[en] Entomopathogen microorganisms such as fungi are biological control agents that are able to disturb host plant – herbivore relations due to their interactions with some target insects. Particularly, these fungi grow on insect hosts, secrete secondary metabolites and finally kill them. Here, we investigated the influence of diverse entomopathogenic fungi (Beauveria, Metarhizium, Aspergillus) on different insect hosts but also on non target beneficials. Aphids and bugs for herbivore guild while aphidophagous predators for tritrophic interactions were selected respectively. Multitrophic approaches were developed to determine potential effects of these fungi on the behaviour of intra- and interguild protagonists. Beside the observation of insect developmental parameters, the orientation preferences were tested by taking into consideration the insect and/or plant fungal infection status. Olfactometry devices were used, complemented by choice tests in Petri dishes and analysis of emitted volatile organic compounds. Also, electropenetrography (EPG) technique was developed to assess the changes of aphid and bug sucking feeding behaviour related to fungal infestation status. Our results are discussed in relation to the complexity of interactions at different trophic levels, with a particular focus on behavioural more than only developmental aspects of the impact of entomopathogenic fungi in plant - insect interactions.
