Intense blue fluorescence in part of the pleural arch of the left half of the metathorax of Aphrophora. (A) Ventral view. The ventral cuticle and muscles of the left metathorax were removed, but the tracheae and some fatty tissue remain medially. (B) Medial view looking outwards after the metathorax had been split at the midline and muscles removed. (C) Lateral view from a montage of photographs. The lateral wall and muscles of the metathorax were removed. The dashed lines indicate the outline of the whole pleural arch. The fluorescent part is clearly curved antero-posteriorly (A and C) and dorso-ventrally (B and C).