Aquatic insect composition at a Simulium breeding site on the River Assop, Plateau State, Nigeria

Abstract

A study of the composition of aquatic insects associated with Simulium species at two sites along a segment of river Assop was carried out at Hawan Kibo and Assop Falls between the months of September to November 1998 and April to June, 1999. The months were selected as representative of the beginning of the dry season and the start of the rainy season. A total of 501 aquatic insects of different taxonomic groupings were collected, identified and classified. Of this number 90.2% constituted the important aquatic taxonomic groupings of Diptera 41.37%, Odonata 16.6%, Plecoptera 13.5%, Ephemeroptera 11.50%, Zygoptera 7.08%, Hemiptera 3.8%, Coleoptera 2.9%, Arctonorixa 1.33%, Naucorida 0.89%, Coleoptera sp. 0.89% and Lepidoptera 0.22% with other orders represented by at least one genus. On the basis of species abundance and distribution in the two stations, some species were more diverse and showed significant evenness even though there were more species in one site than the other. This work has revealed the composition of the aquatic insects associated with Simulium species and should prove useful whenever vector control with larvicides is contemplated in any planned future control of onchocerciasis along the Assop valley.


Key Words: Aquatic insect, Simulium, Breeding site, River Assop, Nigeria


Journal of Aquatic Sciences Vol.19(1) 2004: 9-15