Life History of the Green Oakblue

Butterfly Biodata :
Genus : Arhopala Boisduval, 1832
Species : eumolphus Cramer, 1780
Subspecies : maxwelli Distant, 1885
Wingspan of Adult Butterfly : 45mm

Caterpillar Host Plant : to be identified.

Adult male Green Oakblue




Adult female Green Oakblue

Physical Description of Adult Butterfly : On the underside, the adult butterflies have the post-discal spot in space 4 of the forewing moved out of line with the spots above and below it; and on the hindwing the post-discal spot in space 6 is below the spot in space 7. The adults are tailed and moderately large. The male has a brassy green upperside with the forewing border decreasing in thickness from the tornus to the apex. In contrast, the female has a purple blue upperside, and on the forewing the border usually reaches the apex of the cell.

Field Observations of Butterfly Behaviour : This species is a forest denizen and the adult butterflies have been observed to fly in the vicinity of its host plant within the nature reserve areas of Singapore. Both sexes spend much time resting among foliage on the uppersides of leaves with wings closed. When disturbed they usually take off with a swift flight. In sunny weather, they can be spotted sunbathing on uppersides of leaves with both wings opened flat. This sunbathing behaviour has been observed to be a well-timed event taking place in the afternoon.

Early Stages :

The female oviposits on the underside of a mature leaf of the host plant. Each time a single egg is laid, but as the mature leaf is rather large, sometimes several eggs can be found (singly, not in a cluster) on the same leaf. The egg is small (about 0.5mm in diameter) and white in colour, circular with a slightly depressed micropylar area and a reticulated pattern of intersecting ridges.


Female Green Oakblue with abdomen curved to lay egg on the leaf underside.


Left : Fertile egg of the Green Oakblue ; Right : and Empty egg shell --- partially eaten

After about 2 days, the caterpillar hatches from the egg. As it makes its way out of the egg shell, the tiny young larva consumes the eggshell partially for its exit. As the caterpillar of all instars only eats the soft young leaves of the hostplant, the newly hatched has to move away from the mature leaf (where the egg was laid), and make its way to the younger leaves of the host plant. Upon arrival at the young leaves, the caterpillar nibbles away on the leaf surface, making tiny holes on the leaf and leaving a trail of frass behind it.


Left : The large (up to 30cm in length) and hardened mature leaves of the host plant where eggs are laid on the undersides by the female Green Oakblue. ; Right : Young shoot of host plant with soft leaves for caterpillars of Green Oakblue to chew on.

The caterpillars of all instars have a much flattened appearance and have a large, flattened, semicircular first thoracic segment . They construct loose leaf shelters to which they return for rest and for hiding when their feeding activity nearby is disturbed. Typically the caterpillars of all instars would rest next to the main rib of the growing leaf. The caterpillars also have a dorsal nectary organ and have been observed to be attended by ants of two species. On one site, the attending ants are of the Polyrachis species, but on another site, the attending ants are much smaller and species ID of which is yet to be determined. The Green Oakblue larvae have also been observed to be victimized by a parasitoid of Apanteles sp.

A 4th instar caterpillar being attended to by an ant of Polyrachis sp.

The 1st instar caterpillar is initially light yellowish with a tinge of beige. As it grows, it loses the beige tinge and becomes increasingly yellowish. It starts at about 1mm in length, and grows to about 3mm in 2 days before the moult to the 2nd instar.

The 2nd instar caterpillar is distinctly yellow in color and has a prominent whitish dorsal marking.

The 3rd instar caterpillar has a similar appearance to the 2nd instar caterpillar. Because of its larger size, the body markings are now more prominent. An ``hour-glass’’ mark on the anal segment is also visible now.

1st instar caterpillar on the young leaf next to the evidence of its feasting.

2nd instar caterpillar . More yellowish, more distinct dorsal marking.

3rd instar caterpillar showing more prominent body markings and the ``hour-glass’’ mark on the anal segment.

