Fusarium head blight (FHB) caused by toxigenic Fusarium species is an economically important disease of wheat associated with losses in grain yield, quality and safety. FHB infection occurs during flowering coinciding with infestations by the grain aphid (Sitobion avenae). Thus, in the field, Fusarium pathogens and S. avenae co-occur on their shared host plant ultimately forming a tripartite interaction that can have consequences for disease severity and pest infestation. Our work has shown that the interaction between the pest and the pathogen is bi-directional and mediated by the host. The aphid is capable of substantially increasing disease progression and mycotoxin accumulation by pre-conditioning the host to fungal infection and by dispersal or spread of the pathogen. In contrast, Fusarium pathogens modify the host for the aphid through disease-induced host volatiles impacting on aphid activity and infestation on the disease and vice versa. Fusarium mycotoxins play an important role in altering the host-pathogen-pest interaction to render the host either repellent or more attractive to the aphid resulting in both cases for benefits for the pathogen. The work presented here provides novel insights on how two organisms sharing a host plant influence each other by modifying the host with important consequences for crop protection.