27 February 2012

Send in the Clowns!

Send in the Clowns! Discovery of the Malayan Jester (Symbrenthia hippoclus) A puddling Common Jester first shot on 18 Feb 2012
One late Saturday morning, ButterflyCircle member Federick Ho took a break from his work and took his photographic gear and went out for a couple of hours of butterfly hunting. After walking for some distance and shooting the usual butterflies that he encountered, he noticed a black and orange striped butterfly puddling on a concrete driveway. As he approached it, Federick took the usual "insurance" shots from afar. As he moved closer for a better shot, the butterfly took off speedily and headed for the treetops. Assuming that it was either a Lascar or a Colour Sergeant, Federick didn't think much of his record shot and stored his camera equipment as the dark clouds signalled an imminent downpour.
Later in the week, when Federick processed his shots, he realised that he had shot something new! Upon closer examination, it was concluded that this was one of the Jester species from the genus Symbrenthia. This sparked off a search for this mystery butterfly the following Saturday, but a whole morning of searching the area where Federick last saw this butterfly was in vain. Glimpses of some black and orange butterfly gliding around were made, but the Jester proved elusive.
Undeterred, senior ButterflyCircle member Sunny Chir went again the following day to look for it. Based on the knowledge that the Symbrenthia spp were mainly forest species, Sunny decided to hunt in the nearby forested area where the species was last shot. After a long hot trek looking high and low for the butterfly, Sunny spotted a small colony of individuals of the Jester-like butterflies gliding at the treetops. He waited patiently and an individual flew down, and Sunny was able to take a shot of its underside.
A 2nd individual of a Common Jester shot on 26 Feb 2012
There are four species of the genus Symbrenthia recorded from Malaysia. All the species bear a short pointed tail on the hindwing. The Symbrenthia or Jesters, are black above with orange bands. The undersides are a richly coloured with variegated patterns on a buff or ochreous ground. Initial examinations of the photographs taken by Federick and Sunny indicate that this new discovery for Singapore is most likely a Symbrenthia hippoclus selangorana or referred to by its English Common name, the Malayan Jester.
ButterflyCircle records this officially as species #302 in the Singapore Butterfly Checklist and a new discovery for Singapore. We welcome this new "clown" in town, as the name Jester suggests, to our little island in the sun!
Text by Khew SK : Photos by Federick Ho & Sunny Chir

25 February 2012

Butterfly of the Month - February 2012

Butterfly of the Month - February 2012
The Pointed Line Blue (Ionolyce helicon merguia)

The month of February 2012 is well upon us now, as we head towards the last day of the 29th day of this once-in-every-four years affair for February. This year, 2012, has 366 days instead of the usual 365 days, because of the additional day in February.

A leap year (or intercalary or bissextile year) is a year containing one additional day (or, in the case of lunisolar calendars, a month) in order to keep the calendar year synchronized with the astronomical or seasonal year.

In the British Isles, it is a tradition that women may propose marriage only on leap years. I presume that, in the first instance, the woman has to catch her man first, before doing so. In the cartoon below, the unsuspecting gentleman is as vulnerable as a butterfly sitting and enjoying itself, before the collector's net slams down on it!

Source : Wikipedia 1908 Description: "In 1908 / 'Be Careful, Clara, that's a fine Specimen!'"

Two more observations about leap years - (1) that a leap year will give a full number result if you divided the year by 4, whilst doing so with other years would give you an additional fraction remaining. Also, (2) the Summer Olympics (this year in London) will always also fall on a Leap Year.

The first two months of the year has been rather quiet in Singapore. Other than the 15-day Lunar New Year festivities that were largely over by early February, and Valentine's Day on 14th of February, it had been relatively uneventful for most of us. But a lesson learnt from recent local developments that set social media networks ablaze and coffee-shop gossip, if you want to indulge in extra-marital affairs, stay out of the Singapore civil service and political parties. :)

A flower of a Viola sp. cultivar

The birth flower of the month for February is commonly associated with the Violet. Botanically referred to as Viola spp., (family Violaceae) the Violet is a flowering plant with heart-shaped leaves that often has a purple or blue to it. Essentially a temperate region plant, it prefers cooler climates.

Violet flowers are formed from five petals; four are upswept or fan-shaped petals with two per side, and there is one broad, lobed lower petal pointing downward. Flower colours vary in the genus, ranging from violet, as their common name suggests, through various shades of blue, yellow, white, and cream, whilst some types are bicolored, often blue and yellow.

Our butterfly for February 2012, the Pointed Line Blue (Ionolyce helicon merguia), also features a violet/purple blue colour particularly in the males. A small butterfly with a wingspan of under 30mm, it is a relatively common species and the only member of the genus Ionolyce to occur in Singapore.

