Butterfly of the Month - March 2011

Butterfly of the Month - March 2011

The Common Rose (Pachliopta aristolochiae asteris)

The month of March was a very eventful one globally , with widespread unrest in the Middle East as public protests crippled Egypt and removed its President, Hosni Mobarak, from power. The 'people power' protests spread to other countries like Bahrain and Libya. It would appear that the citizens of these countries, long oppressed by their governments, have had enough of being treated that way, and have risen in unison to overthrow the people behind years of near-dictatorial rule. May these countries and their people find peace again soon.

Over in Asia, on March 11, a massive earthquake calculated at a magnitude 9.0 on the Richter scale occurred near the north-east coast of Honshu, Japan. The devastating tsunami that followed inundated the Miyagi Prefecture, causing at least 10,000 or more deaths. The quake caused damage to the cooling systems at the Fukushima nuclear plants, causing a potential nuclear meltdown and radiation risk to the cities in the vicinity and even further afield in Asia.

Whilst the world reels from this shocking and sad news, our prayers go to the Japanese people that they would recover from this crisis and rebuild their lives.

The month of March is associated with the mineral heliotrope, also known as the Bloodstone. The classic Bloodstone is deep green chalcedony usually with red inclusions of iron oxide or red jasper, giving the stone a dark appearance with blood red spots.

By her who in March was born

No gem save bloodstone shall be worn

They will ensure her constancy

True friendship and fidelity.

- Gregorian Birthstone Poems

A newly eclosed Common Rose clings onto its pupal case.

For the month of March, we feature the spectacular swallowtail, the Common Rose (Pachliopta aristolochiae asteris). The species is moderately common in Singapore, often found in the vicinity of where its caterpillar host plants, Aristolochia spp., are found. Although the preferred local host plant is Aristolochia acuminata, which it shares with the Common Birdwing, it has also been successfully bred on other Aristolochia like A. ringens, A. foveolata and A. grandiflora.

At times, several individuals can be seen in a particular location where the butterfly flies restlessly, always on the move and stopping occasionally to feed at its favourite nectaring plants. During the day, it is always fluttering with a slow unhurried flight, displaying its aposematic warning colouration (a bright red body and red marginal spots on its hindwings) to would-be predators that it is distasteful.

The female Common Mormon mimics the Common Rose for protection from predators by exhibiting similar reddish submarginal spots and white markings on the hindwings.

A female Common Rose oviposits on its host plant, Aristolochia acuminata

In recent years, individuals of the Common Rose have been observed where the hindwings are totally black - this "variation" we call the Black Rose. It consistently appeared for some time from 2008 onwards but became rarer in recent years. The jury is still out on the status of this species. The physical appearance of this Black Rose matches the subspecies antiphus, but in some literature, it has been upgraded to a full species status - Pachliopta antiphus.

In both cases, whether it is Pachliopta aristolochiae antiphus or Pachliopta antiphus, a butterfly of such appearance originates from Borneo. If it were, then it may have been inadvertently brought over from Borneo via human agency through the import of plants, perhaps?

A pristine Black Rose perches on a branch

However, when the Black Rose appeared particularly at the Alexandra Hospital Butterfly Trail and also at the Singapore Botanic Gardens, the black individuals flew and co-existed with the normal subspecies asteris. Could the black "variant" be a morph of subspecies asteris? If it were a distinct subspecies, how then could the two different subspecies co-exist in the same locations?

The Black Rose appeared to be even more common than the Common Rose for a period of time, and then suddenly became rare again! What happened? Natural selection and an unknown evolutionary process that allowed the more 'dominant' subspecies asteris to take control again?

Upperside shot of the Black Rose

Perhaps breeding experiments would prove (or disprove) the status of antiphus. Could a male asteris mate with a female antiphus or vice versa? What would the offspring yield? This opportunity to breed the two "Roses" which were distinctively different in appearance was missed. Until the Black Rose appears again, we will just keep the postulation on the backburner.



