Plant fungal pathogens are a serious threat to global food security and biodiversity. They cause yield losses of up to 80% in calorie crops and epidemics in natural ecosystems leading to population decline and localised extinctions. Disease management relies heavily on synthetic fungicides, however, these are expensive, slow to develop, have low public acceptance, and are harmful to humans and the environment. RNA biopesticides are a highly targeted environmentally friendly alternative. Pathogen-specific double-stranded RNA (dsRNA) is spray applied to plants to trigger RNA interference in the infecting pathogen, silencing targeted genes and inactivating the pathogen. We have been exploring the use of dsRNA as a novel control for diseases such as myrtle rust. Myrtle rust, caused by the rust fungus Austropuccinia psidii, arrived in Australia in 2010 and is pushing iconic Australian Myrtaceae species to the brink of extinction. Critically endangered species are at risk, as well as species significant to indigenous culture and industry (native forestry, cut flower, essential oils, honey, native foods). We have demonstrated that dsRNA is effective as a preventative and curative myrtle rust treatment1,2. Significant reductions in disease coverage were observed in plants treated with dsRNA targeting essential fungal genes 48 h pre-infection up to 14 days post-infection. For curative treatments, improvements in plant health were seen 2–6 weeks post-infection. We are now establishing this approach for other pathogens such as Phytophthora. Our findings demonstrate the potential of dsRNA for management of plant fungal diseases, specifically the >10-year epidemic of myrtle rust in Australia.