11 October 2009

Life History of Semanga superba deliciosa

Life History of Semanga superba deliciosa


Butterfly Biodata:
Genus: Semanga Distant, 1884
Species: superba H. Druce, 1873

Sub-species: deliciosa Seitz, 1926
Wingspan of Adult Butterfly: 28mm
Caterpillar Local Host Plants:
Mallotus paniculatus (Euphorbiaceae), Melastoma malabathricum (Melastomataceae), Saraca cauliflora (Leguminosae), Macrosolen cochinchinensis (Loranthaceae), Kopsia fruticosa (Apocynaceae), Bridelia tomentosa (Euphorbiaceae), Trema tomentosa (Ulmaceae).


A female Semanga superba resting on a leaf.


The upperside of a female Semanga superba.

Physical Description of Adult Butterfly:
Above, the male is lustrous purple with a black border on the forewing and an orange-red distal border on the hindwing. The female is bluish purple with a wider forewing border. Underneath both sexes are buff-brown with narrow reddish brown post-discal line on the forewing. The hindwing has basal area unmarked, but the tornal half broad and reddish-orange with black spots and metallic blue/green zig-zagged lines. The male possesses two pairs of moderately long filamentous tails at the end of veins 2 and 3, whilst the female features one additional short pair at the end of vein 4.


A female Semanga superba feeding on a leaf in the nature reserve.


A male Semanga superba resting on a perch.

Field Observations of Butterfly Behaviour:
This attractive and small species is infrequently encountered in the nature reserves in Singapore, despite the wide distribution of its many host plants throughout the country. In most encounters, adults are sighted flying rapidly in the vicinity of flowering shrubs and trees. Rare photograph opportunities only arise when they stop to sun-bathe or to take nectar from flowers.

Early Stages:
The immature stages of Semanga superba are polyphagous and so far 7 plants have been recorded as local hosts, with species ID for all but one established. Depending on the host, caterpillars of all instars feed on either young leaves or flower buds.


Host plant: Mallotus paniculatus (also host plant for the Malayan).


Host plant: Kopsia fruticosa. Leaves and flowers.

All field sightings of caterpillars in any instar typically come bundled with a number of ants in attendance. Such strong association with ant species has earlier been observed and documented in a 1995 journal paper by Prof. Fiedler and his colleague. Earlier partial breeding attempts (by Prof. Fiedler, and by Butterflycircle members) were successfuly completed with ants in attendance. Recently, Ben Jin Tan, an active Butterflycircle member, managed to accomplish the task of breeding two specimens from the egg stage to adulthood in total absence of ants, a task previously thought to be impossible. The following account of the complete life history of Semanga superba is based mostly on the growth record maintained and provided by Ben Jin.


A caterpillar of Semanga superba in 5th or 6th instar being attended by ants.

Eggs are laid on the leaf underside or on a perduncle/pedicel of an infloresence The white egg , about 0.9mm in diameter, is shaped like a slightly flattened chinese bun with its surface covered with numerous short spikes and a depressed micropylar sitting atop.


An egg laid on Kopsia fruticosa. Diameter: 0.9mm.
The right panel shows the empty egg shell after hatching.



A cluster of three eggs laid against the midrib on a leaf underside of the Singapore Rhododendron.

Each egg takes about 4 days to hatch. The young caterpillar emerges after nibbling away sufficiently large upper portion of the egg shell. Measured at a length of about 1.2-1.3mm, its pale yellow body is cylindrical in shape, sporting moderately long fine setae running lengthwise, a black head capsule, a large dark prothoracic shield and a light brown to greyish anal plate.


Two views of a newly hatched caterpillar of Semanga superba.


An early instar caterpillar being attended by two ants.

As the caterpillar grows, its body broadens sideway, and red to reddish patches appear on the prothorax, mesothorax and posterior abdominal segments. The growth is slow and after about 4-6 days, it only reaches about 3mm in length when it stops for the moult to the 2nd instar.


