Orsotriaena medus

Smooth-eyed bushbrown
Orsotriaena medus mandata from Kerala, India
Orsotriaena medus medus from Mindanao, Philippines
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Lepidoptera
Family: Nymphalidae
Genus: Orsotriaena
Wallengren, 1858
Species: O. medus
Binomial name
Orsotriaena medus
(Fabricius, 1775)

Orsotriaena medus is a butterfly found in South Asia, Southeast Asia, and Australia. The butterfly has historically been called the "nigger",[1][2] but it has been renamed in Australian faunal works to the socially acceptable name of smooth-eyed bushbrown.[3]

Description

Orsotriaena medus medus (left) and Orsotriaena medus mandata (right)
1905 illustration of Orsotriaena medus
Upperside, seen in Kodagu district

Orsotriaena medus is a medium-sized butterfly with wingspan of 45 to 55 mm (1.8 to 2.2 in). The butterfly is dark brown above with a thin marginal pale border. The upper hindwing having a thin submarginal line. There are no eye-spots on the upper side of the wings.[4]


Below, the butterfly has a white discal band which runs across both wings. It has five ocelli beloe (eyespots) on the undersides of the wings. In the forewing, it has two eyespots, with the anterior eyespot slightly smaller. In the hindwing, it has two ocelli on the apical region and a separate ocellus in the tornal (hindmost) region. The uppermost of the eyespots in the hindwing are greatly smaller, while the remaining two are more or less of equal sizes.[4]


The eggs are spherical and yellowish. They are laid on the leaf blades and stems of grasses.[4] The larvae are spindle-shaped, transversely wrinkled, and covered in small tubercles, giving it a rough appearance. Two long brown spines on the head point forward, while a pair of pinkish prongs project from the anal segment. The colour above is rosy-red with a blue dorsal and a white lateral line, below which, the underparts are green.[5]

The pupae are perpendicularly suspended, slender and regular, except that the head-case is produced into a long beak formed of two thin processes like split straws. The colour is whitish brown to yellow, with faint bands of a darker shades. It resembles a large grain of barley or a tiny banana.[5][6]

Orsotriaena medus superficially resemble members of the genus Mycalesis (bushbrowns), but can readily be identified by the number of spots.[6]

Distribution and habitat

Orsotriaena medus is native to India, Sri Lanka, Myanmar, Thailand, South Yunnan, Malaysia, the Indonesian archipelago, the Philippines, New Guinea, New Britain and Australia.[7]

In India, the butterfly occurs in South India, Punjab, Uttar Pradesh, Bihar, West Bengal, Sikkim, Assam, Nagaland, the Andaman and Nicobar Islands.[7][5]

O. medus is very common in grassy habitats up to an altitude of 1,600 m (5,200 ft). A shy, weak-flying insect, it stays low amongst the undergrowth, and when disturbed flies for a short distance before settling down. The butterfly basks in the sun, often with its body aligned parallel to the sun's rays.[4]

Taxonomy

Orsotriaena medus moira, the upper surfaces of the wings of the species are unmarked and plain brown
Mating pair

Orsotriaena medus is classified under the subfamily Satyrinae (the browns) of the brush-footed butterfly family Nymphalidae.[8][7] Orsotriaena medus is divided into several subspecies, listed below with their respective synonyms and geographical ranges.[7]

syn. Orstriaena Young, 1903; Orsotrioena Bingham, 1905
  • Orsotriaena medus (Fabricius, 1775)
syn. Papilio medus Fabricius, 1775; Mycalesis mandosa Butler, 1868
  • Orsotriaena medus cinerea (Butler, 1867) - Sundaland.
syn. Mycalesis cinerea Butler, 1867
  • Orsotriaena medus jopas (Hewitson, 1864) - North Sulawesi.
syn. Mycalesis jopas Hewitson, 1864
syn. Mycalesis mandata Moore, 1857
syn. Papilio hesione Cramer, 1775; Papilio doris Stoll, 1781; Mycalesis runeka Moore, 1857
  • Orsotriaena medus mendice (Fruhstorfer, 1911) - South Sulawesi.
syn. Orsotriaena mendice Fruhstorfer 1911
  • Orsotriaena medus moira (Waterhouse & Lyell, 1914) - Banks Island, Darnley Island, Cape York.
syn. Orsotriaena moira Waterhouse & Lyell, 1914
  • Orsotriaena medus mutata (Butler, 1875) - New Britain.
syn. Orsotriaena mutata Butler, 1875
  • Orsotriaena medus paupercula (Fruhstorfer, 1908) - Sula Islands.
syn. Orsotriaena paupercula Fruhstorfer, 1908
  • Orsotriaena medus zipoetina (Fruhstorfer, 1908) - Sumatra
syn. Orsotriaena zipoetina Fruhstorfer, 1908

Ecology and behaviour

The larvae feed on grasses, including rice plants (Oryza sativa), sugarcanes (Saccharum officinarum),[7][5] and para grass (Brachiaria mutica).[9] They are predominantly crepuscular, but can sometimes be active during daytime.[6]

See also

Wikimedia Commons has media related to Orsotriaena medus.


References

  1. ↑ Evans, W.H. (1932). The Identification of Indian Butterflies, ser no D16.1, pp 123-124
  2. ↑ Krushnamegh Kunte; Madhav Gadgil (2000). India, a Lifescape: Butterflies of Peninsular India. Universities Press. p. 115. ISBN 978-81-7371-354-5.
  3. ↑ Australian Faunal Directory, Government of Australia (Dept of Environment & Water Resources) page on Orsotriaena medus . Accessed 20 September 2007
  4. ↑ 4.0 4.1 4.2 4.3 Haribal, Meena (1992). Butterflies of Sikkim. ser 352, pg 144-145.
  5. ↑ 5.0 5.1 5.2 5.3 Bingham, C. T. (1905). The Fauna of British India, Including Ceylon and Burma. Butterflies. Volume 1
  6. ↑ 6.0 6.1 6.2 Adrian Hoskins. "Butterflies of Thailand, Malaysia & Borneo: Nigger, Orsotriaena medus FABRICIUS, 1775". Learn about Butterflies: the complete guide to the world of butterflies and moths. Retrieved November 30, 2011.
  7. ↑ 7.0 7.1 7.2 7.3 7.4 Markku Savela. "Orsotriaena Wallengren, 1858". Lepidoptera and some other life forms. Retrieved November 30, 2011.
  8. ↑ Card for Orsotriaena medus in LepIndex. Accessed 19 September 2007.
  9. ↑ Kalesh, S & S K Prakash (2007). "Additions ot the larval host plants of butterflies of the Western Ghats, Kerala, Southern India (Rhopalocera, Lepidoptera): Part 1". J. Bombay Nat. Hist. Soc. 104 (2): 235–238.

External links