27 September 2008

Butterfly of the Month - September 2008

BUTTERFLY OF THE MONTH - SEPTEMBER 2008
The Common BlueBottle (Graphium sarpedon luctatius)



The Common Bluebottle is a relatively common species that can be found in the forested areas of Singapore's nature reserves. It is fond of flying rapidly up and down open tracks in the nature reserves, almost reminescent of fast cars zooming along Singapore's expressways. As its preferred caterpillar host plant, Cinnamomum iners is commonly cultivated as a roadside tree along many of Singapore's streetscapes, the species has also been brought out into urban parks and gardens.




The species has a bluish-green macular band which runs from the apex of the forewing to the inner margin of the hindwing on both the upper and underside of the butterfly's wings. The hindwing has a series of blue submarginal spots on the hindwing on the upperside, and an additional red spotting on the underside of the hindwing. There is a red spot near the base of the hindwing on the underside as well.




The males of this species can often be found feeding on roadside seepages or urine-tainted sand in the company of other Graphiums species. Occasionally, more than eight butterflies can be found congregated on one spot, jostling for the best position to imbibe the dissolved nutrients and minerals from the source of liquid food. In flight, one normally catches a glimpse of its blue wings. Females are rarer, but often encountered when she tries to oviposit in areas where the host plants grow in abundance, or when feeding on flowering plants.




In some countries, this species is referred to as the Blue Triangle. Males and females are similar in appearance, except for the scent fold on the hindwing of the male. The wingspan of the Common Bluebottle is typically between 85-90mm.



An interesting observation of this species is that after a long session of puddling, the butterfly often flies off to a nearby perch and then stretches its wings out, as if to sunbathe.



Text by Khew SK ; Photos by Khew SK & Tan BJ

20 September 2008

The Life History of the Commander

Life History of the Commander (Moduza procris milonia)



Butterfly Biodata:
Genus: Moduza Moore 1881
Species: procris Cramer, 1777
Subspecies: milonia, Fruhstorfer, 1906
Wingspan of Adult Butterfly: 60mm
Local Host Plants:
Timonius wallichiana (Rubiaceae), various Uncaria spp. (Rubiaceae)


A Commander puddling on a forest trail


A Commander perching on a leaf in local nature reserves

Physical Description of Adult Butterfly:
Adults have smooth eyes, and strongly crenulated wing borders. Above, the dark reddish brown wings are traversed by a broad white macular band, starting from a large white spot in the cell on the forewing to near the mid-dorsum on the hindwing. Four subapical white spots are found on the forewing. Each hindwing has two series of black submarginal and postdiscal spots, and features an open cell. The underside is marked as above, but the basal halves of the wings are pale greenish grey in contrast to the orangy brown on the upperside.

Field Observations of Butterfly Behaviour:
Locally the sightings of the Commander are restricted to the various local nature reserves where it is not uncommon to find them flying along forest trails, in the neighborhood of streams, or puddling on the ground. Females can occasionally be spotted making oviposition visits to the various species of host plants. The adults are usually found singly, and they fly with a strong and determined flight.

Early Stages:
The first known detailed record of the early stages of the Commander was given by Morrell, R. in his 1948 article in the Malayan Nature Journal, based on his observations made while he was in Singapore. Host plants reported by him included Timonius wallichiana (Common name: Silver Timon) and various species of Uncaria. This is still the case today in our nature reserves where Silver Timon and up to four Uncaria spp. (yet to be properly identified) have been found to be utilized by early stages of the Commander. This current account of life history is based on two caterpillars reared from eggs on one Uncaria sp. (see picture on host plant #2).


Host plant #1: Timonius wallichiana



Host plant #2: an Uncaria sp.

Typically, the mother butterfly lays eggs singly at the leaf tip of the host plant, but on occasions where there are torn or eaten leaf edges, eggs could be laid at the false tip by the "misled" mom. Characteristic of the species in the Limentidini tribe, the eggs are somewhat globular in shape, with surface marked with hexagonal pits and bearing short spines at pit corners, giving them the appearance of minute sea-urchins. Each egg has a diameter of about 1mm, and about 1.1mm in height.


Eggs of the Commander laid at leaf edge (left), and leaf tip (right).


