31 December 2008

Another Exotic Visitor Reaches Singapore's Shores

The Indian Red Admiral lands in Singapore


Around this time last year, Singapore had an American "Lady" visiting us. The Painted Lady (Vanessa cardui) was seen at three separate locations in Singapore and successfully photographed by ButterflyCircle members.


It was therefore without much surprise that again, another similar-looking butterfly was seen again near the same location where the Painted Lady was spotted last year. It was photographed on 23 Dec 08 by ButterflyCircle member James Chia, and then on a subsequent day by Sunny Chir and Federick Ho.




However, upon closer scrutiny, this was no American visitor! The species was confirmed to be the Indian Red Admiral (Vanessa indica indica Herbst, 1794), a close relative of the Painted Lady!



Described on Wikipedia as being "found in the higher altitude regions (above 2000 feet) of India including the Nilgiri hills in southern India. It also occurs on smaller hill ranges in Peninsular India such as the Nandi hills near Bangalore", it again poses another mystery of how it got this far south to Singapore! Another website records it as "East and South Asia, and also the Canary Islands and Madeira; migrates actively northwards and appears regularly in SE Siberia (up to Kamchatka)." It has also been reported from Thailand, Taiwan, Hong Kong and mainland China and as far east as Japan.




As the local butterfly parks are not known to feature this species as part of their live collections, it is unlikely to have been an escapee from these facilities. Whilst it could have been introduced by human agency or accidentally stowed away on a ship that was passing this way, the Indian Red Admiral belongs to a genus of butterflies that is known for their strong migratory tendencies with large flight ranges, and it would not be totally impossible that this species somehow flew all the way here from the Indian SubContinent! It could also have come from Thailand, the nearest neighbouring country where the species is known to exist. But whatever the case may be, Singapore records a new species in the Checklist with this single specimen of the Indian Red Admiral.




On the Butterflies of Sri Lanka website, the Indian Red Admiral is reported to be "... an active butterfly that may be seen day after day in the same location". This habit appears to have held true, as the same individual was seen over 3 days at an urban hill park in Singapore.

The Indian Red Admiral resembles the Painted Lady but the ground-colour is darker both on the upper and under sides, and the orange markings deeper and richer. A medium sized dark gray brown butterfly with reddish orange and white markings. The forewing has orange patches forming a post-discal band, and white apical and subapical spots. The hindwing above is mainly light brown with a series of black submarginal spots on an orange submarginal band. The underside has a blotched appearance with many shades and patterns of brown and gray.



It has a strong flight, and may be territorial, but often stops to feed. It is observed to be partial to human perspiration and has been noted to settle on humans to feed on sweat.



The caterpillars of this species are known to feed on nettles (Family : Urticaceae).


So Singapore welcomes the Indian Red Admiral and has species #285 recorded in its Checklist. It is not known where the individual has flown to, or whether it has ended up in the stomach of a hungry predator or it may have continued its journey southwards. But we hope that we will continue to get visits from these strong migratory visitors during the North-East Monsoon season, where the northern winds may carry unexpected butterflies to our little Red Dot of an island in the sun!



A fitting end to the butterfly biodiversity in Singapore for 2008!

Happy New Year! : )

Text by Khew SK ; Photos by James Chia, Sunny Chir and Federick Ho

References :

27 December 2008

Life History of the Fulvous Pied Flat

Life History of the Fulvous Pied Flat (Pseudocoladenia dan dhyana)



Butterfly Biodata:
Genus: Pseudocoladenia Shirôzu Saigusa, 1962
Species: dan Fabricius, 1787
Sub species: dhyana Fruhstorfer, 1909
Wingspan of Adult Butterfly: 34mm
Caterpillar Host Plants:
Cyathula prostrata (Amaranthaceae)


A male Fulvous Pied Flat sunbathing in the late afternoon.


A male Fulvous Pied Flat visiting a flower of Asystasia gangetica in a forest clearing.


A newly eclosed female Fulvous Pied Flat.

