Effects of the combination of phytosanitary products and entomopathogenic fungi for the control of insect pests

Abstract

The combination of phytosanitary products (PPs) and entomopathogenic fungi (EF) can be used in integrated pest management (IPM) programs. The aim of the present work was to study the effects of PPs, commonly used in Argentina and Brazil, combined with Beauveria bassiana, Metarhizium anisopliae and Cordyceps (Isaria) fumosorosea, for the control of insect pests in the post-harvest of wheat, under laboratory and semi-field conditions. In vitro compatibility was assessed using the biological index (BI) based on the percentages of fungal vegetative growth, sporulation, and germination. The number of colony-forming units (CFUs) was evaluated under semi-field conditions. In all cases, PPs evaluated reduced the mean germination percentages as compared with the control. According to the BI, none of the treatments evaluated were compatible with any of the three isolates, except for the treatment L7 of Lambdacialotrine, which was moderately toxic on B. bassiana. Evaluated PPs did not affect the number of CFUs of B. bassiana or C. fumosorosea with respect to the control. In contrast, PPs affected the number of CFUs of M. anisopliae, independently of the persistence time of fungi on the grains. PPs and EF should be applied separately under semi-field conditions, however, further research under field conditions should be conducted to confirm the compatibility within an IPM strategy.