The 4th instar caterpillar is essentially similarly patterned as the 3rd instar, but it now takes on a light greenish and somewhat translucent appearance. The dorsal markings become distinctively fluorescent yellow in contrast..

4th instar caterpillar in its shallow leaf shelter

The 5th and final instar caterpillar is much bigger with increases in both body length and width. The ``hour-glass’’ mark on the anal segment is longer visible. Initially the caterpillar has a greenish colouration but slowly this gives way to a yellowish colouration as it matures and grows to a length of about 20-22mm.

Two 5th instar caterpillars, with the green one being earlier in growth.


An ill-fated 5th instar caterpillar with cocoons of a Apanteles sp. underneath it. The poor caterpillar eventually died hours later.

About 16 days after its hatching from the egg, the caterpillar ceases its feeding activity and its body color becomes reddish brown. At the same time its body length gradually becomes shorter. This lasts for about one day. The caterpillar then goes into a one and half day of pre-pupation pose within a loose leaf shelter. During this time, the caterpillar prepares for pupation by spinning a silk girdle and a silk pad to which it attaches itself via cremastral hooks.


The late 5th instar caterpillar is reddish brown and shrunk in length a day before pre-pupation.


The preparatory caterpillar hours before pupation. The silk girdle is already constructed.

The pupa has a shape typical of any lycaenid species, and a length of 14-16mm. It is light brown with a short dorsal stripe, and has a somewhat produced anal segment.

After about 10 days, the pupal shell turns transparent and the wings of the soon-to-be-emerging butterfly can be seen through the pupal shell. Eclosion takes place within the next 24 hours, typically one or two hours after dawn.


Two views of a pupa of the Green Oakblue.


All ready for eclosion. The upperside wing pattern of the adult butterfly can be seen through the now transparent pupal case.

An adult male Green Oakblue

Text by Horace Tan ; Photos by Horace Tan, Sunny Chir & Khew SK

Butterfly of the Month - January 2008

BUTTERFLY OF THE MONTH - JANUARY 2008
The Malayan Plum Judy (Abisara saturata kausambioides)

We start off the year 2008 with something auspicious and deep red - A small but nice maroon-coloured butterfly from the family Riodinidae. The species from this family are often referred to by their group common name of 'Metalmarks', probably due to the presence of silvery metallic-looking spots on the underside of the wings of some of the species in the family. The family is also characterised by a number of attractive and strikingly red and orange-red coloured species.

The forelegs of the Riodinidae are imperfect and brush-like in the males, but are usually functionally perfect in the females. The 'Metalmarks' are confined to deep shady forested areas where usually they flit around on low level leaves. A characteristic behaviour is that the species of this family tend to stop on the uppersides of leaves with half open wings, and twist and turn with jerky movements.

The upperside of the male of the Malayan Plum Judy, so named probably because of its deep plum-like colour, is deep crimson ; almost maroon, and unmarked. The underside is slightly paler, with a pair of diffused pale purplish post-discal bands and a series of black submarginal spots on the hindwings.

In the much paler female, the forewing has a diffuse white subapical patch, and the transverse lines on the underside are broader and paler than in the male. In both sexes the hindwing is stepped out, giving an appearance of a 'tail'.

In Singapore, the species is relatively widespread, having been found from the offshore islands of Pulau Ubin and Pulau Tekong, as well as many areas within the nature reserves as well as urban parks. However it is not common, and prefers to remain the shady understorey of forested areas, lurking in the undergrowth and at times, keeping still for long periods of time. Females are more often encountered than males. In Singapore, the species has been successfully bred on Shoebutton Ardisia - Ardisia elliptica (Myrsinaceae).

Early Stages of the Malayan Plum Judy (Abisara saturata kausambioides)

Text by Khew SK ; Photos by Khew SK & Sunny Chir ; Early Stages by Chan SC

Stalking and Shooting Butterflies - A Personal Perspective

Butterfly photography is a rewarding and satisfying hobby, and one can be out in the field for some exercise, fresh air and sunshine and at the same time, learn about photography and butterflies.

