The contact and fumigant toxicity and repellent, antifeedant and nutritional effects of essential oil (EO) isolated from flower spikes of Lavandula angustifolia Miller were evaluated against adults of the granary weevil, Sitophilus granarius (L.). A total of 53 EO constituents were identified by gas chromatography coupled with mass spectrometry (GC-MS) accounting for 98.3% of whole EO. The main EO constituents were linalool (23.8%), 1,8-cineole (12.0%), borneol (10.7%), terpinen-4-ol (10.0%), linalyl acetate (6.9%), (E)-beta-ocimene (6.2%), (E)-beta-farnesene (3.5%), and camphor (2.8%). Contact toxicity of lavender EO significantly increased with dose and time after treatment. At the 0.449 mg/adult dose, mortality reached 91.7 and 100% after 24 and 48 h exposure, respectively. A strong fumigant toxicity was also observed but it was reduced by the presence of wheat grains. The LC50 and LC90 values were respectively 1.5 and 4.1 mg/L in the absence of wheat grains and 10.9 and 47.6 mg/L in the presence of this substrate. A marked repellent activity was found both in filter paper and arena bioassays. In this latter, the EO effectively disrupted adult granary weevil orientation to an attractive host substrate (200 g of wheat grains) starting from the 1.1 mg dose. Flour disc bioassays showed that the EO did not significantly affect feeding activity, growth rate, food consumption and food utilization. Potential applications of lavender EO as a natural alternative to synthetic insecticides for controlling stored-product insect pests are discussed.
Bioactivities of Lavandula angustifolia essential oil against the stored grain pest Sitophilus granarius
Germinara, Giacinto Salvatore
;DELFINE, Sebastiano;
2017-01-01
Abstract
The contact and fumigant toxicity and repellent, antifeedant and nutritional effects of essential oil (EO) isolated from flower spikes of Lavandula angustifolia Miller were evaluated against adults of the granary weevil, Sitophilus granarius (L.). A total of 53 EO constituents were identified by gas chromatography coupled with mass spectrometry (GC-MS) accounting for 98.3% of whole EO. The main EO constituents were linalool (23.8%), 1,8-cineole (12.0%), borneol (10.7%), terpinen-4-ol (10.0%), linalyl acetate (6.9%), (E)-beta-ocimene (6.2%), (E)-beta-farnesene (3.5%), and camphor (2.8%). Contact toxicity of lavender EO significantly increased with dose and time after treatment. At the 0.449 mg/adult dose, mortality reached 91.7 and 100% after 24 and 48 h exposure, respectively. A strong fumigant toxicity was also observed but it was reduced by the presence of wheat grains. The LC50 and LC90 values were respectively 1.5 and 4.1 mg/L in the absence of wheat grains and 10.9 and 47.6 mg/L in the presence of this substrate. A marked repellent activity was found both in filter paper and arena bioassays. In this latter, the EO effectively disrupted adult granary weevil orientation to an attractive host substrate (200 g of wheat grains) starting from the 1.1 mg dose. Flour disc bioassays showed that the EO did not significantly affect feeding activity, growth rate, food consumption and food utilization. Potential applications of lavender EO as a natural alternative to synthetic insecticides for controlling stored-product insect pests are discussed.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
