Review of Current Status of Morphotaxonomy in the Characteristics and Identification of Simulium damnosum Complex (Diptera:Simuliidae)

OFFOR, I.I.

Blackflies are arthropods of the order Diptera and genus Simuliidae which transmit the parasite Onchocerca volvulus responsible for onchocerciasis (river blindness) and other various skin conditions. In carrying out Rapid Epidemiological Mapping to assess the current status of onchocerciasis in any area, the identity of the blackfly is important. Very often, breeding sites are located in remote areas and this leads to delay in field identification of samples. There is need for quick Identification to complement clinical diagnostic methods. The known identification methods for Simulium damnosum complex require time because of the expertise needed and the sophisticated nature of equipments employed. Such methods include molecular
identification using DNA probes, electrophoresis and cuticular hydrocarbon analysis using gas chromatography (GC) for separating members of the complex .. The widely used method has been that of morphological characterization of the adult fly: Although using pictorial keys were cumbersome, blackflies from different geographical belts were
separated successfully. Cytotaxonomic methods were used for the identification of nine sibling species of Simulium damnosum s.l. larvae in Nigeria. Recent workers have employed micro-morphological characters to analyse the known cytospecies from
geographical extremes. The major constraints for field investigations are the time and cost of using laboratories abroad. Still, the need remains for quicker screening methods.

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