Europe eastwards to Iran.

Lifecycle and Phenology. Alternating asexual and sexual generations are known. Molecular data suggest that the sexual generation of this species develops in cryptic bud galls (Stone et al. 2008). The developing spines of young asexual galls become visible from May-June. Some of the galls fall in autumn, and mature on the ground. The remainder stay on the tree, and old galls become black. Some adults emerge in late September – early October, while others emerge in February-March. Unlike other Andricus species, very few A. caputmedusae enter diapause to emerge a year later.