Life History of the Malayan Eggfly

Life History of the Malayan Eggfly (Hypolimnas anomala anomala)

Butterfly Biodata:
Genus: Hypolimnas Hübner, 1819
Species: anomala Wallace, 1869
Subspecies: anomala Wallace, 1869, f. nivas Fruhstorfer, 1913
Wingspan of Adult Butterfly: 75mm
Caterpillar Local Host Plant: Pipturus argentus (Urticaceae, common name: Australian Mulberry).


A Malayan Eggfly -f anomala perching on a vine in a wasteland.


A puddling Malayan Eggfly -f nivas.


A Malayan Eggfly -f anomala featuring prominent blue gloss on the forewing upperside.

Physical Description of Adult Butterfly:
On both upper- and undersides, the wings are dark brown. Both fore- and hindwings have a submarginal series of small white spots and a full post-discal series of white spots. Two forms (-f anomala and -f nivas) of the adults occur in Singapore. In form -f nivas, the hindwing has a diffuse white post-discal band which is absent in the more common form -f anomala. Some specimens also feature a brilliant blue-gloss on the forewing upperside (see the picture above). The Malayan Eggfly is considered a mimic of Euploea species, and is subject to varying degrees of variation among individuals.

Upperside shots of puddling Malayan Eggfly adults. Left: -f anomala; Right: -f nivas.


Malayan Eggfly. Left: -f anomala; Right: -f nivas.

Field Observations of Butterfly Behaviour:
This species frequents lowland forests and is relatively common in Singapore, especially at locations where its host plant is growing, typically in wastelands, hill parks and fringe of nature reserves. Adults have been sighted visiting flowers and puddling in their habitats. Perching adults have the habit of defending its territory by engaging in dog fights with other intruding butterflies.


A Malayan Eggfly -f anomala visiting Syzygium flowers.


A Malayan Eggfly -f anomala visiting Ixora flowers.

Early Stages:
The caterpillars of the Malayan Eggfly feed on leaves of the sole local host plant, the Australian Mulberry. The caterpillars are gregarious (living in groups) in all stages, and they typically occur in such large numbers that they easily defoliate one whole plant before moving on to the next one in the vicinity. One noteworthy point is that the Malayan Eggfly caterpillars are observed to show no interest in eating their shed exuvia after each molt. It is common to observe a large collection of such exuvia in an infested tree in the wild.

Local host plant: Pipturus argentus. A close-up on fruits is given in the right panel.


A mating pair of the Malayan Eggfly.

Two views of a mother Malayan Eggfly standing guard over its eggs.

A view of the cluster of Malayan Eggfly eggs laid on the underside of a leaf.

The eggs of the Malayan Eggfly are laid in a large cluster (up to several hundreds) on the underside of a leaf of the host plant by the mother butterfly. The mother has the habit of standing guard over its eggs, and could stay in the sentry position for a very long period of time. At times, worn and dead mother butterflies could be found in this on-guard posture close to either the developing eggs or early instars of its offspring.

A worn and tattered mother Malayan Eggfly still keeping "an eye" on its offspring (likely 2nd instar) a week after it (in pristine condition) was found standing guard over its eggs (shown in an earlier picture) .

Each egg is golden in colour and somewhat globular in shape. Nine ridges run from the micropylar at the top to the base where the egg is adhered to the leaf surface. Numerous inconspicuous striations runs horizontally between these vertical ridges. Each egg has a diameter of about 0.5-0.6mm, and a height of about 0.7mm.

Two views of an egg of the Malayan Eggfly.


Two views of a mature egg of the Malayan Eggfly. The head capsule is now visible through the egg shell.


A group of mature eggs of the Malayan Eggfly.

The egg takes about 3-4 days to hatch. The young caterpillar emerges by eating away part of the egg shell. Much of the egg shell becomes the first meal for the newly hatched which is 1.9mm in length. It has a cylindrical and yellowish golden body covered with many small and dark tubercles. Long, fine and dark-colored setae emanate from these tubercles. The head capsule is black, mostly round in shape with no visible horns.

