Madagascan Sunset Moth

Chrysiridia rhipheus is a moth in Uraniidae. Its brightly coloured, tailed wings resemble those of butterflies, but its classification places it among the uraniid moths. [1][2]

The wings combine iridescent colour with pigmented dark scales. On the ventral hindwing, adjacent green and purplish red regions form distinct boundaries. [3]

The Madagascan sunset moth occurs in Madagascar. Afromoths lists four Malagasy Omphalea species among its larval hosts. [1]

Recorded larval hosts are Omphalea ankaranensis, O. occidentalis, O. oppositifolia and O. palmata. [1]

Adults fly by day. Oxford University Museum of Natural History describes their conspicuous colour as a warning associated with their toxicity. [2]

Alternating layers of air and cuticle within the iridescent scales produce optical interference. Differences in layer thickness change the light reflected by each scale, contributing to the wing’s colour pattern. [3]

Yoshioka and colleagues found gradual changes in cuticle thickness between neighbouring scales on the dorsal hindwing and abrupt changes at colour boundaries on the ventral hindwing. The ventral green region uses higher-order interference: its multilayer structure produces visible green even though the first-order reflection falls outside the visible range. [3]

Oxford’s museum account reports that toxins acquired from Omphalea persist through development into the adult. Larval feeding therefore supplies compounds involved in the adult moth’s chemical defence. [2]

The species was originally placed in Papilio. Afromoths identifies the historical China locality as erroneous and records Madagascar as its geographical origin. [1]

Dorsal and ventral hindwings differ in both their colour boundaries and the distribution of scale-layer thickness. The optical study illustrates these surfaces separately. [3]

The illustration presents the wing pattern with bold contours and simplified colour fields.

Keep the frame in indirect light, away from heat and persistent damp. Handle it by the edges, keep the enclosure closed and clean only the exterior. Seek conservation advice if loose fragments, moisture or insect activity appear inside.

The sunset moth flies by day. Its bright appearance combines structural colour from microscopic scale layers with pigment in dark scales; its caterpillars feed on Omphalea. [1][2][3]

Afromoths documents nomenclature, distribution and larval hosts. Oxford’s museum account describes daytime flight and host-derived defence. Yoshioka and colleagues explain the optical mechanisms producing the wing pattern. [1][2][3]