23 November 2013

Life History of the Copper Flash

Life History of the Copper Flash (Rapala pheretima sequeira)

Butterfly Biodata:
Genus: Rapala Moore, 1881
Species: pheretima Hewitson, 1863
Subspecies: sequeira Distant, 1885
Wingspan of Adult Butterfly: 31-35mm
Caterpillar Local Host Plants: Mangifera indica (Anacardiaceae, common name: Mango), Hibiscus tiliaceus (Malvaceae), Syzygium zeylanicum (Myrtaceae), Mallotus paniculatus (Euphorbiaceae, common name: Turn-in-the-wind) and Saraca thaipingensis (Fabaceae, common name: Yellow Saraca).

Physical Description of Adult Butterfly:
On the upperside, the male is mostly dark reddish brown, and the female is dull steely blue. On the underside, both sexes are pale brown. Both wings have a broad cell-end bar and a brown post-discal band which is whitened on the outer side. The forewing has a spot in the middle of the forewing cell (which could be absent in some females). The hindwing has a black marginal spot in space 2 and another on the tornal lobe. Between the two spots, the marginal area in space 1b is covered with bluish scaling. There is a white-tipped tail at the end of vein 2. The legs are white and black-banded.

Field Observations:
This species is moderately common in Singapore and can be found in serveral urban parks and nature reserves. The adults are fast flyers and make rapid sorties among foliage. Both sexes have been observed to visit flowers of various plants for nectar.

Early Stages:
The Copper Flash is polyphagous as its early stages feed on a number of host plants from different families. Locally four plants, Mangifera indica, Hibiscus tiliaceus, Syzygium zeylanicum and Mallotus paniculatus, have so far been identified as the larval hosts. One other plant is still awaiting identification. The caterpillars of the Copper Flash feed on the young and tender leaves of the host plants. In the wild, the caterpillars are typically found in the company of the Weaver Ant (Oecophylla smaragdina).

Local host plant #1: Syzygium zeylanicum..

Local host plant #2: Mangifera indica.

The eggs are laid singly on leaves, stems or young shoots of the host plants. Each egg is about 0.6mm in diameter, green in colour. It is burger-shaped with a depressed micropylar at the pole and a surface covered in a reticulated pattern.

Two views of an egg of the Copper Flash.

It takes about 3 days for the egg to hatch. The newly hatched is pale yellowish with lateral brown bands running lengthwise. Its body has a length of about 1.1mm. Dark brown patches can be seen on the 1st, 7th-8th abdominal segments and on the anal plate. It also has a black prothoracic shield and a black head. The body also features moderately long setae dorso-laterally and laterally. After about 2 days of growth in the first instar, and reaching a length of about 2.3mm, the caterpillar moults to the next instar.

1st instar caterpillar, newly hatched, length: 1.1mm.

Two views of a 1st instar caterpillar, length: 2.3mm.

Two views of a late 1st instar caterpillar, dormant prior to its moult, length: 2.1mm.

In the 2nd instar, the prothoracic shield is changed to pale yellowish brown. There are numerous short fine setae emanating from rows of conical projections occurring dorso-laterally. Numerous short setae are also projected sub-spiracularly along the body fringe. The 2nd instar caterpillar reaches a length of about 4mm, and after about 1.5-2 days in this stage, it moults again.

Two views of a 2nd instar caterpillar, length: 3.7mm.

Two views of a late 2nd instar caterpillar, dormant prior to its moult, length: 2.1mm.

Compared to the 2nd instar caterpillar, the yellowish green 3rd instar caterpillar has a more striking appearance with oblique dorso-lateral patches outlined in white. There are conical projections occurring dorso-laterally and along the body fringe, each with a tuff of setae at its tip. The dorso-lateral conical projections on the 7th abdominal segment is reddish in contrast to the pale yellowish coloration for the rest of such projections. On the 7th abdominal segment, the dorsal nectary organ is now more readily observed. The 3rd instar takes about 1.5 to 2 days to complete with the body length reaching about 8.5mm.

Two views of a 3rd instar caterpillar, length: 6mm.

Two views of a late 3rd instar caterpillar, dormant prior to its moult, length: 8mm.

The 4th instar caterpillar has a more prominent appearance, featuring broad triangular to semi-circular dorsal patches in yellow or pink (giving rise to different colour forms), broad triangular lateral patches in lime green to pigment green. It seems that the colour form assumed by the caterpillar is closely associated with the colour of the host plant leaf the caterpillar is feeding on. The 4th instar takes about 2-2.5 days to complete with the body length reaching 15mm.

Two views of a 4th instar caterpillar, length: 10mm.

Two views of a late 4th instar caterpillar, dormant prior to its moult, length: 13mm.

The 5th instar caterpillar has similar markings as in the 4th instar. Conical projections along the body fringe on the 2nd-3rd thoracic segments, 1st, 2nd and 8th abdominal segments are coloured dark red to dark green with the rest are coloured yellow.

Two views of a 5th instar caterpillar, length: 19.5mm.

Two views of a 5th instar caterpillar, length: 24mm.

A 5th instar caterpillar found in the field on a leaf of the host plant yet to be identified.

After about 3.5-4 days of feeding and reaching a length of about 24mm, the caterpillar stops food intake and wanders around for a pupation site. During this time, its body gradually shortened. Typically the caterpillar chooses a concealed space in a leaf litter for its pupation site.

Weaver ants attending to a 5th instar caterpillar of the Copper Flash.

The pre-pupatory caterpillar prepares for pupation by spinning a silk girdle and a silk pad to which it attaches itself via anal claspers. After about 1 day as a pre-pupa, pupation takes place. The pupa is predominantly reddish brown and has numerous small dark speckles. Pupal length: 14-15mm. The pupa has a typical lycaenid shape with a short abdomen.

Two views of a pre-pupa of the Copper Flash.

Two views of a fresh pupa of the Copper Flash, moments after the pupation event.

Two views of a pupa of the Copper Flash.

Nine days later, the pupa turns black, first in the wing pad and thorax, then progressively in the abdomen. The presence and absence of the bluish patch in the wing pads gives an early indication of the gender of the soon-to-emerge adult. The next day, the pupal stage comes to an end with the emergence of the adult butterfly.

Two views of a mature pupa of a Copper Flash.

A newly eclosed Copper Flash.

  • [C&P4] The Butterflies of The Malay Peninsula, A.S. Corbet and H.M. Pendlebury, 4th Edition, Malayan Nature Society, 1992.
  • Butterflies of Thailand, Pisuth Ek-Amnuay, 2nd Edition, 2012.
  • A Field Guide to the Butterflies of Singapore, Khew S.K., Ink On Paper Communications, 2010.
Text by Horace Tan, Photos by Benedict Tay, Bobby Mun, Loke PF, Nelson Ong, Simon Sng, Sunny Chir and Horace Tan

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