Learning of visual cues in the fruit fly parasitoid Psyttalia concolor (Szépligeti) (Hymenoptera: Braconidae)

Abstract

Parasitoids can learn to associate information from the host microhabitat with ovipositional experiences. Psyttalia concolor (Szepligeti) is a koinobiont larval-pupal endoparasitoid of many tephritids. In P. concolor, the role of visual cues learning during host microhabitat location has not been greatly explored. Here, the innate preferences of P. concolor for colours, shapes and patterns were investigated, as well as the effects of sensitisation and associative learning regarding female preferences for these visual cues. Naive females showed no innate preferences for a particular colour, shape or pattern, and their responses were unaffected by sensitisation. In contrast, P. concolor females developed clear preferences after training on Ceratitis capitata larvae associated with a given colour, but not when they were trained on different shapes or patterns. Our findings on how P. concolor learn to pick up visual cues could help to define its optimal environment, and to predict its natural post-release distribution in biological control programs.