Hence the status of the Black Rose is uncertain, and needs to be further researched before ascertaining it as a subspecies (or in some references, as a full and distinct species). So until then, we will leave it as an unsolved mystery and hopefully a job for someone to discover in the near future! In the meantime, let us just enjoy the beauty of the Common Rose.

Text by Khew SK : Photos by James Chia, Sunny Chir, Khew SK, Simon Sng, Horace Tan & Anthony Wong

Further Reading :

• Swallowtails of Singapore
• Aposematism in Butterflies

Life History of the Chocolate Pansy

Life History of the Chocolate Pansy (Junonia hedonia ida)

Butterfly Biodata:
Genus: Junonia Hübner, 1819
Species: hedonia Linnaeus, 1764
Subspecies: ida Cramer, 1775
Wingspan of Adult Butterfly: 55-60mm
Caterpillar Local Host Plants: Ruellia repens (Acanthaceae), Hemigraphis reptans (Acanthaceae)


A Chocolate Pansy displaying its upperside.


A Chocolate Pansy giving us a view of its underside.

Physical Description of Adult Butterfly:
Above, the wings are orangy brown with several indistinct but darker brown bands traversing from the costa towards the dorsum. There are two cell spots on the forewing and a prominent series of reddish brown post-discal ocelli on the hindwing. A much less prominent series of post-discal ocelli is also present on the forewing. Underneath, both fore- and hindwings are in duller brown but each has a dark stripe traversing from the costa to the dorsum. The stripes appear to be continuous across the two wings. A large white spot is present next to the stripe in space 7 of the hindwing. A post-discal series of ocelli is present on both wings, and these ocelli are yellowish brown on pristine specimens.


A Chocolate Pansy visiting flowers.


An adult Chocolate Pansy taking up its position on a leaf.

Field Observations of Butterfly Behaviour:
This species is rather common across multiple habitats in Singapore, with ubiquitous presence in nature reserves as well as urban and suburban areas. It flies in the usual gliding manner of the Junonia spp. and typically several individuals can be seen together in one location. Under sunny conditions, they have a habit of opening their wings wide to sunbathe while resting on a perch.



Early Stages:
The caterpillars of the Chocolate Pansy feed mainly on leaves of the two recorded local host plants, Ruellia repens and Hemigraphis reptans. Both plants belong to the Acanthaceae family, and occur as widespread weeds in Singapore. It is likely that more members of this family serve as the larval food plants for Chocolate Pansy.

Local host plant #1: Hemigraphis reptans.


Local host plant #2: Ruellia repens.

A mating pair of the Chocolate Pansy.

A mother Chocolate Pansy laying an egg on the underside of a leaf of Hemigraphis reptans.

The eggs of the Chocolate Pansy are laid singly on the young leaves or shoots of the host plants. The greenish egg is somewhat globular in shape but with a blunt top. Twelve raised ridges run from this top end to the base of the egg. Each egg has a diameter of about 0.75mm.

Two views of an egg of the Chocolate Pansy. Diameter: 0.75mm.


Two views of a mature egg of the Chocolate Pansy.

The egg takes about 3 days to hatch. The young caterpillar emerges by eating away part of the egg shell, and then proceeds to eat the rest of the egg shell from the outside. The initial length of the newly hatched is about 1.5mm. The cylindrical and pale yellowish body is covered with many small tubercles. Long dark setae emanate from those tubercles occurring dorso-laterally, and long whitish setae occur sub-spiracularly. The head capsule is pale yellowish with two large lateral dark patches.

Two views of a newly hatched caterpillar, length: 1.5mm.

The 1st instar caterpillar feeds on the lamina of young leaves and grows rapidly. After reaching about 3mm in 1.5 days, the caterpillar moults to the 2nd instar.

Two views of a 1st instar caterpillar, length: 2.8mm.


Two views of a 1st instar caterpillar, late in this stage, length: 3mm.

The body of the 2nd instar caterpillar is yellowish brown mainly and is darker brown on the dorsum. Moderately long and branched brownish processes run along the length of the body. Fine setae emanate from these processes and from other small tubercles on the body surface. The head capsule is yellowish to orangy brown and featuring two small dark brown lateral patches. This instar lasts about 2 days with the body length reaching about 5mm.

