The photonic structures found in the cuticle of Calliphora vicina (a–c) and Lucilia richardsi (d–f) are multilayer reflectors, as observed by SEM (a, b, d, e) and TEM (c, f). One such single periodic multilayer is observed in C. vicina’s cuticle (a–c). It is made of two kinds of layer with thickness equal to 98 ± 7 nm and 20 ± 6 nm. L. richardsi’s cuticle comprises three multilayers: a top multilayer with 4 bilayers, the layers of which have a thickness equal to 78 ± 15 nm and 82 ± 12 nm; a middle multilayer containing about 25 layers, namely 13 58 ± 14 nm-thick dark contrasted layers and 12 60 ± 13 nm-thick light contrasted layers; and a bottom aperiodic multilayer composed of 3 light contrasted layers with thicknesses ranging from 175 nm to 370 nm and 3 dark contrasted layers.