Two views of a mature egg of the Commander

The egg takes 3.5 days to hatch. The young caterpillar eats its way and proceeds to finish up the rest of the egg shell. The newly hatched is about 3mm long and
has a cylindrical dark greenish brown body covered with many small tubercles. The head capsule is orange in base color and speckled with dark brown patches. Normally, as the egg is laid at the leaf tip, the newly hatched will start feeding from the tip down the midrib of the leaf and eat its way symmetrically on both sides of the midrib, which is left projecting. At the tip of this exposed midrib, the caterpillar builds a frass chain (frass pellets strung together with silk threads). If hatched from an egg laid at a damaged edge, the newly hatched will simply start feeding from that edge, and builds its frass chain there as well.


Two Commander caterpillars which are only a few hours only,
both are on leaf tips with frass chain already constructed, Length: 3mm (top), 4mm (bottom)



1st instar caterpillar resting on the frass chain, length: 5mm

In addition to the frass chain at the tip of the midrib, the young caterpillar also constructs two rolls, one above and one below the surface of the leaf and at right angles to the the midrib, consisting of its own excrement, bits of leaf lamina and silk. The caterpillar usually rests at the exposed midrib near these two rolls. As the caterpillar grows in length and size, it also grows the rolls in tandem. The rolls have approximately the same length, thickness, colour and apparent texture as the caterpillar itself, making them two unpalatable dummies to discourage any prey. The caterpillar uses its head to push back the rolls as more and more of the leaf lamina is consumed. This system of feeding and building decoys will continue all the way to the penultimate instars.

After 3 days in the first instar and growing to a length of 6-6.5mm, the caterpillar moults to the next star. The 2nd instar caterpillar is brown with darker markings, and the body segments are armed with spiny and tasselled tubercles, of which those on the 2nd and 3rd thoracic segments are the longest. The dark bown head is armed with short and blunt spines. This instar lasts 3 days with the body length reaching 10mm.


2nd instar caterpillar, early in this stage, length: 5mm


2nd instar caterpillar resting against its decoy.

Compared to the earlier instar, the 3rd instar caterpillar has proportionally longer and prominently branched spines. The overall appearance of the caterpillar resembles a collection of its frass pellets in shades of brown and black, just like the two decoy dummies it builds in its proximity. Through all instars, as Morrell first described it, the caterpillar appears to be just "a mass of earthy particles held loosely together, and it moves by tumbling and shunting in a slightly shaky way with sudden stops and jerks". The 3rd instar lasts 3 days with the caterpillar reaching a length of 15-16mm.


3rd instar caterpillar, early in this stage, length: 9mm


3rd instar caterpillar, late in this stage, length: 14mm

The 4th instar caterpillar again has a similar appearance as in the previous instar except for the much longer and larger spines, particularly the two pairs on the 2nd and 3rd thoracic segments. This instar lasts 4 days with the length reaching 23-24mm prior to the next moult.


4th instar caterpillar, early in this stage, length: 16mm


4th instar caterpillar, late in this stage, length: 23mm

The next moult brings the caterpillar to its 5th and final instar. The extraordinarily branched and tessalled dorso-lateral spines are now much more projected and prominent on all body segments, the one on the 3rd thoracic semgnet being the longest. The head capsule is pale brown in base colour with black markings, and dotted with numerous dark pits. Fringed with black short spines, the head also has eight short and round orangy brown tubercles. All in, a head has a very fearsome appearance. When disturbed, the caterpillar adopts a characteristic kung-fu posture with the black quarters raised, anterior body arched and the head tucked beneath the thorax.


5th instar caterpillar, early in this stage, length: 24mm


5th instar caterpillar, late in this stage, length: 40mm


The head of a 5th instar Commander caterpillar.

The 5th instar caterpillar does not bother with the decoy construction process, and in the wild it will roam freely over the host plant. This instar lasts for 5-6 days, and the body length reaches up to 40mm. On the last day, the caterpillar ceases feeding and its body gradually shrinks. It wanders around the plant in seach of a pupation site. Eventually it settles down on a stem or branch where it spins a silk pad from which it hangs vertically to take on the pre-pupatory pose.


