Two species of predatory beetles that locate their prey, Ips pini, by responding to its aggregation pheromone have different chiral preferences to ispdienol than does the herbivore. This suggests that chiral disparity may provide some escape for bark beetles from predation, and that geographic variation in herbivore communication systems may be partially due to predator - imposed selection pressures. These results also suggest ways in which the semiochemical and biological control of North America's most damaging group of forest insects can be improved.