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Testing the toolbox – reducing uncertainty around non-target impacts

The aim of this project is to validate multiple tools that have been developed in previous B3 projects (Table 1).


These tools provide predictions of the risk posed by new biological control agents (BCAs) to non-target species before their introduction. The tools aim to reduce uncertainty around the likelihood of a BCA having negative effects on other species following their release in New Zealand. Validation of these predictions would increase the confidence with which each can be deployed by end-users.


Table 1: Tools used in this study to produce predictions of the species that could be impacted by a BCA, and the potential end-users of those tools.

New chemical ecology methodsBCA’s physiological host range using chemical ecologyApplicants and researchers conducting risk assessment of the proposed BCA


Machine learning modelsBCA’s phylogenetic/trait-based host range
Bayesian Network model (BAIPA)Probability of a non-target species being attacked in individual ecosystems/habitats
Food web toolIdentification of species at risk from indirect effects
Risk threshold modelLikelihood of non-target effects based on laboratory host range testsDecision-makers (e.g., EPA, MPI, DOC) regarding the release of the BCA
Scale of risk toolOverall risk of the BCA compared with others that have been released



The research team will use four case studies to validate the predictions:

(1) will assess the effect of a BCA on the food web

(2) will test a range of predictions using an invasive species that is likely to be exerting effects on non-target species (i.e., a positive control)

(3) will test the effect of a BCA on predicted non-target populations

(4) will test the stability of those effects over time.


Māori students (graduate and undergraduate) are involved in the research to increase capability in biocontrol research. In addition, we are conducting a series of wānanga (workshops) with two aims: (a) to understand the perceptions Māori have of biological control introductions and the effect on Te Taiao (co-ordinated with project A22.3); (b) to understand use and usefulness of the toolbox for BCA applicants.


Contact Project Leader Jacqui Todd: [email protected]


Researchers searching for non-target hosts of biocontrol agents in abandoned apple orchard (Photo by Andrew Pugh, Scion)