Two More Nymphalidae Make it 308!

Two More Nymphalidae Make it 308!
Additions to the Singapore Butterfly Checklist


Horace Tan shot this mysterious orange butterfly in the nature reserves

Whilst out on a leaf-run to document the early stages of a Papilio species, ButterflyCircle member Horace Tan spotted a relatively large fast-flying orange butterfly fluttering around at the tree tops. Unable to get close for a better shot, Horace took an 'insurance' shot from afar.  For a moment, the orange butterfly may have been a male Cruiser (Vindula dejone erotella)

A zoomed in shot showing the mystery butterfly

Upon reaching home, Horace zoomed it on the orange butterfly and it didn't look anything like the Cruiser. The highly cropped shot shown above suggested that it was something that has not been seen for a long time in Singapore. Referring to Butterflies of the Malay Peninsula 4th Edition by Corbet & Pendlebury (C&P4), the butterfly looked very similar to the Malay Yeoman (Cirrochroa emalea emalea)

A shot of a Malay Yeoman taken in Malaysia for comparison

Scrutinising the details of the cropped shot, the underside of the butterfly matched the Malay Yeoman. The forewing discal band which is narrow at the dorsum and widens significantly at the costa can be clearly seen. The distinguishing constriction of the discal band on the hindwing in spaces 5 & 6 can also be seen in the shot, confirming that this species is indeed the Malay Yeoman!


Upperside of the Malay Yeoman (shot in Malaysia)

Further reference to C&P4 indicated that the Malay Yeoman was marked [S] designating it as a "species which, so far as known, have not been taken again in Singapore during the present century". (Note that the present century meaning the 20th century as the 4th Edition of the book was updated in 1992). This species is described as fulvous orange above, with a black distal margin. We now record is as species #307 in the Singapore Butterfly Checklist. As it is a common species in Malaysia, observers should continue to look out for it in the Central Catchment Nature Reserves in Singapore, where Horace Tan saw this species.


An Angled Castor with partially opened wings shot recently in the nature reserves in Singapore

Another species that surprised members of ButterflyCircle on our regular weekend outing on 12 Oct 2013 was the Angled Castor (Ariadne ariadne ariadne). The species has reddish brown upperside traversed by sinous black lines and having a prominent white subapical streak on the forewing. The Angled Castor is described as local and found in forest clearings.


Another shot of the same Angled Castor with wings folded upright

Indeed, ButterflyCircle members Simon Sng and Loke PF came across this species at a forest clearing where other species were present due to the mass fruiting of the Singapore Rhododendron (Melastoma malabathricum). Both photographers managed to take a few shots of the Angled Castor before it made its way to the treetops and disappeared.


A record upperside shot of the same individual showing the subapical white spot on the forewing

The shots shown here confirmed the existence of the Angled Castor beyond any doubt. The single black line just beyond the cell end and the white subapical spot on the upperside and underside of the forewing validates the identity of the Angled Castor. The other likely species that occurs in nearby Johor in Malaysia, is the Malay Castor (Ariadne isaeus isaeus). However, this species is described as having a narrow, zigzagged orange brown band just beyond the cell end of the forewing, and without a white apical spot.


A similar-looking species, the Malay Castor (Ariadne isaeus isaeus) taken in Panti Forest, Johor, Malaysia.  Note no subapical white spot, and the orange-brown band beyond the cell area

Again, a species that was encountered in the forested nature reserves of Singapore suggests that there may still be more surprises in our forests that have yet to be discovered. The Angled Castor is considered a re-discovery, as the C&P4 checklist indicates this species as extant in Singapore. The importance of our central catchment core cannot be overstated, as it is a critical sanctuary to a diverse range of floral and faunal biodiversity in Singapore.


An Angled Castor shot in Penang, Malaysia for comparison

The Angled Castor is added to the Singapore Butterfly Checklist as species #308. It is hoped that these two species will continue to be spotted in Singapore even though at the moment, they would be considered 'seasonal visitors'. However, given the period that both have been spotted in Singapore, the postulation that these species may have been carried over by the prevailing winds from Malaysia may be unfounded. This is because the prevailing winds in the months of mid-Aug to Oct 2013, are largely from the south-west!

The Singapore Butterfly Checklist is hence updated to 308 species as at end Oct 2013. There are a number of Hesperiidae and Lycaeninae which are currently under investigations and will be added to the Singapore Checklist by the end of this year when all the validations are complete.

Text by Khew SK : Photos by Khew SK, Loke PF, Simon Sng & Horace Tan

References :

• [C&P4] The Butterflies of The Malay Peninsula, A.S. Corbet and H.M. Pendlebury, 4th Edition, Malayan Nature Society, 1992
• Butterflies of West Malaysia & Singapore, WA Fleming, 2nd Edition, 1983
• Butterflies of Thailand, Pisuth Ek-Amnuay, 2nd Edition, 2012

Butterflies Galore! : Peacock Royal

Butterflies Galore!
The Peacock Royal (Tajuria cippus maxentius)

The Peacock Royal is a widely distributed butterfly in Singapore, and can be encountered as regularly in urban parks and gardens as it is in nature reserves. It is usually skittish and alert but can be approached easily at times, especially when it is feeding, or just resting with its wings folded upright. The upperside of the male is a iridescent royal blue, whilst the female is pale blue. The underside is greyish white with dark grey striae. The hindwing features a pair of tails.

