The receiver plants were assessed immediately (day 0) after exposure to either VOCwt or VOCos, and subjected to one day post-herbivory by T. urticae (A) orM. separata (B). Uninfested plants incubated for 1 day after VOC exposure served as controls. The bar represents the overall percentages of arthropods choosing either of the odor sources. The figures in parentheses represent the numbers of predators that did not choose either odor source (no choice subjects). A binomial test was conducted to evaluate whether the result in each experiment differed from the null hypothesis in which predators showed a 50:50 distribution between the two odor sources (*: P,0.05, ns: P.0.05).