The tiny sound-producing structures are different in swallowtails: type I, which is shown in Pachliopta kotzebuea; type II in the Epicaliini tribe of the brush-footed butterflies, which is  shown in the Catonephele numilia, and type III in the Heliconiini tribe of the brush-footed butterflies, which is shown in Heliconius hecale. The sound-producing structures are circled. Higher magnifications of each structure are provided in the right two images. (Originally published in Dolle et al 2018, Annals of the Entomological Society of America)