Über natürliche Infektionen und ihre Verbreitung in Mosquito-Larven (Anopheles spp. undCulex spp.) in Tanzania

Abstract

A survey (1983–1985) is given on some pathogenic agents of mosquito-larvae in Tanzania. More than 4,000 specimens of larvae ofAnopheles spp. andCulex spp. (not yet identified to species-level) were collected in different localities (14) in Tanzania. The insect material was brought to the laboratory of Pest Control Section as an integrated part of the project, National Coconut Development Programme (NCDP) in Mlingano, Tanga, and immediately examined for parasites by means of light- and phase contrast microscopy. Three microsporidians of the generaAmblyospora, Vavraia, andParathelohania, and a fungusRubetella inopinata were found to infect mosquitolarvae. The prevalence of infections for all sites investigated (14) was approximately 4%, ranging 10–20% from site to site. Two microsporidians infecting the gut are new species. The mixed infections withAmblyospora andR. inopinata also occured. Studies on ultrastructure of microsporidians will be conducted in the Institute of Microbiology, University of Göttingen, F. R. Germany. Since high infection levels have been recorded in some sites (Maramba, Mkata, Table 1), it is assumed that microsporidians and a fungusR. inopinata can play important role as limiting factors in population dynamics of their hosts than generally recognized.

Zusammenfassung

Es wird über 1983–1985 in Tanzania gewonnene Erkenntnisse zur Art und Verbreitung von Pathogenen bei Stechmücken (Anopheles spp.,Culex spp.) berichtet. Die Larven waren insgesamt zu 4% mit Pathogenen infiziert, die sich auf 4 von 14 untersuchten Standorten beschränkten. Hier betrug die Infektionsrate 10–20%. Festgestellt wurden 4 Arten von Pathogenen, 3 Mikrosporidien (Protozoa):Amblyospora sp.,Parathelohania sp. undVavraia culicis sowie einen Pilz,Rubetella inopinata (Trichomycetes). Die Möglichkeiten von experimentellen Infektionen und künstlichen Ausbreitungen der Pathogene zur biologischen Stechmücken-Bekämpfung werden erörtert.