Plants harbor fungi asymptomatically within their tissues, called endophytes, which may protect the host plant against herbivores. The fungus Beauveria bassiana is an entomopathogen infecting insects, but it has recently also been demonstrated to grow as an endophyte within several plants. In this project I will evaluate the potential of the entomopathogenic fungus B. bassiana as an endophyte for biological plant protection against pests using wheat as a model host. In addition to effects on insect pests, I will for the first time study effects of endophytic B. bassiana on vertebrate pests, and I will establish whether pests favor or avoid infected plants over endophyte-free plants in preference tests. The project will initially establish methods for inoculation of plants with B. bassiana, validation of successful infections using advanced molecular methods followed by behavioral and physiological animal experimentation, and chemical analyses to separate and identify any volatile compounds emitted from the infected plants. This project is unique and highly inter-disciplinary with an unconventional combination of the disciplines of plant ecology, insect pathology and biological control implementing methods from agronomy, ecology, physiology, chemical ecology, and molecular biology. The knowledge obtained through this project will significantly contribute to the European scientific community within biological pest control and increase awareness of the utilization of endophytic fungi for crop protection. This project will likely become the baseline for subsequent studies in other agroecosystems and could pave the way for the effective deployment of entomopathogenic fungi as endophytes for biological pest control in important agricultural crops.