Two views of a newly hatched caterpillar of the Malayan Eggfly, length: 1.9mm.


Two views of 1st instar caterpillar of the Malayan Eggfly, length: 3mm.

The 1st instar caterpillar feeds on the lamina of young leaves, and this diet gives the caterpillar body a strong undertone of dark green. After reaching about 3.5mm in 2.53.5days, the caterpillar moults to the 2nd instar.

One late L1 among a group of freshly moulted L2 caterpillars. Note the shed L1 head capsules.

The body of the 2nd instar caterpillar is yellowish brown in base color with a darkgreen undertone. The same layout of tubercles as seen in the earlier instar is still present, but now short and stubby processes raise from tubercles, and serveral short and fine setae branches from each of these processes. The head capsule is black with two tiny and short apical horns. This instar lasts about 2-3 days with the body length reaching about 6.5-7.5mm.

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


A group of 2nd instar caterpillars.


A group of late 2nd instar (marked by red arrows) and early 3rd instar caterpillars.

The 3rd instar caterpillar resembles the 2nd instar caterpillar closely. Two changes are discernible upon a close examination. The first is the increase in the length of the setae-bearing processes covering the body surface. The second is the increase in the length of the two cephalic horns. This instar takes about 2.5-3.5 days to complete with body length reaching about 10-11mm.

Two views of a 3rd instar caterpillar, length: 8mm.


Two views of a 3rd instar caterpillar, late in this stage, length: 10mm.


A group of late 3rd instar and early 4th instar caterpillars.

The 4th instar caterpillar closely resembles the 3rd instar caterpillar, but with visibly longer body processes and cephalic horns. The body color is dark brown to black. This instar lasts 2.5-3.5 days with the body length reaching about 14-15mm.

An early 4th instar caterpillar (top), length:10mm, and a late 4th instar caterpillar, length: 13.5mm.


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


A group of mostly 4th instar caterpillars defoliating a plant in a wasteland.

The 5th (and penultimate) instar caterpillar has much longer body processes which have become yellowish brown to golden in color. The pair of cephalic horn is now so long that it is roughly equal to the vertical length of the head capsule. The head is also changes from an entirely black coloration to one with intermingling patches of black and reddish brown.

Two views of a 5th instar caterpillar, early in this stage, length: 17.5mm.

Head capsules of a 5th instar caterpillar (left) and a 6th instar caterpillar (right).

Two views of a 5th instar caterpillar, later in this stage, length: 22mm.

The 5th instar lasts for 3-4 days and has its length reaches up to 32mm before the next moult.

A group of 5th instar caterpillars.


Two views of a 5th instar catepillar, late in this stage, length: 32mm..

The 6th (and final) instar caterpillar has rather prominent golden dendrite processes and its cephalic horns is now nearly twice the vertical length of its head capsule. The head capsule has changed to reddisk brown in color, but cephalic horns remain entrely black. This final instar lasts for 4-5 days, and the body length reaches up to 50mm.

Two views of a freshly moulted 6th instar caterpillar, length: 30mm.


A large group of final instar caterpillars found in the field.


Two views of a 6th instar caterpillar, late in this stage, length: 50mm.

On the last day, the caterpillar ceases feeding and wanders around in search of a pupation. In the field, pupation sites have been found at a sizeable distance away from the infested host plant. The pupation site could be the underside of a leaf (not necessary that of the host plant) and stems/branches of a chosen plant. At this site, the caterpillar spins a silk pad from which it hangs vertically to take on the pre-pupatory pose.

A pre-pupa of the Malayan Eggfly.

A pre-pupatory larva assuming its "hanging" posture, and the subsequent pupation event half-day later.

Pupation takes place about 0.5 days later. The pupa suspends itself from the silk pad with no supporting silk girdle. It is entirely pale to golden brown. Dorso-laterally there are several rows of dark brown spiky processes. In the wing cases, the veins are marked in dark brown. Length of pupae: 19-21mm.

Three views of a pupa of the Malayan Eggfly.

Three views of a mature pupa of the Malayan Eggfly.