Two views of a 1st instar caterpillar, late in this stage.

Covered with numerous short setae, the body of the 2nd instar caterpillar is pale yellow in base color. The prothoracic shield is dark and well developed. The body is onisciform in shape and flattened dorso-ventrally. The three thoracic segments and the first 6 abdominal segments bear a pair of lateral cone-shaped projections furnished with a tuft of long and erect setae. The anal end also features cone-shaped projections with long and erect setae. There are also postmedian series of red markings on the first 6 abdominal segments. The growth in this stage brings the caterpillar to a length of about 4mm, and after about 3 days in this stage, it moults again.


A freshly moulted 2nd instar caterpillar.


Two views of a 2nd instar caterpillar, lengths: 3.8mm.

In the 3rd instar, both the prothoracic shield and the anal plate are black and well developed. The lateral projections all around the body have become rather pronounced. There is also a pair of lateral projections on the 8th abdominal segment which is long and elevated with sclerotized black sheaths housing the eversible and whitish tentacular organs. The dorsal nectary organ on the dorsum of the 7th abdominal segment is clearly discernible. This instar takes 3-4 days to complete with the body length reaching about 7mm before the next moult.


3rd instar caterpillar, early in this stage.


Two views of a 3rd instar caterpillar, length: 5mm.

The 4th instar caterpillar bears few changes from the 3rd instar. One visual difference is the increase in color intensity of the red to reddish brown patches at both ends to dark brown or dark reddish brown. The body base color has also changed to pale green. The postmedian markings on 1st-6th abdominal segments are more prominent with white wavy pink/red/dark-brown strips interminging with white. The dorsal nectary organ is now sitting within a pale reddish-brown patch. The tentacular organs are easily observed as their eversions occur frequently. This instar lasts about 5 days with length reaching 10-11mm.


4th instar caterpillar, early in this stage.


4th instar caterpillars, late in this stage, length: 10mm.


A Semanga superba caterpillar of either 3rd or 4th instar being attended by ants.

The 5th instar caterpillar has broader and more contrasting postmedian series of markings, and the patch containing the dorsal nectary organ is now larger and more prominent. A pair of dark dorsal projections on the mesothorax has also become more elevated. This instar lasts about 6 days with length reaching 13-13.5mm.


A 5th instar caterpillar moving past flower buds of Macrosolen cochinchinensis.


Two views of a 5th instar caterpillar, late in this stage.

The 6th (and final) instar caterpillar has much darker postmedian series of markings. Dark patches of varying sizes appear lateraly with those on the 1st abdominal segment being the largest and most discernible. A mid-sized white to beige dorsal patch also appears on the mesothorax. This instar lasts about 11-12 days with the length reaching about 20mm.


A 5th instar caterpillar feeding on flower buds of Macrosolen cochinchinensis


6th instar caterpillars on Trema tomentosa.


A picture illustrating the differences in the posterior ends of 2nd instar (left) and
6th instar (right). Note the everted tentacular organs.

Towards the end of the 6th instar, the caterpillar ceases eating and chooses a spot on the leaf surface for its pupation site. A pupation shelter is made with multiple silk threads joining opposing leaf surfaces. Within the shelter, the pre-pupatory caterpillar readies itself for pupation by spinning a silk girdle and a silk pad. In the wild, some caterpillars have been found to pupate within ant pavillions.


A pre-pupatory larva of Semanga superba.

Pupation takes place after one day of the pre-pupal stage. The pupa has the typical lycaenid shape, silvery white in base colour with many black patches in greenish tinge on the pupal surface. The pupa has a length of about 10-11mm.


A pupa of Semanga superba within a shallow pupation shelter.

Nine days later, the pupa becomes darkened in color signaling the imminent emergence of the adult. The next day the adult butterfly emerges from the mature pupa.


The eclosion sequence of a Semanga superba adult.

