part of develops from ventral postgenal bristle Bristle at the ventral margin of the postgena of the adult head, generally ventral and medial to the postorbital bristles (Haynie and Bryant, 1986). There are approximately four of these on each side (Haynie and Bryant, 1986). https://www.ento.csiro.au/biology/drosophila/melanogaster.html?postgenal%20setae FBbt:00004132 VFB:FBbt_00004132 Renamed from just 'postgenal', since other bristles are present on the postgena. fly_anatomy.ontology postgena ventral occipital bristle presumptive ventral postgenal bristle