Selecting non-target species for arthropod biological control agent host range testing: evaluation of a novel method

Risk assessment to ascertain biosafety of biocontrol agents is often required by regulators before approval for release. Selecting the most informative non-target test species can be challenging. Here we compare traditional test list selection with a more objective method that selects species from a dataset of invertebrates from the receiving environment. A model, PRONTI (Priority Ranking of Non-Target Invertebrates) ranks species using five criteria: hazard, exposure, potential ecological impacts from exposure, anthropocentric value and testability. The braconid parasitoid Microctonus aethiopoides Loan released in New Zealand in 1982 for biocontrol of the pest weevil Sitona discoideus Gyllenhal was used as a case study. We compared species prioritised by PRONTI as worthy of testing with those selected prior to release. Several species which have been attacked in the field by M. aethiopoides since its release ranked highly suggesting that if PRONTI had been available pre-release, better predictions of non-target attack might have been made. The investment in time needed to adopt PRONTI needs to be balanced against its objectivity when comparing it with current conventional methods.