Physical Description of Adult Butterfly:
Both sexes have reddish brown wings on both under- and uppersides. The forewing has a dark submarginal fascia, and the hindwing is traversed by irregular lines composed of dark, diffuse spots. The male has two large, yellow, hyaline spots at the end of the forewing cell, which are conjoined to form a single, outwardly deeply indented spot, and there is a small spot above it in space 11; in addition there are rather large spots in spaces 2 and 3, and small subapical spots in spaces 6, 7 and 8. The female has the same set of spots but most of these are smaller than those present in the male, and the lower cell spot may be absent.


A sequence of three shots of a male Fulvous Pied Flat with the main light source shifted
from front to back to show the hyalinity of the forewing spots.

Field Observations of Butterfly Behaviour:
This species is rarely encountered in Singapore. Sightings are restricted to sites in the Central Catchment Nature Reserves where the host plant can be found. The adults are fast-fliers and can only be observed when they stop to feed on flowers and bird dropping, or when the females are carrying out oviposition routines of leaf hopping. When resting, as with other "flat" skippers, adults have the habit of perching on leaf undersides.

Early Stages:
The host plant, Cyathula prostrata (common names: Hookweed, Nyarang, 倒扣草 , 杯苋), is a creeping and straggling to more or less erect herb. It has opposite, hairy leaves which are oblong or rhomboid in shape. Flowers occur in clusters of 1-3 on spikes. This plant has a wide distribution and can be found in Asia, Australia, Africa and tropical America. Parts of the plant are used as food and medicines for diarrhoea, dysentery, pain-relief etc. Locally, this plant can be found in waste places, forest margins and alongside trails in the northern and western catchment reserves. All early stages of the Fulvous Pied Flat feed on the leaf lamina of the host plant and retreat to their leaf shelters between feeds. Typically, they rest in a curled-up posture within the shelter.


Host plant : Cyathula prostrata. Left: side view of leaves. Right: top view, note one small leaf shelter.


Host plant : Cyathula prostrata; close-up on flowers in the right panel.

The eggs are laid singly on the upperside of a leaf. Each egg is red to pink when freshly laid, but decolorize to white as it matures. It is dome-shaped with vertical ridges, and has a diameter of 0.7mm. Eggs of the Fulvous Pied Flat are not concealed in a mess of fine hairs as is typical for a number of "flat" skippers such as the Chestnut Angle.



Two views of an egg of the Fluvous Pied Flat. Diameter: about 0.7mm


Left: mature egg with the caterpillar ready to emerge Right: empty egg shell.

It takes 4 days for the egg to hatch. The young caterpillar eats just enough of the shell to emerge, and has a length of about 1.8mm. Its cylindrical-shaped body is reddish orange, one red dorso-lateral line along each side of the body, and has a transverse black line right behind a black bilobed head.
After leaving the egg shell, the 1st instar caterpillar makes its way to the leaf edge to construct its first leaf shelter. It rests within the shelter and ventures out to eat the leaf surface nearby. The intake of this diet gives the caterpillar a greenish undertone.


1st instar caterpillar, newly hatched, length: 1.8mm

After 4 days in 1st instar and reaching a length of about 3mm, the caterpillar moults to the next instar within the shelter. It has a light yellowish body with a green undertone. The anal plate has a darker patch on it. The caterpillar reaches a length of about 4mm after 4 days of growth in this instar.


Leaf shelters for Fulvous Pied Flat in the field. Top: 1st instar; Bottom: 2nd instar.


2nd instar caterpillars. Top: 3.5mm. Bottom: late in this stage, 4mm

The 3rd instar caterpillar has a similar appearance as in the previous instar except for a faint dorsal line, and two thin white dorso-lateral lines running the sides of the body. The 3rd instar lasts about 5-6 days with the body length reaches 8mm.



3rd instar caterpillar, length: 6mm


3rd instar caterpillar, late in this stage, length: 8mm

The 4th instar caterpillar looks similar to the earlier instars with the only visible difference being the distinctive white speckles on its body and more distinctive dorso-lateral lines. The 4th instar takes about 6-7 days to complete with the body length reaching 12-14mm.


An early 4th instar caterpillar found feeding on the host plant in the nature reserves.


4th instar caterpillar, length:14mm.

The final and 5th instar caterpillar is similar to the 4th instar caterpillar. The head capsule is dark reddish brown, and its surface is rough and covered with a layer of short fine hairs. This final instar takes about 7 days to complete with the body length reaching about 18-20mm.


