The Diapriidae

 antennae inserted close to the clypeus (figs 1,2).  notauli absent (figs 3,5), with mesocutum broadly arched in lateral view (fig 3).  posterior petiole in dorsal view clearly visible, with no gastral tergite or sternite overlapping it.  antennal formula 15-14.

 antennae inserted on a shelf, or at some distance from the clypeus (figs 1,2,3).  notauli (fig 4, ‘nts’) present or absent, mesoscutm size and shape variable but typically not distinctly arched. posterior petiole in dorsal view hidden or visible.  antennal formula variable, including 15-14.