Quercus cf. robur, France, dép. Ardennes, Mont Vireux © Sébastien Carbonnelle

Quercus robur, Belgium, prov, Hainaut, Mouscron, lieu-dit “Bois Fichaux” © Stéphane Claerebout

cut open

Quercus robur, Belgium, prov, Namur, Doische, Matagne-la-Grande, RN Hurées © Stéphane Claerebout: “gall”

opened

gall

Gall chambers under the bark on unchanged one-year twigs; only the eventual appearance of exit holes betrays their presence.

hostplants

Fahaceae, monophagous

Quercus petraea, robur.

notes

the galls of the sexual generation of Callirhytis erythrocephala, glandium, abd rufescens cannot be told apart.