Two views of the head capsule of a 5th instar caterpillar.


5th instar caterpillar, length: 20mm

Towards the end of 5th instar, the body of the caterpillar gradually shrinks in length and decolorizes to a milky yellow color. Soon it becomes dormant in its leaf shelter and enters the prepupatory phase which lasts for one day.


Two views of a pre-pupatory larva of the Fluvous Pied Flat.

Pupation takes place within the leaf shelter. The pupa secures itself with its cremaster attached to a short transverse band on the leaf surface, and has a silk girdle. The lightly hairy pupa is mostly green in base colour but with abdominal segments mostly in white. It has a short thorax and a rather long abdomen.
There is also a pair of small dark brown projections on the anterior part of the mesothorax. Length of pupae: 14.5-16.5mm.


Top: a pre-pupa very close to the pupation event.
Middle and bottom: Two views of a fresh pupa of the Fluvous Pied Flat.

After 6-6.5 days, the pupa becomes mostly dark brown in color with the spots on the forewing somewhat distinguishable through the now transparent pupal skin. Eclosion takes place the next morning.


Two views of a mature pupa of a male Fluvous Pied Flat.


A newly eclosed male Fluvous Pied Flat drying its wings near its pupal case.


A newly eclosed female Fulvous Pied Flat

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 Pres 1999

Text and Photos by Horace Tan

20 December 2008

The Singapore Red Data Book 2008

The Singapore Red Data Book 2008



After a long 14-year wait, the new Singapore Red Data Book 2008 was finally launched on 29 November 2008.

The first Red Data Book was published in June 1994, by Nature Society (Singapore) with Peter Ng and Wee YC as the editors, with 20 contributors covering many groups of flora and fauna. Pictures were in black and white, and in those days, film was still the mainstay of the authors' and contributors' photographic records.

Fast forward fourteen years later and it is November 2008. Editors Geoff Davison, Peter Ng and Ho Hua Chew took on the task of updating the Red Data Book. Based on the new International Union for Conservation of Nature (IUCN), and with much more information accumulated over the years since the first book, and a new generation of experts and enthusiasts, the new Red Data Book records the changes and new information added to the repository of knowledge amongst the nature community in Singapore. Bigger and now with colour photographs, the Singapore Red Data Book is expected to be an icon of nature conservation in Singapore.


A page from the flora section of the Singapore Red Data Book 2008

With data, photos and documentation from 63 contributors this time around, the book hopes to cover even more information that will be useful to help decision-makers and the governmental authorities to make policy decisions on land use planning, development guidelines and physical development that will also take into account nature conservation and the protection of our natural heritage for future generations of Singaporeans to enjoy.

The Red Data Book has been a source of information for students, researchers, private and governmental organisations and has been cited in numerous technical publications. Many recent Biodiversity Impact Assessment (BIA) reports conducted prior to any development works in the vicinity of sensitive nature areas often use the Red Data Book as a main source of reference. The Red Data Book is an invaluable resource for students and researchers, local and foreign, in their understanding and appreciation of Singapore's biodiversity.


A page from the butterflies section of the Singapore Red Data Book 2008

The Singapore Red Data Book 2008 starts with a chapter on Nature Conservation Laws in Singapore which gives a good overview of the legal protection of flora and fauna in Singapore. The legal framework with which our natural heritage in Singapore is protected has come a long way since 1994. There are now gazetted nature reserves covering specific areas, and new laws (and penalties) governing any breach of these laws.

With this grim preamble on the legal aspects of the protection of nature, the various expert contributors cover various groups of flora and fauna in the following categories :

Flora
  • Bryophytes
  • Ferns and Fern Allies
  • Seed Plants

Fauna - Invertebrates

  • Corals, Worms and Molluscs
  • Springtails, Peripatus & Insects (to Moths)
  • Butterflies
  • Phasmids
  • Spiders
  • Horseshoe Crabs and Decapod Crustaceans
  • Echinodemate

Fauna - Vertebrates

  • Fishes
  • Amphibians
  • Reptiles
  • Birds
  • Mammals

The book concludes with comprehensive checklists of the threatened species covering the above groups of flora and fauna.


