Muturi Ephantus J, Mwangangi Joseph, Shililu Josephat, Jacob Benjamin G, Mbogo Charles, Githure John, Novak Robert J
Department ofMedicine, William C. Gorgas Center for Geographic Medicine, 206C Bevill Biomedical Research Building, 845 19th Street South, University of Alabama at Birmingham, Birmingham, AL 35294, USA.
J Vector Ecol. 2008 Jun;33(1):56-63. doi: 10.3376/1081-1710(2008)33[56:efawtd]2.0.co;2.
Studies were conducted between May and June, 2006 to investigate the environmental factors affecting the distribution of An. arabiensis Patton and Culex quinquefasciatus Say in Mwea, Kenya. The sampling unit comprised all non-paddy aquatic habitats and ten randomly selected paddies and canals located within a 200 m radius from the periphery of the study site. Thirteen physico-chemical variables were recorded for each sampling site in each sampling occasion and a sample of mosquito larvae and other aquatic invertebrates collected. The non-paddy aquatic habitats identified included pools and marshes. Morphological identification of 1,974 mosquito larvae yielded four species dominated by Cx. quinquefasciatus (73.2%) and An. arabiensis (25.0%). Pools were associated with significantly higher Cx. quinquefasciatus larval abundance and less diversity of other aquatic invertebrates compared with other habitat types. In contrast, the abundance of An. arabiensis did not differ significantly among habitat types. Culex quinquefasciatus habitats had higher water conductivity and exhibited a higher abundance of other aquatic invertebrates than An. arabiensis habitats. Chi-square analysis indicated that the two species were more likely to coexist in the same habitats than would be expected by chance alone. Anopheles arabiensis larvae were positively associated with dissolved oxygen and adults of family Haliplidae and negatively associated with emergent vegetation and Heptageniidae larvae. Culex quinquefasciatus larvae were positively associated with dissolved oxygen, total dissolved solids, Chironomidae larvae, and Microvelidae adults and negatively associated with emergent vegetation. These findings suggest that both biotic and abiotic factors play a significant role in niche partitioning among Cx. quinquefasciatus and An. arabiensis, a factor that should be considered when designing an integrated vector control program.
2006年5月至6月期间开展了多项研究，以调查影响肯尼亚姆韦亚地区阿拉伯按蚊（An. arabiensis Patton）和致倦库蚊（Culex quinquefasciatus Say）分布的环境因素。采样单元包括所有非稻田水生栖息地以及从研究地点周边向外200米半径范围内随机选取的10块稻田和水渠。每次采样时，记录每个采样点的13个理化变量，并采集蚊幼虫和其他水生无脊椎动物样本。已确定的非稻田水生栖息地包括水塘和沼泽。对1974只蚊幼虫进行形态学鉴定，共发现4个物种，其中致倦库蚊占主导（73.2%），其次是阿拉伯按蚊（25.0%）。与其他栖息地类型相比，水塘中致倦库蚊幼虫的丰度显著更高，而其他水生无脊椎动物的多样性更低。相比之下，不同栖息地类型中阿拉伯按蚊的丰度没有显著差异。致倦库蚊的栖息地具有更高的水导率，并且与阿拉伯按蚊的栖息地相比，其他水生无脊椎动物的丰度更高。卡方分析表明，这两个物种在同一栖息地中共存的可能性比仅由偶然因素预期的要高。阿拉伯按蚊幼虫与溶解氧、沼梭甲科成虫呈正相关，与挺水植物和短脉纹石蛾幼虫呈负相关。致倦库蚊幼虫与溶解氧、总溶解固体、摇蚊科幼虫和微蚊科成虫呈正相关，与挺水植物呈负相关。这些发现表明，生物和非生物因素在致倦库蚊和阿拉伯按蚊的生态位划分中都起着重要作用，这是在设计综合病媒控制计划时应考虑的一个因素。
