Pre-emptive classical biological control: a novel approach to increase preparedness for potential biosecurity threats

Recent years have seen a substantial increase in invasive insect species invading countries worldwide. Many of these insect species (e.g. brown marmorated stink bug) are highly polyphagous and are considered serious as high-risk biosecurity threats to valued plant systems in many countries, and can result in multi-billion dollar losses to agriculture and horticulture industries. Classical biological control (CBC) is frequently adopted for sustainable management of invasive arthropod pests, and has often proved highly cost effective. However, the severity and imminent nature of some new high-risk insect threats means that it would be highly advantageous if we could avoid waiting for a pest to arrive before adopting CBC. Pre-emptive biocontrol is a novel approach that provides the opportunity to develop CBC for invasive pests before they arrive in the country at risk of introduction. A critical aspect of this approach is that risk assessment is carried out in advance of the arrival of the pest. Implementing pre-emptive biocontrol risk assessment means that natural enemies can be selected, screened in containment or abroad and potentially pre-approved prior to a pest establishing in the country at risk, thus improving CBC effectiveness. However, such an approach may not always be feasible (e.g., suitable natural enemies may not be available, logistic aspects may not allow this). This presentation will show the results of two pre-emptive biocontrol projects, and will discuss a decision framework that can be used to assess the feasibility of conducting pre-emptive risk assessment for candidate biological control agents against high-risk insect pests.