This 285-page book is the culmination of the efforts and hard work of the various expert contributors and will further the iconic status of the Singapore Red Data Book as the 'lighthouse' for nature conservation activities in Singapore.



A page from the fish section of the Singapore Red Data Book 2008

ButterflyCircle has contributed significantly in the section covering 14 pages (main write up) and 8 pages (checklist), featuring 26 species from the IUCN categories Vulnerable, Endangered and Critically Endangered, with the excellent photographs from Sunny Chir, Wong CM, Chan SC, Richard Ong and Khew SK. All butterflies featured are of live field shots, unlike the first Red Data Book, which had to feature dead specimens due to time constraints.

The Singapore Red Data Book 2008 is another successful book launched, and ButterflyCircle is proud to be the reference authority for butterflies in Singapore.



Two generations of authors - Steven Neo who wrote the butterflies section of the 1st Edition and Khew SK who wrote the butterflies section in the 2nd Edition of the Singapore Red Data Book, posing with Professor Tommy Koh at the book launch.

Read about the launch of the Singapore Red Data Book 2008 - courtesy of Ria Tan's Wild Shores of Singapore Blog.


Text by Khew SK ; Photos scanned from the Singapore Red Data Book 2008


The Singapore Red Data Book 2008 is available from Nature's Niche @ Orchidville and Nature Society (S) at a price of S$20.

13 December 2008

Life History of the Green Baron

Life History of the Green Baron (Euthalia adonia pinwilli)



Butterfly Biodata:
Genus: Euthalia Hübner, 1819
Species: adonia Cramer, 1779
Subspecies: pinwilli Pendlebury & Corbet, 1938
Wingspan of Adult Butterfly: 60mm
Caterpillar Host Plants:
Dendropthoe pentandra (Loranthaceae)


A male Green Baron sunbathing in an urban park


A female Green Baron found puddling on a wasteland in the vicinity of a hill park


Another female Green Baron on a high perch in the nature reserve

Physical Description of Adult Butterfly:
The Green Baron is instantly recognisable by their greenish colour and red potting. Male upperside is greenish-brown and the forewing cell has one white spot. The white spot in space 3 is in line with the post-discal spots in spaces 4, 5 and 6; sub-apical white spots in spaces 4, 5 and 6 are not in line, that in 6 shifted in. Male upperside hindwing has a subterminal series of black spots, with the anterior three and the tornal spot outwardly crimson. Female upperside forewing has much larger white sub-apical and post-discal spots than the male's, with the post-discal spots very large and irregular in shapes. Female upperside hindwing has a similar sub-terminal series of spots as the male, and a very broad white discal band.

Field Observations of Butterfly Behaviour:
The Green Baron is a relatively rare species in Singapore and is not often encountered. Typically, adults are sighted and more readily photographed when they descend from their tree-level perch to feed on the blooms of flowering plants like the Singapore Rhododenron, Ixora and Lantana, both in urban packs and in the nature reserves. Both sexes have also been sighted puddling on wet ground on some occasions. The colourful adults are robust, alert and rapid fliers.

Early Stages:
The host plant is a parasitic plant which grows on mature trees in various parts of Singapore. This mistletoe is rather common in urban parks, gardens, housing estates and on trees planted by the roadside. Besides Green Baron, its leaves are also utilized by early stages of Painted Jezebel (Delias hyparete metarete), Great Imperial (Jacoona anasuja anasuja) and Peacock Royal (Tajuria cippus maxentius), and likely a few other lycaenidae species. Whilst caterpillars of Painted Jezebel and Peacock Royal feed solely on the relatively young tender leaves, those of the Green Baron prefer the thicker and harder mature leaves.


Host plant : Dendropthoe pentandra on an Asoka tree

The eggs are laid singly, usually on the uppersides of mature leaves of the host plant. The brown egg is dome-like in shape with a wide bulging base, about 2mm in diameter. The surface is covered with large hexagonal depressions the corners of which have with yellowish hair-like protuberances emerging.


