Butterfly of the Month - January 2009

Butterfly of the Month - January 2009

The Cornelian (Deudorix epijarbas cinnabarus)

As we step into the final year of the first decade of the new millennium with trepidation, anxiety and concern at the tumultuous global economy, where jobs are at stake, and salaries in danger of going southwards, we look in anticipation for a silver lining towards a quick recovery. Whilst we spend the last few days of the Lunar Year of the Rat, and herald the coming of the Year of the (Earth) Ox, there should be some reason for cheer and a more optimistic outlook ahead but let's spare a thought for those who are less fortunate.

This month, we again feature a bright red butterfly species, for good luck and fortune for the start to 2009. This month, we introduce the Cornelian (Deudorix epijarbas cinnabarus). The male is orange red above, with broad black borders on the forewing, and the costal area broadly blackened on the hindwing. The female is dark brown above, and unmarked. The underside is buff to greyish brown, with broad post-discal bands and cell-end bars and defined by narrow white stripes.

So how did the butterfly get its common English name? The word Cornelian is often associated with the semi-precious gemstone "cornelian" which is a red variety of chalcedony, which is cryptocrystalline quartz. Its red colour is due to the presence of iron impurities in the form of iron oxide or hematite. It can vary from a flesh red to a clear red. Looking at the bright orange-red uppersides of the males of the Cornelian, we can understand why it is named so.

It has solid jet-black eyes, and the rather long antennae is orange-tipped. Each hindwing bears a filamentous white tipped tail, and there is a black orange-crowned eyespot at the tornal area of the hindwing, with some bluish-green iridescent scaling. The tornal lobe is pronounced and bears a black spot with some orange borders.

The Cornelian is rare and when encountered, the species is usually observed singly. The butterfly is a rapid flyer, but is often observed easily when it stops to feed at flowering plants in the forest. It is essentially a forest-dependent species, and is rarely seen outside the forested nature reserves of Singapore.

The caterpillars of the Cornelian are known to feed inside the fruits of the pomegranate and lychee, and probably a number of other similar pulpy fruits.

ButterflyCircle wishes all members and visitors a Happy & Prosperous Lunar New Year and Gong Xi Fa Cai!

Text by Khew SK ; Photos by James Chia & Khew SK

Life History of the Common Mime

Life History of the Common Mime (Chilasa clytia clytia)

Butterfly Biodata:
Genus: Chilasa Moore, 1991
Species: clytia Linnaeus, 1758
Subspecies: clytia Linnaeus, 1758
Wingspan of Adult Butterfly: 95mm
Local Caterpillar Host Plant: Cinnamomum iners (Lauraceae) [Synonym: C. initidum, C. paraneuron]


A Common Mime visiting flowers with wings fully opened giving us a full view of its upperside


A Common Mime taking nectar from Lantana in an urban hill park


A Common Mime puddling on a wet sandy area in the nature reserves

Physical Description of Adult Butterfly:
Worldwide, the Common Mime occurs in two morph-groups in both sexes, but In Singapore, only the black-and-white striped form-dissimilis occurs. This form is velvety black with extensive white streaks and spots on the upperside. Underside is similar to the upperside with slightly larger white markings, and on the hindwing there is a row of conspicuous yellow marginal spots. Head, thorax and abdomen are black with prominent white spots.

Field Observations of Butterfly Behaviour: The Common Mime is relatively common in Singapore, and can be seen in both the nature reserves and developed areas. The butterfly mimics the distasteful Danainae species for protection against predators. When the adults visit flowering shrubs, their slow and graceful flight resemble those of the distasteful Blue Glassy Tiger and the Dark Glassy Tiger. The adults have the habit of puddling on wet grounds.

Early Stages:
Across the range where this species occurs, the early stages feed on leaves of serveral plants in the Lauraceae family. The sole recorded local host plant, Cinnamomum iners (Common name: Clover Cinnamon, Wild Cinnamon), is a very common plant all over Singapore, readily found in nature reserves, gardens, parks and wastelands etc. It is a small to medium-sized tree with 3-nerved leaves. Eggs and early stages of the Common Mime are typically found on saplings at heights from knee to waist level.


Host plant : Cinnamomum iners


A female Common Mime taking off after an egg was laid on a wild cinnamon sapling.
Can you spot the egg?

The eggs of the Common Mime are laid on young leaves or petioles of a sapling of the host plant. Sometimes a few eggs could be found on the same sapling, and occasionally in close proximity. The spherical egg is creamy white with the surface coated with a non-uniform layer of orange-yellow granulated substance. Diameter: 1.2-1.3mm.