References:
  • The Butterflies of The Malay Peninsula, A.S. Corbet and H.M. Pendlebury, 4th Edition, The Malayan Nature Society.
  • The mature larva and pupa of Semanga superba, Konrad Fiedler and Peter Seufert, Nachr. entomol. Ver. Apollo, N.F. 16 (1): 1-12, 1995.
Text by Horace Tan, Photos by Benedict Tay, Mark Wong, Sunny Chir, Ben Jin Tan and Horace Tan

07 October 2009

Butterfly of the Month - October 2009

Butterfly of the Month - October 2009
The Saturn (Zeuxidia amethystus amethystus)



This month, we feature a butterfly that almost exclusively lurks around the dark shady forest understorey of Singapore's nature reserves - the Saturn (Zeuxidia amethystus amethystus). This species belongs to the family Nymphalidae ; Subfamily Morphinae, which comprise relatively large butterflies that prefer heavily shaded forested areas and generally fly no more than a few feet above the ground. The majority of the species have drab and cryptic undersides that help the butterflies camouflage themselves amongst the forest leaf litter as they forage for food.


An unusual shot of the upperside of a male Saturn. This unfortunate individual was found in the last moments of its life as it was probably a victim of a poisonous spider bite. Note the transparency of the eyes indicating that it is still alive but paralysed by the bite and unable to fly

The Saturn is a medium sized butterfly, usually attaining a wingspan of 100 mm or more. The males are black above, with a broad iridescent blue discal band on the forewing with a large tornal patch of the same colour on the hindwing. In the female, the blue is replaced with a pale yellow fascia and dull orange on the apical area of the hindwings. The undersides presents a leaf-like appearance with cryptic markings on a brown background and there are large ocelli on the hindwings.




The Saturn is not rare, but remains mainly in the forested areas of the nature reserves. It is often encountered along forest paths, usually feeding on fallen fruits on the forest floor. Its cryptic undersides camouflage it very well amongst dead leaves and twigs. Very often, as one walks along the paths, the butterfly springs up from the ground as it is disturbed and very quickly flies away and settles amongst leaf litter to hide itself once again.


A female Saturn forages for food amongst dead leaf litter on the forest floor

The species is partial to rotting fruit, e.g. papaya, guava or pineapple. In Singapore, the Saturn is often observed feeding on rotting figs that have dropped on the forest floor, and is often found feeding in the company of other Nymphalidae butterflies like the Archduke, Dark Blue Jungle Glory and the Common Faun.


Two male and one female Saturn feeding greedily on rotting pineapple on the forest floor

Butterflies from the same Subfamily as the Saturn are known to frequent areas where palms and rattans grow. The various species are known to feed on different types of palms and rattans. Caterpillars of the Saturn have been bred on a species of Palmae by Igarashi, who observed that the caterpillars preferred to feed only on young tender leaves of the host plant. The caterpillar is green with short dark hairs. The head is horned and it has a pale yellow collar band, with a forked process at the posterior end of the caterpillar. The pupa is green with a pair of long 'horns' at its head and hangs from its cremaster head down along a leaf of the host plant.


The adult butterfly tends to be usually active in the early morning hours and towards the later part of the day. If undisturbed, they can stay perched on a leaf or a branch for long periods of time with its wings folded upright.

A closeup of a male Saturn feeding on a rotting fig fruit

The best time to approach the Saturn is when it is feeding on fermenting or rotting fruit, where it tends to be less skittish. At other times, the butterfly is very alert and is easily spooked by even the slightest movement, and is a difficult subject to photograph as it flies in the thick forested undergrowth.



Text by Khew SK : Photos by Benedict Tay, Bob Cheong, Federick Ho, Henry Koh, Jason Ng, Khew SK & Simon Sng.

