Marina Vemmer1, Mario Schumann2, Wilhelm Beitzen-Heineke3, Bryan W French4, Stefan Vidal2, Anant V Patel5. 1. Fermentation and Formulation of Biologicals and Chemicals, Faculty of Engineering and Mathematics, University of Applied Sciences, Bielefeld, Germany. 2. Agricultural Entomology, Department for Crop Sciences, University of Göttingen, Göttingen, Germany. 3. BIOCARE Gesellschaft für Biologische Schutzmittel mbH, Einbeck, Germany. 4. North Central Agricultural Research Laboratory, Agricultural Research Service, United States Department of Agriculture, Brookings, SD, USA. 5. Fermentation and Formulation of Biologicals and Chemicals, Faculty of Engineering and Mathematics, University of Applied Sciences, Bielefeld, Germany. anant.patel@fh-bielefeld.de.
Abstract
BACKGROUND: CO2 is known as an attractant for many soil-dwelling pests. To implement an attract-and-kill strategy for soil pest control, CO2 -emitting formulations need to be developed. The aim of the present work was to develop a slow-release bead system in order to bridge the gap between application and hatching of western corn rootworm larvae. RESULTS: We compared different Ca-alginate beads containing Saccharomyces cerevisiae for their potential to release CO2 over a period of several weeks. The addition of starch improved CO2 release, resulting in significantly higher CO2 concentrations in soil for at least 4 weeks. The missing amylase activity was compensated for either by microorganisms present in the soil or by coencapsulation of Beauveria bassiana. Formulations containing S. cerevisiae, starch and B. bassiana were attractive for western corn rootworm larvae within the first 4 h following exposure; however, when considering the whole testing period, the maize root systems remained more attractive for the larvae. CONCLUSION: Coencapsulation of S. cerevisiae, starch and B. bassiana is a promising approach for the development of attractive formulations for soil applications. For biological control strategies, the attractiveness needs to be increased by phagostimuli to extend contact between larvae and the entomopathogenic fungus growing out of these formulations.
BACKGROUND:CO2 is known as an attractant for many soil-dwelling pests. To implement an attract-and-kill strategy for soil pest control, CO2 -emitting formulations need to be developed. The aim of the present work was to develop a slow-release bead system in order to bridge the gap between application and hatching of western corn rootworm larvae. RESULTS: We compared different Ca-alginate beads containing Saccharomyces cerevisiae for their potential to release CO2 over a period of several weeks. The addition of starch improved CO2 release, resulting in significantly higher CO2 concentrations in soil for at least 4 weeks. The missing amylase activity was compensated for either by microorganisms present in the soil or by coencapsulation of Beauveria bassiana. Formulations containing S. cerevisiae, starch and B. bassiana were attractive for western corn rootworm larvae within the first 4 h following exposure; however, when considering the whole testing period, the maize root systems remained more attractive for the larvae. CONCLUSION: Coencapsulation of S. cerevisiae, starch and B. bassiana is a promising approach for the development of attractive formulations for soil applications. For biological control strategies, the attractiveness needs to be increased by phagostimuli to extend contact between larvae and the entomopathogenic fungus growing out of these formulations.
Authors: Vivien Krell; Desirée Jakobs-Schoenwandt; Marcus Persicke; Anant V Patel Journal: World J Microbiol Biotechnol Date: 2018-07-03 Impact factor: 3.312