ABSTRACT
The two-spotted spider mite is the most important pest to Brazilian crops. The incorrect use of chemical control leads to serious consequences, such as the presence of residues in fruits and the emergence of resistant populations. There is a need for alternative methods for managing the mite, such as biological control, which has been used as a tool in the management of various pests of agricultural importance in the world. Bioassays were carried out to analyze 120 strains of Bacillus thuringiensis Berliner in regard to their pathogenicity to Tetranychus urticae Koch. Suspensions were prepared of the different strains, containing 3 × 108 spores/mL of distilled water, and applied on Jack-bean (Canavalia ensiformes DC) leaf disks. Each strain constituted a treatment, with 8 repetitions, each containing 10 adult Tetranychus urticae females. The tests in laboratory conditions showed that mortality was significantly, ranging from 6.7% (strains LMJ7A) to 54.9% (strains 1077B and 886f).
KEY WORDS
Biological control; entomopathogen; bacterial; cry toxins; mite