“…During the past five decades many industrial formulations of the famous bacteria Bacillus thuringiensis H-14 and Bacillus sphaericus, beside some plant extracts proved to have mosquitocidal activity. New strains of the environmentally safe bacteria; B.t.i and B. sphaericus are daily added to the known strains (Sun, et al, 1996;Vilarinhos, et al, 1996;Thiery & Hamon, 1998;Lecadet, et al, 1999 ;and Park, et al, 2007). The toxic effect varied according to mosquito species and bacterial crystal structure (Gupta, et al, 1991;Theiry, et al, 1992;Nicolas, et al , 1992;Krieger, et al,1999;Lecadet, et al, 1999 andOtieno-Ayayo, et al,2008 ).…”