Horn similarity index（C） was employed to calculate the similarity of species composition between the two towns. Results A total of 394 larvae samples were collected in 91 specimen collection sites, comprising 313 samples（268 Anopheles and 45 Culex） from Nabang Town and 81 samples（55 Anopheles and 26 Culex） from Pingyuan Town. The Anopheles in Nabang Town were predominated by An.sinensis（183, 68.28%）, followed by An. peditaeniatus（33, 13.31%） and An. minimus（25, 9.33%）, and those in Pingyuan Town were mainly An. sinensis（27, 49.09%）, An. peditaeniatus（24, 43.64%）, and An. vagus（2, 3.64%）.In Yingjiang County, the Ds of Anopheles was 0.33 per dip, with D, H, d and E being 0.54, 1.16, 0.65 and0.50, respectively. The values of N, H, and d were relatively higher in Nabang Town, with an E value approaching0.5, albeit with a slightly lower D value. The values of Ds, N, and H in Nabang Town were higher than those in Pingyuan Town in each month. Puddles were rich in various species of anopheline larvae, with a smaller d and a higher N. D and H were highest in this habitat, and the value of E was most approaching 0.5. Large water habitats（with an area〉 100 m2） had more abundant species, with higher D and H values, smaller d, and an E value more approaching 0.5. Habitats with slightly acidic water（p 〈H 7） had a complicated vector composition.Conclusion There are abundant species of anopheline larvae in habitats with a large area and in puddles with slightly acidic water in the China-Myanmar region in Yunnan Province, with a complicated structure of composition.There is also a high similarity in vectors between the towns.