Senin, 02 April 2012

the Common Lascar (Pantoporia hordonia hordonia)

Butterfly Biodata:
Genus: Pantoporia
Hübner, 1819
Species: hordonia Stoll, 1790
Subspecies: hordonia
Stoll, 1790
Wingspan of Adult Butterfly: 40-50mm
Caterpillar Local Host Plants:
Archidendron clypearia (Leguminosae, Mimosoideae), Parkia speciosa (Leguminosae, Mimosoideae, common name: Petai)

A Common Lascar displaying its wing underside.

A Common Lascar puddling on damp ground in the nature reserve.

Physical Description of Adult Butterfly:
Above, the wings are dark brown to black with orange markings. On the forewing, there is a broad orange cell streak with two small indentations. Post-discal spots in spaces 2 and 3 are in echelon. The orange submarginal line on the forewing  has a thinner grey fascia lying on the inner side. The hindwing has a subbasal streak passing through base of cell, and a basal streak passing along costa. The dorsum of the thorax has a small orange   band aligned with the forewing cell streaks. Underneath, the wings have pale orange markings corresponding to those on the upperside, but generally larger. These markings are set against a background marbled in pale brown to dark brown paterns with intricate details.

Field Observations of Butterfly Behaviour:  
This species is moderately common in Singapore and its distribution is restricted to the Central Catchment and Bukit Timah nature reserves. The adults are weak flyers  but are rather alert  and skittish, and would quickly ascend to the tree top when alarmed.  The adults have been sighted visiting flowers and puddling on wet ground, and would typically open their wings fully when perching.

Early Stages:
Local host plant #1: Parkia speciosa.
The local host plants, Parkia speciosa and Archidendron clypearia, are common at several locations within the local nature reserves. The caterpillars of the Common Lascar feed on the (compound) leaves of these two  host plants. Although the caterpillar has no qualm with  feeding on green leaflets once in a while,  its diet consists mainly of these leaflets in the withered state. Such leaflets are created after the caterpillar cuts  the petiole or rachis of a compound leaf, thus depriving the detached part of water and nutrient supplies. The detached part stays on the host plant with the aid of  silk threads spun by the caterpillar while it works intermittently to cut the petiole/rachis.

A Petai plant with one compound leaf cut by a Common Lascar caterpillar.

Local host plant #2: Archidendron clypearia.

Between feeding, the caterpillar seeks safety and concealment among the leaflets in the drooping part of the cut compound leaf. To  avoid detection by a prey, Its  movement on the rachis is typically slow, jerky and stealthly.  
Common Lascar: eating withered leaflets, movement and concealment among drying leaflets.

A female Common Lascar ovipositing an egg on a leaflet of the Petai plant.

The eggs of the Common Lascar are laid singly on either surface of a  leaflet of the host plant. The eggs are somewhat globular in shape, with surface marked with hexagonal pits and bearing spines at pit corners, giving them the appearance of minute sea-urchins. The micropylar sits atop. Freshly laid eggs are pale green in colour, and would turn yellowish   when maturing. Each egg has a diameter of about 0.8mm, and a height of about 0.9mm.

Two views of an egg of the Common Lascar laid on the Petai plant.

Two views of a mature egg of the Common Lascar. Note the visiable head capsule of the caterpillar.

The egg takes about 3-4 days to hatch. The young caterpillar emerges by eating away part of the egg shell. The rest of the egg shell becomes the first meal for the newly hatched which is about 2mm in length. The pale green  body is cylindrical in shape and is covered with many small tubercles and short setae. The head capsule is pale brown in color.

A newly hatched caterpillar half way through eating its egg shell, length: 2mm.

A 1st instar caterpillar hark at work at cutting the rachis of a Petai leaf, length: 2.8mm.

As the caterpillar grows, the body assumes a green to dark green undertone. Four pairs of subdorsal tubercles, found on the 2nd and 3rd thoracic segments, 2nd and 8th abdominal segments, are noticeable upon close scrutiny.  After reaching about 4.0mm in 4-6 days, the caterpillar moults to the 2nd instar.

