Browsing by Author "Marquis, Bolaji B."

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    The occurrence and distribution of Simulium species in Ife, Ijesa and Ondo divisions
    (Obafemi Awolowo University, Ile Ife, Nigeria, 1985) Marquis, Bolaji B.
    have been investigated for the presence of the larvae of the blackfly Simulium. The larvae were collected from thirty chosen stations of the river systems and identified in the laboratory. Water samples from each site were also taken and analysed in the laboratory. The main features used in identification of the larvae were the external characters especially the presence or absence of dorsal conical tubercles and ventral papillae, pattern of respiratory histoblast and body shape. Larvae of seven species of Simulium were identified. These were S. alcocki, S. johannae, S. impukane, S. schoutedeni, S. griseicelle,L S. griseicolle form tridens, and S. damnosum s.l.. S. alcocki and S. griseicolle were well distributed in the area of study while S. damnosum was found at only five sites. It appears that there is one main area of Simuliid breeding located in the southern part of the area of study and concentrated around River Oni, River Awo and River Owena. At the points where the larvae were found these rivers are mostly swiftly flowing and with rocky beds. Three of the sampling stations, one on River Oshun and the other two on River Oni, were found to have hydrochemical conditions which were conducive to the breeding of cytospecies of S. damnosum s.l. which can transmit human onchocerciasis. These hydrochemical conditions include pH and conductivity. The need to carry out more work on the distribution of Simulium larvae and the rhydrochemical properties of rivers and streams in the southern parts of Nigeria is suggested.