Insect biological control and non-target effects: a European perspective

A 4-year research project on 'Evaluating Environmental Risks of Biocontrol Introductions in Europe' (ERBIC) is described, and early results are presen ted. The project focuses on arthropod biological control (using both microb ial and macrobial agents), and uses literature review, case studies with em pirical work and various types of modelling to illuminate risk to non-targe t organisms. These methods will hopefully lead to the development of usable methodologies and guidelines for risk assessment in arthropod biological c ontrol, by the project's completion in 2002. Reviewing existing published and unpublished data on the classical biologic al control of insects (a first step in this project) has revealed that for only 1.5% of introductions is there some data regarding the realized field specificity of the agent. For a tiny proportion of introductions there are quantitative data regarding mortality in non-targets. From these cases, wit h some extrapolation, we can deduce that 10% or less of classical biologica l control introductions in the past led to population changes in non-target s. Data on population-level effects from simulated uses or trials suggest t hat 49% of inundative or augmentative uses of agents led to (local, short-t erm) population changes for non-targets. Case studies into: (i) exotic specialist parasitoids used in the greenhouse ; (ii) exotic generalist parasitoids used inundatively in the field; (iii) exotic generalist predators used inundatively; and (iv) fungi and nematodes used as bioinsecticides, are outlined. The results so far demonstrate: (i) the apparent safety of Trichogramma (generalist parasitoid) releases in Sw itzerland, despite rare species within its host range; (ii) the lack of ove rwintering capability in northern Italy in one generalist predator (Orius i nsidiosis), but its presence in another (Harmonia axyridis); (iii) little e vidence that the predation of certain stages of native predators by introdu ced predators will enhance environmental risks in the cases in question; an d (iv) the apparent safety of bioinsecticide releases of particular pathoge n strains for important naturally occurring predators when exposed directly or by feeding on infected prey.