he Orange
Emigrant, together with its close cousin, the
Lemon Emigrant, are often
encountered in parks and urban areas. It is only found in lower
elevation and rather local but may be
fairly common where it occurs. It is
slightly smaller than the Lemon Emigrant but has similar characteristics
- medium sized, robust, flies swiftly 2-3m above ground with energetic and rapid 'jumping' flight
maneuvers. Above, its forewing is white with a black distal border and
the hindwing is chrome-yellow. The female (see photos on the top-right
and on the right) is slightly larger, paler
yellow, with subapical black spots on the upperside forewing and triangular
wedges on the upperside hindwing. The Orange Emigrant is easily
identified on account of their flight pattern and their overall
chrome-yellow colour.
The Orange Emigrant's host plants include Cassia biflora (Bushy Cassia),
Cassia tora and Cassia fistula. In Singapore, Cassia biflora, which is
commonly found along road sides, is its favorite host plant.The life-history of Orange
Emigrant follows the Pieridaes : It's eggs are spindle in shape
and milky
white in colour, usually laid singly on either side of the hostplant leaf. It's
caterpillars are long (40 mm at the last instar), green and smooth with round head. The caterpillar goes through five instars, from totally
green to yellowish-green with a few minute black dots above a white lateral
line. The pupa is 26mm long, green overall, yellow along the edge and does
not have any markings. It is anally attached to the stem or leaf of the
host plant and supported in an upright position by a girdle around it.
It has an oval
stage lasting 1.5 to 2 days, larval stage lasting 11-13 days and pupal
stage lasting 7 days. |
|
Mating pair - female
below |
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|
Cassia biflora |
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