Several insects are harmful to apples grown in Brazil, especially the leafroller Bonagota salubricola (Lepidoptera, Tortricidae), usually controlled with chemical insecticides. The purpose of the present study was to investigate the use of Metarhizium anisopliae strains in the control of the apple leafroller, by assessing their virulence to B. salubricola larvae in bioassays with suspensions of 2 x 10(5) to 2 x 10(9) conidia/mL as well as their relationship with protease expression. The most effective strain underwent a compatibility test with chemical insecticides. The M. anisopliae E6 strain showed a good performance, with up to 88% mortality and a LT50 of 1.66 days. The virulence was positively correlated with a higher enzymatic activity. The E6 strain was compatible with tebufenozide, evidencing its potential to control B. salubricola.
entomopathogenic fungi; apple; biological control; leafroller
