develops from stage 14 embryo dorsal closure embryo stage 15 embryo FBbt:00005332 fly_anatomy.ontology DEPRECATION WARNING. Stage 15 begins with the appearance of the second midgut constriction. During this stage the 1st and 3rd midgut constrictions form, dorsal closure is completed, and epidermal segmentation is accomplished. This stage ends when the intersegmental grooves can be distinguished at mid-dorsal level. Duration at 25 degrees C: approximately 100 minutes (680-780 minutes after egg laying).