Life History of the Malayan

Life History of the Malayan (Megisba malaya sikkima)

Butterfly Biodata:
Genus: Megisba Moore, 1881
Species: malaya Horsfield, 1828
Sub-species: sikkima Moore, 1884
Wingspan of Adult Butterfly: 21mm
Caterpillar Local Host Plants: Mallotus paniculatus (Euphorbiaceae, common name: Turn-In-The-Wind)

Physical Description of Adult Butterfly:
The Malayans are small butterflies. Above, both sexes are dark brown with a white discal patch which is more prominent in the female. The underside is white to dull grey. The forewing has a series of costal spots, one spot in the cell, a cell-end bar, a postdiscal curved series of transverse spots or short bars from costa to dorsum, a submarginal series of broader transverse spots and a thin anticiliary line. The hindwing has three spots near base in transverse order, a large prominent black spot near the apex, a cell-end bar, a broken postdiscal series of faint spots, and as in the forewing, a submarginal series of broad transverse spots and a thin anticiliary line. A pair of short tails is found at end of vein 2 in the hindwing. Elsewhere in the region these tails might be absent in some races, but the species found in Singapore has consistently been found to possess the tails.


One Malayan perching on a leaf in the nature reserve.


Another Malayan on another perch.

Field Observations of Butterfly Behaviour:
The Malayan was not recorded as being extant in Singapore by early researchers, and it was only discovered recently in surveys conducted during '90s. A casual look would easily have one mistaken it for the Common Hedge Blue (Acytolepis puspa lambi). The two species can be separated by checking the color of the upperside and the presence/absence of costal spots on the forewing underside. The adults of the Malayan have a weak erratic flight and can be found both the nature reserves and the Southern Ridges in wooded areas, particularly in the vicinity of its local host plant. The males have been observed to puddle on damp patches, animal dung and bird droppings.

Early Stages:

Mallotus paniculatus is a bushy tree with ovate and pointed leaves about 12-17cm long. The leaves are whitish to pale brown and thinly scurfy on the underside. Fruits are 3-lobed spiny, about 1-1.2cm wide, and are found on large panicles. This is a common tree found in waste lands, track sides in the nature reserves and the Southern Ridges. The early stages of the Malayan feed on the flower buds and flowers of this host plant.


Clusters of flower buds of Mallotus paniculatus.

Eggs of Malayan are laid singly at a flower bud, rachies or pedicel near the flower buds. The egg is small (about 0.4-0.5mm in diameter) and light green in colour, circular with a slightly depressed micropylar area and a reticulated pattern of intersecting ridges.


A mother butterfly laying her eggs at a cluster of flower buds of Mallotus paniculatus.


An egg of the Malayan laid among the flower buds, diameter: 0.4mm-0.5mm.

An egg of the Malayan: Freshly laid (left); Empty egg shell (right).

Three days later, hatching takes place after the young caterpillar has nibbled away sufficiently large upper portion of the egg shell to emerge. Measured at a length of about 0.8mm-0.9mm, its pale yellow body is cylindrical in shape, sporting long fine setae (hairs) and a dark head capsule.


A newly hatched caterpillar of the Malayan, length: 0.8mm

With the egg laid amongst or near the flower buds, the newly hatched has no problem finding its food supply. It works its way through the tomentous surface of the flower buds and bore into it for the goodies within. As it feeds and grows, it gradually takes on a pale brown base color with series of small pale yellow patches running sub-dorsally and spiracularly.


Two 1st instar caterpillars feeding on flower buds, length: 1.2mm

After about 3-4 days of growth and reaching a length of about 2mm, the caterpillar moults to the next instar. The 2nd instar caterpillar resembles the late 1st instar caterpillar in body color and markings, but the setae are now much shorter in proportion.


Two 2nd instar caterpillar, early in this stage, length: 1.8mm



2nd instar caterpillar, length: 2.5mm

The 2nd instar caterpillar reaches a length of about 4mm, and after about 4 days in this stage, it moults again. The 3rd instar caterpillar has proportionately shorter but still numerous body hairs. The sub-dorsal pale whitish patches run from the 2nd thoracic segment to the 6th abdominal segment, larger on the first twto segments. The dorsal nectary organ (on the 7th abdominal segment) is ringed in dark brown markings. This instar takes 3-4 days to complete with the body length reaching about 5.5-6mm.


3rd instar caterpillar, length: 4mm

3rd instar caterpillar, late in this stage, length: 5mm

The 4th (and final) instar caterpillar is more striking in general appearance as there are prominent white patches interleaved with smaller pale brown to green patches. There are numerous tiny "asterick"-shaped specks, of white, brown and green coloration, sited at the base of setae. These structures could serve as mechano-receptors or might be glandular in nature. At a larger scale, the typical lycaenid nectary organs (both the dorsal nectary organ on the 7th abdominal segment and tentacular organs on the 8th abdominal segment) are now easily spotted.

