30 April 2010

Observation Notes on the Behaviour of Two Genera of Butterflies

Observation Notes on the Behaviour of Two Genera of Butterflies
Gandaca and Arhopala

For information regarding butterflies of the Malay Peninsula and Singapore, the book by Corbet & Pendlebury (revised by Col John Eliot) 4th Edition is still by far the most definitive work to date. Although updated in 1991 by Col Eliot, a large proportion of the information contained in the book dates from the early 60's to 70's which were taken from the 3rd Edition of the book - mostly still relevant. The book, aptly named "Butterflies of the Malay Peninsula" 4th Edition (which we refer to as C&P4) is published by the Malaysian Nature Society and is still in print and available at good nature bookstores.

The detailed write ups of many of the butterfly species, as well as overviews of the families, subfamilies, genera and so on, make the information valuable to students and enthusiasts of butterflies in Malaysia and Singapore. The colour plates in the book, taken by renowned photographer and collector, Bernard D'Abrera, add to the informative value of the book.

It is assumed that much of the anecdotal information and observations of butterfly behaviour were the result of the personal experiences in the field by the authors and Col Eliot. However, some of the observations are of contention today, as members of ButterflyCircle have recorded, time and again, of certain genera and species behaviour.

In this short article, we present ButterflyCircle members' field observation findings on two unrelated genera. The first is genus Gandaca. The genus is represented by only 1 species in the region - Gandaca harina distanti or commonly referred to by its English name of Tree Yellow.

The Tree Yellow (Gandaca harina distanti) - Field observations of feeding behaviour

In C&P4, the narrative of Gandaca harina distanti on page 100, reads "Although it is often found in the same localities as the Eurema species, it is a more shade-loving butterfly, and males are never found congregated at moist spots on the roadside or on the banks of streams." Unquote.

A group of puddling Tree Yellows

In our experience, this observation is rather curious, as the definitive word never found would suggest that earlier observations by the authors indicate in no uncertain terms, that this species does not engage in puddling activities, either singly or in groups. Our field observations suggest otherwise.

Photos by ButterflyCircle members show very clearly that the species does puddle (though only the males do) and on certain occasions, we have encountered up to no fewer than 8 individuals congregated at the banks of a reservoir within the nature reserves of Singapore. The species has also been found in the company of other Pieridae, in particular the Eurema spp. puddling at damp spots along footpaths and banks of streams.

We would therefore disagree with the description in C&P4 that the Tree Yellow are "never found congregated at moist spots" i.e. puddling.

The OakBlues (Arhopala spp) - Field observations of feeding behaviour

An Arhopala feeding at the flowers of a Palmae sp.

The genus Arhopala features one of the largest number of species of butterflies in the region. Featuring nearly 100 species, the many lookalike species in the genus presents a rather challenging situation for observers and in particular where field shots of species cannot be easily identified with certainty.

However, the subject of this blog article is not about the huge diversity of species in the genus. Again in C&P4 on page 268 in the overview description of Arhopala, the early authors made reference to the fact that "They (referring to the Arhopala) are rather unobstrusive in habit, do not visit flowers (nor, indeed, seem to feed at all, despite having a fully developed proboscis), and spend much time settled on the leaves of shrubs and bushes some 4 to 10 feet from the ground, whence they make only occasional short flights".

The issue here that we are opening for discussion, is that the authors have indicated, from their own field observations, that Arhopala do not visit flowers. The suggestion that they may not seem to feed at all, though not stated with a definitive certainty, implies that the authors may not have even seen the butterflies feeding, if at all, in their field observations.

An Arhopala feeding at the flowers of the Mile-A-Minute bush

Our own field observations indicated that species of Arhopala do indeed visit flowering plants, particularly those that are favoured by the Lycaenidae (and indeed seen in the company of other species on such flowering plants). There have also been observations that Arhopala in particular A. centaurus nakula, feeding on the ripened fruits of Melastoma malabathricum as well. There have also been further observations that species of Arhopala appear to be feeding on damp decomposing material e.g. possibly tree sap.

An Arhopala feeding off moisture from a leaf

However, the species in this genus are not often observed to feed, behaving as described generally by the authors in C&P4 - where the butterflies prefer to lurk in the shady recesses of heavily forested areas. Even so, we would like to categorically state that from field observations particularly in Singapore (and in one case shown here, an example from Koh Samui in Thailand), that Arhopalas do indeed feed, as well as visit flowers to feed.

