Life History of the White Four-Line Blue

Life History of the White Four-Line Blue (Nacaduba angusta kerriana)

Butterfly Biodata:
Genus: Nacaduba Moore, 1881
Species: angusta H. Druce, 1873
Subspecies: kerriana Distant, 1886
Wingspan of Adult Butterfly: 30mm
Caterpillar Local Host Plants: Entada spiralis (Fabaceae)


A female White Four-Line Blue perching on a leaf near its host plant in between oviposition visits

Physical Description of Adult Butterfly:
As a member of the pavana group (the Four-Line Blues), the adult does not have a basal pair of lines in the underside forewing cell. Above, the male is purplish blue with a thin black border, about 1mm broad towards the apex; the female has broad black border on the forewing and a light blue ground colour with diffuse greyish markings on both wings. Beneath, both sexes has greyish ground colour with very broad and diffuse whitish-grey stripes. On each hindwing, there is an orange-crowned tornal spot lightly speckled with bluish-green metalic scaling. i Next to the tornal spot, a pair of filamentous white-tipped tails occurs at end of vein 2. Marginal and submarginal spots are black and stand out against the whitish bacground. The prominent rounded black sub-marginal spot in space 6 of the hindwing serves as an important identification key for this species.

A male White Four-Line Blue perching on a branch


A male White Four-Line Blue perching another branch


A sunbathing male White Four-Line Blue showing its upperside

Field Observations of Butterfly Behaviour:
Though included in the early authors' checklists for Singapore, this species has eluded the local butterfly enthusiasts in recent years before its recent re-discovery in the December 2008. Sightings have been confined to a single location where its host plant is thriving at tree top levels. The adult has an erratic flight, and typically makes its appearance in sunny weather. Encounters usually take place in sunlit spots with the adult sunbathing or flitting from perch to perch in the vicinity of its host plant.

Early Stages:
The host plant, Entada spiralis, is a woody climber with bipinnate leaves, usually with 4 pairs in a pinna. Flowers are small and occur in dense racemes. Seed pods are curled with 5-11 very large seeds to each pod. This tree-topping vine can be found in the Central Catchment Nature Reserves as well as in the Southern Ridges. Besides the White Four-Line Blue, locally this plant also plays host to the Large Four-Line Blue (Nacaduba pactolus odon), Common Line Blue (Prosotas nora superdates) and the Common Grass Yellow (Eurema hecabe contubernalis). The early instars of the White Four-Line Blue feed on young leaves of this plant by grazing away the upper layer of lamina. The later instars nibble away the lamina from the leaf edge, as well as the outer layer of young stems.


Host plant : Entada spiralis


Young shoots of Entada spiralis.


A mating pair of White Four-Line Blue


A mother White Four-Line Blue making an oviposition visit to young shoots of E. spiralis.

Eggs are laid on the young shoots of the host plant, typically in spaces between very young and yet to be unfurled leaves. It is not uncommon for a number of eggs to be found on the same shoot, however the eggs occur singly rather than in clusters. Each egg is pale yellowish green, circular and has a depressed micropylar area. The surface is criss-crossed with numerous tightly-spaced lines. Each egg has a diameter of about 0.4mm.


Two eggs of the White Four-Line Blue. Diameter: 0.4mm.

It takes 2-3 days for the egg to hatch. The young caterpillar consumes part of the egg shell to emerge. With a length of about 0.7-0.8mm, it has a pale yellowish body with long setae (hairs) dorsally and sub-spiracularly. The caterpillar assumes the typical woodlouse body shape as it grows. The body color also changes gradually to a brighter shade of yellow. A diamond-shaped pro-thoracic shield and a slight depression on the anal segment can be distinguished easily through contrasting and darker shades of coloration.


