Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 3/12/2010
Publication Date: 5/12/2010
Citation: Smith, L. 2010. Assessing difficult targets - when is biological control feasible?. Meeting Abstract. IOBC Symposium, May 11-13, 2010, Niagara Falls, Ontario, Canada.
Technical Abstract: How can we, a priori, determine whether a project is likely to be successful and when should we abandon prolonged projects that have not yet controlled the target pest? I review a variety of examples involving biological control of arthropods (filth flies at dairy farms, a grain weevil in stored maize, and a tetranychid mite on cassava) and weeds (spotted knapweed, yellow starthistle and Russian thistle). Many pest targets, especially those in highly managed systems, depend on integration of biological control with other control strategies, which is the case for filth flies at dairy farms and a grain weevil in stored maize. In projects that depend primarily on classical biological control, success requires finding agents that are sufficiently host specific to be safe, and that multiply sufficiently to impact the target population. Distance of phylogenetic relatedness between the target and nontarget species, and the rate of discovery of species during foreign exploration are helpful predictors. Efficacy of prospective agents is more difficult to predict, but it depends on adaptedness to the abiotic environment, degree of direct impact on the target pest, and invulnerability to natural enemies. Several "old" projects resulted in success because of the persistence to discover new agents, or because of advances in taxonomic understanding.