Butterfly of the Month - July 2010

Butterfly of the Month - July 2010
Horsfield's Baron (Tanaecia iapis puseda)

The month of July is famous in that it is the only month of the year that was first named after a human being - Julius Caesar in 46 BC. The month has 31 days, and in the northern hemisphere, it is usually the peak of the summer months and is the hottest month of the year.

However, in Singapore, like in 2009, the weather has been rather wet - exceptionally wet actually, where floods occurred persistently following some of the wettest days on record. It had some residents up in arms when flood waters inundated their homes and commercial premises more than once during the month! A symptom of global warming and climate change? We'll have to wait and see. In the meantime, park your cars on high ground!

If the first of July be rainy weather,

It will rain, more or less, for four weeks together.

Source: English Proverb

Despite the rainy weather, our butterfly friends continue to thrive. A moment's respite from the bad weather will see our winged jewels up and about, feeding hungrily at flowers and other sources of food.

This month, we feature the sexually dimorphic species, the Horsfield's Baron (Tanaecia iapis puseda). This species prefers the sanctuary of the forested areas in Singapore, although they are sometimes found in public parks and gardens. Males are more often seen than females. The male of this species exhibits 'territorial' behaviour, where it perches on a few favourite locations and dives to chase away any intruders into its space - even a stone thrown into its domain of supervision will be similarly chased away!

The male Horsfield Baron is a rich velvety black above with a broad bright blue marginal border on the hindwing and reaching the tornal area of the forewing. The underside is a pale buff with light brown markings.

The female is a pale ochreous brown resembling the Malay Viscount. The submarginal “V” shaped markings are less distinct than those of the associated species. In some individuals, light blue washes can be more distinct on the wings, especially on the white areas of the wings.

The male Horsfield Baron has a flap-glide flight and is skittish and alert to movements. Often, individuals are encountered where they return persistently to a few favourite perches time and again, even after being disturbed. It appears to prefer stopping to rest with its wings opened flat rather than with its wings closed upright. Very rarely, males have also been observed to puddle at roadside seepages.

A male Horsfield's Baron puddling at a roadside seepage

The female, on the other hand, is usually found flying amongst shrubbery and particularly its preferred caterpillar host plant - the Singapore Rhododendron (Melastoma malabathricum). The female is more often found feeding on flowering plants, rotting fruit and the ripened fruit pods of the Singapore Rhododendron.

The caterpillar is unique in appearance, with its 'spiky' processes making it appear much larger and sinister than it really is. It is actually quite harmless.

Where the species is found, sometimes several individuals are encountered. Whilst it cannot be said to be common, the Horsfield's Baron makes a regular appearance in many parts of the nature reserves and even in public parks and gardens.

Text by Khew SK ; Photos by James Chia, Sunny Chir, Federick Ho, Khew SK, Koh Cher Hern & Sum CM

Life History of the Anderson's Grass Yellow

Life History of the Anderson's Grass Yellow (Eurema andersonii andersonii)

Butterfly Biodata:
Genus: Eurema Hübner, 1819
Species: andersonii Moore, 1886
Subspecies: andersonii Moore, 1886
Wingspan of Adult Butterfly: 40mm
Caterpillar Local Host Plant: One plant found in the Central Catchment Area (species ID to be determined). [21 July 2012: Plant identified as Ventilago maingayi; another host plant Ventilago malaccensis also recently recorded.]


An Anderson's Grass Yellow perching on a fern frond.

Physical Description of Adult Butterfly:
Above, the wings are lemon-yellow with the hindwing having a thin black border and the forewing having a thick black border which is deeply excavated between veins 2 and 4, but not more deeply excavated in space 2 than in space 3. The inner edge of the black border in spaces 1a and 1b inclined slightly towards the tornus. Underneath, the wings are yellow with several rusty brown spots. There is no spot at the base of space 7 on the hindwing, but a single spot is present in the forewing cell. Usually, a rather broad dark subapical stripe can be seen in the forewing. Males have an elongate patch (the brand) lying along the cubital vein on the forewing.

An Anderson's Grass Yellow having its mineral intake on a damp patch.


An Anderson's Grass Yellow perching on a grass blade.

Field Observations of Butterfly Behaviour: Anderson's Grass Yellow is not as commonly seen as its close cousin, Common Grass Yellow, (Eurema hecabe contubernalis) as it is mainly a forest denizen with sightings restricted to the Central Catchment Area (CCA). Where its host plant thrives within CCA, Anderson's Grass Yellow can be sighted with relative ease. Typically on a sunny day, adults can be seen fluttering along forest trials, visiting flowers, puddling on wet grounds and making oviposition visits to its host plant.


An Anderson's Grass Yellow taking nectar from flowers of mile-a-minute weed.


