Laboratory rearing and distribution of the breeding sites of simulium species in Kaduna State

Abstract

Between November 1992 and July 2000, immature and adult simuliid fauna were collected from rivers and streams across four bioclimatic zones comparising 96 sampling stations in 62 sites for rearing and identification. Adult man-biting simuliids were allowed to feed on human bait and later maintained in the laboratory on 10% sucrose solution. They were induced to oviposit by immersion in water contained in capped plastic tubes. Larvae hatched from the single batch eggs were reared to late instar and identified cytologically. Developing larvae from the wild were reared in aerated cylinder system and identified cytologically. Pupae reared in emergence cages and adults of non-anthropophilic species were identified morphologically. A total of 652 man-biting adult females were caught, (and identified using published keys) 3927 larvae reared and 811 larvae identified cytologically. Three sibling species, S. damnosum s.s., S. sirbanum and S. squamosum were identified cylologically from their F1 larval progeny. Apart from these known vectors of onchocerciasis, seven non-anthropophilic species were identified using morphological keys, namely: S. ruficorne, S, hargreavesi, S, alcocki, S. adersi. S. cervicornutum, S. unicornutum and S. aureosimile.The composition of S. damnosum s.s. larvae within either the rivers or months and the interaction among the months and rivers was not significant (P>0.05). Analysis of variance of biting females of Simulium squamosum with either the rivers or months was not significant.


Key words: rearing, Simulium, identification


Journal of Aquatic Sciences Vol.18(2) 2003: 131-140