A pre-pupatory larva of the Commander

Pupation takes place a day later. The pupa suspends itself from the silk pad with no supporting silk girdle. When disturbed, the abdominal segments flex laterally, and could stay in that position for a period of time. It is almost entirely brown in color with segments and parts outlined in dark brown to black. The pupa has a pair of curved and broad cephalic horns. Overall, the pupa has the appearance of a "tightly rolled withered leaf" as Morrell described it. Length of pupae: 18-19mm.



A pupation sequence of the Commander


Three different views of a pupa of the Commander


Two views of a mature pupa of the Commander.

After 7 days of development, the pupa turns black in the wing pad area as the development within the pupal case comes to an end. The following day, soon after day break, the adult butterfly emerges from the pupal case.



A newly eclosed Commander drying its wings on its pupal case


A newly eclosed Commander showing its uppersides next to its pupal case


References:


  • Notes on the larvae of some common Malayan butterflies, Morrell, R., Malayan Nature Journal, vol.3, no.2, 1948, pages 1-6.

  • 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 and Photos by Horace Tan

13 September 2008

Book Review - The Book of Indian Butterflies by Isaac Kehimkar

Book Review : The Book of Indian Butterflies





Description : The Book of Indian Butterflies describes 735 species of butterflies that commonly occur in the Indian subcontinent. Most descriptions are illustrated with color images of specimens from the Bombay Natural History Society's collection as well as with color photographs of butterflies from across the country in their natural habitats. The book also includes color photographs showing the life history of different butterfly groups and their adaptation techniques.Besides highlighting the rich biodiversity of India's butterfly fauna, this book is a highly enjoyable guide for nature lovers. Isaac Kehimkar discusses the biology and identification of butterflies, as well as butterfly watching, photography, and rearing. Written by an expert in the field, The Book of Indian Butterflies is a comprehensive and updated guide to India's butterflies.

Product Details : 520 pages; 500 color photographs & color plates; 5-1/2 x 8-1/5; ISBN13: 978-0-19-569620-2ISBN10: 0-19-569620-4

About the Author : Isaac Kehimkar is an avid naturalist, keen photographer, and writer who regularly contributes photographs and articles to various nature publications. Currently working as General Manager, Programmes of the Bombay Natural History Society (BNHS), he is the joint editor of BNHS's quarterly natural history journal, Hornbill. Kehimkar is a Fulbright scholar and also is the referee for papers on butterflies that appear in the Journal of the BNHS.

Book Review : When Isaac wrote me an email some years back, asking me for some of my butterfly photos for the book that he was working on, I readily agreed, even though I sought some clarifications on the relevance of my photos, taken mainly in Singapore, for a book which featured Indian butterflies. Isaac mentioned that most of the Indian species would be virtually indistinguishable from their cousins in South East Asia.

It was a book worth waiting those long years, and I had almost forgotten about it when Isaac wrote to me again, inviting me to the launch of his 520-page labour of love on 5 Jun 2008 at Hornbill House by the Deputy Governor, Reserve Bank of India, Mrs Usha Thorat. Much as I would have loved to attend the launch of this book, which took Isaac almost 10 years in the making, unfortunately, I had to decline his invitation.

The book is basically organised into three main sections - the first dealing with information about butterflies, covering structure, life cycle, variation, behaviour, adaptations, migration and biogeography. These topics are adeptly handled by Isaac, and covers the topics in simple language, appropriately supported by illustrations and photographs. I found the section on biogeography interesting, as India, being such a large and diverse country has the entire spectrum of habitats in which butterflies are found - from coastal mangroves to the highland montane regions.

A section of the book also attempts to assist the amateur butterfly watcher with a "key" of sorts, separating butterflies into identifiers like size, colour and habitat. I did not find this section particularly useful, as it can only hope to narrow down observations to perhaps the genus level for some species.

The second section of the book, which covers the five families of butterflies - Hesperiidae (97), Papilionidae (71), Pieridae (66), Lycaenidae (194) and Nymphalidae (296), in that order, deals with 724 species (although the book mentions that 735 species that occur in the Indian subcontinent have been described). Perhaps the anomaly in the number of species featured was something that I may have overlooked in the book.


Each family is divided into two subsections, the first gives more detailed descriptions about each species, with important information like wingspan, status, distribution, habits & habitat and details of the adult butterfly. Not all species are accompanied with a photo, but in this section, all the photos feature live shots of the butterflies in their environment. The second subsection features plates of preserved specimens, taken from the Bombay Natural History Society collection.


