Maureen O’Callaghan and Michael Brownbridge
Biocontrol, Biosecurity & Bioprocessing, Lincoln Science Centre AgResearch Ltd Christchurch 8140 New Zealand.
A range of bacteria, viruses, fungi, protists and nematodes has been used for control and eradication of invasive pests. Insect pathogens vary in key characteristics such as specificity, mode of action and persistence, all of which determine their safety profile with respect to impacts on non-target species. Laboratory testing against beneficial species and post-application monitoring of impacts support the view that, while they are not entirely free of hazards to non-target organisms, in comparison with other control methods these microbial control agents are environmentally benign. When considering actions against new pest incursions, where the potential for damage to crops and/or impacts on indigenous ecosystems is enormous, rapid steps must be taken to mitigate or eradicate these pests. In such situations, biopesticides can be attractive control options, and their use is likely to have minimal impact on beneficial and other non-target species. Such advantages have been clearly demonstrated with Bacillus thuringiensis, which has not precipitated any major ecological disturbances, even when used in very intensive and prolonged eradication programmes.