(Ai) Delphacidae, Stenocranus acutus. (Aii) Issidae, Thionia bullata. (Aiii) Acanaloniidae, Acanalonia conica. (Aiv) Flatidae, Metcalfa pruinosa. (Av) Caliscelidae, Bruchomorpha oculata. In each of these nymphs the right pleural arch is viewed dorsally to show its articulation with the coxa, the tendon of the trochanteral muscle, and the gears on the trochanter. Inset: mesothoracic struts of A. conica that give rise to the mesothoracic pleural arch in the adult. (B) Mesothoracic arches of an adult Flatormenis proxima viewed dorsally, imaged using red autofluorescence (C). Metathoracic arches of F. proxima viewed ventrally. Arrows denote articulation sites of the arches; arrowheads, articulations with a wing hinge. (D) Schematic representation based on confocal data showing relative the positions of the meso- and metathoracic pleural arches viewed medially.