2011-12-03 Lower Austria, district Bruck/Leitha - Braunsberg northern flank (180 msm Quadrant 7867/2).Gall on
Quercus (most likely Quercus pubescens).According to a monograph written in German by
Gustav L. Mayr, Die mitteleuropischen Eichengallen in Wort und Bild (Jahresb[uch] d[er] Rossauer Communal-Oberrealschule, Wien - Vienna 1870-71) this oak apple = gall should be one from
Cynips caput-medusae; the species obviously has been renamed (see remark of
treegrow below) to
Andricus caputmedusae.(Compare also
photo of same species here.)