Fumigant toxicity of five medicinal plant essential oils agianst the date sap beetle, Carpophilus hemipterus (Linnaeus) and identification of their chemical composition
Fumigant toxicity of five medicinal plant essential oils including Eucalyptus globulus Labill., Salvia mirzayanii Rech. var. Hormoz., Ducrosia anethifolia Boiss., Thymus vulgaris L. var. Hormoz. and Majorana hortensis Moench was investigated against fourth instar larvae and adults of Carpophilus hemipterus (Linnaeus). Mortality was evaluated at five concentrations, 1, 5, 10, 20 and 50 μL/75 mL volume for adults and 3 concentrations, 10, 20 and 50 μL/75 mL volume for larvae at 24, 48 and 72 hour exposure time and with 3 replications with control. The results showed that by increasing concentration and time, mortality rate was increased so that after 72 hours at the highest concentration(50 ml/75 ml volume), adult mortality was 80, 90, 100, 86/66 and 100 percent and larval mortality was 100, 100, 80, 100 and 100 percent, respectively. Essential oils chemical composition analysis showed 1,8- cineole and α-Pinene in the Eucalyptus essential oil, ß-Pinene and linalool in the Majorana essential oil, linalool and camphor in the Salvia, carvacrol and p-cymene in the Thymus essential oil, and cis- Chrysanthenyl acetate and ß-eudesmol in the Ducrosia essential oil, were the main compounds. Based on the good fumigant toxicity of the studied essential oils, they can be used as an alternative to chemical insecticides in control programs of this pest.