Plants may detect imminent threat of herbivore damage, even before the initiation of feeding, through various environmental cues. We investigated whether the presence of a generalist predator could serve as an environmental cue that primes plant defenses prior to herbivory. We examined the expression level of a few defense genes using the technique of real-time PCR in young tomato plants (Solanum lycopersicum L.) when caged with the facultative predator Orius insidiosus (Say)(Heteroptera: Anthocoridae). We discuss results with respect to the potential of tomato plants to induce physiological defenses under varying environmental stimuli.