The Blue Mormon
( Papilio polymnestor
) is a large swallowtail butterfly
found in South India
and Sri Lanka
- See glossary for terms used
Males have the upper wings rich velvety black. The fore wing has a postdiscal band composed of internervular broad blue streaks gradually shortened and obsolescent anteriorly, not extended beyond interspace 6.
The hindwing has the terminal three-fourths beyond a line crossing the apical third of the cell pale blue, or greyish blue, with superposed postdiscal, subterminal and terminal series of black spots—the postdiscal spots elongate, inwardly conical; the subterminal oval, placed in the interspaces, the terminal irregular, placed along the apices of the veins and anteriorly coalescing more or less with the subterminal spots.
The underside is black with and on the base of the cell in the fore wing is an elongate spot of dark red; the postdiscal transverse series of streaks as on the upperside but grey tinged with ochraceous and extended right up to the costa; in some specimens similar but narrow streaks also in the cell. Hind wing with five irregular small patches of red at base, the outer three-fourths of the wing grey touched with ochraceous, but generally narrower than the blue on the upperside; the inner margin of the grey area crosses the wing beyond the cell; the post-discal and subterminal black spots as on the upperside. In some specimens this grey area is greatly restricted, its inner margin crossing the wing well beyond the apex of the cell; the subterminal spots merged completely with the terminal spots and form a comparatively broad terminal black band. Antennae, head, thorax and abdomen blackish brown.
Female very similar but the inter-nervular streaks on the fore wing paler, extended into the cell both on the upper and undersides. Hind wing: the pale blue area on the upperside and the corresponding grey area on the underside paler. In some specimens there is a diffuse short crimson streak at the base of the cell of the fore wing on the upperside.
Endemic to India
and Sri Lanka
. In India it is restricted to the Western Ghats
, Southern India
and the East coast. It has been recorded as far north as Gujarat
. It is often seen even in the gardens and sometimes in the middle of busy traffic in large cities such as Mumbai
. Wynter-Blyth recorded it in Madhya Pradesh
, West Bengal
Not uncommon. Not thought to be threatened. Occurs throughout the year but more common in the monsoon
and immediately after it.
The butterfly is most common in heavy rainfall areas, such as evergreen forests. Also common in deciduous forests and wooded urban areas, primarily due to the cultivation of its host plants, ie the Citrus species.
Frequents forest paths and streams. The male is fond of sun and avoids the shade. It frequents flowers especially of Mussaenda frondosa
, Ixora coccinea
, Jasminum spp.
and Asystasia gangetica
. Periodically raids thicker forest patches, especially where Atalantia spp.
are to be found in search of females to mate with.
Has a rapid unidirectional flight and frequently changes course, hopping up and down in its flight path. Difficult to catch.
Known to bask in the sun. Attracted to damp patch and has greater tolerance to other butterflies and humans while lapping up the mineral rich moisture. Known to visit animal droppings.
are laid singly on the upper surfaces of the leaves on rutaceous
plants at ten feet or so above the ground. The newly laid egg is spherical and light green but darkens over time to orange-yellow.
The newborn caterpillar
makes the eggshell its first meal and then rests on a silken bed that it spins for itself near the edge of a leaf.The little caterpillar mimics a bird dropping with its olive green body and white 'uric acid' markings. The sheen enhances its resemblance to fresh bird dropping.
While small in size, this camouflage permits the caterpillar to rest on the centre of a leaf and nibble around the edges. Later its growing size forces it to keep to twigs and the undersides of leaves except when it is feeding on leaves.
Moves slowly and haltingly. It has a unique habit of securing its balance by weaving silk on the substratum.
The caterpillar can be distinguished from the Common Mormon, which it resembles, by its larger size, greenish head and a blue streak in the eye-spot in segments 4 to 5. It has a deep red osmeterium
also resembles that of the Common Mormon
but is much larger in size and can be easily distinguished by the prominent folds on the lower side of the abdominal protsion.
The larva have been recorded to feed on small rutaceous forest trees and large shrubs. The list of host plants includes :
- Collins, N.M. & Morris, M.G. (1985) Threatened Swallowtail Butterflies of the World. IUCN. ISBN 978-2-88032-603-6
- Evans, W.H. (1932) The Identification of Indian Butterflies. (2nd Ed), Bombay Natural History Society, Mumbai, India
- Gay,Thomas; Kehimkar,Isaac & Punetha,J.C.(1992) Common Butterflies of India. WWF-India and Oxford University Press, Mumbai, India.
- Haribal, Meena (1994) Butterflies of Sikkim Himalaya and their Natural History.
- Kunte,Krushnamegh (2005) Butterflies of Peninsular India. Universities Press.
- Wynter-Blyth, M.A. (1957) Butterflies of the Indian Region, Bombay Natural History Society, Mumbai, India.