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

Insect pests are worldwide a main cause of losses in stored food. Sitophilus oryzae (L.) (Coleoptera Curculionidae) is one of the most widespread and destructive primary insect pests of stored cereals and shelved products. Control insect pests mainly depends upon synthetic insecticides and fumigants, which however, have undesirable effects on non-target organisms, persistence of residues with environment and human health concern. Parasitoids and predators of storage pests are notable for their potential as biological control. 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 pteromalid wasp Lariophagus distinguendus (Hymenoptera Pteromalidae). Bioassays have been conducted in an olfactometer by a two-choice test. The results showed that C. verum EO, is attractive towards S. oryzae but repellent against L. distinguendus depending on the dose. These results suggest that C. verum EO, in appropriate doses, may be used in selective traps attractive to the insect pest but avoided by the parasitoid, in integrated pest management programs of warehouse stored-product pests’ infestation.