4th instar caterpillar, length: 7mm


4th instar caterpillar, length: 9.5mm


Left: Dorsal nectary organ (DNO) and tentacular organs (TOs) on posterior segments;
Right: Prothoracic shield and anterior segments

After 5 days of growth and reaching a maximum length of around 8.5-9.5mm in the final instar, the body of the caterpillar gradually shrinks, and takes on a pinky coloration. Soon the caterpillar seeks out a spot on the stem amongst the flower buds or the surface of an adjacent leaf to station itself. At this site, it enters the pre-pupatory phase where it readies itself for pupation by spinning a silk girdle and a silk pad. The caterpillar secures itself to the silk pad via claspers on its posterior end.


Two views of a pre-pupa of the Malayan.

Pupation takes place after one day of the pre-pupal stage. The pupa has the typical lycaenid shape. It is pale yellowish brown with a hint of pink. The surface is covered with a layer of short fine hair, and decorated with a few brown and black specks. Each pupa has a length of about 6.5-7.5mm.


Two views of a fresh pupa of the Malayan.

Five days later, the pupa becomes darkened in color signaling the imminent emergence of the adult. The next day the adult butterfly emerges from the mature pupa to begin the next phase of its life cycle.


Two views of a mature pupa of the Malayan.


A newly eclosed Malayan.


Another newly eclosed Malayan

References:

• The Butterflies of The Malay Peninsula, A.S. Corbet and H.M. Pendlebury, 4th Edition, Malayan Nature Society.

Text by Horace Tan, Photos by Sunny Chir, James Chia and Horace Tan

Butterfly of the Month - March 2009

Butterfly of the Month - March 2009
The Cruiser (Vindula dejone erotella)

The month of March usually heralds the beginning of the butterfly season in SouthEast Asia, which peaks in April & May. These are the few months of the year when the weather is generally hot and humid, and when butterflies are abundant in Malaysia, and to a lesser extent, in Singapore as well.

We feature a relatively common butterfly in Singapore - the Cruiser (Vindula dejone erotella). The species is very much a forest-dependent species, and is rarely, if ever, found in urban parks and gardens. A regular in the forested nature reserves of Singapore, the Cruiser is a relatively large Nymphalid belonging to the subfamily Heliconiinae. This species displays a classic example of sexual dimorphism, where the male and female of the species are distinctly different in appearance.

The male Cruiser is a rich fulvous orange above, and has a broad post-discal band of slightly paler colour on both wings. The band is broad at the forewing, and narrows almost to a point near the tornus of the hindwing. There are distinct black marginal and submarginal lines which give the wing a zig-zag appearance. There is a small orange apical spot on the forewing, and six black-centred ocelli on the hindwing, usually small in size. There is a short pointed tail at vein 4 of the hindwing. The undersides are lighter orange in colour.

The female is usually larger in size, but is coloured a pale greenish grey. The post-discal band is white. The hindwings have three pairs of orange-yellow black-centred ocelli which are large and distinct. There is a small white apical spot on the forewing. The tail at vein 4 of the hindwing is longer than that of the male.

The larval host plant is reported to be a species of Adenia (Passifloraceae) which is a vine with spring-like tendrils.

In the nature reserves, males are often found puddling on fermenting organic matter, carrion and at urine-tainted banks of streams. They may also be observed puddling at muddy footpaths. They are less skittish when puddling and can be observed of one approaches them slowly. Males are also fond of sunbathing with their wings opened flat but they are skittish when not feeding.

Females rarely puddle but can be found flying at great speeds high in amongst the treetop level. They are often seen perched on leaves at high level, with wings either opened flat or closed upright. Like the males, they are skittish, and take off quickly if they sense movement towards them. However, when they are encountered feeding on flowering plants, they are likely to be more cooperative for a closer observation.

A female Cruiser feeding on the flower of the Singapore Rhododendron (Melastoma malabathricum)

At public parks on the fringes of the nature reserves, both males and females have been observed together, feeding greedily on the flowers of Ixora and Lantana bushes. When feeding on flowers, they have a habit of opening and closing their wings regularly, and turning around.

A female Cruiser feeding on the flowers of Ixora sp.

The Cruiser is a sun-loving butterfly and is active on bright hot days, and is probably one of the first few butterflies that a beginner butterfly watcher is likely to encounter in Singapore's forested nature areas.

Text by Khew SK ; Photos by Khew SK

This blog article is dedicated to Tan Ben Jin, a veteran butterfly watcher and photographer, and a long-time friend and active supporter of ButterflyCircle.

