07 December 2013

Life History of the Chestnut Bob

Life History of the Chestnut Bob (Iambrix salsala salsala)

Butterfly Biodata:
Genus: Iambrix Watson, 1893
Species: salsala Moore, 1866
Sub-species: salsala Moore, 1866
Wingspan of Adult Butterfly: 23-27mm
Caterpillar Local Host Plants: Ottochloa nodosa (Poaceae), Axonopus compressus (Poaceae, common names: Wide-leaved Carpet Grass, Cow Grass).

Physical Description of Adult Butterfly:
On the upperside, both sexes are dark brown. On the forewing, the male has an obscure, pale rusty-coloured post-discal band whilst the female has a short series of white spots instead. On the underside, the wings are dark brown in the lower half of the forewing but yellowish brown on the entire hindwing and the costal half of the forewing. On the forewing, there is a spot at cell-end and there are post-discal spots in spaces 1b, 2-6 and 8. On the hindwing, there are post-discal spots in spaces 1b, 5 and 7. These spots are typically embedded in black and some of these spots could be absent in various specimens.

Field Observations of Butterfly Behaviour:
Chestnut Bob is a rather common skipper species in Singapore and can be readily encountered across the island in parks, gardens and also in the nature reserve, typically in sunlit grassy patches. The adults visit small wild flowers for nectar and fly close to the ground.