References :
  • The Butterflies of The Malay Peninsula, A.S. Corbet and H.M. Pendlebury, 4th Edition, The Malayan Nature Society.
  • The Life Histories of Asian Butterflies Vol 1, Igarashi Suguru & Fukuda Haruo

30 September 2009

New Taxon for Malaysia

New Taxon for Malaysia
Discovery of a new butterfly species on Pulau Langkawi - Dryas iulia



On a recent trip to Pulau Langkawi, members of ButterflyCircle chanced upon a species of butterfly that has hitherto not been recorded in Malaysia. On location at Tanjung Rhu Beach, it was deja vu, as this was the place where I saw my first Leopard Lacewing (Cethosia cyane) back in 2001. Fast-forward to Sep 2009, another new species was spotted at almost the very same location where I saw the Leopard Lacewing!


A shot of the Tg Rhu Beach area where the pair of Dryas iulia was seen.

Whilst walking amongst the coastal vegetation, ButterflyCircle members Bobby Mun, Ellen Tan and I spotted a rather large orange butterfly fluttering amongst the wild flowers at low level. I instantly knew that this wasn't the usual Tawny Coster as the size and the flight characteristics were different. Upon closer examination, we found that the large orange butterfly, a male, was fluttering around a female of the same species which was feeding on the flowers.



The male, startled by our intrusion, beat a hasty getaway, and flew away towards the safety of the forested area. The female, however, continued with her unflustered fluttering amongst the herbage, looking for nectar from the wildflowers. As she continued to feed, we observed that her wings were badly tattered. Despite that, she was still able to fly nonchalantly from flower to flower, allowing the three of us to fire off several shots, as she paused at various flowers to feed.



After a short while, she also sensed our presence, and flew off towards the tree canopy and disappeared into the forested area.



Upon closer scrutiny of our photos, I realised that this unknown butterfly could very well be a new record for Malaysia. (Subsequent confirmation by Dr Laurence Kirton of FRIM established that this is a new record for Malaysia) The species was a Dryas iulia (or commonly known as the Julia Heliconian or Julia Butterfly). From literature research on the Internet, about 15 subspecies of Dryas iulia have been described. The species is native to South America, occuring from Mexico to Colombia and Brazil, and has a range reaching the North American states of Florida, Texas and as far north as Nebraska.

The Julia Heliconian is the sole representative of the genus Dryas and is described to be a fast flyer and a rather large butterfly with a wingspan ranging from 82 to 92mm. Its elongated forewings are characteristic of this species, whilst the hindwings are small in relation to the forewings.


Two shots of Dryas iulia taken at the Phuket Butterfly Farm

I have observed this species bred at the Phuket Butterfly Farm when I was on vacation in 1997 and from the numbers flying around within the enclosure, it appeared to be an easily bred butterfly, even in captivity. I also later saw a few individuals flying outside the enclosure, at the garden of the hotel where I stayed, the Allamanda Laguna Phuket.


A male free-ranging Dryas iulia shot recently on the Thai resort island of Koh Samui

Over at Koh Samui, ButterflyCircle member Leslie Day has also regularly encountered Dryas iulia flying freely on this resort island on the eastern coast of the Thai Peninsula. It is interesting to note that this species, probably brought in from Brazil to be featured at a Thai Butterfly Farm at Phuket (and likely others) has escaped and spread throughout southern Thailand in the late 90's and early part of this decade.


A shot of a female Dryas iulia taken at Koh Samui. The markings on this individual correspond very closely to the one shot at Tg Rhu Beach at Langkawi

The Julia Heliconian is described as a tenacious survivor that is distasteful to birds, and has a long life span (some reports have it at 3-4 months!). Its host plants are predominantly species of Passifloraceae, and it is highly likely that in Thailand, the species shares the same host plant as the Leopard Lacewing and the Tawny Coster - Passiflora foetida. Indeed, this host plant was also present at the forested patch at Tanjung Rhu Beach.

It is also to be highlighted that the species was not featured in Pisuth Ek-Amnuay's Butterflies of Thailand 1st Edition, suggesting that the Julia Heliconian may be a very recent immigrant to Thailand, and not considered as part of Thailand's butterfly fauna. However, its appearance as a free-ranging species in parts of southern Thailand would suggest that it has been able to survive and thrive in our SouthEast Asian environment that is somewhat climatically similar to its region of origin in South America.