After about 6 days of development, the pupa turns dark as the pupal skin becomes translucent and the coloration and the markings on the forewing upperside become discernible as a result. The eclosion event takes place the next day.

A Malayan Eggfly emerges from its pupal case.

A newly eclosed Malayan Eggfly resting on its pupal case.

References:

• [C&P4] The Butterflies of The Malay Peninsula, A.S. Corbet and H.M. Pendlebury, 4th Edition, Malayan Nature Society.
• Butterflies of Thailand, Pisuth Ek-Amnuay, 1st Edition, 2006

Text by Horace Tan, Photos by Benjamin Yam, Koh Cher Hern, Loke P F, Anthony Wong, Federick Ho and Horace Tan

The Wanderer wanders back to Singapore

The Wonderful Wanderer wanders back to Singapore
Re-discovery of the Wanderer and Species #299

A shot of the female Wanderer (Pareronia valeria lutescens) shot at Pulau Ubin. This is the first reliable evidence of this species in SIngapore since the early authors' observation of this species in the 60's or 70's.

Whilst out on a group outing at Pulau Ubin on Saturday 26 Feb 2011, ButterflyCircle members Federick Ho, Sum CM, Koh CH, Tan KY, Simon Sng and Khew SK headed for the usual spots for butterfly shooting on this small offshore island in Singapore. The group was excited to see that the Common Jay (Graphium doson evemonides) that was first discovered on Ubin, was still around and indeed, there were at least 3-4 individuals flying around, though they weren't cooperative enough for a good shot.

Another shot of the latest re-discovery for Singapore

The butterfly activity on this hot and breezy Saturday morning was quite good, and there were other species flying around the trails. Whilst Tan Ke Yang and Federick Ho were busy shooting a male Great Mormon feeding at a bush of pink Lantana flowers, Ke Yang spotted a slow-flying butterfly fluttering by. He thought that it looked like a Yellow Glassy Tiger (Parantica aspasia aspasia) and gave chase, hoping to get a good shot of it. Federick followed suit and chased the fluttering butterfly, which stopped and perched to rest on the top surface of leaves occasionally.

Ke Yang's record shot of the resting female Wanderer

It stopped long enough for Ke Yang to take a record shot, and Federick to take a better field shot of the butterfly. However, upon initial inspection, it didn't quite look like a Yellow Glassy Tiger. When I inspected Federick's shot, I knew instantly that this was no Yellow Glassy Tiger, but a female Wanderer (Pareronia valeria lutescens) instead!

A shot of the male Wanderer taken in Bunker Trail in Johor

There was an earlier reported sighting of the male of this species in the early 1990's but there was no reliable evidence of it. Hence this is the first sighting with photographic evidence of this species in Singapore for a long time. The pristine individual of the female Wanderer suggests that it may have been an offspring that has bred on Ubin, from an earlier seasonal migration of this species from south Johor.

A shot of the upperside of a female Wanderer taken at Bunker Trail, Johor

The Wanderer belongs to the genus Pareronia of which two species are found in Malaysia. Both species display sexual dimorphism (where the males and females look different from each other) The species Pareronia valeria lutescens was recorded as extant in Singapore in the early authors' checklists. The male Wanderer is pale blue above, with prominent black veins on both wings. It is fast-flying, with a swift restless flight but stops to feed at flowers.

A female Wanderer perches on a leaf to rest - taken at Bunker Trail in Johor

In the less often-seen female, the wings bases are yellowish with broadly black-dusted veins. When in flight, the upperside of the female closely resembles the Yellow Glassy Tiger. The underside is paler and the colours muted, almost resembling a weathered individual of a Yellow Glassy Tiger. The flight of the female closely mimics that of the distasteful Danaid, as compared to the speedy flight of the male Wanderer. (See earlier article on Survival Strategies)

The pretty blue upperside of a male Wanderer - shot at Bunker Trail in Johor


The butterfly host plant is reported to be Capparis heyneana which should be looked for on Pulau Ubin, as there could be a sustainable population of this species, if there is adequate supply of the caterpillar host plant.

