Two new cytoforms of the Simulium damnosum complex (Diptera: Simuliidae) from Malawi and Tanzania and potential onchocerciasis vectors
During a distribution survey of Simulium damnosum s.l. around the Tukuyu onchocerciasis focus at the northern tip of Lake Malawi/Nyasa (Tanzania), we discovered two new cytoforms of the S. damnosum complex in onchocerciasis-free areas. The Nyika form is related to Simulium thyolense, a vector of onchocerciasis, and can be identified by the new inversion 3L-L on the long arm of chromosome 3. It was found breeding in five rivers in northern Malawi and neighbouring Tanzania and is assumed to be zoophilic. The Njombe form represents a member of the Sanje group of the complex and is characterized by the new diagnostic inversion 2L-35 on chromosome 2. So far, it is only known from around Njombe town in southern Tanzania, where it breeds at remarkably high altitudes. Anthropophily for the Njombe form is well known. The medical importance and systematic position of the new forms within the S. damnosum complex are discussed.
Document Type: Research Article
Affiliations: 1: Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany 2: National Institute for Medical Research, Tukuyu Research Station, Tukuyu, Tanzania 3: The Natural History Museum, Cromwell Road, London, UK
Publication date: July 1, 2004