Selective activity of Cinnamomum verum essential oil against the rice weevils Sitophilus oryzae and its parasitoid Lariophagus distinguendus in post-harvest pest management

Abstract: Insect pests are a worldwide main cause of losses in stored food. Sitophilus oryzae (L.) (Coleoptera: Drypophthoridae) is one of the most widespread and destructive primary insect pests of stored cereals and shelved products. Currently, insect pests control mainly depends upon synthetic insecticides, which however, have undesirable effects on non-target organisms, environment and human health. As an alternative, insect parasitoids and predators may have a potential. In this study, we evaluated the biological activity (repellency/attractiveness) of the essential oil (EO), extracted from the bark of Cinnamomum verum J. Presl. against S. oryzae and its parasitoid, the wasp Lariophagus distinguendus (Hymenoptera: Pteromalidae). Two-choice test Bioassays conducted in olfactometer showed that, at the same dosage, C. verum EO is attractive towards S. oryzae but repellent against L. distinguendus. These results suggest that C. verum EO, in appropriate doses, may be used in selective traps attractive to the insect pest in integrated pest management programs of warehouse stored-product pests’ infestation.