Having found a pair of the species fluttering freely on Pulau Langkawi, a not-too-long distance from where I first encountered the species on Phuket Island in Thailand, it does not come as a great surprise that this robust butterfly has now spread southwards into Malaysia, and may have colonised some areas between Thailand and Malaysia.

It now remains to be seen how fast this species can move southwards down Peninsula Malaysia like the immigrant Leopard Lacewing and Tawny Coster, both of which eventually ended up in Singapore (and are now "permanent residents") about 8-10 years after first being spotted in the northern part of Malaysia.

Will this South American beauty end up as a resident species in foreign talent-friendly Singapore? Keep your eyes peeled for this species as it begins to samba its journey southwards.

Text by Khew SK ; Photos by Bobby Mun, Ellen Tan, Khew SK, Leslie Day and Simon Sng.

Acknowledgements : Special thanks to Dr Laurence Kirton of FRIM who confirmed that the photos were indeed of Dryas iulia. However without a specimen to examine, we are unable to confirm the subspecies that now occurs on Pulau Langkawi. It is most likely the same subspecies that has been bred in Thailand, but that remains for other researchers to establish in the near future.

26 September 2009

Life History of the Rustic

Life History of the Rustic (Cupha erymanthis lotis)


Butterfly Biodata:
Genus: Cupha Billberg, 1820
Species: erymanthis Drury, 1773
Subspecies: lotis Sulzer, 1776
Wingspan of Adult Butterfly: 55mm
Caterpillar Local Host Plants: Flacourtia rukam (Flacourtiaceae)
, F. inermis (Flacourtiaceae)


A Rustic puddling on wet ground in the nature reserves.


A Rustic perching on a leaf.

Physical Description of Adult Butterfly:
Above, the forewing is orange brown in the basal area and black at the apical area with several subapical spots lying within; in between there is a broad pale yellowish discal patch containing three or four dark brown spots in spaces 2, 3 and 4. The hindwing is mainly orange brown and have narrow marginal, submarginal and postdiscal bands with a discal series of black spots in spaces 2 to 6. Underneath, the wings are much paler and the apical area in the forewing is pale brownish. On the forewing, there is a narrow discal line bordered outwardly by a series of black spots, and on the hindiwng there is a postdiscal pale lunular band and a discal series of pale lunules bordered outwardly by black spots.

Another puddling Rustic in the nature reserve.


Field Observations of Butterfly Behaviour: This species is rather common in the Central Catchment Nature Reserve. The fast flying adults can be frequently seen flying around shrubs and bushes found alongside various trekking trails in the nature reserve. However, on the wing, one can easily confuse it with Banded Yeoman (Cirrochroa orissa orissa). The restless adults make it rather difficult to photograph them in the field. Rare opportunities to do so only arise when they stop briefly to visit flowers or to puddle on wet grounds.

Early Stages:
The local host plant found in the Central Catchment Reserve, Flacourtia rukam, is a small evergreen tree with thorny stems and branches. Its leaves are elliptic and crenulate, and reddish brown to red when they are young. Its flowers are small and unisexual and occur in axillary clusters. The pink to reddish berry is globose and is good for making jam. The caterpillars of the Rustic feed mainly on young leaves of the host plant.


Local host plant: Flacourtia rukam in the nature reserves.

A mating pair of the Rustic.

The eggs of the Rustic are laid singly on the undersides of young leaves, typically on a young sapling of the host plant. The white or pale yellow eggs are somewhat globular in shape and more produced near the top where the micropylar is. The surface is marked with small pits which are roughly hexagonal higher up and rectangular lower down. Each egg has a diameter of about 0.9mm, and a height of about 1mm.


A female Rustic ovipositing on a young sapling of Flacourtia rukam.



