Repellent effect of ethanol extracts from plants of the family Lamiaceae on Colorado Potato Beetle adults (Leptinotarsa decemlineata SAY)

摘要

The effect of ethanol extracts, from 9 plants of the family Lamiaceae applied on potato leaves, on the feeding behaviour of adult individuals of Colorado potato beetle was studied in laboratory. Extracts of Salvia splendens, Origanum majorana, Hyssopus officinalis, Salvia officinalis and Marrubium vulgare were strongly repellent (84-98 % repellency). Thymus vulgaris, Ocimum bassilicum and Origanum vulgare showed a medium repellency (61-74%) and Mellisa officinalis had a weak repellency (28%). After 24 and 48 hours there were 50 and 90%, respectively, of control leaves eaten. Leaves with extracts of S. splendens, O. majorana, H. officinalis, S. officinalis and M. vulgare showed long antifeedant activity as they were not eaten at all or a little (lessthan 7%) even after 48 hours of exposure. Leaves treated by T vulgaris and O. bassilicum had a medium antifeedant activity - eaten by less than 28%. Finally, leaves treated by O. vulgare and M, officinalis showed weak'antifeedant effect as being eaten by 46-71%.