Der Einfluss der Wasserstoffionen- und Gesamtionenkonzentration sowie der Ionenkomposition auf die aquatischen Stadien zweier Zytoarten des Simulium damnosum-Komplexes (Diptera, Simuliidae) Ostafrikas
Grunewald, J.; Grunewald, EB.
Archiv fur Hydrobiologie 82(1-4): 419-431
1978
ISSN/ISBN: 0003-9136
Accession: 020822050
The establishment of laboratory colonies of cytospecies of the S. damnosum complex would be of great value, since some cytospecies are known to transmit Onchocerca volvulus, a filarioid nematode causing human onchocerciasis in Africa. In order to rear different cytospecies from the egg to the adult stage the influence of various parameters on the aquatic stages was investigated. Larvae of Simulium damnosum Kibwezi and S. damnosum Kisiwani both developing in natural breeding sites at pH values ranging from 7.7-10.0, and at conductivity values ranging from 400-950 .mu.S were reared in the laboratory in water with pH and conductivity values similar to those found in the field; the rate of survival was 20% and 53%, respectively. It was not possible to rear the larvae of both Kibwezi and Kisiwani in water with pH values near 7 and conductivity values near 70 .mu.S, values measured in a breeding site of S. damnosum Sanje. A change of the anionic composition of the culture water had no effect on the Kisiwani larvae, while Kibwezi larvae showed some slight effect which might be attributed to the change. For rearing larvae of any cytotype of the S. damnosum complex pH value, the conductivity and the ionic composition of the culture water should be adjusted and maintained at levels similar to those found in natural breeding sites.