Costs of persisting unreliable memory: reduced foraging efficiency for free-flying parasitic wasps in a wind tunnel

Abstract: Parasitic wasps, such as Cotesia glomerata, are known to improve their foraging efficiency after learning of herbivore-induced plant volatiles (HIPVs) upon encountering their hosts on these plants. However, learned information on these HIPVs could become unreliable by no longer correctly predicting host presence, due to spatial and temporal variation of herbivore communities. Here we present how persistent memory, containing unreliable information, affects the foraging efficiency for hosts in Cotesia glomerata. Wasps were given different conditioning experiences that result in different levels of memory persistence, after which they were allowed to forage in a wind tunnel setup that was either conflicting or congruent with their conditioning experience. Based on this experiment we conclude that persistent memories, such as formed after 3 experiences spaced in time, can lead to maladaptive foraging behaviour if the contained information becomes unreliable. Full details of this study can be found in the original publication of de Bruijn et al., 2018.