Based on these facts we compared the olfactory response of predatory mite P. persimilis between lima bean plants exposed to VOCos and VOCwt followed or not by T. urticae infestation (Figure 4A). As expected, VOCos-receiver plants fed upon by T. urticae were preferred by P. persimilis, compared to the infested VOCwt-receiver plants (P,0.05, binomial test). In contrast, the predatory mites did not unambiguously discriminate volatiles of VOCos-receiver bean plants from those of the VOCwt-receiver plants in the uninfested condition (Figure 4A). Similar effects were observed on the flight responses of C. kariyai females to the two groups of VOCos-receiver and VOCwt-receiver maize plants in a cage. The parasitoids did not discriminate volatiles of VOCos- receiver plants from those of VOCwt-receiver plants in the uninfested conditions but started to prefer the VOCos-receiver plants relative to VOCwt-receiver plants after M. separata infestation (Figure 4B).