Abstract

Learning in the context of foraging is a widespread phenomenon in both vertebrate and invertebrate animals. Among arthropods, learning has been mainly studied in insects and within insects in eusocial and parasitoid hymenopterans. In contrast, learning is far less well documented for predatory arthropods, in particular mites. Studies on mites dealt with herbivorous spider mites and long-distance olfactory learning by predatory mites. There exist no reports about the effects of learning in early life on adult performance. However, experience with a given prey in the early stages of life may have profound impacts on feeding performance of adults. Moreover, although learning is generally assumed to be adaptive, the adaptive significance of learning has been rarely documented. I here give two examples of how learning in the juvenile phase may affect predation performance and fitness of adult predatory mites. The first example deals with adaptive learning in the specialist predatory mite P. persimilis. Adults emerging from juveniles experienced with alternative prey attacked this prey sooner than those emerging from inexperienced juveniles. Learning was adaptive because it increased the survival prospects of adults. The second example shows that adult generalist predatory mite females, Neoseiulus californicus, have an improved predation performance on the alternative prey western flower thrips, Frankliniella occidentalis, after having had contact with this prey in the early stages of development. I argue that the putative learning mechanisms are priming/sensitization and/or food imprinting.