alternative definition added about 14 years ago by Istvan Miko
In Mymaridae, a transverse groove extending entirely across the head between the eyes behind the vertexal sulcus.
Reference: Gibson , G. A. P., J. D. Read , and R. Fairchild. 1998. Chalcid wasps (Chalcidoidea): illustrated glossary of positional and morphological terms ..
Cross reference:
None provided.