14 June 2014

Life History of the Formosan Swift

Life History of the Formosan Swift (Borbo cinnara)

Butterfly Biodata:
Genus: Borbo Evans, 1949
Species: cinnara Wallace, 1866
Wingspan of Adult Butterfly: 30-34mm
Caterpillar Local Host Plants: Paspalum conjugatum (Poaceae; common name: Buffalo Grass), Setaria barbata (Poaceae; common name: Bristly Foxtail Grass),

Centotheca lappacea (Poaceae, common name: Sefa).

A female Formosan Swift.

A male Formosan Swift.

Physical Description of Adult Butterfly:
On the upperside, the wings are brown with the basal area yellowish green. The forewing has a yellow non-hyaline spot in space 1b and a decreasing series of hyaline spots from spaces 2 to 4, 6 to 8 and two spots in the cell. In some specimens, one or both cell spots could be absent. The hindwing has a few obscure hyaline spots, and does not have any cell spot. On the underside, the wings yellowish brown with greenish scaling. The hindwing has whitish spots in spaces 2-4 and 6, where the spot in space 4 is typically small or even absent.

The upperside view of a female Formosan Swift.

The upperside view of a male Formosan Swift.

A worn specimen of a male Formosan Swift.

Field Observations of Butterfly Behaviour:
The Formosan Swift is relatively common in Singapore. Sightings are rather frequent and spread over many parts of Singapore, at locations such as nature reserves, neighbourhood parks, offshore islands, wastelands and park connectors. The swift flying adults have been observed to visit flowers and sunbath in sunny weather.