Butterflies of the Singapore Botanic Gardens

Butterflies of the Singapore Botanic Gardens

Late last year, I had the honour of being invited to write an article about the butterflies of the Singapore Botanic Gardens in the SBG Newsletter - Gardenwise. This was the second time that I had written for the Gardenwise, the first time being in Volume 17 published in July 2001. Another article published after ButterflyCircle's "Butterflies Thru' the Lens" exhibition at the SBG Visitor Centre appeared in Volume 27 in July 2006.

So, after an eight year absence, the article Butterflies of the Singapore Botanic Gardens was published in Volume 32 Jan 2009 issue of Gardenwise.

The Gardens is one of my favourite sanctuaries when I need to get away from stressful situations at work, and a walk amongst the lush greenery and abundance of nature is very often a therapeutic stress-reliever. The Gardens hosts one of the largest collections of plants – both native and exotic, in Singapore. The bird life (see Gardenwise 30 (2008) 14-19) is healthy, with over a third of the total number of species seen in Singapore occurring here.

Amongst the plants and flowers of the Gardens, insect life is equally abundant. A casual observer will surely encounter a number of butterflies frolicking in the sunshine, busily feeding at flowers or just lurking around in the shaded understorey of the Rainforest at the Central Core of the Gardens.

This is the first attempt at compiling a checklist of butterflies of the Butterflies of the Singapore Botanic Gardens Gardens. Whilst there have been many observations and personal checklists made by enthusiasts and visiting experts, it would be ideal to maintain a repository of sightings, preferably with photographs. Over the years, I have kept a personal checklist of the butterflies that I’ve observed whenever I visit the Gardens, and also sightings made by other enthusiasts and observers, some of whom have kindly sent photographs of butterflies that they have encountered.
The list will, undoubtedly, keep growing as new species are found.

Butterflies can be rather choosy about their habitats, and being rather plant specific, many butterfly species are usually found more often in the vicinity of their caterpillar host plants. For example, the recent cultivation of Aristolochia acuminata and Passiflora foetida has brought in showy species like the Common Birdwing, Common Rose (and its subspecies, the Black Rose) as well as recent immigrants like the Leopard Lacewing and the Tawny Coster. The collection of Zingiberaceae and Palmae in the Gardens has attracted the skippers – Hesperiidae, of which a few species are rare and not often seen elsewhere. The caterpillars of the Hesperiidae create leaf shelters out of their host plants, and hence can often be easily spotted (and dispatched) by a sharp-eyed gardener who would consider these pests!

Two rare species which are noteworthy enough for special mention are the Orange Tail Awl (Bibasis sena uniformis) and the Blue Nawab (Polyura schreiber tisamenus). The former was a recent discovery for Singapore where it was found in the forested areas of the Central Catchment Reserves. Hence it came as a surprise to me when a small colony of caterpillars was found in the Gardens feeding on a common ‘wild’ shrub near the Tanglin Core. I have personally not seen an adult butterfly of this species in the Gardens, but upon breeding the caterpillars to adulthood, it was confirmed that the species is indeed the Orange Tail Awl.

The Blue Nawab is another curious resident of the Gardens. A rare species in Singapore, the caterpillar of this species was originally recorded on rambutan (Nephelium lappaceum) but subsequently recorded by ButterflyCircle members on the red saga (Adenanthera pavonina), a Bauhinia species (along the trellises near Les Amis Au Jardins), and on the exotic but common Australian wattle (Acacia auriculiformis). It has been sighted regularly in the Gardens, and some years ago I was having a meeting on the 2nd storey of one of the bungalows when a Blue Nawab decided to stop and rest on a tree branch just outside the window!

Another species to look out for is the Bamboo Tree Brown (Lethe europa malaya) which was spotted at the bamboo collection at the Bukit Timah Core. It is a rare species which is usually active only in the early hours and late hours of the day. A surprising find in the Gardens was the Courtesan (Euripus nyctelius euploeoides) of which a male was spotted some time back by Dr Ian Turner who emailed me a photo taken whilst on a routine walk around the Gardens. Even the parasitic plant Dendrophthoe pentandra which grows innocuously on its hosts’ branches way up in the treetops supports a number of beautiful butterfly species like the Painted Jezebel (Delias hyparete metarete), Green Baron (Euthalia adonia pinwilli) and a number of beautiful Hairstreaks like the Peacock Royal (Tajuria cippus maxentius).

The other species in the checklist are predominantly urban butterflies that are relatively common in Singapore, but nonetheless contribute life and variety to the Gardens. As butterflies are mobile and some species can fly long distances in search of both nectaring and caterpillar host plants, it is beyond doubt that more species will be added to the checklist as time goes by, adding to the biodiversity and colour of the Gardens.

Text by Khew SK ; Photos by Khew SK

Acknowledgments : Special thanks to Director/SBG - Dr Chin See Chung, and General Manager/SBG - Dr Wong Wei Har.