Left: egg freshly laid as featured in the previous picture.
Right: a group of three eggs on the petiole of a young leaf


Left: freshly laid egg; Middle: developing egg; Right: mature egg

The egg takes 3 days to hatch. The young caterpillar eats its way out of the mature egg, and then proceeds to finish up the rest of the egg shell. The newly hatched has a dark brown head, rows of short dorsal-lateral tubercles with long setae, and an initial body length of about 3mm. It is mainly pale brown with white patches on the the middle and posterior segments.


Newly hatched Common Mime caterpillar eating egg shell, length: 3mm

As it feeds and grows, the body color darkens to feature black lateral markings, and both yellowish brown and whitish dorsal patches. The head capsule also turns black. In this and the next three instars, the Common Mime caterpillars resemble bird droppings as they rest on the leaf surface.


1st instar caterpillar, length: 3p5mm

As the 1st instar caterpillar grows to a length of about 6.5mm, the dark lateral markings decolorizes and disappears. There is a white saddle on the 3rd-4th abdominal segments and white markings on the posterior abdominal segments. After about 2-3 days in 1st instar, the caterpillar moults to the next instar.


1st instar caterpillar, length: 5mm (top); 6.5mm (bottom)

The 2nd instar caterpillar has a similar appearance to the 1st instar caterpillar except for the longer and stubby processes, brighter shade of orange on dorsal patches, and distinctly white color on the saddle mark and posterior abdominal segments. The growth is rather rapid and this instar lasts only 1-2 days. The body length reaches about 10-11mm before the next moult.


2nd instar caterpillar, early in this stage, length: 10.5mm

In the 3rd instar, again there is no drastic change in physical appearance except for the greater contrast between the black and orange markings. This instar takes 2 days to complete with body grown to about 19mm in length.


3rd instar caterpillar, early in this stage, length: 11mm

The 4th instar caterpillar has more extensive white markings on it body. The white patch on the posterior abdominal segments has extended to the whole of abdominal segment 7 and white lateral patches appear on the thoracic segments. This instar lasts 3 days with body length reaching about 33mm.


4th instar caterpillar, early in this stage, length: 20mm


A 4th instar Common Mime caterpillar found in the Jurong Lake area

The next moult brings the caterpillar to the 5th and final instar with a dramatic change in appearance. The body is dark greyish black in base color with numerous inconspicuous black spots embedded. On each side of the body, there are two rows of fleshy processes on segments 1 to 4 and single row on the other segments. A crimson red spot is featured at the base of each fleshy process. A sub-spiracular row of crimson red spot also occurs in the abdominal segments. The body also features large creamy yellow patches organized as follows: 1) a dorsal row of large irregularly-shaped patches; 2) a short lateral row on the posterior abdominal segments starting from abdominal segment 7, and 3) a front lateral row of yellow patches spanning all thoracic segments and abdominal segments 1, 2 and 3. The front lateral row connects with the dorsal row in abdominal segment 3.


5th instar caterpillar, second day after the moult, length: 50mm


A 5th instar Common Mime caterpillar found in a clearing in the Southern Ridges.

All instars of the Common Mime possess a fleshy organ called osmeterium in the prothoracic segment. Usually hidden, the osmeterium can be everted to surprise any intruder when the caterpillar senses the threat, The osmeterium is pale brown in the first four instars, and light indigo-blue in the final instar.


Partially everted osmeterium of a 1st intar Common Mime caterpillar


The dark to light brown osmeterium of a 4th instar Common Mime caterpillar


The indigo blue osmeterium of a final instar Common Mime caterpillar

The 5th instar lasts for 4 days, and the body length reaches up to 55mm. Toward the end of this instar, the body gradually shortens in length. Eventually the caterpillar comes to rest on the lower surface of a stem and becomes a pre-pupatory larva.


A pre-pupatory larva of Common Mime.
Top: preparing its anchor point; Bottom: having completed its silk girdle

Pupation takes place a day later. The pupa suspends itself with a silk girdle from the stem. The pupa resembles a broken twig about 38-40mm long, brownish with streaks and blotches,. The posterior segment is so modified that the pupa appears to have grown out of the branch to which the pupa anchors.

A Common Mime caterpillar molts to its pupal stage. [Added on 29 May 2011]

Two views of a twig-like pupa of the Common Mime.

After 11-12 days, the pupa turns black as the development within the pupal case draws to a close. The white spots on the forewings are now visible through the pupal skin at the wing pad area. The next morning the adult butterfly emerges from the pupal case.


The eclosion of the Common Mime in a grid mosaic.



A newly eclosed Common Mime drying its wings near the empty pupal case


A newly eclosed Common Mime

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

Text by Horace Tan, Photos by Bobby Mun, Federick Ho, James Chia, Khew SK and Horace Tan

Pulau Semakau Butterfly Survey

Pulau Semakau Butterfly Survey - Dec 08

ButterflyCircle was invited to participate in the biodiversity survey of Pulau Semakau as part of the Semakau Book Project, an initiative of the National Environment Agency. The book project is expected to document the various flora and fauna that exists and thrive on the 350Ha landfill for waste disposal.

