Characterization of new strains of Bacillus thuringiensis for the control of important insect pests in agriculture

Bacillus thuringiensis Berliner produces protein crystals that act effectively on the control of pests for several relevant crops. The cry genes codes for these proteins are named Cry proteins. The cry gene profile can potentially set each bacterial isolate as a potential pest control agent. Aiming to analyze new isolates for the controlling of pests belonging to the orders Lepidoptera and Coleoptera, 76 samples were molecularly analyzed and had their potential for control evaluated through bioassays with larvae of Spodoptera frugiperda (J.E. Smith), Sphenophorus levis Vaurie and Tenebrio molitor Linnaeus. Based on molecular analysis data, 11 samples (14.5%) were able to control lepidopteran specific pests due to their cry genes content, and 17 samples (22.37%) exhibited coleopteran specific cry genes. The bioassays results indicated two samples with highly effective against S. frugiperda, one against S. levis and six with high toxicity against T. molitor larvae development. The selected B. thuringiensis isolates may be promising for the biological control of these pests.