Identifying emerging weeds as targets for biocontrol in New Zealand: what can we learn from the Survey of Rural Decision Makers?

New Zealand is challenged by exotic weeds that threaten ecosystems and productive land. Weed biocontrol, involving introduced natural enemies like insects or fungi, offers a sustainable solution but is often limited to widespread weeds due to high upfront costs. Targeting emerging weeds early, especially those already biocontrolled elsewhere, could be more efficient. We examine data from a Survey of Rural Decision Makers (SRDM) to identify whether important emerging weeds in the rural sector have been overlooked, and to assess the potential for cost-effective biocontrol using agents developed elsewhere. Since 2013, SRDM surveys c. 5,000 rural stakeholders on land management issues, including weeds, biennially. In 2019, 2021, and 2023, respondents identified emerging weeds they expected may require management within five years. Most weeds identified are already targeted for biocontrol, confirming the effectiveness of current prioritisation. In this study, we identified weeds of concern to farmers that have been targeted with biocontrol elsewhere, highlighting the potential for cost-effective repeat biocontrol programmes. SRDM provides a valuable source for insights into emerging weed threats, complementing existing processes. Monitoring these trends can refine biocontrol priorities, ensuring timely, strategic interventions for weed management in New Zealand.