The final part of the book covers environmentally contemporary issues of conservation, butterfly gardening and the study of butterflies in India. Two chapters deal with butterfly photography and watching.

Whilst the author has put in a decade of hard work into the book, how I wish that the photographs of the species were depicted in a larger size. As it is, the near-thumbnail size does not do enough justice to the beauty and detail of each species. Perhaps the text could have been somewhat summarised, but that is something that is often easier said than done, as Isaac's enthusiasm and knowledge obviously shows in the detail and information that he covers for each species.



All said and done, the Book of Indian Butterflies is a great piece of work by Isaac Kehimkar, and I would like to extend my heartiest congratulations to Isaac for a job excellently done!

Text by Khew SK : Photos of the book (c) Isaac Kehimkar.

06 September 2008

Life History of the Lance Sergeant

Life History of the Lance Sergeant (Athyma pravara helma)


Butterfly Biodata:
Genus: Athyma Westwood, 1850
Species: pravara Moore, 1858
Subspecies: helma, Fruhstorfer, 1906
Wingspan of Adult Butterfly: 60mm
Caterpillar Host Plants: Uncaria spp. (Rubiaceae)



A female Lance Sergeant checking out a leaf for oviposition


A Lance Sergeant puddling among leaf debris on a forest trail

Physical Description of Adult Butterfly:
Above, the Lance Sergeant is dark brown to black with an interrupted, white, macular and curved fascia running from mid-costa on the forewing to near the base of the dorsum on the hindwing. There are submarginal lines of white markings irrorated with dark scales on both wings, that on the hindwing taking the form of a broad band running from the apex to dorsum. Lance Sergeant can be distinguished easily from other similar Athyma species in that the cell-streak in the forewing is entire and clavate at its distal end. The underside is greyish brown with markings as on the upperside.

Field Observations of Butterfly Behaviour:
Locally the Lance Sergeant is uncommon. Sightings of adults have been confined to a few locations in the northern and western part of the Central Catchment Nature Reserves where its host plants, Uncaria spp. are growing. The adults fly with a strong swift flight. Individuals have been seen puddling on trails and at stream banks during past sightings.

Early Stages:
Species of Uncaria are climbers with opposite leaves and short petioles. They climb with the aid of a pair of cat-like claws which are modified lateral branches at the base of the leaves. For this reason, the South American U. tomentosa is called Uña de Gato (Cat's Claw). Some Uncaria species are medicinal plants in various parts of the world. Notably, one species, U. gambier, played an important part in Singapore's early history (and economy) prior to the introduction of Rubber.


Host plant #1: Uncaria sp.


Host plant #2: another Uncaria sp.


The "claws" on an Uncaria plant.


A female Lance Sergeant ovipositing on a leaf of the host plant.
Left: abdominal tip just touches the leaf tip; Right: egg laid at leaf tip.


The eggs of the Lance Sergeant are laid singly at the tip of a leaf on the host plant. In a behavior typical of Athyma spp. (and some other species), the mother butterfly first lands on the surface of the leaf, and with its head pointing towards the petiole, it reverses until its abdomen tip reaches the drip tip of the leaf, and there it lays an ovum. Damaged leaf edges, caused by other insects or even the feeding activity of an early caterpillar, could be mistaken as the leaf tip, with the result of an egg being laid there. Diameter of egg: about 0.8mm.


Eggs of Lance Sergeant at laid at leaf tips of the host plant.
Left: freshly laid; Right: mature egg. Diameter: 0.8mm.


The egg takes 3 days to hatch. The young caterpillar eats its way out of the mature egg, and then proceeds to finish up the rest of the egg shell. The newly hatched has a cylindrical dark greenish brown body covered with many small tubercles. The head capsule is orange in base color and speckled with dark brown patches.


Newly hatched Lance Sergeant caterpillar, length: 2mm

The 1st instar caterpillar feeds from the leaf tip and works its way towards the base on each side of the midrib, which is left protruding. At the tip of this exposed midrib, the young caterpillar also laboriously builds a frass chain which is made up of frass pellets strung together with silk thread. Between feeds, the caterpillar rests on either the exposed midrib or the frass chain. If disturbed when feeding on the nearby leaf lamina, it also makes a hasty beeline for this resting position. In later instars, the caterpillar tends to rest near where the protruding midrib joins the remaining lamina. At this site, it also attempts to disguise itself with a collection of frass pellets secured with silk on the lamina. After reaching about 5mm in about 3 days, the caterpillar moults to the 2nd instar.