In this feature article, ButterflyCircle member, Sunny Chir shares his tips and secrets of how he is able to get those amazing and awesome shots of butterflies over the past two years of picking up this hobby.

Photographing Butterflies

Butterflies are beautiful creatures and they are my main subject in photography. Being skittish in nature, shooting them is not as easy as it appears. They are amongst the most difficult subjects to get close to in the wild in macro photography.

I have always been asked about my equipment setup and how to get close to them from beginners picking up this hobby. Here are some tips and tricks that I have learnt in the past 2 years and many hours of hard work and practice out in the field.

Stalking the Butterfly

In general, there are two broad categories of butterflies, the sun loving and the shade loving. So, depending on what you are stalking, choose your location accordingly. Some species of butterflies can also be very localised and found only within a small radius of their preferred habitat.

Knowing their host plants and nectaring plants before stalking will increase your chances of finding a particular species, so do a bit of research on what plants they lay their eggs on (host plants) and what types of flowers they feed on (nectaring plants). Concentrate your search at locations where such plants are abundant, and that will save you kilometers of footwork. The common flowering nectaring plants most butterflies feed on are Ixora, Lantana, Coat Button (Tridax procumbens), Snakeweed (Stachytarpeta indica) and Mile-a-minute (Mikania cordata) flowers. Some species feed on tree sap, seed pods and fermented fruits. Some species tend to stay in the vicinity of their preferred host and nectaring plants for days.

Puddling and sunbathing are behaviours exhibited by a number of species of butterflies. In certain families of butterflies only the males puddle, using their proboscis to extract mineral contents from damp spots on the ground. The mineral contents are stored as a “nuptial package” to be transferred to the female during mating. These puddling grounds are a bonanza for a photographer, for up to hundreds of butterflies may be seen at these spots during a feeding frenzy on some sunny days. Some species tends to congregate at certain spots and at a particular time, either to mate or to sunbathe themselves. For such species once you get to know their habits and timing, it becomes relatively easy to find them.

The best time to shoot butterflies is when they are pre-occupied in warming up their dew covered wings in the early morning, or when they are feeding or mating. In the wild, butterflies are sighted mainly when they are in flight, by their motion and contrast with the surrounding vegetation. In the cool morning hours, they tend to be more sluggish, as they are “solar powered” and need to warm up before taking flight. So, unless you have intimate knowledge of a particular species and its favourite hangout, finding a Lycaenid size butterfly amongst the foliage drying its wings is tough. To me, the best times to hunt for most butterflies are around 10am-12pm and 2-4 pm on sunny days when they are actively feeding.

Butterflies are sensitive to bright colours and objects, hence avoid bright coloured clothing. Wear drab or camouflaged clothing to avoid spooking them. In the field, scout around their host plants and nectaring plants, and use your peripheral vision as the surveillance mode to detect movement. Your peripheral vision will cover a wider angle and increase your probability of detecting movement within your field of view.

After detecting them, your eyes will automatically switch to tracking mode, following its flight path till it lands. All butterflies, and for that matter all insects, have their respective ‘circles of fear’ - a radius at which they will take flight when there is abrupt movement or intrusion. Do not be in a hurry to rush in for the shoot, as the butterfly will still be at very high alert state after being startled by your presence. Wait perhaps 10 -20 seconds, let it settle down and get used to your presence, before trying to approach closer for the shoot.

Think of how you want to frame the butterfly and select the angle of approach accordingly from a distance, with camera at chest level Approach the butterfly in a straight line slowly with minimum sideways movement that will alarm the butterfly. Avoid casting your shadow on the butterfly as it reacts instinctively to interpret a moving shadow as a potential predator attack.

Equipment Setup

If you have approached the butterfly without startling it off, set yourself up and let the equipment do most of the work. Spend more time working on your composition and background and this will improve your chances of keepers.

