Biocontrol of Cymbalophora rivularis (Menetries) (Lepidoptera: Erebidae) larvae by entomopathogenic bacteria and fungi

Abstract

BackgroundSainfoin, alfalfa and clover are important forage crop plants in terms of their food value, efficiency and adaptation capabilities. Cymbalophora rivularis (Menetries, 1832) (Lepidoptera: Erebidae) causes significant damage to these plants. Chemicals are not recommended for pest control. Cultural pest control practices also remain insufficient. In this study, which was conducted to determine whether biological control can be applied in pest control, the pathogenic effects of Pseudomonas putida K-19B, Pantoea agglomerans RK-79 and RK-92, Bacillus megaterium TV-3D, P. fluorescens RK-1979, B. pumilus RK-1980 bacterial strains at a concentration of 1 × 108 CFU/ml and Beauveria bassiana (Bals.-Criv.) Vuill. (Cordycipitaceae) ET 10 fungal isolate at a concentration of 5.7 × 105 conidia/ml were tested under controlled conditions.ResultsAccording to the results of this study, at the end of 216 h, the tested biological control agent showed an efficacy ranged from 43.33 to 96.67% in the 1st and 2nd larval instars and 70 to 95% in the last instar larvae of C. rivularis. In the case of applications to 1st and 2nd larval instars, after 216 h, the efficacy of ET 10 fungal isolate was 96.67 and 83.33% of K-19B bacterial strain. In the last instar larvae, after 216 h, the efficacy of the strains TV-3D, K-19B and RK-1979 was 95, 90 and 90%, respectively. The efficacy of ET 10 and K-19B applications was found to be statistically not different from the efficacy of pathogenic application.ConclusionEnvironmentally friendly P. putida and B. megaterium bacterial strains and B. bassiana fungal isolate were determined and can be successfully used in the biological control of this pest.