Suction marks in nutrition cells of a gall on leaves of Acer pseudoplatanus L., caused by Eriophyes macrorrhynchus typicus Nal.

Leaf galls on Acer pseudoplatanus, caused by Eriophyes macrorrhynchus, were investigated in order to demonstrate suction marks in the nutritive tissue. After a special treatment that removed the cell content and the cell wall matrix, small holes with a diameter of approximately 0.35 pm were found in the cellulose skeleton of the cell walls. The holes originate by physical and enzymatical action of the stinging parasite.