EN
The study evaluates the antifeedant activity of rutin and quercetin (flavonoids of buckwheat Fagopyrum esculentum) and the extract from the leaves of black alder Alnus glutinosa on the development and the extent of damage caused by the beetles of cockchafer Melolontha melolontha in laboratory and semi−field conditions. We found increased mortality and decreased intensity of beetle feeding on the Quercus robur leaves sprayed with a solution of rutin. The treatment of Q. robur leaves with solutions of quercetin and extract from the leaves of black alder had no effect on the development of beetles and fertility of females, and did not inhibit feeding of cockchafer.