31 May 2014

Life History of the Blue Jay

Life History of the Blue Jay (Graphium evemon eventus)

Butterfly Biodata:
Genus: Graphium Scopoli, 1777
Species: evemon Boisduval, 1836
Subspecies: eventus Fruhstorfer, 1908
Wingspan of Adult Butterfly: 50-65mm
Local Caterpillar Host Plant: Artabotrys wrayi (Annonaceae).

A pair of puddling Blue Jay.

A Blue Jay perching on a leaf.

Physical Description of Adult Butterfly:
As with most Graphium species, the wings are produced at the forewing apex and hindwing tornus, and the inner margin of the hindwing bends inwards. On the upperside, the wings are black with a broad bluish macular band running from the sub-apical area of the forewing to the basal area of the hindwing. There is also a series of blue streaks in the cell of the forewing. A series of blue submarginal spots is present in both fore- and hindwings. On the underside, the same spotting pattern can be found against a dark brown base, with the spots larger and more silvery green. Additional red and black spots are featured on the hindwing. Unlike the lookalike species, the Common Jay, the black costal bar in the hindwing of the Blue Jay does not have a red spot, and it is joined to the black basal band.

A puddling Blue Jay.

Another Blue Jay puddling with fully open wings.

Field Observations of Butterfly Behaviour:
Blue Jay is common in Singapore and is oftern seen flying up and down jungle tracks in the nature reserve on sunny days. The males are often observed puddling at damp forest paths and stream banks. The adults are fast flyers and have an "erratic" flight.