This Peacock Royal was photographed by ButterflyCircle member Loke PF. The species' full life history is recorded on its preferred host plant, Dendrophthoe pentandra, a common parasitic plant.

Butterflies Galore! : Apefly

Butterflies Galore!
The Apefly (Spalgis epius epius)

The common name for this species probably originated from its pupa which, when viewed from a certain angle, resembles the face of an ape. The species is quite widespread in Singapore, although it is by no means common. The caterpillars of the Apefly feed on coccids or mealy bugs, hence the butterfly appears where its caterpillar's food source is available. The species is therefore not dependent on any particular species of host plant.

This female Apefly was photographed by ButterflyCircle member Sunny Chir. The species usually flies around restlessly but occasionally stops to rest on the top surfaces of leaves with its wings folded upright. On rare occasions, it is observed to open its wings partially to show its uppersides when sunbathing.

Butterflies Galore! : Colonel

Butterflies Galore! 
The Colonel (Pandita sinope sinope)

This skittish species is a moderately rare butterfly in Singapore, but can be seen in areas where its caterpillar host plant, Uncaria sp., is found. Usually found in forested areas, it can be approached much easier when it is feeding, particularly on the ripened fruits of the Singapore Rhododendron (Melastoma malabathricum). The wings of the Colonel are orange above with dark brown stripes and markings. The underside is paler orange but the basal area of the wings are a greenish grey.

This individual was shot whilst it was distracted when feeding. It is usually very alert and has a wide circle of fear. When alarmed it takes off to the treetops and perches in a safe location on the top of a leaf. Its life history has been fully recorded in Singapore and can be found here.

Life History of the Orange Emigrant

Life History of the Orange Emigrant (Catopsilia scylla cornelia)

Butterfly Biodata:
Genus: Catopsilia Hübner, 1819
Species: scylla Linnaeus, 1763
Subspecies: cornelia Fabricius, 1787
Wingspan of Adult Butterfly: 50-60mm
Caterpillar Local Host Plant: Senna surattensis (Fabaceae).

An Orange Emigrant taking nectar from a flower.

A male Orange Emigrant displaying its upperside.

A close-up view of the head of an Orange Emigrant.

Physical Description of Adult Butterfly:
On the upperside, the forewing is white with a black border and the hindwing is deep chrome-yellow. In addition, the female has a black post-discal fascia on the forewing and a series of black marginal spots on the hindwing. On the underside, the wings are yellow with intermittent, faint brown post-discal spots. A brown ring marking can be found at the cell-end on both wings.

Field Observations of Butterfly Behaviour:
The Orange Emigrant is considered a common butterfly in Singapore, though its occurrence is rather localized. The fast flying adults are typically found in parks, park connectors and gardens where its local host plant, Senna surattensis, is cultivated. As with the other Catopsillia spp., the adults have the habit of visiting flowers and puddling on damp grounds.

A close-up view of a portion of the hindwing showing the diffuse post-discal fascia is composed of loosely scattered brown scales.

Early Stages:
Across the region, the Orange Emigrant has several host plants in the Senna genus, including S. fistula (The Golden Shower). However the popular host plant in Singapore, and the only one found utilized so far, is Senna surattensis. This plant is commonly cultivated across Singapore in gardens, parks, park connectors and even on the divider along major expressways. The caterpillars of the Orange Emigrant feed on the leaflets of the host plant. At times, one could find numerous Orange Emigrant caterpillars feeding on the same plant, causing a serious degree of defoliation as a result.

Local host plant: Senna surattensis

A mating pair of the Orange Emigrant.

Eggs of the Orange Emigrant are typically laid singly on the upperside of a leaflet of the host plant. At times, more than one egg can be found on the same leaflet. The long spindle shaped egg is laid standing at one end with a length of about 1.8-1.9mm. It is white in color with vertical ridges and numerous indistinct and intermittent horizontal ridge lines. The micropylar sits at the tip of the standing egg.

Left: A mother Orange Emigrant laying an egg on a leaflet. Right: The mother butterfly took off, giving a view of its upperside and the egg laid (indicated by the red arrow).

Left: fresh egg. Right: mature egg showing the mouth part near the top.

The egg takes about 2 days to hatch. The newly hatched has a length of about 2.4mm. It has a white head capsule bearing several short setae. Its body is creamy white and featuring dorsal, dorso-lateral and lateral rows of small tubercles running lengthwise. Each tubercle has a short seta emerging from the middle of it.

Two views of newly hatched caterpillar eating the remnant of its egg shell.

After hatching, the young caterpillar proceeds to devour the remnant of the egg shell. The leaf diet will soon follow, and with that the body turns yellowish green. The growth is moderately fast paced and the body length reaches about 4.7mm in this 1st instar which lasts about 2 days before the moult.

