Cytotaxonomy of Simulium soderense sp. nov. and a redescription of the ‘Kulfo’form (Dunbar, 1969) of Simulium damnosum s.l. (Diptera: Simuliidae) as Simulium kulfoense sp. nov. in Ethiopia
Date
2008
Journal Title
Journal ISSN
Volume Title
Publisher
International Journal of Tropical Insect Science
Abstract
The exact taxonomic identity of members of the Simulium damnosum Theobald
complex in Ethiopia was not known until recently. A cytotaxonomic analysis of larval
chromosomes from the Kulfo River area in southern Ethiopia, from where the ‘Kulfo’ form
was reported, and from the Awash River at Sodere in central Ethiopia has revealed the
existence of two newly recognized species, namely Simulium kulfoense and Simulium
soderense. Although three fixed and 11 floating inversions in the chromosomes of the ‘Kulfo’
form were described in an idiogram, in the present study four fixed and 17 floating
inversions were observed, out of which only seven floating inversions were the same as
Dunbar’s, indicating that the remaining 10 inversions were either missed or misinterpreted.
Though both species share many inversions, S. kulfoense sp. nov. has a diagnostic inversion
on chromosome II, IIL-E6, with no sex-linked chromosomal arrangement, while S. soderense
sp. nov. has a sex-linked inversion, IIS-3, which warrants it as a distinct species. Both of these
new species also share many inversions with the recently described new species from southwestern
Ethiopia, Simulium kaffaense, including the fixed inversions IIL-E1 and E3. Since
both the study sites are known to be free of onchocerciasis, and the flies are not
anthropophilic, both the species are not presumed to be vectors of human onchocerciasis.
The presence of IS-1 and a complex inversion possibly involving IL-3 strongly indicates that
the two species belong to the ‘Nile’ phylogenetic group of S. damnosum
Description
Keywords
Diptera, Simuliidae, Simulium damnosum complex,, onchocerciasis,, Simulium kulfoens, Simulium soderense