Byasa polyeuctes

Superregnum: Eukaryota
Regnum: Animalia
Subregnum: Eumetazoa
Cladus: Bilateria
Cladus: Nephrozoa
Cladus: Protostomia
Cladus: Ecdysozoa
Cladus: Panarthropoda
Phylum: Arthropoda
Subphylum: Hexapoda
Classis: Insecta
Cladus: Dicondylia
Subclassis: Pterygota
Cladus: Metapterygota
Infraclassis: Neoptera
Cladus: Eumetabola
Cladus: Endopterygota
Superordo: Panorpida
Cladus: Amphiesmenoptera
Ordo: Lepidoptera
Subordo: Glossata
Cladus: Coelolepida
Cladus: Myoglossata
Cladus: Neolepidoptera
Infraordo: Heteroneura
Cladus: Eulepidoptera
Cladus: Ditrysia
Cladus: Apoditrysia
Cladus: Obtectomera
Superfamilia: Papilionoidea

Familia: Papilionidae
Subfamilia: Papilioninae
Tribus: Troidini
Subtribus: Troidina
Genus: Byasa
Species: Byasa polyeuctes
Subspecies: (4)
B. p. lama – B. p. letincius – B. p. polyeuctes – B. p. termessus
Name

Byasa polyeuctes (Doubleday, 1842).

Type locality: North India, Sylhet.

Holotype: BMNH.
Synonymy

Papilio polyeuctes Doubleday, 1842 in Gray,J.E. Zoological Miscellany (2d): 74.
Papilio philoxenus polyeuctes [ab.] Doubleday; Rothschild, 1895: 265.
Atrophanerua polyeuctes (Doubleday); D'Abrera, 1982: 36; C. Smith, 1993: 28.
Atrophaneura polyeuctes polyeuctes (Doubleday); Butterflies in Indo-China [Yutaka Inayoshi].
Byasa polyeuctes (Doubleday); Chou, 1994: 113.

References

D'Abrera, B., 1982. Butterflies of the Oriental Region, Part I Papilionidae, Pieridae, Danaidae: pp. xxi+ 1-244. Hill House, Melbourne. Reference page.
Chou, I. & Gu, 1994. In Chou I. (ed.), Monographia Rhopalocerum Sinensium, 1-2.
Gray, J.E. 1831: The Zoological Miscellany. To Be Continued Occasionally. London: Published by Treuttel, Wurtz and Co. (1831)
Rothschild, L.W. 1895. A Revision of the Papilios of the Eastern hemisphere, exclusive of Africa. Novitates Zoologicae 2(3): 167–463, pls 8–10. BHL Text, plates. Reference page.
Smith, C., 1993. Illustrated Checklist of Nepal's Butterflies, 128pp. Rohit Kumar, Lashkar (Gwalior), India. ISBN 974-88810-7-5 Reference page.

Vernacular names
বাংলা: পংখিল
English: Common Windmill
中文（臺灣）: 大紅紋鳳蝶
中文: 多姿麝鳳蝶

Byasa polyeuctes, the common windmill, is the most common member in India of the windmills genus (Byasa), comprising tailed black swallowtail butterflies with white spots and red submarginal crescents.

Range
A common windmill spotted in Murree, Pakistan.

This butterfly lives in Pakistan, northern ranges of India, Nepal, Bhutan, Myanmar, northern Thailand, Laos, Vietnam, southern China (including Yunnan) and Taiwan.

In India, the Himalayas from Himachal Pradesh to Sikkim, Assam onto Chinese South Tibet region and northern Myanmar.
Status

Overall, the butterfly is not rare. It is common in parts of Sikkim but becomes rarer westwards. It is extremely scarce in Shimla though not rare from Kangra.

In the west it ranges from the Azad Kashmir disputed territory part of the wider Kashmir region of Pakistan and India.
Description
Mounted
Mud-puddling of common windmill found in Jayanti river bed, Buxa Tiger Reserve, West Bengal, India.

Length 110 to 140 mm
Sexes alike
Black and white above with prominent swallowtail
Red bodied - tail has a red tip
Forewings completely black above and below
Hindwings crenulated deeply twice on each side of swallowtail. Large oblong white discal spot in 5 (both upperside and underside) and sometimes in 4. Upperside hindwing has irregular marginal red crescents in 1a, 2 and 3 and a small white spot in 4.

Taxonomy

Atrophaneura philoxenus Gray is considered a synonym.
A species Atrophaneura lama (Oberthür), described from western China, is regarded as a subspecies of A. polyeuctes (now Byasa) by some.

Subspecies

It has four subspecies, two of which occur in India:

B. p. polyeuctes Doubleday Sikkim to Myanmar - common
B. p. philoxenus Gray Kashmir to Nepal - not rare
B. p. lama (Oberthür, 1876) West China
B. p. termessus (Fruhstorfer, 1908) Taiwan

Related species

The three common species of windmills can be recognised by the differences in shape, number and location of white spots.
Rose windmill, Byasa latreillei, has a white discal band in 2, 3, 4 beyond the cell which is clearly trifurcated by black veins. A slightly smaller butterfly, the rose windmill has rose coloured lunules.
Great windmill, Byasa dasarada, has a number of two white spots in 4, 5 on the upperside of the hindwing and three spots on 4, 5 and 6 on the underside of the hindwing. It is a slightly larger butterfly with a broader swallowtail.
Other windmills are smaller, rarer and have small differentiating characters from the above three common windmills. See the individual articles for more information:
de Nicéville's windmill (Byasa polla, de Nicéville)
Nevill's windmill (Byasa nevilli, Wood-Mason)
Black windmill (Byasa crassipes, Oberthür)
Chinese windmill (Byasa plutonius, Oberthür), two subspecies of which occur in India.

Habitat

This butterfly prefers forests and woods. It frequents river valleys. It occurs at low elevations (1,000 to 5,000 feet (300 to 1,520 m)) in north east India but is found at higher altitudes in the western extent of its range – up to 11,000 feet (3,400 m) in Kashmir.
Habits

This butterfly has a leisurely flight high above, but is easily recognisable by the thin long forewings and hindwings. It is attracted to flowers and visits Clemanthe, Buddleia, Lantana and Rhododendron blossoms.

It is mimicked by a day flying moth Epicopa (or Epicopia) polydorus, which flies at the same period and over the same range as the common windmill and has much the same manner and habits.
Life cycle

This species has several broods where it finds suitable climate. It is seen on the wing between April and September. The imago has a foul odour.
Food plants

Family Nepenthaceae
Nepenthes species
Family Aristolochiaceae
Aristolochia griffithi
Aristolochia shimadai