Expanding our eradication toolbox in NZ: Is biocontrol a feasible tool to incorporate in a response?

Invasive insect species, including the brown marmorated stink bug (BMSB, Halyomorpha halys), pose serious threats to biodiversity, food security, and economies globally. New Zealand faces potential multi-billion dollar losses in its agricultural and horticultural sectors due to the impact of BMSB.

Classical Biological Control (CBC) is frequently adopted as a cost-effective component of long-term integrated pest management programmes, but it typically experiences multi-year delays in the approval and implementation phases, during which time pest impacts accelerate.

A timelier approach could involve the pre-emptive approval to introduce and release a new Biological Control Agent (BCA) or leveraging existing BCAs through inundative biocontrol, aiming for eradication during an incursion response. However, no known successes have been recorded globally using this strategy in an eradication response.

This research seeks to fill this knowledge gap, focusing on assessing the feasibility of using inundative biological control as a viable eradication tool. To do so we are developing and validating a mathematical model of the eradication process. The model leverages data from different insect groups, and its parameterization is backed by a comprehensive review of both published and unpublished literature.

We are particularly interested in identifying the most important parameters for predicting the success or failure of various eradication tools, including BCAs. By exploring the potential of BCAs like the Samurai wasp (Trissolcus japonicus) — already approved for release in New Zealand in the event of a BMSB incursion — in combination with other tactics such as mass trapping and insecticide treatments, the study aims to provide a new approach to invasive insect eradication.

Contact Project Leader Rachael Horner: rachael.horner@plantandfood.co.nz