Muturi Ephantus J, Shililu Josephat I, Jacob Benjamin G, Mwangangi Joseph M, Mbogo Charles M, Githure John I, Novak Robert J
Department of Medicine, William C. Gorgas Center for Geographic Medicine, University of Alabama at Birmingham, Birmingham, AL 35294, USA.
J Am Mosq Control Assoc. 2008 Sep;24(3):349-58. doi: 10.2987/5675.1.
Knowledge of mosquito species diversity, occurrence, and distribution is an essential component of vector ecology and a guiding principle to formulation and implementation of integrated vector management programs. A 12-month entomological survey was conducted to determine the diversity of riceland mosquitoes and factors affecting their occurrence and distribution at 3 sites targeted for malaria vector control in Mwea, Kenya. Adult mosquitoes were sampled indoors by pyrethrum spray catch and outdoors by the Centers for Disease Control and Prevention light traps. Mosquitoes were then morphologically identified to species using taxonomic keys. The characteristics of houses sampled for indoor resting mosquitoes, including number of people sleeping in each house the night preceding collection, presence of bed nets, location of the house, size of eaves, wall type, presence of cattle and distance of the house to the cowshed, and proximity to larval habitats, were recorded. Of the 191,378 mosquitoes collected, 95% were identified morphologically to species and comprised 25 species from 5 genera. Common species included Anopheles arabiensis (53.5%), Culex quinquefasciatus (35.5%), An. pharoensis (4.7%), An. coustani (2.5%), and An. funestus (1.6%). Shannon's species diversity and evenness indices did not differ significantly among the 3 study sites. There was a marked house-to-house variation in the average number of mosquitoes captured. The number of people sleeping in the house the night preceding collection, size of eaves, distance to the cowshed, and the nearest larval habitat were significant predictors of occurrence of either or both An. arabiensis and Cx. quinquefasciatus. The peak abundance of An. arabiensis coincided with land preparation and the first few weeks after transplanting of rice seedlings, and that of Cx. quinquefasciatus coincided with land preparation, late stage of rice development, and short rains. After transplanting of rice seedlings, the populations of Cx. quinquefasciatus were collected more outdoors than indoors, suggesting a shift from endophily to exophily. These results demonstrate that irrigated rice cultivation has a strong impact on mosquito species occurrence, distribution, abundance, and behavior, and that certain house characteristics increase the degree of human-vector contact.
了解蚊虫种类的多样性、出现情况和分布是媒介生态学的重要组成部分，也是制定和实施综合媒介管理计划的指导原则。在肯尼亚姆韦亚的3个疟疾媒介控制目标地点进行了为期12个月的昆虫学调查，以确定稻田蚊虫的多样性以及影响其出现和分布的因素。室内采用除虫菊酯喷雾法捕捉成蚊，室外使用疾病控制和预防中心的诱蚊灯诱捕成蚊。然后使用分类检索表对蚊虫进行形态学鉴定。记录了为室内栖息蚊虫采样的房屋特征，包括采集前一晚每户睡眠人数、蚊帐的使用情况、房屋位置、屋檐大小、墙壁类型、是否有牛以及房屋到牛棚的距离，以及与幼虫栖息地的距离。在采集的191378只蚊虫中，95%通过形态学鉴定到种类，共包括5个属的25个种类。常见种类包括阿拉伯按蚊（53.5%）、致倦库蚊（35.5%）、法老按蚊（4.7%）、库斯塔尼按蚊（2.5%）和富氏按蚊（1.6%）。3个研究地点的香农物种多样性和均匀度指数没有显著差异。每户捕获的蚊虫平均数量存在明显的逐户差异。采集前一晚屋内睡眠人数、屋檐大小、到牛棚的距离以及最近的幼虫栖息地是阿拉伯按蚊和致倦库蚊出现与否的重要预测因素。阿拉伯按蚊的丰度高峰与土地翻耕和水稻秧苗移栽后的头几周一致，致倦库蚊的丰度高峰与土地翻耕、水稻生长后期和短雨期一致。水稻秧苗移栽后，致倦库蚊在室外捕获的数量多于室内，表明其从嗜内性向嗜外性转变。这些结果表明，灌溉水稻种植对蚊虫种类的出现、分布、丰度和行为有强烈影响，并且某些房屋特征会增加人与媒介的接触程度。
