The blue wave, blue-banded purplewing, tropical blue wave, whitened bluewing, or royal blue (Myscelia cyaniris) is a butterfly of the Nymphalidae family.
The length of the fore wings reaches about 34–36 mm (1.3–1.4 in). The dorsal sides of the upper wings are bright blue with white transversal bands and white spots.
The sapphire blue of the upper wings may appear black or neon blue depending on how the light is reflected. The under sides of the hind wings have a cryptic coloration, as they are mottled with different shades of color, varying from gray to brown, while the under sides of the fore wings are black with white patches. The larvae feed on Dalechampia triphylla and Adelia triloba (Euphorbiaceae family). Adults usually feed on rotting fruit and animal dung.
It is found in Central America and northern South America, from Mexico to Honduras, Costa Rica, Panama, Venezuela, Ecuador, and Peru.