Bioinsecticide activity of some strains of Bacillus sphaericus & B.thuringiensis species on Culex pipiens larvaes

Abstract

The study included the isolation, identification and the ability of B. sphaericus and B.thuringiensis species to kill Culex larvaes. These isolates were obtained from different air and soil enviroment in Nenavah Governerate using Nutrient Yeast Salts Medium Glucose (NYSMG) enhances the growth of most of the Bacterial spores. Isolation of B. sphaericus species resistance to streptomycin was carided out using the Selective Media Nutrient Yeast Salts Medium Streptomycin (NYSMS). Comparing the two medium we conclude that the (NYSMS) reduced the numbers bacterial spores growth (85-90%) to most of the samples. We study the ability of isolates to kill Culex pipiens larvaes one isolate from the two species and control species B.thuringiensis could kill (100%) from culex larvaes during the first day of incubation time in the room temperature (30+2) C and one isolate from the species B.thuringiensis could kill also (100%) during the second day and three isolates from two species could kill (100%) during the fifth day. Nine isolates from of B. sphaericus and eight isolate from B.thuringiensis could kill the larvae’s during the fifth days of incubation time.