And so, with thanks and congratulations to ButterflyCircle members Ke Yang and Federick, we add species #299 to the Singapore Checklist with the re-discovery of the Wanderer!

Text by Khew SK ; Photos by Sunny Chir, Federick Ho, Khew SK, Ellen Tan and Tan Ke Yang

Butterfly of the Month - February 2011

Butterfly of the Month - February 2011
The Purple Duke (Eulaceura osteria kumana)

The short month of February is almost coming to an end, and the rainy weather that kept many a butterfly photographer in Singapore cooped up at home is also changing for sunny humid days. It will be butterfly season again soon, and members of ButterflyCircle started the year with great excitement, recording two new species to the Singapore Checklist - the Malay Dartlet and the White Banded Flat, and just as this article is being prepared, at least 2 other species have been observed!

Singapore, the Little Red Dot at the end of the Malay Peninsula, is thus far blessed with protection from natural disasters like earthquakes and typhoons. Even the 2004 tsunami, considered the deadliest tsunami in history, spared Singapore because of its location where it was shielded by Sumatra and Malaysia. The deadly tsunami, which was triggered by a 9.0 Richter scale quake which had its epicentre in the Indian Ocean near the west coast of Sumatra, killed at least 150,000 people across 11 countries and made millions homeless. And yet, Singapore was spared from the killer waves, despite its proximity to Sumatra.

The month of February, which is also the month in which I was born in 1959, is usually associated with the gemstone Amethyst. This gemstone is a purple-violet variety of quartz and ancient civilisations believed that the stone protected its owner from drunkenness! They were also believed to heal people and keep them cool-headed. Amethyst is usually associated with the colour purple and is the birthstone for the month of February.

The February born shall find,

Sincerity and peace of mind,

Freedom from passion and from care,

If they, the amethyst will wear.

- Gregorian Birthstone Poems

A male Purple Duke perches on the underside of a leaf

This month, we feature a Singapore butterfly with purple in its common name - the Purple Duke (Eulaceura osteria kumana). This species belongs to the subfamily Apaturinae, of which there are only two species found in Singapore. It is the sole representative of its genus in Singapore.

A male Purple Duke sunbathes with its wings opened flat

The male is pale purple brown above with a white discal band increasing in width from the forewing to mid-tornal area of the hindwing. The underside is tinged bluish-violet in a side light, and features ocelli in the sub-tornal area of both wings. The female is dull ochreous brown with obscure white markings on both wings. In flight the female resembles one of the females of the Euthalia or Tanaecia species.

A female Purple Duke shows the upperside of its wings as it sunbathes

The Purple Duke is a forest-dependent butterfly, and is not found outside the nature reserves of Singapore. It prefers shaded habitats in the forest understorey, and rarely leaves the safety of the forests.

The Purple Duke's typical perched pose, on the underside of a leaf. Note that the violet-blue sheen on the wings is sometimes more obvious when light from the flash hits the wings at a certain angles

The butterfly can be seasonally common, where up to half a dozen or more individuals can be seen flying around low shrubbery amongst shaded forest paths. It has a rapid flight and zips from perch to perch quickly. Both sexes of the Purple Duke have a unique habit of flying rapidly from its perch and settles on the undersides of leaves. If disturbed, it will take off and zips under another leaf to hide.

There are occasions, however, that the butterfly perches on the uppersides of leaves and occasionally open its wings flat to sunbathe, especially in the cool morning hours when the sun is just beginning to warm up the environment.

A newly-eclosed female Purple Duke opens her wings to sunbathe amongst low shrubbery

The Purple Duke's caterpillar host plant is a common forest plant, Gironniera nervosa, which is shares with another butterfly species, the Grey Sailor. The early stages of the Purple Duke has been recorded in Singapore and can be found on an earlier blog article here.

A female Purple Duke feeds on the ripened fruits of the Singapore Rhododendron

And so we end this 28-day February in the year 2011 as we look forward to the remaining months of the year with exciting new butterfly discoveries for Singapore!

