The distal one of the two plates in the axillary area of the wing along which the costa of the wing articulates. The tegula is the proximal one.
Synonyms: humeral plate, subepaulet.
Image given: http://www.dgrc.k..._plate.gif
Does someone has a scan of Nartshuk E.P. 2003. Key to families of Diptera (Insecta) of the fauna of Russian and adjacent countries. Proceedings of the Zoological Institute Vol. 294: 1-252 for me?
Unfortunately the image is missing