The Bembicinae is a large subfamily of crabronid

Crabronidae

Crabronidae is a large family of wasps, that includes nearly all of the species formerly comprising the now-defunct superfamily Sphecoidea. It collectively includes well over 200 genera, containing well over 9000 species. Crabronids were originally a part of Sphecidae, but the latter name is now...

 wasps, that includes over 80 genera, and over 1800 species. Bembicines were originally a part of a single large family Sphecidae

Sphecidae

Sphecidae is a cosmopolitan family of wasps that include digger wasps, mud daubers and other familiar types that all fall under the category of thread-waisted wasps.The are predominently solitary wasp,distributed world wide.At present this family consist of eight subfamilies and three tribes...

, then for many years were treated as a separate family, and recently have been placed back into a larger family, the Crabronidae this time. The different subgroups of Bembicinae are each quite distinctive, and rather well-defined, with clear morphological and behavioral differences between them.