EN
Morphological, anatomical and chemical plant properties play an important role during host’s recognition by the aphids. Removal of the surface compounds with the use of organic solvents clearly increased studied parameters of the grain aphid Sitobion avenae and bird cherry-oat aphid Rhopalosiphun padi on the waxy genotype RAH 122. Moreover, extracts from RAH 122 genotype applied on of wax-less genotype RAH 366, significantly decreased the number of alate forms and percentage of infested plants by both aphid species.