1st instar caterpillar, late in this stage. Lengths: 1.5mm (top) and 1.2mm (bottom)

The first instar lasts for 2 days and the body length reaches about 1.5mm before the moult to the 2nd isntar. The long dorsal setae are absent in the 2nd instar caterpillar. The body color is mainly yellow with a greenish undertone. The prothoracic shield is less prominent, being slightly paler than the yellow base color. The 2nd instar also lasts for 2 days and the caterpillar grows to a length of about 3m to 3.5mm.


2nd instar caterpillar, freshly moulted to this instar, length: 1.5mm



2nd instar caterpillar, late in this stage. Lengths: 2.5mm (top) and 3mm (bottom).

The 3rd instar caterpillar is still yellowish green but with an increasing emphasis in green. Faint markings in much paler yellow appear on both sides of the dorsal line. After 2 days in this stage with the body length reaching a maximum about 6-7mm, the next moult takes place to bring the caterpillar to its final instar.


3rd instar caterpillar, Lengths: 3.5mm (top) and 4.5mm (bottom)


3rd instar caterpillar, late in this stage, length: 6mm

The 4th instar caterpillar initially resembles the 3rd instar caterpillar in the day prior to the moult. However as it proceeds to feed and grow in this final instar, the body quickly takes on a much lighter shade of green with the whitish dorsal-lateral shadings more prominent than in the 3rd instar. The prothorcic shield is whitish with a few brown spots, and the dorsal nectary organ and ventacular organs are distinguishable on the posterior segments.


4th instar caterpillar of lengths: 8mm (top) and 11mm (bottom).


Body features of a 4th instar caterpillar. Left: dorsal nectary organ (DNO) and tentacular Organ (TO).
RIght: prothoracic shield.

The 4th instar lasts for 4 days and the body grows up to a length of about 11-12mm. On the last day of this stage, the caterpillar ceases food intake and its body shrinks in length. It wanders around for almost a full day before it comes to rest on a spot among leaves for pupation. The pre-pupatory caterpillar prepares for pupation by spinning silk threads to shape the leaves into a pupation shelter. Within the tight interior of the shelter, the pre-pupatory caterpillar stations itself with silk girdles and the attachment of the cremaster.


Two views of a pre-pupa of the White Four-Line Blue

The next day, after 9-10 days of larval growth, pupation finally takes place. The pupa has the typical lycaenid form, and is 8-9mm in length. It is mostly pale brown and speckled with black spots of various sizes and shapes.


Two views of a fresh pupa of the White Four-Line Blue

Six days later, the pupa becomes darkened in color signaling the imminent emergence of the adult. The markings on the forewing upperside becomes increasing obvious through the upal skin. The next day the adult butterfly emerges from the mature pupa.


Two views of a mature female pupa showing the markings on the forewing upperside in the wing pad.


Two views of a mature male pupa showing the purplish blue forewing upperside in the wing pad


A newly eclosed White Four-Line Blue resting on its pupal case


Another newly eclosed White Four-Line Blue

References:

• 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 Sunny Chir and Horace Tan

Two More Lycaenids Make it 287!

Two More Lycaenids Make it 287!
Re-discovery of Metallic Caerulean (Jamides alecto ageladas) & White Four-Line Blue (Nacaduba angusta kerriana)

Over the course of last year, in 2008, the hardworking ButterflyCircle members continue to make observations of several butterfly species which have yet to be recorded in the Singapore Butterfly Checklist. A few are still under scrutiny and verification by experts from Malaysia and overseas, and will be announced when their identities are validated in due course.

In the meantime, ButterflyCircle is proud to announce the re-discovery of two species of Lycaenids which make them species #286 and #287 for the Singapore Checklist. These two species were originally recorded in the early authors' checklists for Malaysia and Singapore, but in recent years, these species were not observed.

The Metallic Caerulean (Jamides alecto ageladas)

A Metallic Caerulean feeds on the flower of Leea rubra.

Back in 2008, one of them, the Metallic Caerulean (Jamides alecto ageladas) was observed in numbers at a location towards the northern central part of Singapore. The species was photographed even earlier, but dismissed as the more abundant Common Caerulean (Jamides celeno aelianus). However, after closer scrutiny, the white striations on the hindwing of this species differs from the Common Caerulean. Subsequent sightings of the species was recorded and observations were also made of a female of the species ovipositing on the flowers of the Torch Ginger (Nicolaia elatior), a plant which was not known to be a host plant of the Common Caerulean.

