18 September 2016

Life History of the Felder's Royal v2.0

Life History of the Felder's Royal (Tajuria mantra mantra)

Butterfly Biodata:
Genus: Tajuria Moore, 1881
Species: mantra C. & R. Felder, 1860
Subspecies: mantra C. & R. Felder, 1860
Wingspan of Adult Butterfly: 31-35mm
Caterpillar Local Host Plant: Macrosolen cochinchinensis (Loranthaceae common names: Common Chinese Mistletoe, 鞘花). .

Physical Description of Adult Butterfly:
On the upperside, the male is shining greenish-blue and the female is paler purplish blue. Both sexes have a broad apical black border in the forewing, and a black costal border in the hindwing with inner edges evenly curved to below vein 6 in male and to vein 4 in female. The female has additional marginal spots at tornus and in spaces 1b, 2 to 4. On the underside, both sexes are drab greyish-brown. The forewing post-discal line is much closer to termen than to the cell-end. The hindwing has large black tornal spots in spaces 1a and 2 which are broadly orange-crowned. There are two pairs of white-tipped tails at ends of veins 1b and 2 respectively.

Field Observations:
This species was recently re-discovered in Singapore in 1999. It is relatively rare locally. Sightings of this species have been more frequent in the Southern Ridges than in the Central Catchment Reserve Area. Around noon, the fast-flying adults have been sighted taking nectar at flowering plants in both hill parks and in gardens sited along the fringe of nature reserves. At times several adults could be seen dog-fighting at tree-top level in the mid afternoon.

Early Stages:
Only one local host plant has been recorded for the Felder's Royal. The plant, Macrosolen cochinchinensis is a parasitic plant growing on branches of other plants. Caterpillars of the Felder's Royal feed on the young and developing leaves of this host, with the 1st instar initially skimming the leaf surface and the later instars eating the leaf along the edges.

Local host plant: Macrosolen cochinchinensis.

Eggs are laid singly on the underside of leaves, young shoots, on or in the vicinity of flower buds of the host plant. Each egg is about 0.8mm in diameter, white with a strong greenish tinge when freshly laid. It is burger-shaped with a depressed micropylar at the pole and a surface reticulated with rather large polygonal depressions.

Two views of an egg of the Felder's Royal, laid among leaf buds of the host.

An egg of the Felder's Royal laid on the leaf bud of host.

It takes 3-4 days for the egg to hatch. The young caterpillar consumes just enough of the egg shell to emerge. With a length of about 1.2mm, it is with pale brownish lateral bands. Long setae (hairs) run along the length of the body dorsally as well as sub-spiracularly. The caterpillar assumes the typical woodlouse body shape as it grows in this instar which lasts about 3 days and sees the body length increased to about 3.3mm. On the last day of this instar, raised dorsal tubercles become prominent and reddish brown patches appear laterally.

Two views of a 1st caterpillar, newly hatched, length: 1.2mm.

Two views of a 1st instar caterpillar, length: 2.75mm.

Two views of a late 1st instar caterpillar, length:3.3mm.

The 2nd instar caterpillar has a diamond-shaped prothoracic shield dark in color. Dorsally, it bears prominently projections, one to each of abdominal segments 1 to 6, and two to each of thoracic segments 2 and 3. Reddish brown and pale patches decorate sides of the body. The posterior segments from the 7th abdominal segments onwards are fused together to take on a shield-like appearance with a dark patch sitting on top of it. The 2nd instar lasts for 3 days and reaches a length of about 5.5-6mm. Even in this early stage, the dorsal nectary organ and tentacular organ are very prominently featured on the shield-like posterior. The dorsal projections on segments 2, 3 and 6 turn greenish towards the end of this instar.

Two views of a 2nd instar caterpillar, newly moulted, eating its exuvia, length: 3.8mm.

Two views of a 2nd instar caterpillar, length: 4.2mm.

Two views of a 2nd instar caterpillar, late in this stage, length: 5.3mm.

The 3rd instar caterpillar looks similar to the late 2nd instar caterpillar but with greater contrast between pale beige coloration with dark brown to black coloration on the body. As the body grows in size to a length of about 10-11.5mm, the color of shading on both the anterior and posterior parts also darkens. After 3 days in this stage, it moults again.

Two views of a 3rd instar caterpillar, length: 8.9mm.

Two views of a 3rd instar caterpillar, length: 11.5mm.

The 4th (and final) instar caterpillar initially resembles the late 3rd instar caterpillar. Over the next 2 days, the color of the body gradually darkens. Mid body segments (excluding the dorsal ridge) become dark brown in color. Both the anterior and posterior segments are dominated by brown shadings. The carapace-shield also features a wrinkled surface. In addition, the dorsal projections on abdominal segments 2, 3 and 6 lose their green coloration and take on the same pale yellowish brown of the other dorsal projections.

Two views of an early 4th instar caterpillar, newly moulted and eating exuvia, length: 10.5mm.

Two views of a 4th instar caterpillar, length: 17mm.

The 4th instar lasts for 4 days and the body reaches a length of about 19-21mm. In the last day of this stage, more dramatic color changes take place. The shield-like posterior segments take on a bright orangy brown coloration where the mid body segments assume a contrasting dark green coloration. The anterior body segments turn lighter brown in coloration. Nearing the end of this instar, the caterpillar ceases feeding, and its body shrinks in length. Soon it comes to rest at a spot on the leaf surface and prepares for its pupation.

A 4th instar caterpillar of the Felder's Royal feeding on an Ixora flower.

The pre-pupatory caterpillar prepares for pupation by spinning a silk pad to which it attaches itself via anal claspers. Even during this pre-pupal stage, color changes continue to take place (see the next two pictures).

Two views of an early pre-pupa of the Felder's Royal.

Two views of a late pre-pupa of the Felder's Royal.

Pupation takes place after about 1 day of the pre-pupa phase. The pupa is held firmly via its cremaster to the silk pad on the leaf surface. It is 12-13mm in length, mostly green with yellowish green patches. There are two sets of brown to reddish brown dorsal markings. The pupa was observed to react to an external disturbance by jerking up and down.

Two views of a pupa of the Felder's Royal.

Seven days later, the pupa becomes darkened, mostly in the thorax and wing pads. The bluish patch on the forewing upperside can now be seen in the wing pads. The next day the adult butterfly emerges from the mature pupa.

Two views of a mature pupa of a Felder's Royal.

A newly eclosed Felder's Royal.

  • [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, 2nd Edition, 2015.
Text by Horace Tan, Photos by Jonathan Soong, Nelson Ong, Anthony Wong and Horace Tan

No comments: