Selecting biological control agents

Predicting direct non-target impacts

Modelling non-target impacts

The focus of this section is on evaluating whether models can help predict the impacts of a candidate biological control agent (BCA) on its target and nontarget hosts prior to release. Note that this also has direct application to the broader issue of predicting the risks posed by any new species, whether deliberately or accidentally introduced.

A particular challenge for models is to make effective use of the limited information that is typically available before an introduction. In most cases we will know the life cycle and offshore distribution of the candidate BCA. Pre-release testing is likely to provide indications of host range in the proposed area of introduction, attack rates, and development rates at particular temperatures. The literature may provide further information, but for the purpose of developing general approaches to predicting impacts, the models must be able to be parameterised from these limited data.

A vision for the future is that a suite of validated modelling approaches will be available for predicting the impacts of candidate BCAs on resident species. The models will utilise different levels of biological detail so that some insight can be derived from the most minimal data, with greater accuracy and precision being possible with increasing biological knowledge. Some information on resident species is needed, but the models will help to target the collection of relevant data and utilise it for different introductions. Ultimately, the models will allow more robust decisions to be made about deliberate introductions and their likely risks and benefits.

This section briefly reviews the models and approaches that have been developed to date, and describes how they could be further progressed to better predict the impacts of deliberate introductions.