Two views of a  1st instar caterpillar, length: 2.8mm.

The body of the 2nd instar caterpillar is pale  brownish with a green undertone.  The head is pale brown.  The  surface of both the body and the head is covered with numerous tiny whitish tubercles bearing short setae. This instar lasts about 5-7 days with the body length reaching about 7mm.

Two views of a 2nd instar caterpillar, early in tthis stage, length: 4mm.

Two views of a 2nd instar caterpillar, later in tthis stage, length: 5.6mm.

The 3rd instar caterpillar could occur in two colour forms: green form or brown form  where the body and the head are  pale green or brown respectively.  A long dorsal saddle, which runs from the dorsum of the 2nd abdominal segment and tapers to a narrow dorsal band at the posterior end, begins to take shape towards the end of this instar.  At the same time, faint lateral oblique stripes become noticeable on 2nd, 3rd and 4th abdominal segments. The subdorsal tubercles on 2nd and 3rd thoracic segments, 2nd and 8th abdominal segments are still short but more  pointed than in the 2nd instar.  A pale brown or whitish band runs sub-spiracularly along the side of the abdodmen. This instar takes about 5-7 days to complete with body length reaching about 10mm.

Two views of a 3rd instar caterpillar, early in this stage, length: 6.8mm

Two views of a 3rd instar caterpillar, late in this stage, brown form,  length: 9.8mm.

Two views of a 3rd instar caterpillar, late in this stage, green form,  length: 9.5mm.

The 4th instar caterpillar resembles the 3rd instar caterpillar closely with the same colour forms. In some specimens, one or more of the lateral oblique stripes on the 2nd, 3rd and 4th abdominal segments are darkened and contrast strongly against the body base colour. The 4 pairs of subdorsal spines, though still  diminished in length, are now more prominent in this instar. The long dorsal saddle become more prominent as it appears in lighter shade than the rest of the body.  This instar lasts 6-8 days with body length reaching about 14mm.

Two views of a 4th instar caterpillar, green form, length: 13.8mm.

Two views of a 4th instar caterpillar, brown form, length: 12.5mm.

The 5th instar caterpillar resembles the 4th instar closely.  A general and observable  trend is the slight but noticeable increase in length in the 4 pairs of subdorsal spiones. The long dorsal saddle also gains greater prominence through greater contrast in its colour against the rest of body, and that its front and rear boundary are typically highlighted with dark borders. 

Two views of a 5th instar caterpillar, early in this stage, length: 13mm.

Two views of a 5th instar caterpillar, later in this stage, length: 21mm.

Two views of a 5th instar caterpillar, green form, length: 23mm.

Two views of a 5th instar caterpillar, brown form, length: 23mm.

The 5th instar lasts for about 7-9 days, and the body length reaches up to 22-23mm. On the last day, the color of the body decolorises slightly to a pale shade of brown or green. The caterpillar ceases feeding and stations itself at the underside of the rachis or the mid rib within the cut and withered part of the leaf.  At this pupation site, the caterpillar spins a silk mound  from which it soon hangs vertically to take on the pre-pupatory pose.

The pre-pupa  and the fresh pupa of a brown form  Common Lascar caterpillar.

The pre-pupa and the fresh pupa of a green form Common Lascar caterpillar.

The pupa suspends itself via a cremastral attachment to the silk mound with no supporting silk girdle. Depending on the colour form assumed by the final instar caterpiollar, the fresh pupa could be either brownish or greenish.  The thorax and anterior part of the abdomen are broad, and  the wing cases are dilated laterally. The dorsum of the thorax is raised and angular. Several silvery spots adorn the dorsum of the mesothorax, metathorax and first abdominal segment. The head is bluntly cleft at its front edge with small pointed lateral vertices. Length of pupae: 10-13mm.

Three views of a pupa of the Common Lascar.

