Characterization of Bacillus thuringiensis isolated from soils in the Jazan region of Saudi Arabia, and their efficacy against Spodoptera littoralis and Aedes aegypti larvae.

Pest control in Saudi Arabia depends on applying chemical insecticides, which have many undesirable considerations and impacts on the environment. Therefore, the aim of this study was to isolate from different rhizosphere soil samples in the Jazan region for the biological control of and larvae. The samples were collected from the rhizosphere of different plants located in eight agricultural areas in Jazan, Saudi Arabia. Out of 100 bacterial isolates, four bacterial isolates belonging to species were selected namely JZ1, JZ2, JZ3, and JZ4, and identified using classical bacteriological and molecular identification using 16S . JZ1 and JZ2 isolates were identified as . SDS-PAGE analysis and the detection of the gene were used to describe the two isolates JZ1 and JZ2 in comparison to reference strain (BTSK) were revealed that slightly different from each other due to the place of their isolation and namely Khlab JZ1 and Ayash JZ2. The EC of JZ1 and JZ2 isolates, BTSK and the commercial biopesticide DiPEL 6.4 DF against the second-instar larvae of were 207, 932, 400, and 500 ppm respectively, while EC against first-instar larvae of were 193.93, 589.7, 265.108, and 342.9, ppm respectively. Isolate JZ1 recorded the highest mortality while JZ2 isolate gave the lowest mortality. It can be concluded that the local isolate of JZ1 and JZ2 can be developed for bio formulations to be used in and biological control programs.