Two views of a 2nd instar caterpillar, newly moulted, length: 2.5mm


Two views of a 2nd instar caterpillar, late in this stage, length: 4.5mm

The 3rd instar caterpillar has proportionately longer dorso-lateral and lateral processes. The body is mostly dark brown to black, except for the posterior end which is yellowish to orangy brown. This instar takes about 2 days to complete with body length reaching about 8.5mm.

Two views of a 3rd instar caterpillar, newly moulted, length: 4.5mm.


Two views of a 3rd instar caterpillar, late in this stage, length: 8mm.


Two views of a 3rd instar caterpillar, about to moult. Inset: head capsule.

The 4th instar caterpillar closely resembles the 3rd instar caterpillar, except for the proportionately longer processes and the change to an orange base color for the head capsule. The body color is almost entirely black except for a short section of yellowish brown at the posterior end. A fair number of small white specks appear on the body surface. The 4th instar lasts 2-2.5 days with the body length reaching about 12mm.

Two views of a 4th instar caterpillar, early in this stage, length: 9mm.


Two views of a 4th instar caterpillar, late in this stage, length: 11mm.


Two views of a 4th instar caterpillar, about to moult, length: 11.5mm.

The 5th (and penultimate) instar caterpillar is similar to the 4th instar caterpillar.One discernible difference is the presence of a dense set of moderately long fine setae covering the entire body surface. This instar lasts for 2.5-3 days, and the body length increases rather dramatically and reaches up to 23.5mm.

A 5th instar caterpillar, newly moulted, length: 11mm.

Two views of a 5th instar caterpillar, early in this stage, length: 12.5mm. Inset: head capsule.


Two views of a 5th instar caterpillar, about to moult, length: 22mm.

The 6th (and final) instar caterpillar is similar to the 5th instar caterpillar but has an even denser carpet of whitish fine setae on the body surface. Upon closer examination, pitch black triangular patches, one to each body segment, can be discerned against a lighter shade of black for the body base colour. The head capsule is bright orange and has two black patches on both sides of the "face".


Two views of a 6th instar caterpillar, early in this stage, length: 23mm.


Two views of a 6th instar caterpillar, length: 36mm.

The 6th instar lasts for 4-4.5 days, and the body length reaches up to 40mm. The caterpillar ceases feeding and wanders around. Eventually it stops at a spot on the underside of a leaf, young shoot/stem and spins a silk pad from which it hangs vertically to take on the pre-pupatory pose.

A pre-pupa of the Chocolate Pansy.

The pupation event of a Chocolate Pansy caterpillar.

Pupation takes place about 0.5 days later. The pupa suspends itself from the silk pad with no supporting silk girdle. It is entirely greyish brown with a series of dorso-lateral pairs of short and pointed processes, one pair to each segment. The dorsum is sharply raised at the mesothorax. Black markings are also featured in the wing pads. Length of pupae: 18-19mm.

Three views of a pupa of the Chocolate Pansy.

Three views of a mature pupa of the Chocolate Pansy.

After about 5 days of development, the pupal skin of the mature pupa turns translucent and the pupa turns dark brown as a result. Patches of orangy brown can also be noticed in the wing pad. The adult butterfly emerges from the pupa the next day.

The eclosion event of a Chocolate Pansy caterpillar.

A newly eclosed Chocolate Pansy 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.
• A Field Guide to the Butterflies of Singapore, Khew S.K., Ink On Paper Communications, 2010.
  

Text by Horace Tan, Photos by Simon Sng, Federick Ho, Sunny Chir and Horace Tan

300 !!!

300 !!! - Discovery of the Yellow Streak Darter
Species #300 on the Singapore Checklist

And so, after many years, Singapore's Butterfly Checklist has passed the 300 mark once again. The early authors had recorded at least up to 361 species (Ref : Butterflies of the Malay Peninsula and Butterflies of West Malaysia and Singapore), but many have gone extinct or have not been reliabily seen in the past two decades. At the same time, many new species not recorded by the early authors have also be documented and added to the checklist.