(This article appeared in the Feb 2009 Volume 32 of the Singapore Botanic Gardens Newsletter - Gardenwise on pages 18-20)

Download a PDF copy of Gardenwise here.

Butterfly Predators - Death in the Wind

Butterfly Predators - Death in the Wind

A Robberfly, a vicious and efficient killing machine, impales a No Brand Grass Yellow and perches with its prize kill whilst sucking the nutritious juices out of the paralysed butterfly

It is quite well-known that butterflies are harmless insects that do not bite, sting, scratch or cause any harm to other animals. They are therefore vulnerable to the wide variety of predators in the animal world. Whilst many butterfly species have adapted themselves with survival strategies (which will be the subject of a future blog article here), they are still susceptible to ending up in the stomachs of various birds, animals and insects which prey on them.

A pair of Chestnut Headed BeeEaters with one Jamides sp. captured

Most observers will notice butterflies fluttering around flowers, frolicking in the sunshine, feeding, mating and going about their usual daily activities. However, dangers always lurk where the butterflies don't realise... until it's too late. Predators adopt a whole range of tactics to capture the unsuspecting butterflies - stealth, speed, surprise, traps and so on.

A dragonfly captures a Lycaenid

A butterfly's life is therefore fraught with dangers as they go about their daily routine. In this article, we feature a range of predatory attacks on butterflies by various predators. It is never a pretty sight to see any victim of a predator in the animal world, and even though the death of a butterfly comes with much less blood and gore, it is still nevertheless a pitiful sight, as the poor butterfly struggles for its last breath of life in the jaws of its nemesis.

A dragonfly with a Lycaenid prey in its jaws

The first category of predators use a combination of speed and stealth. These predators - birds, dragonflies, mantises, lizards, robberflies and wasps tend to wait till the unsuspecting prey comes close enough for the predator to launch a high speed attack on the butterfly. Very often, these attacks are not necessarily successful, and the butterfly escapes with a part of its wings torn off, or in some cases, the predator misses altogether when the butterfly makes a last-minute maneuver to get out of harm's way.

A mantis rips the head off a Tawny Coster whilst chewing up the body

The next group of predators combine stealth with poison - e.g. the Crab Spider. These masters of camouflage are often seen hiding amongst flowers and waiting for a hapless butterfly to fly close enough to be grabbed and bitten. The poison of these spiders appear to act swiftly, immobilising the prey within a few seconds, and paralysing the butterfly quickly as the spider sucks the life out of it.

A Crab Spider holds on tightly to an immobilised Nigger


Another Crab Spider, well camouflaged amongst the flowers of Pseuderanthemum sp, with a dead Centaur OakBlue in its jaws

Predators which use entrapment - usually web-weaving spiders of various species, often trap the unsuspecting butterflies that fly into the sticky web and get themselves entangled. From field observations, the butterflies that get themselves into this life-ending situation are those that are old and weathered. The stronger butterflies often have a chance of flapping violently and we have seen many that have escaped the jaws of the spider in good time, before the spider can sink its fangs into the butterfly.

A Golden Orb Spider makes a meal out of a trapped Great Eggfly


A spider drags a paralysed Palm Bob to its lair

In the natural world, the weak and old are often fair game for most predators. Once a butterfly is old, tattered and flying erratically due to injury or old age, they become easy prey to various predators which help end their lives swiftly and viciously.

A wasp rips apart a dead butterfly

Whilst an adult butterfly's life is always subject to dangers from predators as it goes about its daily activities, its early stages are also vulnerable to a variety of parasitism, particularly at the egg, caterpillar and pupa stages . Parasitic wasps and flies can often wipe out an entire clutch of eggs and experts often estimate that, in the wild, anything between only 1-5% of all the eggs that a single female lays in her lifetime produces the next generation of adult butterflies. The majority of the rest will perish due to predation and parasitism.

Even caterpillars are not spared. Here, the caterpillar of a Mottled Emigrant falls prey to Kerengga ants (Oecophylla smaragdina)


A Commander caterpillar with parasites on its body

A caterpillar surrounded by the pupae of parasites

Whenever we encounter a pretty butterfly fluttering amongst flowers and we admire its beauty and grace, we should always be reminded that these 'flying jewels' of the insect world are always in danger of ending up dead in the jaws of a predator in the next few moments.

Indeed, one can always argue that the biggest 'predator' may also be Man himself, as the destruction of habitats and the spraying of pesticides often kill far more butterflies in all stages of their life histories than any other predator can. As we take stock of our biodiversity in Singapore, and as more species are threatened by a variety of causes, there should be a strategy for the conservation of habitats and sanctuaries for our butterfly fauna to survive for our future generations to enjoy.

Text by Khew SK ; Photos by Con Foley, Chan SC, Horace Tan, Marcus Chua, Michael Lim, John Lee, Henry Koh, Jason Ng & Khew SK