Two views of a 1st instar caterpillar, length: 3.7mm.

Two views of a late 1st instar caterpillar, dormant prior to its moult, length: 4.8mm.

The 2nd instar caterpillar is yellowish green on all body segments and the head. The body is covered in rings (about five for each body segment) of numerous small dark tubercles from which very short setae emerge. The head capsule also features numerous similar tubercles. This instar lasts about 2 days with the body length reaching 7-8mm.

Two view of a 2nd instar caterpillar, length: 7mm.

Two views of a late 2nd instar caterpillar, dormant prior to its moult, length: 8mm.

The 3rd instar caterpillar resembles the 2nd instar caterpillar closely. This instar takes about 2 days to complete with body length reaching about 11-12mm.

Two view of a 3rd instar caterpillar, newly moulted, length: 8mm.

Two views of a 3rd instar caterpillars, length: 10.5mm.

A white to yellowish band running across the spiracles appears in the 4th instar caterpillar. Above the line, some of the black tubercles blanketing the body surface are larger than the rest, but these do not appear in great numbers to give an appearance of a dark band (as in the case for the Lemon Emigrant and the Mottled Emigrant). This penultimate instar lasts 2 days with body length reaching about 22-23mm.

Two views of a 4th instar caterpillar, early in this stage, length: 12.5mm.

Two views of a 4th instar caterpillar, length: 15mm.

The 5th instar does not usher in any significant change in appearance of the caterpillar. Now the dark tubercles covering the body surface are proportionately smaller, and the lateral white-yellow bands are more prominently featured. This 5th instar lasts for 4-5 days, and the body length reaches up to 40-42mm.

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

Two views of a 5th instar caterpillar, late in this stage, length: 38mm.

A 5th instar caterpillar sighted in a local university campus.

On the last day of the 5th instar, the body of the caterpillar shortens and changes to a dull shade of pale green. It ceases feeding and comes to rest on the midrib on the underside of a leaflet or the stem/stalk on the host plant. Here the caterpillar spins a silk pad and a silk girdle to secure itself and then becomes immobile in its pre-pupatory pose.

A pre-pupatory larva of the Orange Emigrant on the underside of a leaf stalk.

An Orange Emigrant caterpillar moults to its pupal stage.

Pupation takes place about 0.5-1 day later. The pupa secures itself with the same silk girdle as in the pre-pupal stage, but with a cremaster replacing claspers in attaching its posterior end to the silk pad on the stem. The pupa has a pointed head, and its yellow to yellowish green body has a bright yellow lateral line on each side. There is a dorsal protrusion with a yellow ridge line on the thorax. The keel formed by the tapering wing case is much less pronounced than those seen in the Eurema spp. Length of pupae: 25-26mm.

Two views of a pupa of the Orange Emigrant, dull yellowish green in colour.

Two views of a pupa of the Orange Emigrant, bright yellowish green in colour.

A pupa of the Orange Emigrant found on a S. surattensis plant in a local university campus.

Two views of the mature pupa of a male Orange Emigrant.

Two views of the mature pupa of a female Orange Emigrant.

After about 6 days of development, the pupal skin turns translucent as the development within the pupal case comes to an end. The yellow coloration and black borders on the forewing upperside are now discernible. The following day, the adult butterfly emerges from the pupal case.

An Orange Emigrant butterfly emerges from its pupal case.

A newly eclosed Orange Emigrant resting near its pupal case.

References:

• [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, 2010.

Text by Horace Tan, Photos by Henry Koh, Brian Goh, Koh Cher Hern, Nelson Ong, Anthony Wong, Tan Ben Jin, Federick Ho, Sunny Chir and Horace Tan

Butterflies Galore! : Colour Sergeant

Butterflies Galore!
The Colour Sergeant (Athyma nefte subrata)

The Colour Sergeant has two female forms - f-neftina with orange and black bands, and f-subrata with brown and black bands. Of the two forms, f-neftina is the one that is more commonly encountered. The species is widely distributed in Singapore, and can be found in urban parks, although its preferred habitat is still the forested areas.

This shot, taken by veteran ButterflyCircle member Sunny Chir, shows a female f-neftina Colour Sergeant's upper wing surfaces. At certain opportune angles, an accomplished photographer can focus on the butterfly itself, and throw the background completely out of focus to enable the subject to stand out prominently, as shown in this shot.

Butterflies Galore! : Purple Duke

Butterflies Galore!
The Purple Duke (Eulaceura osteria kumana)

Yesterday, we featured a female Purple Duke feeding on the ripened fruit of the Singapore Rhododendron (Melastoma malabathricum). Today's feature butterfly is yet another Purple Duke, but this time, it's a male , also feeding on the ripened fruit of the same plant. The species is common in Singapore, and at times, up to 6 or more individuals can be seen in a small patch of forest. Can you spot and compare the difference between the male and female of the species?

The Purple Duke has a propensity of flying rapidly for short distances and then settling on the underside of a leaf with its wings folded upright when it is disturbed. This behaviour is quite consistent with the regular sightings of this species. This shot was taken by ButterflyCircle member Huang CJ at the nature reserves last weekend.