Emerald Swallowtail / Papilio palinurus

Not the most photogenic of backgrounds, but I was still lucky that this gorgeous Emerald Swallowtail landed on the window in the ENMAX Conservatory at the Calgary Zoo. Taken on September 1st.

"Papilio palinurus has a wingspan reaching about 8–10 centimetres (3.1–3.9 in). This species is one of the very few green butterflies, that are unusual in nature. The dorsal sides of the wings are covered by a powder of green scales and the background vary from dark greenish to black, with broad bright emerald green metallic bands. The undersides are black with orange, white and blue spots along the edges of hind wings, that show extended tails at the end.

The flight of these butterflies is swift and quite fast. Caterpillars feed on plants of genus Euodia belonging to the Rutaceae, commonly known as the rue or citrus family.

The iridescent green sheen of the bands of this butterfly is not produced by pigments, but it is created by the microstructure of the wing scales. They refract the light and give rise to blue and yellow visible reflections, producing the perception of green colour when additively mixed."

en.wikipedia.org/wiki/Papilio_palinurus