A female Metallic Caerulean ovipositing on the flower of its host plant, Torch Ginger

Further careful observations were made, as well as documentation of a mating pair of the species. References were carefully checked and consultation made with a foreign expert in Lycaenidae confirmed that the species was indeed the Metallic Caerulean (Jamides alecto ageladas).

A male Metallic Caerulean puddles on bird droppings.

The Metallic Caerulean, described as the largest species in the elpis subgroup, which is characterised by the post-discal band on the forewing beneath is completely dislocated at vein 3. The male of the species has a black diffuse border on the forewing, expanding to about 1mm at the apex and a series of black marginal spots on the hindwing . In the female, the forewing border extends narrowly along the costa to the base. Also rather unique in this species, is the tornal bands of the hindwing beneath which are interconnected rather than dislocated when compared with the Common Caerulean.

The Metallic Caerulean has bright metallic blue uppersides, and grey ground colour on the undersides with the usual white banding. On the hindwing, there is a black centred orange-crowned eyespot at the tornal area, with some additional submarginal orange markings along veins 1b and 4. There is a white-tipped filamentous tail at vein 2 of the hindwing. The species has banded legs and antennae, and the eyes are a solid jet black. It has a rather quick erratic flight, and for most of the day, is active and flies amidst low vegetation and stays close to its host plant, the Torch Ginger. Males tend to stay higher up and chase each other in the bright sunshine. Very often both sexes stop to rest in the shade on the uppersides of leaves and demonstrates the movement of the hindwings and tails in the usual Lycaenid fashion.

The White Fourline Blue (Nacaduba angusta kerriana)

The 2nd re-discovered species is more characteristic in its physical appearance, and has more distinctive markings with which the species is easily identifiable without much doubt. This species, the White FourLine Blue (Nacaduba angusta kerriana) was first spotted towards the end of the year 2008, at an urban park in the Southern Ridges of Singapore. Whilst on a routine weekend outing with some of the regulare members, Sunny Chir stumbled upon a mating pair of the species, where he immediately recognised as something new that he had not seen before.

Upon closer scrutiny, it was discovered that, indeed, this species of the Nacaduba has not been recorded in the Singapore Checklist before. The female of the species is so distinct in that a view of the upperside would put the identity of the species beyond any doubt. A member of the pavana group (characterised by the lack of a pair of subbasal lines in the cell of the forewing beneath) of the genus Nacaduba, the White FourLine Blue has a prominent rounded black sub-marginal spot in space 6 of the hindwing.

A newly-eclosed White Fourline Blue perched on its pupal shell

A follow up by ButterflyCircle early stages specialist, Horace Tan, discovered the caterpillars of the White FourLine Blue feeding on the host plant, Entada spiralis and successfully recorded the Early Stages of this newly re-discovered species. The Life History will be documented and featured in a future Blog article.

The male White FourLine Blue is purplish blue above with a thin black border, which is about 1mm broad towards the apex. The hindwing is unmarked but with a thin submarginal black border. The hindwing cilia is white. The female has broad black border on the forewing and has a light blue ground colour with diffuse greyish markings on both wings. The underside is greyish, with broad whitish-grey bands and dark grey spaces in between. There is an orange-crowned black spot at the tornal area of the hindwing beneath, with some light bluish-green metallic scaling. There is a filamentous white-tipped tail at vein 2 of the hindwing.

The White Fourline Blue has an erratic but rather weak flight, and prefers to stay under shade, fluttering amongst thick vegetation along the forest edge. Males tend to stay higher up in the forest canopy, and descend lower to find a mate, or to feed.

