Andricus zappellai Kieffer, 1901
Quercus trojana galls (from Houard, 1908a)
The axis of a male catkins is transformed into a fleshy, red gall, 4-6 mm thick and 5-13 mm long. The gall has a number of swellings, each one containing a gall chamber wit a thin, woody wall. The flowers have totally disappeared; a part of the gall bears erect, greyish hairs.
Fagaceae, narrowly monophagous
distribution within Europe