Connecting the dots: Do laboratory bioassays predict disruption of BC in the field?

Laboratory tests of nontarget effect of pesticides on natural enemies have been conducted for decades in hopes of preserving biological control. This process has been institutionalized by the IOBC with specific protocols involving a series of tests. In the organophosphate era, acute toxicity was typically the only form of routine screening, and was likely reasonably predictive. Newer pesticides, however, have a wider variety of modes of action, presumably on pest and predator alike. Sublethal effects of the new pesticides may greatly exceed the lethal effects, increasing the complexity of testing and decreasing the reliability of predictions. In addition, simple versus complex predator-prey systems may greatly alter field outcomes. Two case studies are presented, a simple tetranychid mite/predatory phytoseiid system, and a more complex system of an aphid prey, with a natural enemy complex composed of a specialized parasitoid and generalist aphidophagous predators from four taxa.