Efficacy of entomopathogenic fungi against Rhyzopertha dominica (Fabricius) (Coleoptera: Bostrichidae) under laboratory conditions

ANAHI MUSSO; JOSE EDUARDO MARCONDES ALMEIDA; SUSANA PADIN; ELIANA ORDOQUI; CLAUDIA CRISTINA LOPEZ LASTRA

Revista FCA UNcuyo

Universidad Nacional de Cuyo - Facultad de Ciencias Agrarias

Lugar: Mendoza; Año: 2020 vol. 52 p. 317 - 324

1853-8665

Rhyzopertha dominica (Fabricius) (Coleoptera: Bostrichidae) is a primary insect pest ofstored grains. The aim of this study was to evaluate the efficacy of 10 different isolates ofentomopathogenic fungi as biocontrol agents against R. dominica. The chosen isolates wereBeauveria bassiana CEP 545, CEP 560 and CEP 567, Metarhizium robertsii CEP 381 and CEP401, M. anisopliae sensu lato CEP 615, CEP 616 and CEP 617 and Cordyceps (=Isaria) fumosorosea CEP 303 and CEP 309. Insects were sprayed with a conidial suspension of eachfungus and incubated for 15 days under laboratory conditions. Insect mortality (expressedas percentage) and median survival times (MST) were estimated. Beauveria bassiana causedthe highest mortality (47-65%), whereas the other fungal isolates caused a maximummortality of 21%. The B. bassiana CEP 545 and CEP 567 isolates led to an MST of 8 and 9days, respectively. Among all the isolates tested, B. bassiana CEP 545 was the most efficientas a biocontrol agent. The median lethal concentration (LC50) of this isolate was calculatedwith five concentrations on day 15 after the treatment. The insect mortality increased withthe highest isolate concentrations and the LC50 was estimated in 9.54x109 conidia mL-1.This study confirmed that some B. bassiana isolates, especially CEP 545, could be used asbiocontrol agents against R. dominica.