Papilio protenor, the spangle, is a butterfly found in South East Asia belonging to the swallowtail family.

Hindwing: a broad pale yellowish-white subcostal streak; interspaces 4 to 6 irrorated (sprinkled) with bluish scales; tornal angle marked with red.

Underside: forewing dull black; adnervular streaks distinctly grey and much broader than on the upperside.

Upperside: ground colour deep brownish-black; adnervular streaks on forewing yellowish; irroration of blue scales on outer portions of hindwing more dense; no white subcostal streak; red patch at tornal angle large with an oval medial black spot; another similar black spot subterminally in interspace 2 posteriorly bordered by a crescent-shaped red mark.

[2] Northern Pakistan, Jammu and Kashmir, Garhwal Himalaya (Govind Wildlife Sanctuary), Sikkim, Assam, Bangladesh, Burma, southern China (including Hainan), Vietnam, northern Laos, Taiwan, North Korea, South Korea and Japan.Nepal Many species of butterfly occupy only a limited range of the host plant.

[6] Flavanone glycosides such as naringin and hesperidin were investigated and both elicited positive responses from the female adults.

[14] 5th larvae secretion is mainly aliphatic acid and their esters, while the previous instars contain primarily mono- and sesquiterpenoids.

Research indicates that there is not one major determinant, but the colouration is due to reciprocal balance of all sorts of environmental stimuli.