With these two re-discoveries, the Singapore Butterfly Checklist now has 287 species recorded. ButterflyCircle, with its bigger number of enthusiasts who are keenly photographing and learning about butterflies, their habitats, early stages, conservation and ecology, it is without doubt that more species will be added to the checklist in the near future.

Text by Khew SK : Photos by Horace Tan, Sunny Chir, Henry Koh, Bobby Mun, Anthony Wong & Khew SK

References:

• The Butterflies of The Malay Peninsula, A.S. Corbet and H.M. Pendlebury, 4th Edition (1992), Malayan Nature Society.
• Butterflies of Thailand, Ek-Amnuay, Pisuth, English Edition (2006), Amarin Publishing and Printing Public Co Ltd

Life History of the Common Bluebottle

Life History of the Common Bluebottle (Graphium sarpedon luctatius)

Butterfly Biodata:
Genus: Graphium Scopoli, 1777
Species: sarpedon Linnaeus, 1758
Subspecies: luctatius Fruhstorfer , 1907
Wingspan of Adult Butterfly: 90mm
Local Caterpillar Host Plants: Cinnamomum iners (Lauraceae, common name: Wild Cinnamon), Cinnamomum camphora (Lauraceae, common name: Camphor Tree), Lindera lucida (Lauraceae), Neolitsea zeylanica (Lauraceae).

Physical Description of Adult Butterfly:
The Common Bluebottle has a macular band which runs from the apex of the forewing to the inner margin of the hindwing on both the upper and underside. This band varies from pale green through various hues of bluish-green to deep blue. The hindwing has a series of blue submarginal spots on the upperside, and additional red spotting on the underside of the hindwing. There is a red spot near the base of the hindwing on the underside as well.


A Common Bluebottle puddling in the nature reserves


Group puddling of Common Bluebottle adults


Another puddling Common Bluebottle in an open-wing pose

Field Observations of Butterfly Behaviour: The adults fly with a fast, agile flight typically at tree-top level. The males of this species can often be found feeding on roadside seepages or urine-tainted sand. Occasionally, a large puddling group can be found congregated on one spot. This swift-flying butterfly is common both in the nature reserves and urban parks. In flight, one normally catches a glimpse of its blue wings. Females are rarer, but often encountered when she tries to oviposit in areas where the host plants grow in abundance.

Early Stages:
The early stages of the Common Bluebottle feed on leaves of serveral plants in the Lauraceae family. There are four recorded local host plants, Cinnamomum iners (Common name: Clover Cinnamon, Wild Cinnamon), Cinnamomum camphora (Lauraceae, common name: Camphor Tree), Lindera lucida and Neolitsea zeylanica. Eggs and early stages of the Common Bluebottle are typically found on saplings at low heights.


Local host plant #1: Cinnamomum iners


Local host plant #2: Lindera lucida

A mating pair of the Common Bluebottle

A female Common Bluebottle was spotted laying an egg was on a sapling of wild cinnamon.
Can you spot the egg?

The eggs of the Common Bluebottle are laid on very young leaves or petioles of a sapling of the host plant. The spherical egg is creamy white with a diameter of about 1.2mm.

Left: egg laid on a young shoot.
Right: close-up on the egg shown in the left panel

Two close-up views of a mature egg of the Common Bluebottle.
Can you spot the mandible?

The egg takes 3 days to hatch, and the newly hatched has a body length of about 3mm. Immediately after emergence, it turns around and eats the entire egg shell as its first meal. Its body is initially pale yellowish brown but turning dark greenish brown hours later. It has a pair of lateral spines each of the three thoracic segments, and another white pair at the anal segment. The body also features rows of short dorsal-lateral tubercles with long setae. Between feeds, the Common Bluebottle caterpillar of all instars rests on the upper leaf surface, usually alongside the midrib.


Two views of a newly hatched Common Bluebottle caterpillar.
Almost done with the egg shell in top view. Length: 3mm


Two views of 1st instar caterpillar, 1-day old, length: 4mm

After two days of feeding on young and tender leaves, the 1st instar caterpillar grows to a length of about 5mm. Now the body looks pumped up, and assumes a yellowish brown coloration with a green undertone. After a period of inactivity, the caterpillar moults to the next instar.
1st instar caterpillar, late in this stage, length: 5mm.

