An ecological perspective to host-specificity testing of biocontrol agents

摘要

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. Host-specificity 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 host-range of long-established 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 Zealand's Environmental Risk Management Authority for approval to release the parasitoid Pseudaphycus maculipennis (Hymenoptera: Encyrtidae) against the obscure mealybug, Pseudococcus vibuhi (Hemiptera: Pseudococcidae). The data from New Zealand and elsewhere indicate that new encyrtid parasitoids of mealybugs have shownno propensity to attack native species over time.