Chemical Composition and Evaluation of Insecticidal Activity of Seseli bocconei Essential Oils against Stored Products Pests

In this study, the chemical composition of the essential oils (EOs) obtained from different aerial parts (flowers, leaves, and stems) of Seseli bocconei Guss., a wild species endemic of Sicily, was investigated. Furthermore, the EOs’ biocidal effects towards two pests of stored products, Sitophilus oryzae and Callosobruchus maculates, were evaluated. This activity was evaluated in Petri dish bioassays to establish the survival rate of adults treated with the EOs comparing them with solvent and a commonly used insecticide (pyrethrum). The data obtained from the toxicity bioassay evidenced that stems’ EOs and leaves’ EOs have a contact/fumigation effect towards the two insect species tested, while the EOs from the flowers did not exhibit a different mortality than the solvent. The EOs from the stem and leaves of S. bocconei, tested at 10 mg/petri dish, determined a LT50 of 53.38 and 42.97 h, respectively, on S. oryzae adults, and of 45.23 and 42.97 h, respectively, on C. maculatus adults. The promising bioactivity of S. bocconei leaves’ EOs and stems’ EOs toward S. oryzae and C. maculatus is encouraging in the perspective to test these oils and their main constituents for further experiments in the laboratory and field.