dorsal diaphragm
From ZooTerms (Dictionary of Invertebrate Zoology)
dorsal diaphragm: (Arthropoda: Insecta) Muscular sheets of tissue extending from the ventral wall of the heart and vessels to the laterodorsal parts of the body wall, usually incomplete laterally; it may or may not delineate the pericardial sinus from the perivisceral sinus.
