03 October 2015

Life History of the Dingy Bush Brown

Life History of the Dingy Bush Brown (Mycalesis perseus cepheus)

Butterfly Biodata:
Genus: Mycalesis Hübner, 1818
Species: perseus Fabricius, 1775
Subspecies: cepheus Butler, 1867
Wingspan of Adult Butterfly: 35-45mm
Caterpillar Local Host Plants: Ischaemum ciliare (Poaceae, common names: Smut Grass), Axonopus compressus (Poaceae, common names: Wide-leaved Carpet Grass, Cow Grass).

Physical Description of Adult Butterfly:
On the upperside, the wings are dark greyish  brown with a large but obscure ocellus in space 2 of the forewing. The male has a small, dark brown sex brand in space 1b of the forewing, and another one at vein 7 of the hindwing overlaid with a pale yellow hair tuff. On the underside, both wings are pale brown in ground colour (with the male in darker brown than the female) and have a clear-whitish post-discal band. There is a series of ringed ocelli in the submarginal area on both wings. In the forewing, the submarginal ocelli usually include only one ocellus in each of spaces 2 and 5, and two smaller ocelli in between.  In the hindwing, there is a thin, dark indentation line  stretching down to (but not beyond) vein 1b. Furthermore, the submarginal series of ocelli has an arched appearance with the ocellus in space 2 moved inwards and out of alignment with those in spaces 1b and 3.

A pair of Dingy Bush Brown. Left: male; Right: female.

Field Observations of Butterfly Behaviour:
The Dingy Bush Brown is a moderately common butterfly in Singapore. Adults can be sighted flying low, in and around grassy patches at several locations across the island. As with other Satyrinae members, the adults fly in an erratic and jerky manner as their wings are closed for a relatively long period during flights.