Social learning in noncolonial insects?

Social-information use has generated great interest lately and has been shown to have important implications for the ecology and evolution of species [1-6]. Learning about predators or predation risk from others may provide low-cost life-saving information and would be expected to have adaptive payoffs in any species where conspecifics are observable and behave differently under predation risk. Yet, social learning and social-information use in general have been largely restricted to vertebrates ([1-3, 5, 7-9], but see [10-16]). Here, we show that crickets adapt their predator-avoidance behavior after having observed the behavior of knowledgeable others and maintain these behavioral changes lastingly after demonstrators are gone. These results point toward social learning, a contingency never shown before in noncolonial insects. We show that these long-lasting changes cannot instead be attributed to long re-emergence times, long-lasting effects of alarm pheromones, or residual odor cues. Our findings imply that social learning is likely much more phylogenetically widespread than currently acknowledged and that reliance on social information is determined by ecological rather than taxonomic constrains [17, 18], and they question the generally held assumption that social learning is restricted to large-brained animals assumed to possess superior cognitive abilities.