(a) SEM of the dorsal wing scales of Heliophorus saphir (Lycaeninae: Lycaenidae) showing cover scales (Co) overlaying basal scales (Ba). The figure is orientated left to right, towards the wing edge. (b) An unbleached Morpho rhetenor. (c) A bleached M. rhetenor showing paler blue appearance due to melanin degradation. (d) SEM of the dorsal wing scales of Eumaeus childrenae (Theclinae: Lycaenidae) showing scales curling away from the wing membrane beneath. (e,f) Pieris brassicae (Pierinae: Pieridae). (e) SEM of a single scale indicating the longitudinal ridges (Lr). (f) Nanostructure of a cover scale (Cr, cross rib; Fl, flutes; Lu, lumen; Pig, pigment granules; Sc, scutes; Tr, trabecula).