Study of Combined Pesticidal Effect of Black Onion Seed (Nigella sativa) and Bacillus thuringiensis on Red Flour Beetle (Tribolium castaneum)
Bacillus thuringiensis, commonly referred to as B.t. is a gram positive bacterium that produces insecticidal crystal proteins. This bacterium occurs naturally in the environment and has been used as a biological pesticide for more than 50 years. In order to manage the loss of stored grains and other agricultural products from insect infestation, many plant products have been evaluated for their toxic properties against different stored grain pests. In the present study, B.t. isolates from collected samples were grown on T3 (Tryptone, Tryptose, Yeast extract) media. Bio-toxicity was checked individually and by combination of Black onion seed (Nigella sativa) and Bacillus thuringiensis, against Tribolium castaneum. The LC of 50 Black onion seeds powder (N. sativa) was 0.35 g/g against second instar larvae of T. castaneum. Toxicity was increased when this compound was combined with three isolates of B.t. (Shaf1, Sd1 and Sid1).The mortality data of T. castaneum was analysed by applying probit analysis programme, determined that larvae are more susceptible and show significant results as compared to adults.