Biological control of invasive plants 2026/27

Invasive non-native plant species like Himalayan balsam (HB) and Australian swamp stonecrop (ASS) significantly reduce biodiversity by crowding out native vegetation and limiting plant and animal species diversity. ASS deoxygenates water and reduces numbers of small invertebrates, amphibians and fish. Traditional methods for the control of HB and ASS are generally ineffective. Chemical control with herbicides is the most effective but often inappropriate next to or in waterbodies or protected nature conservation sites.

The contract includes field and lab based experiments and release of relevant biological control agents (mites and rust fungus) to manage these two plant species. Pilots and testing projects are an important part of understanding the benefits and effectiveness of biological controls and the problems these species cause. This investment now in biological control methods and their effective implementation have the potential to provide considerable benefits in terms of reduced costs and impacts as described above in future years.