It was a memorable outing for ButterflyCircle members on 26 Feb 2011. It was on this day that BC members re-discovered the Wanderer. Amidst the excitement of finally seeing that elusive species in Singapore, there was another less attractive butterfly that was shot by BC member Simon Sng. Coincidentally, this outing was organised by Simon and it is a well-deserved 'prize' that Simon bagged with the shot of this skipper which will be recorded as Singapore's 300th species.

Simon's shot is the first one taken of this species in Singapore

Although Simon's record shot was not of his usual standard of photography, it was sharp enough to show that this species was not anything that has been seen in Singapore before. The deep yellow undersides marked with rather distinctive markings revealed that this was a species that is new to Singapore.

A bit of artistic licence to dramatise the celebration of the 300th species in Singapore! Image copyright © Warner Bros

With this species, we have reached the 300 mark - a long way from the time when veteran Steven Neo started recording a checklist for Singapore in the early 90's. Species that Steven documented, like the Red Base Jezebel, Common Pierrot and Pointed Palmfly, to name a few, have yet to be seen again in Singapore since the days he was active in maintaining the Singapore Checklist.

Another shot of the Yellow Streak Darter taken by Simon on 26 Feb 2011

Steven and I co-wrote a paper in the Gardens' Bulletin Singapore, a refereed journal by the National Parks Board in 1997. The paper, entitled "Butterfly Biodiversity in Singapore with Particular Reference to the Central Catchment Nature Reserve" was published in Issue 49 (1997) of the Gardens Bulletin. The paper appears on pages 273-296 of the publication. Back then, armed with film SLRs and a net, we managed to record only 236 butterfly species in Singapore.

With the growth of ButterflyCircle's membership in the 2000's and especially after 2005, and over the past 5-6 years, we have added a total of 64 additional species to the Singapore Checklist. With more eyes (and sharp lenses) over the years, and hardworking members of ButterflyCircle have added a number of rare species to the Checklist. When ButterflyCircle launched its Field Guide to the Butterflies of Singapore in Oct 2010, we had reached a total of 296 species.

Coming back to our little "Spartan" species #300, - Long-time butterfly photographer, Simon knew at once that he had shot something different, though the butterfly sped off after he shot it. When Simon showed me the skipper, I was also stumped as I'd never seen this species before in my years of collecting and studying butterflies.

At BC's forums, other experts joined in and we narrowed it to a Salanoemia sp. with the closest recorded species being Salanoemia similis in Malaysia. Determined to nail down the ID of this mystery species, I went to the same location on Pulau Ubin the next day, and after about 3 hours of searching, the yellow skipper zipped right in front of me. With better shots of the skipper, we concluded that the skipper is a Yellow Streak Darter (Salanoemia tavoyana), as the distinctive markings of this individual puts the ID well beyond doubt, after cross-referencing to various books and internet resources.

What is surprising is that C&P4 states that this species is found in Kedawi (Kedah and Langkawi in the north of the Malay Peninsula) and Myanmar. How it appeared so far south of its normal geographical distribution is beyond our comprehension. We found a caterpillar near the location where this individual was shot, so we hope that we may have discovered the early stages of this species as well.

The pristine individual observed suggests that it may have eclosed recently, and is definitely not the condition that a butterfly would be in, if it had migrated to Singapore after a long flight. So will we see more of this species in future? It's anybody's guess. But in future, we will surely take a second look at any yellow skipper that flies in our paths.

So Singapore welcomes its 300th species on 26 Feb 2011. There will certainly be more to come, and we have already confirmed the existence of species #301! Watch this space!

Text by Khew SK ; Photos by Khew SK & Simon Sng

References :

• [C&P4] The Butterflies of The Malay Peninsula, A.S. Corbet and H.M. Pendlebury, 4th Edition, Malaysian Nature Society.
• Butterflies of West Malaysia & Singapore, W.A. Fleming, 2nd Edition, Longmans
• Butterflies of Thailand, Pisuth Ek-Amnuay, 1st Edition, 2006

Acknowledgements :

• Special thanks to Dr Laurence Kirton of FRIM for his comments on the ID of this species.