After about 5 days of development, the pupal turns dark as the development within the pupal case comes to an end. The orange markings on the forewing upperside become discernible through the pupal skin. The following day, the adult butterfly emerges from the pupal case.

Three views of a mature pupa of the Common Lascar.

A Common Lascar emerges from its pupal case.

A newly eclosed Common Lascar.

  • The Butterflies of The Malay Peninsula, A.S. Corbet and H.M. Pendlebury, 4th Edition, The Malayan Nature Society.
  • Butterflies of Thailand, Pisuth Ek-Amnuay, 1st Edition, 2006.
Text by Horace Tan, Photos by Federick Ho, Khew SK and Horace Tan

Common Mime (Chilasa clytia clytia)

Butterfly Biodata:
Genus: Chilasa Moore, 1991
Species: clytia
Linnaeus, 1758
Subspecies: clytia
Linnaeus, 1758
Wingspan of Adult Butterfly: 95mm
Local Caterpillar Host Plant: Cinnamomum iners (Lauraceae)
[Synonym: C. initidum, C. paraneuron]

A Common Mime visiting flowers with wings fully opened giving us a full view of its upperside

A Common Mime taking nectar from Lantana in an urban hill park

A Common Mime puddling on a wet sandy area in the nature reserves

Physical Description of Adult Butterfly:
Worldwide, the Common Mime occurs in two morph-groups in both sexes, but In Singapore, only the black-and-white striped form-dissimilis occurs. This form is velvety black with extensive white streaks and spots on the upperside. Underside is similar to the upperside with slightly larger white markings, and on the hindwing there is a row of conspicuous yellow marginal spots. Head, thorax and abdomen are black with prominent white spots.

Field Observations of Butterfly Behaviour: The Common Mime is relatively common in Singapore, and can be seen in both the nature reserves and developed areas. The butterfly mimics the distasteful Danainae species for protection against predators. When the adults visit flowering shrubs, their slow and graceful flight resemble those of the distasteful Blue Glassy Tiger and the Dark Glassy Tiger. The adults have the habit of puddling on wet grounds.
Early Stages:
Across the range where this species occurs, the early stages feed on leaves of serveral plants in the Lauraceae family. The sole recorded local host plant, Cinnamomum iners (Common name: Clover Cinnamon, Wild Cinnamon), is a very common plant all over Singapore, readily found in nature reserves, gardens, parks and wastelands etc. It is a small to medium-sized tree with 3-nerved leaves. Eggs and early stages of the Common Mime are typically found on saplings at heights from knee to waist level.

Host plant : Cinnamomum iners

A female Common Mime taking off after an egg was laid on a wild cinnamon sapling.
Can you spot the egg?

The eggs of the Common Mime are laid on young leaves or petioles of a sapling of the host plant. Sometimes a few eggs could be found on the same sapling, and occasionally in close proximity. The spherical egg is creamy white with the surface coated with a non-uniform layer of orange-yellow granulated substance. Diameter: 1.2-1.3mm.

Left: egg freshly laid as featured in the previous picture.
Right: a group of three eggs on the petiole of a young leaf

Left: freshly laid egg; Middle: developing egg; Right: mature egg

The egg takes 3 days to hatch. The young caterpillar eats its way out of the mature egg, and then proceeds to finish up the rest of the egg shell. The newly hatched has a dark brown head, rows of short dorsal-lateral tubercles with long setae, and an initial body length of about 3mm. It is mainly pale brown with white patches on the the middle and posterior segments.

Newly hatched Common Mime caterpillar eating egg shell, length: 3mm

As it feeds and grows, the body color darkens to feature black lateral markings, and both yellowish brown and whitish dorsal patches. The head capsule also turns black. In this and the next three instars, the Common Mime caterpillars resemble bird droppings as they rest on the leaf surface.

1st instar caterpillar, length: 3p5mm

As the 1st instar caterpillar grows to a length of about 6.5mm, the dark lateral markings decolorizes and disappears. There is a white saddle on the 3rd-4th abdominal segments and white markings on the posterior abdominal segments. After about 2-3 days in 1st instar, the caterpillar moults to the next instar.