Left: Fresh egg of the Rustic. Right: Mature egg of the Rustic.
Diameter: 0.9mm; height: 1mm.
The egg takes about 2.5 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 has a cylindrical and creamy white body covered with many small tubercles and short setae. In the abdominal segments, reddish and yellowish internal structure can bee seen through the translucent skin. The head capsule is yellowish brown with the front portion black.


Two views of a newly hatched caterpillar of the Rustic, length: 2mm.

The 1st instar caterpillar feeds on the lamina of young leaves and between feeds, it typically rests on leaf underside against the midrib. As it grows rapidly in this instar, the base body changes to yellow, and thoracic segments and posterior abdominal segments turning reddish. After reaching about 4mm in 1.5-2 days, the caterpillar moults to the 2nd instar. Noteworthy is the prominent enlargement of a number of tubercles at the base of the setae towards the end of the 1st instar. These tubercles will give rise to the branched processes in the 2nd instar.


Two views of a 1st instar caterpillar, length: 3mm.

Two views of a late 1st instar caterpillar, prior to its moult, length: 4mm.


The body of the 2nd instar caterpillar is yellowish brown in base color with a green undertone. As in the late 1st instar, the thoracic segments and last few abdominal segments are mainly reddish brown. Long and branched white processes run along the length of the body. On each side of the body, there are three series of such processes: One occurs dorso-laterally, one super-spiracularly and the last, the shortest, runs sub-spiracularly. The head capsule is yellow with two large black patches on the front portion. This short instar lasts about 1.5 days with the body length reaching about 6mm.


Two views of a 2nd instar caterpillar, length: 6mm


Three snapshots of the moult from the 2nd instar to the 3rd instar.
Top: late 2nd instar; Middle: with old skin just shredded; Bottom: with the new processes inflated.



Moulting to the 3rd instar and the inflation of the new processes at 4x speed.



The 3rd instar caterpillar has the dorso-lateral and super-spiracular processes black in color. A white band links up the base of the sub-spiracular processes. Above this white band, the body color is dark red with a green undertone. This instar takes about 1.5 days to complete with body length reaching about 10-11mm.


Two views of a 3rd instar caterpillar, late in this stage, length: 11mm.


Compared to the 3rd instar, the 4th instar caterpillar has proportionately longer processes. Otherwise, there is essentially no change in external appearance. The 4th instar lasts 3 days with the body length reaching about 18mm-20mm.


Two views of a 4th instar caterpillar, length: 16.5mm.


Two views of a 4th instar caterpillar, late in this stage, length: 20mm.

The 5th and final instar is similar to the 4th instar caterpillar except for the appearance of numerous small white spots on the body surface and that the sub-spiracular processes are black in their distal halves.


Two views of a 5th instar caterpillar, length: 27mm.


Frontal view of the head capsule of a 5th instar caterpillar.

The 5th instar lasts for 3 to 3.5 days, and the body length reaches up to 26-28mm. On the last 0.5 day, the color of the entire body changes to yellow and then eventually to lawn green or yellow green. The caterpillar ceases feeding and wanders around. Eventually it stops at a spot on the underside of a leaf, and spins a silk pad from which it hangs vertically to take on the pre-pupatory pose.


The 5th instar caterpillar with its body color changed at the end of this instar.


Two views of an immobile pre-pupatory larva.

Pupation takes place about 0.5 days later. The pupa suspends itself from the silk pad with no supporting silk girdle. It is entirely green. Dorso-laterally there are five long pairs of red and black-tipped processes, and five pairs of small tubercles. Each long process has a broad silver-colored base. There is also a slender silver patch along the leading edge of the wing pad. Length of pupae: 18-19mm.


Two views of a shining pupa of the Rustic.


Two views of a mature pupa of the Rustic. Note the prominent discal patch in the black wing pad.

After about 4 days of development, the pupal skin of the mature pupa turns translucent and the broad discal patch on the forewing upperside become discernible as a result. The eclosion event takes place the next day.


A newly eclosed Rustic drying its wings at its pupal case.


A newly eclosed Rustic resting on the young leaves of its host plant.

References:
  • 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 S K and Horace Tan