Browsing by Author "Shayo, Alex"

Now showing 1 - 1 of 1
  • Thumbnail Image
    Item
    Biopotency of Moringa Oleifera seed extracts on selected species of mosquitoes (Diptera: culicidae)
    (University of Dar es Salaam, 2009) Shayo, Alex
    A growing body of literature emphasizes Domestic Water Storage Containers (DWSC) as important breeding of disease transmitting mosquitoes throughout the tropics. In this study, Aedes aegypti, Anopheles gambiae s.s and Culex quinquefasciatus were identified to breed in commonly used DWSC within the City of Dar es Salaam, Tanzania. Crude extracts of defatted seed of the pan-tropical tree; Moringa oleifera were tested for potential bioactivities on first instar larvae (Ll), third instar larvae (L3), and on gravid females of all these three mosquito species under laboratory conditions. Either distilled water (1: IO w/v) or a 3% aqueous sea salt solution (1:5 w/v) was used as extraction medium. The bioactivities of both, Water Extract (W.E) and Aqueous Sea Salt Extract (ASSE) were observed as acute toxicity leading to larval mortality on 24 hours of exposure as well as cumulative larval mortality. Furthermore, there was delayed pupal to adult emergence by an average of 24 hours leading to an overall elongation of the aquatic lifespan upon extended exposure. There was no significant difference (p> 0.05) in response between LI and L3 for both ASSE and W.E. ASSE was however, significantly more toxic (p<0.05) than W.E in LI but this difference was not significant (p> 0.05) in L3. In addition, gravid females showed negative oviposition indices (-0.12 ) the presence of a water clarifying component in Moleifera seeds or defatted seed extracts for water treatment in the tropical developing countries like Tanzania.