Entomopathogenic fungi from Argentina for the control of Schistocerca cancellata (Orthoptera: Acrididae) nymphs: fungal pathogenicity and enzyme activity

The South American locust Schistocerca cancellata (Serville) was the most serious agricultural pest in Argentina during the first half of the last century and remains as a threat when preventive control measures are relaxed in the outbreak area. In this study, we analysed in the laboratory, the effectiveness of 26 fungal strains (isolated from both insects and soil collected in Argentina) for S. cancellata control and determined the relationship between the chitinase, protease and lipase levels in these fungi and their insecticidal activities. We observed that Beauveria bassiana (isolate LPSC 1067) caused the highest mortality (90 +/- 1.03%), the highest values of chitinolytic, proteolytic and lipolytic activity were 6.13 +/- 0.05, 2.56 +/- 0.11 and 2.33 +/- 0.47, respectively, and the lowest median lethal time was 5.96 days. This is the first time that a wide variability in chitinase, protease and lipase activity as well as in virulence has been reported in a representative sample of different entomopathogenic fungal strains from Argentina.