An Arhopala feeding on moisture at the base of a tree

Our own observations, with photographic proof, indicate that the field observations on Gandaca harina and the Arhopala by the early authors, as presented in C&P4, are not necessarily accurate. However, these few isolated inaccuracies do not detract from the fact that C&P4 is still an amazing piece of work done on the butterflies of the region and remains one of the best reference books available to date.

Text by Khew SK ; Photos by James Chia, Leslie Day, Federick Ho, Khew SK, Loke PF, Ellen Tan & Horace Tan

24 April 2010

Life History of the Knight

Life History of the Knight (Lebadea martha parkeri)

Butterfly Biodata:
Genus: Lebadea C.&R. Felder, 1861
Species: martha Fabricius, 1787
Subspecies: parkeri Eliot, 1978
Wingspan of Adult Butterfly: 60mm

Caterpillar Host Plants: Ixora congesta (Rubiaceae), I. javanica (Rubiaceae) and one un-identified plant in the nature reserve.

A male Knight showing us its underside.

A sunbathing male Knight displaying its upperside.

Physical Description of Adult Butterfly:
The forewing is falcate at vein 6, and is long and narrow, more so in the male than in the female. The upperside is ochreous brown and marked with a rather complex pattern. A prominent white discal band is seen on the forewing for both sexes, and in male this band is more prominent and continues onto the hindwing where it tapers towards the tornus. The forewing has a series of white post-discal lunules in spaces 2-6, lying on the outer margin of the white discal band. The apical area of the forewing is strongly whitened in the male. As a characteristics of the subspecies parkeri, the distal part of the hindwing is broadly laved with varying extent of pale mauve.

A female Knight on a leaf perch showing us its upperside.

A newly eclosed female Knight giving a view of its underside.

Field Observations of Butterfly Behaviour:
This species is not uncommon in Singapore and has a rather wide distribution. Adults have been sighted at multiple locations such as areas within nature reserves, several urban parks and even outlying islands. In sunny weather, both sexes can be found flying in the vicinity of flowering shrubs and having energy intakes from nectar and ripened fruits.

A female Knight enjoying the ripened fruit of the Singapore Rhododendron.

Early Stages:
Thus far, two Ixora species and one un-identified plant in the catchment reserves have been identified as local host plants.

Host plant: Ixora sp. found in the Southern Ridges.

The unidentified host plant in the catchment reserve.

The mother lays an egg singly at the leaf tip on the host plant. The yellowish green egg is globular-shaped and has its surfaces marked with hexagonal pits and short spines at pit corners. The micropylar sits atop. Diameter of the egg is about 1.1-1.2mm.

A female Knight laying an egg on the tip of an Ixora leaf in the Southern Ridges.

Two views of an egg of the Knight. Diameter: about 1.1mm.

Two views of a mature egg of the Knight.

The egg takes about 3-4 days to hatch. The young caterpillar emerges by eating away the upper portion of the egg shell. The rest of the egg shell is typically consumed soon after. The newly hatched is about 2.5mm in length and has a cylindrical yellowish green body covered with many small tubercles and short setae. Tubercles running dorso-laterally and sub-spiracularly are larger in size and appear paler in coloration. The pale brown head capsule is round, relatively smooth and sporting a few short setae.

Two views of a newly hatched caterpillar of the Knight, length: 2.5mm.

Two views of a 1st instar caterpillar of the Knight. Length: 3mm.
Note the frass pallets stuck to its body surface.

The caterpillar feeds on the lamina in a rather systematic manner. At a short distance from the tip, it makes a cut on the lamina from the edge to the midrib, creating an isolated leaf fragment which it then dines on. Two to three such fragments can be present at one time. As existing leaf fragments are exhausted, new ones are made further away from the tip.

A view of the leaf tip where a 1st instar caterpillar had taken up residence.
Note cut-off leaf fragments, frass bundles and the intact midrib.

Frass pallets are gathered by Knight caterpillars to make rather large bundles near the receding edge of the feeding site. In particular, the first instar caterpillar has the habit of adhering frass pallets to its body, possibly for the purpose of enhancing its disguise/concealment when resting in close proximity to the frass bundles.

Two views of a 1st instar caterpillar of the Knight. Length: 5mm.

After reaching about 5.0mm in 3-4 days, the caterpillar moults to the 2nd instar. The body color of the 2nd instar caterpillar is pale brown with a yellow undertone. Besides tiny tubercles covering most of its body surface, the 2nd instar caterpillar also features short (but distinct) branched spines dorso-laterally and sub-spiracularly. A small lateral dark patch sitting atop a light patch can also be found below each dorso-lateral spine. The head capsule is dark brown and dotted with a small number of conical tubercles. This instar lasts about 3-4 days with the body length reaching 7-8mm.

