Polyura schreiber

Taxobox
name = Blue Nawab


image_width =
image_caption =
regnum = Animalia
phylum = Arthropoda
classis = Insecta
ordo = Lepidoptera
unranked_familia = Rhopalocera
superfamilia = Papilionoidea
familia = Nymphalidae
subfamilia = Charaxinae
tribus = Charaxini
genus = "Polyura"
species = "P. schreiber"
binomial = "Polyura schreiber"
binomial_authority = (Godart, 1819)
synonyms = "Polyura schreiberi" (unjustified emendation)

The Blue Nawab ("Polyura schreiber") is a butterfly species found in tropical Asia. It belongs to the Charaxinae (Rajahs and Nawabs) in the brush-footed butterfly family (Nymphalidae). It occurs from South India and Assam through Myanmar, Tenasserim and Southeast Asia to southern China and to Java, Indonesia.

Description [After Bingham (1905).]

"Polyura schreiber wardi"

The South Indian subspecies.

Male has upperside ground colour black, glossed slightly with dull indigo-blue, or, in some specimens, light green at the base of the wings. Fore and hind wings with a broad white discal bar from interspace 4 in fore wing to just below the apex of the median vein in the hind wing, narrowing on the latter wing to a point. This bar has, on the outer side on both fore and hind wings, an irregular border of small-blue, which is narrowest anteriorly and broadens posteriorly respectively on both fore and hind wings. Fore wing with, in addition, a white rectangular spot in interspace 5 and a small whitish speck above it. Hind wing with a subterminal row of small white dots, a terminal row of deep ochraceous spots, and some small-blue markings on the tails and margins near the tornal angle. Underside pearly white, broadly brownish pink along the dorsal margin of hind wing. Fore wing: two black spots at base of cell; a broad olive-green band edged on both sides with black, followed by a discal bluish-white band, as on the upperside, and continuation of that on the fore wing, terminating on vein 1, followed by a broad discal, posteriorly narrowing, white bar as on the upperside. Beyond this a postdiscal series of deep Indian-red lunules, placed on an olive-green ground, and margined on the inner side by an interrupted broad black line ; finally, a sub-terminal narrow green band and terminal ochraceous lunules. Tails black touched with small-blue; above tornal angle a black line from vein 1 to dorsum. Antennae, head, thorax and abdomen black ; thorax and abdomen on the sides and beneath whitish.

Female. Differs very slightly from the male; but can be distinguished at once by the greater width of the transverse discal band, and also by the two spots above it being larger and joined on to the band.

Wingspan: 92-116 mm.

"Polyura schreiber assamensis"

From Assam to Yunnan and through Southeast Asia to Thailand.

Typically lacks the spots in interspaces 5 and 7 of the fore wing, but a specimen from Shillong in the British Museum has these spots, only they are placed prominently in echelon with one another as in the form from the Malay Peninsula, Borneo and Sumatra. Burmese and Tenasserim specimens resemble the Assam ones.

Immature stages

Caterpillar green, with a yellow band on 7th segment. Head with four curved and tuborculated processes.
Pupa green, with a longitudinal row of red dots on each side.

Footnotes

References

* (1905): "Fauna of British India, etc. Lepidoptera, Volume 1"