Screening of Argentine native fungal strains for biocontrol of the grasshopper Tropidacris collaris relationship between fungal pathogenicity and chitinolytic enzyme activity

S. A. PELIZZA; LORENA ELIADES; M. C. N. SAPARRAT; M. N. CABELLO; A. C. SCORSETTI; C. E. LANGE

WORLD JOURNAL OF MICROBIOLOGY & BIOTECHNOLOGY

SPRINGER

Lugar: Berlin; Año: 2011 vol. 28 p. 1359 - 1366

0959-3993

Tropidacris collaris (Orthoptera: Romaleidae)(Orthoptera: Romaleidae) 10 is a large and voracious grasshopper, which, in recent years,is a large and voracious grasshopper, which, in recent years, 11 has become a recurrent pest in increasingly extensive areashas become a recurrent pest in increasingly extensive areas 12 of Argentina’s northern provinces. In the present work chi-of Argentina’s northern provinces. In the present work chi- 13 tinase activity was measured in 59 entomopathogenic fungaltinase activity was measured in 59 entomopathogenic fungal 14 isolates native to Argentina, and the relationship betweenisolates native to Argentina, and the relationship between 15 enzymatic activity and fungal virulence was assessed. Isolateenzymatic activity and fungal virulence was assessed. Isolate 16 LPSC 1067 caused the highest mortality on T. collarisLPSC 1067 caused the highest mortality on T. collaris 17 nymphs (97.7 ± 1.22%). Nine isolates caused no mortality,nymphs (97.7 ± 1.22%). Nine isolates caused no mortality, 18 while the remaining 49 caused mortalities ranging from 6.6 ± 0.3% (LPSC 770) to 91.06 ± 1.51% (LPSC 906). 19 6.6 ± 0.3% (LPSC 770) to 91.06 ± 1.51% (LPSC 906). 19 while the remaining 49 caused mortalities ranging from 6.6 ± 0.3% (LPSC 770) to 91.06 ± 1.51% (LPSC 906). 19± 0.3% (LPSC 770) to 91.06 ± 1.51% (LPSC 906). 19 Several isolates revealed chitinolytic capabilities on test 2020 plates, although the activities differed with respect to the 2121 ratio of the chitin-decay–halo and fungal-colony diameters. 2222 A principal component analysis indicated that isolate LPSC 2323 1067, obtained froma long-horned grasshopper (Orthoptera: 2424 Tettigoniidae), would be a potential candidate for T. collaris 25T. collaris 25 biocontrol because the strain exhibited the highestmortality, 2626 a shorter median lethal time, and a high enzymatic activity 2727 and growth rate.