1st instar caterpillar resting on the frass chain, length: 5mm

Besides the tiny tubercles covering most of its body surface, the 2nd instar caterpillar also features bigger and more prominent branched spines dorso-laterally and spiracularly. Black spots also line the basal part of the dorso-lateral spines. The head capsule is now brown to dark brown in coloration.
This instar lasts 3 days with the body length reaching 7mm.


2nd instar caterpillar, early in this stage, length: 5mm


2nd instar caterpillar resting on its frass chain

Compared to the earlier instar, the 3rd instar caterpillar has longer dorsolateral spines, with the pairs on thoracic segments particularly longer. Its head capsule is dark brown to black irorated with pale brown tubercles of both rounded and pointed shapes. Sub-spiracular white patches can be found on abdominal segments 2, 6-8, enveloping the short branched spines found there. This instar takes 3-4 days to complete with body length reaching about 12mm. On the last day of this instar, the dorsal band takes on a greenish tinge.


3rd instar caterpillar, early in this stage, length: 8mm


3rd instar caterpillar, late in this stage, length: 12mm


3rd instar caterpillar, dormant before the moult to the next instar.
Note the bulge behind the head capsule, this will become the new head.

The 4th instar caterpillar has a wide dorsal band which is briefly yellowish green at first but soon turns bright green for most part of this instar. The sub-spiracular white patches are now more prominent, and the dorso-lateral spines have grown further in length and changed to crimson red in color. The head capsule has two faint vertical pale stripes running vertically. This instar lasts 4 days with body length reaching about 16mm.


4th instar caterpillar, early in this stage, length: 10.5mm


4th instar caterpillar, length: 13.5mm

The next moult brings the caterpillar to its 5th and final instar. Now there is a drastic change in appearance. The branched dorso-lateral spines are now very well developed on all body segments, those on the meso- and metathorax being the longest. Newly moulted caterpillar has a broad green dorsal band and is dark yellowish green laterally, but soon the green on the dorsal band spread laterally giving the caterpillar an overall green appearance. The two white vertical stripes on the head capsule also become much more prominent in this instar. 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.


5th instar caterpillar, early in this stage, length: 16mm


5th instar caterpillar of Lance Sergeant

The 5th instar lasts for 6-8 days, and the body length reaches up to 29-31mm. On the last day, its body color changes dramatically. The color changes first to yellowish green and then pale brown. The caterpillar ceases feeding and wanders around for a pupating site which could either be a branch or a leaf surface. Once a suitable spot is found, the caterpillar spins a silk pad, and from which it hangs vertically to take on the pre-pupatory pose.


5th instar caterpillar, last day in this instar


5th instar caterpillar, a few hours before the dormant pre-pupal stage.


A pre-pupatory larva of Lance Sergeant

Pupation takes place a day later. The pupa suspends itself from the silk pad with no supporting silk girdle. When disturbed, the abdominal segments flex laterally, and could stay in that position for a period of time. It is almost entirely silverly-gold in color with segments and parts outlined in brown. The pupa has a pair of curved and pointed cephalic horns. The abdominal segments are slender, and the thoracic portion being larger and expanded laterally. Dorsally, there are two prominent processes curved towards each other. Length of pupae: 17-19mm.



Two different views of a pupa of the Lance Sergeant.


A pupa of the Lance Sergant: fresh pupa (left), mature pupa (right).

After 7 days of development, the pupa turns black in the wing pad area as the development within the pupal case comes to an end. The spots and streak on the forewing upperside are also discernible. The following day, soon after day break, the adult butterfly emerges from the pupal case.


An eclosion sequence of a Lance Sergeant


A newly eclosed Lance Sergeant


Another newly eclosed Lance Sergeant, showing us the undersides.

References:
  • The Butterflies of The Malay Peninsula, A.S. Corbet and H.M. Pendlebury, 4th Edition, Malayan Nature Society.
  • The Butterflies of Hong Kong, M. Bascombe, G. Johnston, F. Bascombe, Princeton University Press 1999
Text and Photos by Horace Tan