2. Emerald Swallowtail
The emerald swallowtail is a member of large family of swallowtail butterflies. There are 550 different species of swallowtail butterflies in the world. The emerald butterfly is also one of most colorful and largest butterflies in the world. The mainly found in Southeast Asia.
The fascinating emerald swallowtail has wings of shining green bands. The structural coloration on their wings also make blue and yellow reflections. The underpart of emerald swallowtails wings are black and orange. A number of blue spots can also found at the edges of underside of the wings.
Papilio palinurus has a wingspan reaching about 8–10 centimetres. 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 hindwings, 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 is structural coloration produced 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 color when additively mixed.