Technical scale production of encapsulated Saccharomyces cerevisiae and Metarhizium brunneum attractive to wireworms

ABSTRACTWireworms (Coleoptera: Elateridae) have recently become an increasing problem as agricultural insect pests due to the phasing out of effective control options. Entomopathogenic fungi such as Metarhizium brunneum have proven to be a promising microbial antagonist for wireworm control. Here, we tested whether the efficacy of M. brunneum can be increased through a combination with CO2, emitted by Saccharomyces cerevisiae, as an attractant (=attract-and-kill). We aimed at a technical scale production of a formulated biological control agent offering a practical and economically feasible application for wireworm control. Therefore, a novel technical formulation process for encapsulated S. cerevisiae (Attract beads) and M. brunneum (Kill beads) was investigated. For the bead production by jet cutting, the parameters nozzle diameter, pump speed, cutting device speed and collecting distance were evaluated. In order to dry the beads in a short time while maintaining a high cell viability, different drying ...