Entomopathogenic nematodes associated with Swiss agricultural soils: improving soil health by integrating soil and chemical ecology approaches

Entomopathogenic nematodes (EPNs) belonging to the families Heterorhabditidae and Steinernematidae are known to be excellent candidates for biological control of numerous soil insect pests. For decades, EPNs have been widely used as biological control organisms in agriculture. Research on belowground tritrophic interactions (plant-insect-nematode) suggests that nematode behaviour can be manipulated in order to increase their efficiency in controlling root herbivores. Current knowledge on EPNs native species from Switzerland and their efficiency as biocontrol agents against root herbivores is scarce. Moreover, the interactions among these nematode species and the presence of other beneficial organisms such as the root colonizing bacteria of the genus Pseudomonas and arbuscular mycorrhizal fungi are unknown. The aim of this project is to evaluate the efficiency of native EPNs species in controlling larvae of root herbivores feeding on wheat plants in different Swiss soils and distinct ecological scenarios. We will integrate information from different soil and chemical ecology approaches to evaluate the EPN effectiveness under different types of soils, to determine the existence of an herbivore induced plant volatile in wheat roots attacked by a specialist (Delia coartacta) and generalist (Diabrotica balteata) and to figure out the interactions of EPNs with other beneficial soil organisms, such as the root colonizing Pseudomonas bacteria and arbuscular mycorrhizal fungi.