Another puddiling Anderson's Grass Yellow deep in the nature reserve.

Early Stages:
The host plant grows in relative abundance in certain areas within CCA. It appears to be a liana which has young leaves in dark to reddish brown, but turning green when they mature. The early stages of the Anderson's Grass Yellow feed on relatively young leaves of this host plant. Noteworthy is that the same plant is also utilized by early stages of the Tree Yellow (Gandaca harina distanti).

The host plant of Anderson's Grass Yellow with young leaves shown.

The eggs of the Anderson's Grass Yellow are laid singly on the surface of a young leaf of the host plant. The long spindle shaped egg is laid standing at one end with a length of about 1.1-1.2mm. It is creamy white in color and has many fine vertical ridges and numerous indistinct and intermittent horizontal ridge lines. The micropylar sits at the tip of the standing egg.

An egg of the Anderson's Grass Yellow sighted on a young leaf within the nature reserve.

A close-up view of an egg of the Anderson's Grass Yellow.

The egg takes about 2-3 days to hatch with the newly hatched eating away part of the egg shell to emerge. Measuring about 1.8-1.9mm in lenght, the newly hatched sports a creamy white head capsule and a cylindrical and pale whitish body covered with rows of tubercles running lengthwise. Each tubercle has a setae emerging from the middle of it. The two rows of tubercles flanking the dorsal line are much larger but with shorter setae than the rest. A miniscule droplet of fluid can be found at the tip of some of the setae.

A newly hatched caterpillar of the Anderson's Grass Yellow, length: 1.9mm.

The newly hatched has the rest of the empty egg shell as its first meal before moving on to eat the lamina of the young leaf. The body and the head become more yellowish as the caterpillar feeds and grows. The body also assumes a strong green undertone as the caterpillar grows to a length of about 4mm in about 2-2.5 days for this instar.

Two view of a 1st instar caterpillar, length 2.7mm.

The 2nd instar caterpillar have numerous setae-bearing tubercles on its body with the length of the setae proportionately shorter than in the first instar. The head capsule is yellowish green and sporting a few rather fine setae. This instar lasts about 2-3 days with the body length reaching 8mm.

Two view of a 2nd instar caterpillar, early in this stage, length: 3.5mm


Two late 2nd Instar caterpillars, moments before their respective moult to the next instar.

The 3rd instar caterpillar has a yellowish green body with a similarly-coloured head capsule. Its numerous setae are proportionately shorter compared to the previous instar. A closer scrutiny reveals that the body is essentially yellow in base colour, and each body segment has up to 6 rings of small tubercles which are green to dark green in colour. Typically each tubercle has one short and fine setae protruding from it, and the end of each setae has one tiny fluid droplet. A white lateral band is seen on either side of the body, rather faint at this stage. This instar takes about 1.5-2.0 days to complete with body length reaching about 11-12mm.

Two views of 3rd instar caterpillar, early in this stage, length: 7.5mm


A very late 3rd instar caterpillar, soon to moult to the 4th instar.

The appearance of the 4th instar caterpillar is little changed from the 3rd instar. The lateral whitish bands are broader and thus more prominent. This instar lasts 1.5-2.0 days with body length reaching about 18mm.

Two views of a 4th instar caterpillar resting on the midrib of a young leaf, early in this stage, length: 9.5mm.


A 4th instar caterpillar, late in thie stage, length: 18mm

The 5th and final instar caterpillar resembles the 4th instar caterpillar closely. The one visible change is in the lateral white bands which have become prominent and well defined in their outlines. The 5th instar lasts for 3-4 days, and the body length reaches up to 29mm.

Two views of a 5th instar caterpillar, length: 25mm.

A 5th instar caterpillar, length: 27mm.

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 underside of a stem/stalk on the host plant. Here the caterpillar spins a silk pad and a silk girdle, with which the caterpillar soon become immobile in its pre-pupatory pose.

A pre-pupatory larva of the Anderson's Grass Yellow on a stem of the host plant.

Pupation takes place about 0.5 day later. The pupa secures itself with the same silk girdle as in the pre-pupal stage, but with cremaster replacing claspers in attaching the posterior end to the silk pad on the stem, The yellowish green pupa has a pointed head, a slight dorsal protrusion, and a large wing case tapering into a keel. A pale brown dorsal band, rather broad in width, runs from the anterior to the posterior end. A pale brown line also runs laterally on each side from the thorax to the posterior end. Length of pupae: 17mm.

Two views of a pupa of the Anderson's Grass Yellow.

Close-up on the cremastral attachment to the silk pad on the substrate.
The attachment is achieved through brown hooks on the cremaster catching the mesh of silk threads.


Two views of a mature pupa of the Anderson's Grass Yellow.
The now transparent wing pad show s the yellow forewing upperside with its black border.