It appears in urban parks and gardens as well as forested areas of the nature reserves. It is a fast flyer and flies erratically, sometimes up to treetop levels. The wings of the male of this species are more angular than the closely related Nacaduba.

The male Pointed Line Blue is deep purple blue on top with a very thin black margin but otherwise unmarked. The female is brown on top with the discal area of the forewing and both basal areas lightly overlaid with bluish purple. In addition, hindwing has a series of dark spots along the wing margin. Underneath, they are both dull brown with narrow whitish wavy lines. There is an orange-crowned eye spot and a filamentous tail at vein 2 of the hindwing.

A newly eclosed female Pointed Line Blue

On hot sunny afternoons, the males of this species are observed to engage in aerial "dogfights". They fly rapidly from their favourite perches, and often stop and open their wings flat to sunbathe, displaying their spectacular violet-purple uppersides.

More often than not, the species is encountered puddling at damp spots in the nature reserves with wings folded upright. Females are much rarer, and found feeding on florets of flowering bushes. They also resemble the Nacaduba species and can easily be confused with similar lookalikes from this other genus of butterflies.

And we end this article by wishing a Happy Birthday to all the special people whose birthdays fall on the 29th of February, and who technically celebrate their birthdays only once every four years!

Text by Khew SK : Photos by James Chia, Sunny Chir, Kenneth Er, Khew SK, Koh CH, Nelson Ong, Horace Tan, Mark Wong, Wong CM, Benjamin Yam & Zhuang YY

18 February 2012

Life History of the Hoary Palmer

Life History of the Hoary Palmer (Unkana ambasa batara)

Butterfly Biodata:
Genus: Unkana Distant, 1886
Species: ambasa
Moore, 1858
Sub-species: batara Distant, 1886
Wingspan of Adult Butterfly: 50-65mm
Caterpillar Local Host Plants: Pandanus amarylifolius (Pandanaceae, common name: Pandan), Pandanus tectoris (Pandanaceae, common name: Seashore Pandan, Screw Pipe)

A female Hoary Palmer.

A male sighted in early morning in a western wasteland.

The upperside of a newly eclosed male, showing the yellowish spots on the forewing.

Physical Description of Adult Butterfly:

Adults are rather large in size. The females are typically larger than the males. Above, both sexes are dark brown with hyaline spots on the forewing: a large spot in the cell, four post-discal spots in spaces 2-5 in decreasing  size and three small sub-apical spots in spaces 6-8. These spots are white in the female but pale yellow in the male. The female has a large white patch covering the basal two-thirds of the hindwing. Underneath, the wings are dark brown with a slight purple wash in  the female but a much stronger wash in the male (for pristine specimens).  The whole hindwing is  strongly whitened between the veins except for the tornal area. In contrast, the forewing is only partially whitened. The adult has a  rather long  proboscis which is red in colour.

The upperside of a newly eclosed female, revealing  the whitish spots on the forewing.

A female on a leaf perch in the late afternoon sun in a wetland reserve. Note the predominantly white hindwing.

A female taking nectar from Ixora flowers. Note the particularly long reddish proboscis.

Field Observations of Butterfly Behaviour:
This species is moderately rare in Singapore. The adults are seldom seen, due likely to its crepuscular habit. The adults are typically observed on flowering trees or shrubs at forest edge or near mangrove habitats, taking in nectar with their long proboscises. 

A male  Hoary Palmer taking nectar from Syzygium flowers.

Another female enjoying nectar of Ixora flowers at a forest edge.

A  male visiting Syzygium flowers.

Early Stages:
The local host plants are members of the genus Pandanus of the Pandanaceae family. One recorded plant is the Pandan (Pandanus amarylifolius), a widely cultivated plant which has its aromatic leaves commonly used in Southeastern Asian cooking. The other plant, Seashore Pandan (Pandanus tectoris) is found in coastal and mangrove areas. Its leaves have been used in making mats, baskets and even grass skirts. Besides these two   plants, Hoary Palmer has also been observed to utilize at least two other Pandanus spp. in the Central Catchment reserve.  The caterpillars of the Hoary Palmer feed on leaves of the host plant, and live in shelters made either by joining two opposite edges of a  blade together with silk threads or by joining one edge of a cut segment to the blade.

Local Host plant #1: Pandanus amarylifolius (Pandan)

Local Host plant #2: Pandanus tectoris.

Leaf shelters of Hoary Palmer caterpillars found in the field.

The eggs are laid singly on either side of a leaf of the host plant.   The  hemispherical egg is in a medium brownish shade of red (when fresh). The micropylar sits atop in a darker patch. The egg is rather large with  a base diameter of about 2.1mm, and a height of about 1.5mm.

An egg of the Hoary Palmer.

A mature egg with the young caterpillar already nibbled away the polar part of the egg shell.