Text by Khew SK : Photos by Sunny Chir, Chng CK, Federick Ho, Khew SK, Loke PF, Nelson Ong, Johnny Wee & Wong CM

Re-Discovery of the White Banded Flat

Re-Discovery of the White Banded Flat

Species #298 on the Singapore Checklist

It was on one of their regular butterfly-shooting outings that ButterflyCircle members Nelson Ong and Yiming decided to take a different route to explore areas that they had not ventured before. The intention was to hopefully find something new and unrecorded.

A White Banded Flat perched on a rocky surface

Their sense of adventure and pioneering spirit was rewarded with the sighting and a few shots of a species that was extant in Singapore in the early authors' checklist, but has not been seen in recent years. What was interesting, was that they didn't just chance upon only one individual of this species, the White Banded Flat (Celaenorrhinus asmara asmara), but stumbled on a small colony of them! The skippers were observed zipping up and down a forested path, and dogfighting with other individuals of the same species, as well as other Hesperiidae species.

The shot that started all the excitement of the re-discovery of the White Banded Flat. This individual was first spotted by Yiming and Nelson

After the sighting was reported, another group of ButterflyCircle members headed for the location and observed the same behaviour in the colony of the species. At certain times of the day, the White Banded Flats were observed stopping and sunbathing on the top surfaces of leaves, almost repeating a fixed routine where they fly rapidly, and then returning to the a favourite perch to sunbathe.

A White Banded Flat checking out the flash of one of the BC members

Occasionally, they even stop on rocks in the same manner, and one even stopped on one of the photographer's camera flash, as if to check out the intruders into their territory! However, this behaviour appeared to be just for sunbathing and resting after their rapid flight. None of them were observed to be feeding on the leaves or perches, as their proboscis were not extended for feeding.

When it has had enough of sunbathing on the top surfaces of leaves, it reverts to the habit of perching on the undersides of leaves with its wings opened flat as shown in this photo

After a period of time, they reverted to the typical behaviour of the subfamily Pyrginae (Flats) whereby they stop on the undersides of leaves with their wings opened flat. Further visits and observations indicated that there was at least half a dozen or more individuals of this species in that location. However, after a period of activity and chasing each other in rapid bursts of active flight, the butterflies abruptly disappeared mysteriously altogether!

This observation is quite consistent with some species of the subfamily Pyrginae, where their active period during the day is very time-sensitive, almost like clockwork, and then beyond their magical "hour" (sometimes longer, sometimes shorter), they will mysteriously disappear suddenly, only to appear at the same time and location the following day, over a period of time.

The White Banded Flat belongs to the genus Celaenorrhinus, which occurs in the tropics of Asia, Africa and America. Some 80 species are known to exist, although only 10 are recorded in Malaysia. In the reference checklist (Ref : Corbet & Pendlebury), one species, C. asmara asmara was recorded in Singapore. However, until this recent re-discovery, the species has not been seen in Singapore over the past two decades or more.

Mr Hairy Legs! The erectile hair tuft on the hind tibia of the male of the White Banded Flat

The males of the species in the genus have erectile hair tuft on the hind tibia which gives the legs a rather hairy and unique appearance. The White Banded Flat has been described as uncommon but widely distributed in the lowlands of Malaysia. On the forewing above, the forewing cell spot is not continued above the radius and there is no white spot in cell 1b. The discal fascia is white and does not extend below vein 2. There are some obscure darker brown markings on the hindwings above.

The host plant is Clerodendrum fragrans. The caterpillar is described as stout with a short neck and a lustrous black head. It is also noteworthy that the scientific name of the species comes from the Malay word asmara which means "romance or love". Whether Butler intended the name of this species to have been derived from the Malay word when he described this species back in 1879 is a subject for further investigation.

With this re-discovery, credited to ButterflyCircle members Nelson and Yiming, the Singapore Butterfly checklist edges closer to the 300 mark as we record this as species #298.

Text by Khew SK : Photos by Sunny Chir, Chng CK, Khew SK, Nelson Ong & Anthony Wong

References :

The Butterflies of The Malay Peninsula, A.S. Corbet and H.M. Pendlebury, 4th Edition, The Malayan Nature Society.