Two views of a newly moulted 2nd instar caterpillar, length: 4.5mm

2nd instar caterpillar, late in this stage, length: 7mm

The 3rd instar caterpillar resembles the 2nd instar caterpillar but with noticeably longer dorso-lateral spines, with the pair on 3rd thoracic segment much longer than the rest., and the pair on the 8th abdominal segment moderately longer. Its head capsule is dark brown to black irorated with a few tubercles and short peripheral spines. A fine line beige to pale brown in coloration runs along the dorsum. Faint markings with diamond-shape outline appear dorsally with the one on the 2nd abdominal segment half marked in beige. This instar takes about 3-4 days to complete with body length reaching 11-12mm.

3nd instar caterpillar, early in this stage, length: 8.5mm

A 3rd instar Knight caterpillar found on its resident leaf on the unknown
host in the nature reserve.
Note the neatly cut leaf fragments.

Two views of 3rd instar caterpillar, late in this stage, ready for the moult to the 4 instar.

The 4th instar caterpillar resembles the 3rd instar caterpillar in most features. The various dorsal and lateral markings are now more strikingly presented with the body being dominated in black. The spines on the head capsule are now proportionately longer, and there are two whitish to yellowish line flanking the lateral halves of the head capsule. This instar lasts 3-5 days with body length reaching 17-18mm.

Two views of a newly moulted 4th instar caterpillar, length: 9mm.

Two views of 4th instar caterpillar, length: 10mm.

In the 5th (final) instar, the newly moulted caterpillar resembles the 4th instar caterpillar closely. The branched dorso-lateral spines are now very well developed on all body segments, and those on the 3rd thoracic and the 8th abdominal segment the longest and thickest.

Two views of a new moulted 5th instar caterpillar, length: 18mm.

In about a day, the body color soon changes drastically to yellowish brown on the anterior portion and dark brown to black in the posterior portion. The new appearance is dominated by two large lateral patches, in bright lime green, on the 2nd-4th abdominal segments. There is a large saddle mark, beige and meshed in appearance, nearly covering the entire 5th abdominal segment. Large markings oval to diamond in shape also appear on the dorsum with the one on the 2nd abdominal segment prominently colored in beige. The yellowish brown head capsule has much longer and pointed spines.

Two views of a 5th instar caterpillar, later in this stage, length: 31mm.

As with other members of the Limenities subgroup, when disturbed, the caterpillar adopts a characteristic posture with the anterior body arched and the head tucked beneath the thorax.

A 5th instar caterpillar adopting an on-guard stance when sensing the presence of an intruder.

A 5th instar caterpillar tending to its frass bundle.
Note an egg was mistakenly laid by a mother butterfly at the bundle.

The 5th instar lasts for 4-7 days, and the body length reaches up to 31-33mm. On the last day, the base body decolorizes rather dramatically. The lime green lateral patches changes to pink/beige, and the other pale markings become now almost whitish in appearance.

Two views of a 5th instar caterpillar preparing its pupation site, length: 32mm.
Note the color changes in various markings.

The caterpillar eventually ceases feeding and wanders around. It chooses a spot on the underside of a branch/stem and spins a silk pad from which it hangs vertically to take on the pre-pupatory pose.

A pre-pupatory larva of the Knight.

Pupation takes place a day later. The pupa suspends itself from the silk pad with no supporting silk girdle. It is almost entirely pale coffee brown in color with segments and parts outlined in a darker shade of brown. Pink to white patches also adorn the pupal surface at the head region. The abdominal segments are slender, and the thoracic portion being larger and expanded laterally. Dorsally, there are two short processes curved towards each other. Length of pupae: 23-24mm.

Three views of a pupa of the Knight.

After about 7 days of development, the pupal skin turns translucent as the development within the pupal case comes to an end. The markings on the forewing upperside also become discernible. The next day, the adult butterfly emerges from the pupal case.

Three views of a mature pupa of the Knight.

Newly eclosed adults drying wings on the pupal case.
Left: male; Right: female.

A newly eclosed male Knight. Note the narrower forewings.

A newly eclosed female Knight. Note the broader forewings.

  • The Butterflies of The Malay Peninsula, A.S. Corbet and H.M. Pendlebury, 4th Edition, The Malayan Nature Society.
  • Butterflies of Thailand, Pisuth Ek-Amnuay, 1st Edition, 2006.

Text by Horace Tan, Photos by Ellen Tan, Bobby Mun, Federick Ho, Sunny Chir and Horace Tan.