It takes about 7 days for the egg to fully mature. The egg is in light salmon colour at this stage.  The young caterpillar eats just enough of the shell to emerge, and will devour the rest of the egg shell after emergence. The newly hatched has a length of about 6mm. Its has a cylindrical body shape, very short dorso-lateral and sub-spiracular setae and a tuff of long setae at the posterior end. The body is creamy yellow with a prominent black collar on the dorsum of the prothorax. The head capsule is entirely black.

A newly hatched 1st instar caterpillar in the process of nibbling away its egg shell.

An early 1st instar caterpillar resting part way through the construction of its first leaf shelter.

The body color changes to pale yellowish green after a few feeding sessions on the leaf. The newly hatched constructs its leaf shelter soon after it is done with the egg shell. Between feedings on the nearby leaf lamina, the caterpillar retreats to its shelter for rest and security. 

Two views of a 1st instar caterpillar, late in this stage,length: 10mm.

One noteworthy  observation is that the caterpillars of Hoary Palmer, unlike most other skipper species which eject their frass pellets far away from their shelter,  have rather poor "toilet" discipline and do not seem to mind having frass pellets piling up in their shelter. By the time the caterpillar lies dormant in its shelter for the moult to the 2nd instar, its length has reached about 11mm. The 1st instar takes about 3.5 days to complete.

A 1st instar caterpillar resting it its leaf shelter between feeds. Note the collection of frass pellets in its shelter.

A 1st instar caterpillar in a dormant state prior to its moult, length: 10.5mm.

The 2nd instar caterpillar is pale yellow with a strong green undertone. A large black patch fully cover the anal plate.  The head capsule varies from  black to a dark shade of reddish brown.  The black collar is no longer present on the prothorax.  This instar lasts about 5-6 days with the body length reaching about  16-17mm.

Two views of a 2nd instar caterpillar, length: 11.5mm.

A 2nd instar caterpillar in a dormant state prior to its moult, length: 15.5mm.

The 3nd instar caterpillar resembles the 2nd instar caterpillar closely. One slight difference is on the anal plate where the black patch is somewhat smaller.  This instar lasts about 5-6 days with the body length reaching  23-24mm.

Two views of a 3rd instar caterpillar, length: 18mm.

A 3nd instar caterpillar in a dormant state prior to its moult, length: 23mm.

The 4th instar caterpillar again resembles the 3rd instar caterpillar closely. The black patch on the anal plate is slightly more constricted on its two sides. The head capsule is very dark reddish brown to black.   This penultimate instar lasts 6-7 days with the body length reaching up to 37-38mm.

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

A 4th instar caterpillar in a dormant state prior to the moult, length: 37mm.

The 5th (and final) instar caterpillar has one distinct difference from the earlier instars in the black patch on the anal plate: The patch is now much smaller within the plate and has a bi-lobed shape.  This instar takes about 10-12 days to complete with the body length reaching up to  55-60mm.

Two views of a 5th instar caterpillar, early in this stage, length: 39mm.

Two views of a 5th instar caterpillar, late in this instar, length: 55mm.

The head (left) and anal plate (right) of a 5th instar caterpillar.

Towards the end of the 5th instar, the body of the caterpillar shortens and its color  changes to yellow with a slight green wash. As it enters the pre-pupal phase within the leaf shelter, the caterpillar excretes  copious amount of white substance which can be found coating its body and lining  the inner wall of the shelter. It laboriously seals both ends of the shelter  with silk bands and layers of silk shields. The floor of the shelter  is also covered with a mat of silk threads. Finally the pre-pupa secures itself by a silk girdle around mid-body. As the pre-pupa purges its "stomach" content before it enters this dormant state, an egg-shaped fluid sac formed from the expelled fluid  can be found lying next to the pre-pupa. The sac is eventually broken by further purging action of other solid substance from the "stomach".

Two views of a pre-pupa of the Hoary Palmer.

An egg-shaped fluid sac in the pupation shelter.

The maize yellow  pupa  secures itself to the substrate with a cremastral attachment to the silk pad and the previously constructed silk girdle. It has a long abdomen  and two small reddish lateral markings on the prothorax. The sheath containing the developing proboscis is rather long and extends well beyond the posterior end of the abdomen.  Length of pupae: 30-34mm.

Two views of a pupa of the Hoary Palmer.

On the last day of the pupal period, the pupa becomes mostly   black. Yellowish/whitish  spots against a black background are now visible in the wing cases. The sheath holding the proboscis is now reddish, reflecting the colour of its content.  Finally, after about 12-13 days of pupal phase, eclosion takes place with the adult emerging from the pupal case.

Two views of a mature pupa of the Hoary Palmer.

A newly eclosed female Hoary Palmer.

  • [C&P4] 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 Henry Koh, Loke PF, Anthony Wong, Federick Ho, Khew SK  and Horace Tan