Bacillus thuringiensis (Bt) is an aerobic, spore-forming bacteria
that produces crystalline inclusions during the sporulation phase,
which are toxic to insects from the orders of Lepidoptera, Diptera
and Coleoptera as well as to other invertebrates [1]. Nowadays,
Bt is commonly used as a biological pesticide and the introduction
of Bt genes into commercialization of Bt transgenic crops
results in successful and environmentally sound insect pest control
[2]. However, the extensive use of Bt products has led to
augmented selection pressure for the development of insect resistance
and reduced Bt insecticidal effects [3]