The rising global population puts constant pressure on food production and intensive agricultural practices. Alongside the injudicious use of insecticides, this has modified agrarian ecosystems, causing more plant vectorborne viral diseases than ever before. The EU-funded GuardSym project will focus on the whitefly Bemisia tabaci, one of the worst pest insects, as a vector to investigate its multitrophic interactions with its bacterial symbionts, vectored virus, and host plants. The project will form the basis for the development of population modification strategies where natural populations are replaced with virus-resistant ones that can no longer cause plant disease.