Mikania micrantha (mile-a-minute weed or South American Climber) is a major invasive alien weed in many of the tropical moist forest regions of Asia. This neotropical vine is able to smother plants in agricultural ecosystems, agroforestry and native habitats. Conventional control methods of manual removal (slashing) or herbicide application, are expensive, ineffective, not sustainable, and can be environmentally damaging. Classical biological control was considered the best option to manage this weed, and CABI was funded by DIFID (UK- Department for International Development) to implement this strategy in India. The research culminated in the release of a coevolved, host specific, rust pathogen (Puccinia spegazzinii), from the South America native range of the weed, into Kerala and Assam. This rust pathogen infects all aerial parts of the plant (leaf, petiole and stem), leading to cankering and whole plant death (see image below).