Two protagonists on aphidophagous patches: effects of learning and intraguild predation

In aphidophagous systems, trophic interactions between parasitoids and predators, termed intraguild predation, are frequently asymmetric. To mitigate predation risk for themselves and their offspring, intraguild prey may exploit associative learning to gain accurate information about patch quality. Therefore, costs of unnecessary escape behavior are avoided. We used sweet pepper patches (Capsicum annuum L., cv. ‘Mazurka’) (Solanaceae), sustaining Macrosiphum euphorbiae (Thomas) or Myzus persicae (Sulzer) (Homoptera: Aphididae) aphids, as a model system to quantify the foraging behaviors of the parasitoid Aphelinus abdominalis (Dalman) (Hymenoptera: Aphelinidae), when confronted with predatory second instar Chrysopa carnea (Stephens) (Neuroptera: Chrysopidae). The behavior of predator‐naive or predator‐experienced A. abdominalis foraging in a patch with or without C. carnea was recorded and analyzed using a multiple video observation system. We investigated (i) whether A. abdominalis could learn to detect the presence of a predator in a patch, (ii) the impact of the predator presence on the learning and motor learning of the parasitoid, and (iii) the effects of the aphid species on the guild interactions. Results showed that the presence of, or experience with the predator does not affect A. abdominalis learning or motor learning. We discuss the behavioral and ecological implications of our finding. Overall, predator‐induced aphid mobility increased the frequency and allocation time of Aphelinus oviposition activities, especially when Ma. euphorbiae was the host. The predator imposed indirect fitness costs on the parasitoid. Aphelinus abdominalis searched more often and longer, resulting in a tendency towards reduced Ma. euphorbiae parasitism rate in patches harboring C. carnea.