You have to be familiar with the equipment you use and employ them effectively. I use either a Canon 20D or 40D coupled to a Tamron 180mm macro lens and a Canon 580EX flash. The Tamron 180mm provides a longer working distance for shooting butterflies and it is legendary for being a sharp macro lens. The sweet spot of this lens is around f/8 to f/11. All my shots taken on the 20D or 40D are recorded in RAW format to provide the flexibility to post-process the images in Photoshop.

Even with the reach of the Tamron 180mm you are likely to be within the ‘circle of fear’ of most butterflies. With small butterflies, you will have to get closer to the subject to get the magnification you desire. At times, you might have problem finding small butterflies through your viewfinder while the lens is focusing. Just open both eyes and look at the subject using the other eye that is not glued to the view finder. The butterfly should appear approximately at the center of your view finder when the AF sensor snaps the image into focus.

Typically, you will have perhaps 1-4 sec to focus, compose and take your shots before it flies off. To me, there is no time to set up a tripod or fiddle with camera settings. For this reason, I preset my camera settings and shoot hand-held most of the time. I use high speed servo mode to increase my chances of having some keepers for the brief encounter. For rare species, it might be the only chance in your lifetime to get a shot. I only use a monopod when the vegetation and situation allow.

My camera is always set at ISO 400, AWB, AV mode, aperture at f/8-f/11 range and ready to shoot. I let the camera take care of the shutter speed and accept whatever shutter speed it computes. You can experiment with your camera and if the shutter speed is too low to prevent motion blur due to hand shake, increase the ISO until you have developed a more steady hand holding technique. With most of the fiddling out of the way, I concentrate on focusing, framing and getting a clean background for the shot. I use auto-focus most of the time, but when lighting is poor, I switch to manual focusing. In low light situations, I make adjustments to whatever f/ setting that is required to get proper exposure; which at times can result in shutter speeds as low as 1/30 sec, so a steady hand with correct breathing techniques helps.

To reduce handshake I hold the camera with arms close to the body, leaning on whatever available support nearby to stabilise myself. If the butterfly is at a lower level, I kneel down on one leg and half bend the other, rest my elbow on my half bent thigh and control my breathing when I squeeze the shutter. If all these are not enough, a higher ISO setting will be selected to increase the shutter speed. With some practice most photographers should be able to handhold at 1/120sec (using a 180mm lens) with a high keeper rate.

There will never be enough depth-of-field (DOF) in macro photography. One has to juggle between DOF, background, exposure and shutter speed to get the picture you can best produce under the given conditions. I try to help by maximizing the DOF by getting the camera sensor parallel to the butterfly as much as possible with my active AF point placed on the eyes of the butterfly.

I use the 580EX flash mainly as a fill-flash in "Rear sync", to bring out the finer details of the butterfly. Once the flash is on the camera and set to ETTL, rear sync mode (second curtain mode) I do not fiddle with it, and aim directly at the butterfly. With the "rear sync" mode set, after letting sufficient ambient light in, the camera and flash are intelligent enough to figure out what is the optimal power to bring out the details of the subject, so I do not try to outsmart or confuse it by adjusting or tilting the flash and use additional diffuser or Omibounce.

Knowing the theory is not good enough for any photographer - you will have to be able to do it through hands-on practice. Joining outings regularly organised by ButterflyCircle would be a great way to learn shooting in the field. At these outings, the experienced and friendly photographers in the group are always ready to help newbies into the hobby. Such outings are fun and relaxing for a weekend morning and well worth the time and effort, and much more effective in improving your skills than just reading about it on the Internet.

A convenient place for beginners to practice and shoot some butterflies is the Alexandra Hospital Butterfly Trail, where over 100 species of butterflies have been recorded so far. There will be at least 4-5 species of butterfly present at anytime during daylight hours to hone your skills.

Most of what I have written above is learned from fellow butterfly shooters and some from my own observations. I hope by sharing these observations, you can try them out and use some of them to improve your success rate of keepers in shooting butterflies

......otherwise, shoot and shoot and shoot till you succeed!

