AbstractConservation biological control aims to enhance the efficacy of biological control agents, such as predators and parasitoids, by providing them access to key requisites, for example floral or other alternative food resources. However, the occurrence of floral resources in agricultural systems may have positive effects not only on natural enemies but also on the pests themselves. For this reason, we have studied in laboratory common Mediterranean plants as potential food resources for an important lepidopteran olive pest, the olive moth, Prays oleae. The effects of 15 wild flowering plants from olive grove ecosystems, and four sugars present in floral nectars, on key biological parameters of P. oleae (i.e. longevity, pre‐oviposition and oviposition periods, fertility and fecundity) were evaluated. The three pest generations were analysed. Only few of the plants tested increased some reproductive parameters of the insect individuals compared to the water‐fed controls, while sugars generally improved them. This could be due to a higher concentration of sugars provided by individual sugars than by flower nectar. These results indicate that, in general, P. oleae will not benefit from the availability of the floral resources tested.