An egg of the Green Baron

After about 3-4 days, the 1st instar caterpillar emerges, eating the eggshell as its first meal. It then proceeds to feed on the leaf lamina by eating along the edge. The caterpillar is yellow in body colour, has a black head and sports ten pairs of short dorso-lateral protuberances complete with long setae. It grows from an initial length of about 3.5mm to 7mm in three days. The subsequent moult takes it to the 2nd instar.


Newly hatched 1st instar caterpillar, length: 3.5mm.
Note the remnant of the egg shell (the circular mark) to the upper right of the caterpillar.


1st instar caterpillar, length: 6mm

The body of the 2nd instar caterpillar is predominantly greenish yellow dotted with small white spots. The head has changed to light brown in color and featured quite a few short setae. The ten pairs of short protuberances seen in the 1st instar have lengthened considerably. Projected horizontally with numerous branched spines and almost always pressed to the leaf surface, these protuberances not only give the caterpillar a very unique shape but also serve to break up the shape and shadow of the body. When resting on the mid-rib of the leaf, the branched spines give the caterpillar some measure of camouflage from predators. The middle section and the tip portion of each protuberance are colored dark brown to black. The 2nd instar lasts for three days with the body length reaching about 11mm before the moult to the 3rd instar.


2nd instar caterpillar of the Green Baron with its branches spines, length: 7.5mm

The 3rd instar caterpillar is similar in appearance to the 2nd instar, but the spines have grown much longer. The branched spines appear almost like a bird's feather, with the secondary spines arranged neatly and nearly perpendicular to the main spine. The body color is predominantly pale green and the head is light brown. Large and prominent dark brown dorsal spots appearing on the anterior part of the first two thoracic segments, the first two abdominal segments, and abdominal segments 4, 5 6 and 7. The two dorsal spots on the first two abdominal segments are connected with a dark brown patch sporting small white dots. The 3rd instar lasts for 3 days and reaches a length of 16mm before the next moult.


3rd instar caterpillar, length: 11mm

The 4th instar caterpillar has similar appearance as in the 3rd instar. Comparing it to the earlier instar, the body color has a lighter shade of green and the dorsal spots are milky brown in appearance. Each dorsal spot is decorated with a prominent small white spot (variable in size, and some are diamond in shape) at the center of the leading edge. The black section on each protuberance is now drawn closer to the black tip, roughly about one-third way from the tip. After 5 days in this instar, and growing to a length of about 30mm, the caterpillar moults to the the 5th and final instar.


A 4th instar caterpillar which has just shed its old skin. length: 17mm


4th instar caterpillar, length: 27mm

The 5th instar caterpillar features a brighter shade of green. Side spines of the previously black sections and tips of the protuberances have changed color to pink. On each protuberance, the "interior" section has almost fully married up with the pink tips, if not for an intervening white section.


5th instar caterpillar, late in this stage, length: 49mm


Left to right: Changes in the appearance of one protuberance from the 2nd to the 5th instar.
Note the increase in the density of side spines.


This final instar lasts for 5-6 days with the caterpillar reaching a mature length of about 50mm. On the last day, its body becomes shortened and decolorized. Soon after it adopts the pre-pupatory pose on the leaf underside or on a nearby stem. All dorsal spots disappear at this juncture and a bi-color saddle mark can be seen on the 2nd abdominal segment.



A pre-pupa of the green Baron

After 1 day of the pre-pupal stage, pupation takes place with the pupa suspended with its cremaster firmly attached to the silk pad on leaf surface. The pupa is smooth and tapers steeply towards each end from a high transverse dorsal ridge. The light green pupa has a series of brownish spots arranged symmetrically. Length of pupae: 20-21mm.


Two views of a fresh pupa of the Green Baron with its old coat caught dangling


Two views of a pupa of the Green Baron

Ten days later, the pupa has developed to the point of revealing the upperside wing markings in the wing pad area. The next day, the adult butterfly ecloses in the morning hours. It stays on the empty pupal case for an hour or two before taking off to feed, find a mate and continue the circle of life and propagation of the next generation.


Left: mature pupa on a branch; Right: a newly eclosed male Green Baron


Another newly eclosed male Green Baron



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 Pres 1999
Text by Horace Tan, Photos by Tan Ben Jin, Federick Ho and Horace Tan