Cheers!

Text and Photos by Sunny Chir

A Christmas Exclusive - Singapore's own Painted Lady

A pretty American visitor comes to Singapore


A Painted Lady (Vanessa cardui) feeds on the flowers of the Mile-a-Minute (Mikania cordata) bush whilst visiting Singapore!

Some time late last year, when the migration of the birds was in full swing, as they flee the cold weather in the northern hemisphere for the warmer temperatures of the south, the Monarchs were also migrating via their usual and well-charted routes from Canada, to the USA and all the way down to South America.

A much smaller and lesser known migrant also made its way to warmer temperatures. The Painted Lady (Vanessa cardui) is described as "the most widespread of all butterflies" and having migratory habits which can rival those of the Monarch. It is one of the most widespread of all butterflies, found on every continent except Antarctica.

The Painted Lady is a pretty Nymphalid, with orange, black and whilte markings on the upperside, whilst the undersides feature a series of cryptic lines mottled with grey patches with submarginal ocelli and a wash of rose on the forewing. It is also known as the Thistle Butterfly or the Cosmopolite.

Its favourite host plant is the thistle (Asteraceae). The species is described to be abundant in the USA, and a website described that "Larvae were so common in the city of Orange (California) that in late April 1973, the city sprayed a vacant lot literally infested with the larvae. The spraying was in response to complaints by homeowners that the larvae were turning swimming pools black with their bodies, in addition to feeding on numerous ornamentals."

The Painted Lady Arrives in Singapore

Three of our ButterflyCircle members were fortunate enough to encounter two pristine specimens of the Painted Lady at different locations in Singapore. One was observed at one of our urban hill parks, whilst the other was spotted at an open wasteland in the north near one of Singapore's minor rivers.

Whilst definitely not as abundant as in its home country, the discovery of the Painted Lady in Singapore was not an unexpected surprise. It was a matter of time before one showed up here, given its reputation for being a renowned 'world traveller'. The two pristine specimens were spotted and photographed, before taking off to their next unknown destinations. How did they appear in Singapore? Were they bred specimens, inadvertently 'imported' with some goods from the west or brought back by some hobbyists?

We will never know. Nevertheless, it was still a pleasure for those of us who were lucky enough to make the encounter with this pretty Lady from the west. We hope she will visit sunny Singapore again soon!

Text by Khew SK ; Photos by Horace Tan, Richard Ong and Sunny Chir

References :

• Garden Butterflies of North America by Rick Mikula
• Field Guide to Butterflies - National Audobon Society by Robert Michael Pyle
• A Field Guide to the Butterflies of Eastern North America by Jeffrey Glassberg

Singapore's Sun-Loving Pansies - Part 2

Singapore's Sun-Loving Pansies
- Part 2

In Part 2 of this feature article of Singapore's Sun-Loving Pansies, we feature the remaining two - Grey Pansy and Peacock Pansy. Both these species are comparatively rarer than the Blue Pansy and Chocolate Pansy, but still can be found regularly in their favourite locations in Singapore.

The Grey Pansy (Junonia atlites atlites)

The Grey Pansy is the rarest of the four Pansies in Singapore. However, it appears quite seasonally, and in certain locations more than 3-4 individuals may be found. The butterfly is a pale grey above, with the undersides lighter. Both wings have dark brown irregular post discal and submarginal lines. The more prominent ocelli are orange crowned with black spots. The species is characterised by distinct wet and dry season forms where the underside markings are more pronounced and darker in the wet season, with the markings showing a tendency towards obsolescence in the dry season form.

The species flies with a flap-glide manner and on bright sunny days, it stops to rest on the upper surfaces of leaves with its wings opened flat. It tends to return repeatedly to its favourite perch after flying sorties to chase away any 'intruders' into its space.

The caterpillar is a dull black with white longitudinal stripes and feeds on a small-leaved host plant which can be found in water-logged areas. The known host plant is Hygrophila sp.