After about days 5.5-6.0 days of development, the pupal skin turns translucent as the development within the pupal case comes to an end. The yellow coloration and back borders on the forewing upperside are now discernible. The following day, the adult butterfly emerges from the pupa.

A newly eclosed Anderson's Grass Yellow drying its wings near its pupal case.

References:

• 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 Simon Sng, Federick Ho, Khew SK and Horace Tan

Butterfly Bunkers

Butterfly Bunkers

An Outing to Bunker Trail, Panti Forest Reserve, Johor

Just as there are swanky restaurants of shooting sites for the upper-crust photographer connoisseur, complete with Peruvian adventures, difficult terrains and stories to tell the grandchildren, there are also the quick fast food getaways into the nearest rainforest just 90 minutes away from the bustling concrete city to get that much needed Nature’s quick fix.

A quick pit-stop at the famous Johor "bah kut teh" roadside stall for breakfast, four hungry Singapoeans tuck in to a delectable concoction of pork ribs stewed in a secret herbal recipe.

Bunker Trail, located on the eastern boundary of Panti Forest, is no macro photographer’s best kept secret. The site is famous to bird watchers and bird photographers. The forest reserve is regarded by many ornithologists and bird enthusiasts as one of Malaysia’s important bird habitats.

The area around Bunker Trail suffered significant habitat damage in the last few decades to make way for oil palm plantations, sand quarrying, logging and other nature-unfriendly activities, leaving only limited patches of the original forested areas, that, surprisingly is still rich with biodiversity.

Coming off the main road to Mersing, at milestone #167, there are remnants of two WWII bunkers, presumably used by the military as armoured outposts during the Japanese occupation. The much-delayed opening of the Bunker Trail by the Johor administration is still outstanding, even as the visitor centre and ranger stations have been completed.

Upon reaching "base camp" at around the 8 km mark from the main road, where there is a shaded forest clearing often used by the Malaysian Armed Forces during training exercises, four impatient ButterflyCircle members jumped out of the car fully armed with their latest in digital photography technology.

Stepping off excitedly into the forested trails, it was hard to ignore the huge numbers of Jamides and Arhopalas. Both these genera of butterflies are equally difficult to distinguish and accurately identify. The combination of their numbers, erratic flight and characteristically flighty behaviour resulted in a nasty game of needing to be fast and stealthy enough to snipe a shot at one Arhopala before a Jamides haphazarded into it, sending both off into a drunken uncoordinated dance further into the foliage.

Thanks to the good concentration of birds and their droppings, this Sky Blue (Jamides caeruleus caeruleus) was fascinated enough to stay put for its mug shot.

Photographing butterflies at Bunker Trial on this particular day in June turned out to be nothing short of an adult version of child’s play, complete with the luxury of a harmonious orchestra of bird singing in the background and no leeches.

The concentration of such a large number of species of butterflies and insects in such a small place resulted in every bush yielding a different subject at every interval of the chase. It was literally the butterfly Paris fashion show in suburban middle class Cologne with none of the budget cuts on show, variety and Lepidotera equivalent of big names in the fashion industry.



Shortly after the elusive the Wanderer (Pareronia valeria lutescens) landed and graced a few shots, the rare Yellow Bodied Clubtail (Atrophaneura neptunus neptunus) appeared, looking for a host plant.

Seemingly absorbed in finding a choice home to lay her precious eggs, the Clubtail ignored the frantic shuttering and flashing of 3 photographers as it circled the bush a few times, lilting up and down with unflustered indecision.

Lunch time in the forest, and the butterflies get a reprieve!

The turnover on each “catwalk” was so intense, the fashion photographers had to eat in the field next to their subjects. I survived on nothing but redbull as I had no appetite for salty noodles in the forest.

There were a good number of Royal Assyrians hopping around all over the place and dodging under leaves.

There were even a couple of Plushes chasing a Witch that was hiding in the bushes.

We shot from 9:30a.m. to 4p.m. and to top off the already great day, Cher Hern spotted a pair of mating Green Imperials (Manto hypoleuca terana) which stayed long enough for all of us to get our fill of shots.

Bunker Trail truly is choice beef hugged in healthy wheat burger buns slapped into a fast food wrap. You get everything you could shoot in 2 days in just 1 day and you don’t even need to stay the night.

Ellen contemplating if that hole in the ground is big enough for her needs

Just be prepared to dig a hole if you need to do the “big one” and bathe naked with melted ice water from the cooler box under a tree in full view of the laughing monkeys because Bunker Trail has only one toilet facility… and it’s all locked up.

Text by Ellen Tan : Photos by Sunny Chir, Koh Cher Hern, Nelson Ong and Ellen Tan