Mexican thorn is the most damaging invasive species on Ascension Island. Introduced purposely, this weed has naturalised and spread rapidly, outcompeting native vegetation and negatively impacting wildlife, while encouraging other invasive rodents. This project will take a strategic and integrated approach to controlling thorn on Ascension including a rigorous assessment of further biocontrol and improved chemical and mechanical treatment. The project will ensure local capacity is built to deliver those most appropriate and cost-effective for Ascension. The outcome will be a step-change in our ability to control Mexican thorn and result in a long-term contraction of its range and restoration of habitats.