An ecological perspective to hostspecificity testing of biocontrol agents

Abstract

Classical biological control programmes have historically been viewed positively but in the new social context of all new invaders are bad the perceived environmental threats from new natural enemies are regarded by some as unacceptable Hostspecificity testing of proposed biocontrol agents is required to provide environmental safety assurances but laboratory methods are likely to be flawed and cannot mimic the reality of nature It is proposed that analysis of the realised hostrange of longestablished exotic parasitoids may help to predict the impacts of proposed new biocontrol agents and supplement laboratory testing This approach was used in 1999 when applying to New Zealands Environmental Risk Management Authority for approval to release the parasitoid Pseudaphycus maculipennis (Hymenoptera Encyrtidae) against the obscure mealybug Pseudococcus viburni (Hemiptera Pseudococcidae) The data from New Zealand and elsewhere indicate that new encyrtid parasitoids of mealybugs have shown no propensity to attack native species over time