Chemical components and insecticidal effects of essential oils from three lavender cultivars against adult Sitophilus granarius (L., 1758) (Coleoptera: Curculionidae)

The study was conducted to determine the insecticidal and behavioral effect of essential oils (EOs) extracted from three lavender cultivars, Hemus, Raya and Yubileina, against adult stage of Sitophilus granarius (L., 1758) (Coleoptera: Curculionidae) under laboratory conditions. The contact, fumigant and repellent effects of plant EOs were investigated and possible germination inhibitory effects of the EOs on wheat germination were evaluated. EOs were extracted from the plant samples using a Neo-Clevenger type apparatus where the plant material is subjected to hydro distillation. The chemical constituents of EOs were detected by gas chromatography-mass spectrometry. The experiments were conducted under laboratory conditions in 2019 and 2020. As a result of the study, it was determined that the fumigant activity changed according to the cultivars. While the LC90 value in the fumigant activity of the EOs of the Hemus was determined as 0.157 µl/ml air, this value was recorded as 0.139 µl/ml air and 0.118 µl/ml air in Raya and Yubileina, respectively. Six h after treatment, the highest repellent activity was 86% at 0.05 µl/cm2 with Yubileina. Main EOs components of each cultivar were: Yubileina, linalool (36.0%), linalyl acetate (24.2%) and lavandulyl acetate (5.86%); Hemus, linalool (28.5%), linalyl acetate (23.1%) and lavandulyl acetate (6.59%); and Raya, linalool (42.5%), linalyl acetate (30.0%) and -terpineol (5.45%). There was no negative effect on the germination of wheat with any of essential oils. These results show that lavender EOs could be useful for the control of S. granarius. © 2021 Entomological Society of Turkey. All rights reserved.