On 20 Dec 2008, a group of ButterflyCircle members, together with 2 NParks staff and our energizer-bunny nature expert, Ria Tan, met at the West Coast Ferry Terminal for the boat to take us to Pulau Semakau. After a quick security check, we boarded the boat, and were on our way to Singapore's only landfill for waste disposal. The boat was fast, and we were told that a larger ferry would normally take slightly more than half an hour to reach Pulau Semakau. But our fast boat delivered us to the Semakau Jetty in 20 mins flat!

Filling up forms on the boat, and arrival at Semakau!

Upon arrival, we were briefed by Ria on the island and the friendly NEA staff was on hand to further tell us all about the operations of the facility. The group was also fortunate to have the bus on hand, and we were shown around the island from the comfort of an airconditioned bus. The landfill capacity was 63 million m3 and is expected to meet Singapore's need for landfill space beyond the year 2045.

Ria briefing the group on where we would be going, and what to expect on the island

More interesting anecdotes by Ria, and ButterflyCircle members' guns out and ready to go!

At the southernmost tip of the landfill, we stopped at a weather monitoring station and had a group photo taken to commemorate ButterflyCircle's first trip to Pulau Semakau. It was a hot, sunny and windy day!

From L to R : Mark , John , Ben Jin, Khew, Jacqueline, Ria, Benedict, Wong, Bobby, Chung Pheng, Keneric and Anthony

It was extremely windy, and we were surprised to encounter a few Blue Pansys, Lesser Grass Blues and Palm Darts.. It was a pleasant surprise to see butterflies on this little island, as I did not expect to see any butterflies on this little island so far south from Singapore. How did these butterflies end up here? Perhaps with the plants that were delivered to the island? We may never know for sure. But the Palm Darts which were zipping around, kept returning to the coconut palms, suggesting that this may be their host plant.

The wind was blowing strongly!

Shooting each other... but where's the butt??

After we were dropped off at the western part of the island where there was a patch of mangrove swamp, and vegetation, presumably from the original Pulau Semakau, before the rock bund was constructed to combine Semakau and Pulau Sakeng to form the current landfill island.


Coastal mangrove habitat

Over on the coastal side, there were two main habitats - the coastal mangrove environment, and shaded forested mangrove areas. Across from this patch of forest, were the landfill cells - one of which had been filled, and grasses and vegetation had begun to re-generate in this cell. This formed the third habitat, one of open grassland and secondary growth.

Forested back-mangroves - and mosquito-infested country!

Open grassland habitat

ButterflyCircle members then proceeded to cover the small area to look for butterflies. Surprisingly, at the end of the trip, we counted no less than 18 species of butterflies! This had far exceeded our expectations of the butterfly fauna of this island. Of particular interest, was the discovery of the Two Spotted Line Blue (Nacaduba biocellata) here! This species was a recent discovery in Singapore and reported in the Blog here, where the species, a common butterfly in Australia, was first found in Singapore. How it came to be on Semakau is a very interesting mystery. There may be more species than our very short survey had observed, and a second survey is on the cards soon.

All shacked out after a long hot day out looking for butterflies

Checklist of Butterflies Observed at Pulau Semakau on 20 Dec 2008.

1. Common Grass Yellow (Eurema hecabe contubernalis)
2. Common Tiger (Danaus genutia genutia)
3. Black Veined Tiger (Danaus melanippus hegesippus)
4. Blue Glassy Tiger (Ideopsis vulgaris macrina)
5. Tawny Coster (Acraea violae)
6. Perak Lascar (Pantoporia paraka paraka)
7. Autumn Leaf (Doleschallia bisaltide bisaltide)
8. Great Eggfly (Hypolimnas bolina bolina)
9. Blue Pansy (Junonia orithya wallacei)
10. Common Palmfly (Elymnias hypermestra agina)
11. Centaur Oakblue (Arhopala centaurus nakula)
12. (Hypolycaena thecloides thecloides)
13. Long Banded Silverline (Spindasis lohita senama)
14. Two Spotted Line Blue (Nacaduba biocellata)
15. Tailless Line Blue (Prosotas dubiosa lumpura)
16. Lesser Grass Blue (Zizina otis lampa)
17. Palm Dart (Telicota augias augias)
18. Palm Bob (Suastus gremius gremius)
    

Text by Khew SK ; Photos by Khew SK, Benedict Tay, Bobby Mun, Mark Wong, Wong CM and Jacqueline Lau.

Relevant Links :

• National Environment Agency (NEA)
• NEA - News flash on Semakau
• Wikipedia - Notes on Pulau Semakau
• WildSingapore - News about Pulau Semakau