17 April 2010

Requiem for the Butterflies

Requiem for the Butterflies

A dead female Leopard Lacewing floats in a pond at a Butterfly Farm

As the controversy over the installation art piece featuring 109 pristine butterflies at the Singapore Art Museum begins to wane, but not forgotten, we would like to feature a final commentary with regard to the use of intentionally killed butterflies for the sake of art.

A torn and tattered Red Spotted Duke at a Butterfly Farm - and it's not even at the end of its life yet!

Much has been said and done by the members of ButterflyCircle to highlight to like-minded nature lovers regarding the repulsive display featured at the SAM. The feedback on the TODAY online news article reflects the number of people who had chastised the artist and also the Director of SAM who had cluelessly repeated what the artist had told him - that the butterflies were acquired from an insect farm and that "these were insects collected at the end of their lives..." - thereby justifying the use of "already dead" butterflies in the art piece.

Thus far, this blog has featured butterflies at their best - pristine, vibrant and healthy. Unfortunately, this is not how butterflies will look towards the end of their natural lifespan - usually on an average of 2 - 4 weeks. The butterflies - even those in flight cages at butterfly farms, would be tattered, faded, scales on their wings scratched off. Free-ranging butterflies would face even more perils as they are targets for predators and even if they get lucky, the daily wear and tear would make the butterfly look worn out and unlike the day it eclosed from its pupa.

For those who continue to believe or think that butterflies can repair their wings, or remain pristine throughout their natural lives, please take a little effort and check out the many sites and literature that describe the biology and physical attributes of butterflies - invertebrates with exoskeletons, and which do not grow in size nor able to rejuvenate its wings.

Once the butterfly ecloses from the pupa, it pumps fluids into its wings, which then harden before it makes its maiden flight. From here on, the daily wear and tear would continue and the wings will deteriorate, fade and become tattered as the butterfly goes about its daily business of feeding, finding a mate, ovipositing and fleeing from predators. It is battered by strong winds, heavy rainstorms, harsh sunshine, all of which will continue to take its toll on the pristine wings from the day it is 'born'.

Over a casual conversation, I was told that an associate who is with the museum/art circle continues to justify the art piece and even said that in her experience, she had seen "numbers of butterflies" that died in pristine condition - like those which were featured in the art piece.

I wish that these clueless individuals would stick to their area of expertise (whatever that may be) and not continue to spread their ignorance about butterflies to others. I am very sure that these individuals who cannot even tell the difference between a butterfly and a moth, would continue to believe that they are right. There is probably nothing that any lepidoptera expert nor community of nature enthusiasts like ButterflyCircle who have studied and observed butterflies - some of whom had been doing so for more than four decades, can do to change the closed minds of such individuals.

A quick check with the Director of a reputable butterfly farm in Malaysia yielded this comment : "Generally, we agree with you that they are not collected at the end of their life. There is no way they can repair the wings..." He added that "To conceptionalize butterflies by arranging pinned specimens on dinner plates, in bowls and wine glasses laid out on a dinner table is certainly DISGUSTING to many nature lovers".

Enough said. We do not have anything against the art pieces of the artist FX Harsono, particularly those that do not require the killing of any living thing to portray his message. None of us know the artist personally but it is hoped that this controversy would wake him up to the fact that what he has done is cruel, unethical and unacceptable in today's world of art. Perhaps the artist will carry on what he thinks is perfectly fine. What next then? An art piece with 200 pristine dragonflies that were "collected at the end of their lives"? 400 starfishes? 600 seahorses? 800 birds?

Such work like his "Bon Appetit" is not welcome in Singapore and definitely not amongst those of us who love nature and butterflies, and we are sure the work is not welcomed in other civilised countries in Asia either.

This blog article is accompanied by shots of butterflies that face their natural wear and tear in the course of their lives. Many have been shot at butterfly parks and farms. They have not yet lived their full natural lives, and are definitely not in the pristine condition that the Director of SAM and the artist FX Harsono believes them to be, when they drop dead at the end of their lives. The 109 butterflies in the art piece were definitely killed within a day or even shorter, after they eclosed from their pupa - never even given a chance to live - for the sake of art?

We are glad that Prof Tommy Koh, the Chairman of the National Heritage Board, responded positively and said to the ButterflyCircle member who cared enough to write to him - "You have, however, made an important point, and, going forward, I will request all our museums and curators to keep in mind the ethic that we should treat all animals with respect."

Food for thought? Bon Appetit !!

Text and Photos by Khew SK