Bioactivity of Essential Oils from Mediterranean Plants: Insecticidal Properties on Sitophilus zeamais and Effects on Seed Germination

The essential oils extracted from plants are potentially an interesting alternative to the chemical control of insect pests of stored grains. Goal of the study was the evaluation of bioactivity of essential oils extracted from four Mediterranean plants, Laurus nobilis, Citrus bergamia, Foeniculum vulgare and Lavandula hybrida. These compounds were assayed for their insecticidal effects on adult Sitophilus zeamais and their effect on the germination of corn and durum wheat seeds. Maize-weevil adults were bioassayed with both contact and fumigant protocols. Fennel and lavandin showed the highest insecticidal properties in contact and topical bioassays but bay laurel and lavandin were most active in inhalation bioassays. At the tested doses, all essential oils significantly inhibited seed germination compared to controls. According to the obtained results, some of the essential oils tested showed interesting insecticidal properties and their performances could be evaluated at a more refined step of evaluation.