postphragma
From ZooTerms (Dictionary of Invertebrate Zoology)
Arthropoda: Insecta) 1. Internal plates developed from the antecostal ridges at the front and back of the mesothorax and the back of the metathorax that provide attachment for the large longitudinal muscles moving the wings. 2. In Diptera, a well developed phragma at the posterior extension of the postnotum.
postphragma (noun; Latin post, after; Greek phragma, fence): (