part_of labium prementum HAO:0000804 The sclerite that is median, is connected via conjunctiva along its proximolateral margins to the stipites, is articulated with the labial palps, is continuous along its distal margin with the ligula and distolateral margins with the distal hypopharynx and receives the site of attachments of the extrinsic labial palp muscles. labiostipides mentum premental shield sternum labial stipulae sclerite