尼日利亚西南部奥孙河沿线黑蝇Simulium damnosum Theobald complex的形态分类研究(双翅目:蚋科)

黑蝇Simulium damnosum sensu lato是由多个姊妹种组成的复合体,这些种在生态学和盘尾丝虫病的传播方面各不相同.本文对奥孙河沿线的尼日利亚西南部森林区域的黑蝇S.damnosum s.l.复合体的组成以及成虫的形态学特征进行了研究.本研究所用的黑蝇S.damnosum s.l.成虫标本来源于奥孙河沿线的3个区,分别是Osun Eleja,Osun Ogbere和Osun Budepo.标本采集通过人体诱捕的方式,采集时间从2008年2月至2009年6月上午7:00到下午6:00,每两周采集1次.通过观察成虫的翅毛簇(wing tufts)和其他形态特征,对其进行分类研究.结果表明:存在同域分布的森林种和稀树草原种.在奥孙河沿线3个区内,森林种为优势种,占总捕获量的99.18%,而稀树草原种仅占0.82%;森林种和稀树草原种在多度上存在显著差异(P<0.05).所捕获的所有稀树草原种的翅毛簇均为灰白色,而捕获的森林种的翅毛簇颜色存在显著差异(P<0.05).为了更清楚地揭示该地区黑蝇S.damnosum s.l.的物种组成,建议进行更深入的研究.

Morphotaxonomic studies on Simulium damnosum Theobald complex(Diptera:Simuliidae)along Osun River,Southwestern Nigeria

Simulium damnosum sensu lato is a complex made up of many sibling species which differ in their ecology and contribution to onchocerciasis transmission. The present study was carried out to provide information on morphological composition of the biting adults of S. damnosum s. 1. along Osun River in a forest zone of Southwestern Nigeria. Adult flies were collected on human baits from 07 ;00 a. m. to 06 :00 p. m. every fortnight at three communities, Osun Eleja, Osun Ogbere and Osun Budepo along Osun River from February 2008 to June 2009. The wing tufts and other taxonomic characters of the flies were observed and classified using standard protocol. The results revealed the sympatric existence of both forest and savanna dwelling flies. The forest flies constituted the predominant species representing 99. 18% of the flies caught in the three locations while savanna dwelling flies recorded 0. 82% of the total catch. The difference in abundance of the forest and savanna flies was statistically significant (P <0. 05). All the savanna flies encountered had pale wing tufts but there was significant difference in wing tufts colours observed among the forest flies (P <0. 05). Further studies are therefore recommended so as to shed light on the species composition of S. damnosum s. 1. in the study area.