A laboratory assessment for the potential of entomopathogenic fungi to control Rhyzopertha dominica (F.) (Coleoptera: Bostrichidae)

Abstract

The pathogenecity of Beauveria bassiana and Isaria fumosorosea was evaluated by immersion bioassays against adults and 3rd instar grubs of Rhyzopertha dominica during years 2011-2013. Five concentrations i.e., 1.0- 5×108 spores/ml of each fungus were made by serial dilution. The results depicted that lowest LT50 values with highest concentration of B. bassiana 5×108 spores/ml were 3.60 days for both stages. Conversely, B. bassiana (LC50) on 7th day post-treatment were 1.54×108 and 2.29×108 spores/ml both stages, respectively. The lowest LT50 values with highest concentration of I. fumosorosea 5×108 spores/ml were 3.58 and 3.04 days for both adults and grubs, respectively, while the LC50 value of I. fumosorosea on 7th day were 1.39×108 and 2.23×108 spores/ml for both stages, respectively. Comparison of LC50, LT50 and percent mortalities indicated fungal virulence to R. dominica. The findings of the current research illustrate that these fungi can be used for the management of R. dominica.