1st instar caterpillar, length: 5mm (top); 6.5mm (bottom)

The 2nd instar caterpillar has a similar appearance to the 1st instar caterpillar except for the longer and stubby processes, brighter shade of orange on dorsal patches, and distinctly white color on the saddle mark and posterior abdominal segments.
The growth is rather rapid and this instar lasts only 1-2 days. The body length reaches about 10-11mm before the next moult.

2nd instar caterpillar, early in this stage, length: 10.5mm

In the 3rd instar, again there is no drastic change in physical appearance except for the greater contrast between the black and orange markings. This instar takes 2 days to complete with body grown to about 19mm in length.

3rd instar caterpillar, early in this stage, length: 11mm

A time-lapse sequence of the moulting from the 3rd to the 4th instar

The 4th instar caterpillar has more extensive white markings on it body. The white patch on the posterior abdominal segments has extended to the whole of abdominal segment 7 and white lateral patches appear on the thoracic segments. This instar lasts 3 days with body length reaching about 33mm.

4th instar caterpillar, early in this stage, length: 20mm

A 4th instar Common Mime caterpillar found in the Jurong Lake area

The next moult brings the caterpillar to the 5th and final instar with a dramatic change in appearance. The body is dark greyish black in base color with numerous inconspicuous black spots embedded. On each side of the body, there are two rows of fleshy processes on segments 1 to 4 and single row on the other segments. A crimson red spot is featured at the base of each fleshy process. A sub-spiracular row of crimson red spot also occurs in the abdominal segments. The body also features large creamy yellow patches organized as follows: 1) a dorsal row of large irregularly-shaped patches; 2) a short lateral row on the posterior abdominal segments starting from abdominal segment 7, and 3) a front lateral row of yellow patches spanning all thoracic segments and abdominal segments 1, 2 and 3. The front lateral row connects with the dorsal row in abdominal segment 3.

5th instar caterpillar, second day after the moult, length: 50mm

A 5th instar Common Mime caterpillar found in a clearing in the Southern Ridges.

All instars of the Common Mime possess a fleshy organ called osmeterium in the prothoracic segment. Usually hidden, the osmeterium can be everted to surprise any intruder when the caterpillar senses the threat, The osmeterium is pale brown in the first four instars, and light indigo-blue in the final instar.

Partially everted osmeterium of a 1st intar Common Mime caterpillar

The dark to light brown osmeterium of a 4th instar Common Mime caterpillar

The indigo blue osmeterium of a final instar Common Mime caterpillar

The 5th instar lasts for 4 days, and the body length reaches up to 55mm. Toward the end of this instar, the body gradually shortens in length. Eventually the caterpillar comes to rest on the lower surface of a stem and becomes a pre-pupatory larva.

A pre-pupatory larva of Common Mime.
Top: preparing its anchor point; Bottom: having completed its silk girdle

Pupation takes place a day later. The pupa suspends itself with a silk girdle from the stem. The pupa resembles a broken twig about 38-40mm long, brownish with streaks and blotches,. The posterior segment is so modified that the pupa appears to have grown out of the branch to which the pupa anchors.

A Common Mime caterpillar molts to its pupal stage.

Two views of a twig-like pupa of the Common Mime.

After 11-12 days, the pupa turns black as the development within the pupal case draws to a close. The white spots on the forewings are now visible through the pupal skin at the wing pad area. The next morning the adult butterfly emerges from the pupal case.

An animated time-lapse sequence of the early portion of the eclosion event.

The eclosion of the Common Mime in a grid mosaic.

A newly eclosed Common Mime drying its wings near the empty pupal case

A newly eclosed Common Mime
  • The Butterflies of The Malay Peninsula, A.S. Corbet and H.M. Pendlebury, 4th Edition, Malayan Nature Society.
  • The Butterflies of Hong Kong, M. Bascombe, G. Johnston, F. Bascombe, Princeton University Press 1999