The Peacock Pansy (Junonia almana javana)

The Peacock Pansy is bright orange above with prominent white-eyed ocelli which may have given it its common name "Peacock". Both the forewings and the hindwings have a prominent ocelli each, with the one on the hindwings larger and coloured orange, black and white. The undersides are paler and the eye-spots are more lightly marked.

The species is relatively common, and can be found in parks, gardens as well as in the nature reserves. It is a fine-weather species, and tends to be more active in open grassy areas in bright sunshine. Like its other cousins in the Junonia genus, it adopts a flap-glide flying style and rests on its favourite perches with its wings opened flat. When the weather cools down, it stops with its wings folded upright and tries to camouflage itself amongst the grass and leaves.

The caterpillar is pale ochreous brown with black longitudinal stripes and has been bred on Ruellia repens. An interesting observation of ovipositing females of this species is that the females often lays her eggs on nearby plants instead of directly on its host plant. There was even an occasion when it laid an egg on a stone! However, the actual host plant is always nearby, and it is likely that the emerging caterpillar will be able to find the hostplant to eat, albeit having to crawl much further to reach the host plant than usual.

Text by Khew SK : Photos by Sunny Chir and Khew SK

Singapore's Sun-Loving Pansies - Part 1

Singapore's Sun-Loving Pansies
- Part 1



Singapore is home to four different Pansies - Blue Pansy, Chocolate Pansy, Grey Pansy and the Peacock Pansy. The four Pansy species belong to the genus Junonia (Hubner. 1819) which is characterised by their falcate forewings, brightly coloured uppersides and more sombre undersides.

The Junonia species are very susceptible to seasonal variation and often occur in both wet- and dry- season 'forms' In the latter, the underside has a cryptic pattern resembling a dead leaf and reduced ocelli.

The caterpillars of the Pansies tend to feed on species of Acanthaceae.

In Singapore, the four species can be considered common, perhaps with the exception of the Grey Pansy, which tends to be seasonally seen. Of the four, the Chocolate Pansy is by far the commonest species, occuring in the most varied habitats from urban grassland to forested areas of the nature reserves.

All four species tend to prefer open grassy areas and are most active in full sunshine. They also tend to be territorial, often returning to their favourite perches and chasing any other butterfly that comes within its 'circle of control'. They have a habit of frolicking with another individual of the same species, or engaging in aerial 'dog-fights' with each other.

The Blue Pansy (Junonia orithya wallacei)

The male of the Blue Pansy is considered the prettiest and most colourful of all the four Pansies. The forewing is black, with a whitish subapical band, post-discal ocelli. The hindwing is a bright blue with an orange-red subtornal ocellus. The female is more sombre, usually featuring only brown uppersides, and occasionaly sporting a reduced patch of blue on its hindwings as compared with the males. The females' hindwing ocelli are generally much larger than those of the males. The undersides are a pale greyish brown, with cryptic markings and ocelli.

The butterfly is common in parks, gardens and open grassy wasteland and flies in an able gliding fashion. It often stops with its wings open flat to sunbathe in the sunshine.

It has been bred on the very common and abundant secondary vegetation species of Acanthaceae, the Common Asystasia (Asystasia gangetica). It is highly likely that it has alternative host plants.

The Chocolate Pansy (Junonia hedonia ida)

The Chocolate Pansy is the most common species amongst the four Pansies. It is a reddish brown above and features a prominent row of post-discal spots on both wings. The undersides are a lighter brown, with pale purplish bands on both wings. The post-discal ocelli on the undersides are much lighter, more orange than reddish-brown ocelli on the uppersides. The median stripe on the underside of both wings gives it the butterfly a leaf-like appearance when it stops to rest amongst leaf litter, rendering it some measure of camouflage from predators.

The caterpillars have been bred on a dimunitive weed, Ruellia repens which is common in open fields and cultivated areas. It is also likely that the species has other alternative host plants.




Text by Khew SK ; Photos by Khew SK and Sunny Chir