In the 2nd instar caterpillar, the thoracic segments are much enlarged from the 2nd to 3rd segment, compared to abdominal segments which taper towards the anal spine. The basal ends of the thoracic spines turn black while the distal ends are still yellowish brown. The body color is dark yellowish green with the abdominal segments in alternating shades of yellow to dark green. The growth is again rather rapid, after just 2 days and the body length reaches about 6-8mm, the caterpillar moults to the next instar.


Two Common Bluebottle caterpillars (1st and 2nd instar) sighted resting on the upper surface
of Wild Cinnamon leaves in the Southern Ridges.


2nd instar caterpillar, length: 7mm

There is no drastic change in appearance in the 3rd instar caterpillar. Noteworthy are the change to completely black (with bluish shines) thoracic spines, and greater contrast between the yellow and dark green ``rings'' on the abdominal segments. This instar takes another 2 days to complete with body grown to about 10-12mm in length.


3rd instar caterpillar, length: 9.5mm

The body of the 4th instar caterpillar is mainly yellowish green, speckled with small yellow markings. Dorsally, a prominent yellow transverse band connects the two spines on the 3rd thoracic segment. A faint and thin yellow band runs laterally on each side. In contrast to yellowish green in the precedingr segments, the anal segment is bluish green. This instar lasts a further 2 days with body length reaching about 19-20mm.


Two views of a 4th instar caterpillar, length: 27mm

A 4th instar Common Bluebottle caterpillar found in the Southern Ridges

The 5th instar caterpillar closely resembles the 4th instar. The only noticeable change is the more prominent yellow transverse band connecting the 3rd pair of thoracic spines, and the basal ends of the first two pair of thoracic spines and the anal pair turning white. The 3rd pair of thoracic spine is almost completely white with the basal end circled in alternating black and yellow.

5th instar caterpillar, early in this stage, length: 29mm

As with the Common Mime featured in an earlier life history article, the Common Bluebottle caterpillars also possess an osmeterium in the prothoracic segment. This informative Australian site shows the fully everted osmeterium of the final instar caterpillar.

The 5th instar lasts for 4 days, and the body length reaches up to 40-43mm. Toward the end of this instar, the body gradually shortens in length, the body color turning almost entirely green after the fading away of the yellow transverse band and most yellow speckles. Eventually the caterpillar comes to rest on the surface of a leaf in an upright position and becomes a pre-pupatory larva.

Two views of a pre-pupatory larva of the Common Bluebottle.
Pupation takes place a day later. The pupa suspends itself with a silk girdle from the leaf surface, further secured with and a firm anchor at the posterior end. The pupa is green with a slender and obtusely pointed thoracic process. Lateral and yellow ridges run from the cremaster to the tip of pointed thoracic process giving the pupa a veined leaf appearance.



Two views of a late pre-pupatory larva of the Common Bluebottle,
with the pupation just minutes away.

A time-lapse pupation sequence of a Common Bluebottle

Two views of a leaf like pupa of the Common Bluebottle.

The pupal period lasts for 10 days, and the pupa turns black in the wing pads the night before eclosion. The bluish-green spots on the forewings also become visible through the pupal skin at this stage. The adult butterfly emerges the next morning to commence the ``high-flying'' phase of its life cycle.


Maure pupa of a Common Bluebottle caterpilar, with the left picture taken hours earlier than the right.
The orange band on the adult abdomen is also visible in the right panel.

A newly eclosed Common Bluebottle resting near its pupal case.

A newly eclosed Common Bluebottle

References:

• 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
• Don Herbison-Evans & Stella Crossley: "Caterpillar of Australia", Life History of Graphium sarpedon choredon.

Text by Horace Tan, Photos by Benedict Tay, Anthony Wong, Tan Ben Jin, Khew SK and Horace Tan