acorn gall wasp, andricus quercuscalicis, on acorn of a pedunculate oak, quercus robur, bavaria, germany, europe

abnormal acorn andricus apple background bavaria botanical botany branch brown canipid closeup cup cynipidae damage disease europe forest gall galls gallwasp german germany green growth hymenoptera infected infection insect knopper leaf leaves natural nature neuroterus oak parasite pedunculate plant quercus quercuscalicis robur summer tree wasp wasps wild wildlife woodland woods