Life History of the Green Baron

Life History of the Green Baron (Euthalia adonia pinwilli)



Butterfly Biodata:
Genus: Euthalia Hübner, 1819
Species: adonia Cramer, 1779
Subspecies: pinwilli Pendlebury & Corbet, 1938
Wingspan of Adult Butterfly: 60mm
Caterpillar Host Plants: Dendropthoe pentandra (Loranthaceae)


A male Green Baron sunbathing in an urban park


A female Green Baron found puddling on a wasteland in the vicinity of a hill park


Another female Green Baron on a high perch in the nature reserve

Physical Description of Adult Butterfly:
The Green Baron is instantly recognisable by their greenish colour and red potting. Male upperside is greenish-brown and the forewing cell has one white spot. The white spot in space 3 is in line with the post-discal spots in spaces 4, 5 and 6; sub-apical white spots in spaces 4, 5 and 6 are not in line, that in 6 shifted in. Male upperside hindwing has a subterminal series of black spots, with the anterior three and the tornal spot outwardly crimson. Female upperside forewing has much larger white sub-apical and post-discal spots than the male's, with the post-discal spots very large and irregular in shapes. Female upperside hindwing has a similar sub-terminal series of spots as the male, and a very broad white discal band.

Field Observations of Butterfly Behaviour:
The Green Baron is a relatively rare species in Singapore and is not often encountered. Typically, adults are sighted and more readily photographed when they descend from their tree-level perch to feed on the blooms of flowering plants like the Singapore Rhododenron, Ixora and Lantana, both in urban packs and in the nature reserves. Both sexes have also been sighted puddling on wet ground on some occasions. The colourful adults are robust, alert and rapid fliers.

Early Stages:
The host plant is a parasitic plant which grows on mature trees in various parts of Singapore. This mistletoe is rather common in urban parks, gardens, housing estates and on trees planted by the roadside. Besides Green Baron, its leaves are also utilized by early stages of Painted Jezebel (Delias hyparete metarete), Great Imperial (Jacoona anasuja anasuja) and Peacock Royal (Tajuria cippus maxentius), and likely a few other lycaenidae species. Whilst caterpillars of Painted Jezebel and Peacock Royal feed solely on the relatively young tender leaves, those of the Green Baron prefer the thicker and harder mature leaves.


Host plant : Dendropthoe pentandra on an Asoka tree

The eggs are laid singly, usually on the uppersides of mature leaves of the host plant. The brown egg is dome-like in shape with a wide bulging base, about 2mm in diameter. The surface is covered with large hexagonal depressions the corners of which have with yellowish hair-like protuberances emerging.

An egg of the Green Baron

After about 3-4 days, the 1st instar caterpillar emerges, eating the eggshell as its first meal. It then proceeds to feed on the leaf lamina by eating along the edge. The caterpillar is yellow in body colour, has a black head and sports ten pairs of short dorso-lateral protuberances complete with long setae. It grows from an initial length of about 3.5mm to 7mm in three days. The subsequent moult takes it to the 2nd instar.


Newly hatched 1st instar caterpillar, length: 3.5mm.
Note the remnant of the egg shell (the circular mark) to the upper right of the caterpillar.


1st instar caterpillar, length: 6mm

The body of the 2nd instar caterpillar is predominantly greenish yellow dotted with small white spots. The head has changed to light brown in color and featured quite a few short setae. The ten pairs of short protuberances seen in the 1st instar have lengthened considerably. Projected horizontally with numerous branched spines and almost always pressed to the leaf surface, these protuberances not only give the caterpillar a very unique shape but also serve to break up the shape and shadow of the body. When resting on the mid-rib of the leaf, the branched spines give the caterpillar some measure of camouflage from predators. The middle section and the tip portion of each protuberance are colored dark brown to black. The 2nd instar lasts for three days with the body length reaching about 11mm before the moult to the 3rd instar.


2nd instar caterpillar of the Green Baron with its branches spines, length: 7.5mm

The 3rd instar caterpillar is similar in appearance to the 2nd instar, but the spines have grown much longer. The branched spines appear almost like a bird's feather, with the secondary spines arranged neatly and nearly perpendicular to the main spine. The body color is predominantly pale green and the head is light brown. Large and prominent dark brown dorsal spots appearing on the anterior part of the first two thoracic segments, the first two abdominal segments, and abdominal segments 4, 5 6 and 7. The two dorsal spots on the first two abdominal segments are connected with a dark brown patch sporting small white dots. The 3rd instar lasts for 3 days and reaches a length of 16mm before the next moult.

3rd instar caterpillar, length: 11mm

The 4th instar caterpillar has similar appearance as in the 3rd instar. Comparing it to the earlier instar, the body color has a lighter shade of green and the dorsal spots are milky brown in appearance. Each dorsal spot is decorated with a prominent small white spot (variable in size, and some are diamond in shape) at the center of the leading edge. The black section on each protuberance is now drawn closer to the black tip, roughly about one-third way from the tip. After 5 days in this instar, and growing to a length of about 30mm, the caterpillar moults to the the 5th and final instar.

A 4th instar caterpillar which has just shed its old skin. length: 17mm


4th instar caterpillar, length: 27mm

The 5th instar caterpillar features a brighter shade of green. Side spines of the previously black sections and tips of the protuberances have changed color to pink. On each protuberance, the "interior" section has almost fully married up with the pink tips, if not for an intervening white section.


5th instar caterpillar, late in this stage, length: 49mm


Left to right: Changes in the appearance of one protuberance from the 2nd to the 5th instar.
Note the increase in the density of side spines.

This final instar lasts for 5-6 days with the caterpillar reaching a mature length of about 50mm. On the last day, its body becomes shortened and decolorized. Soon after it adopts the pre-pupatory pose on the leaf underside or on a nearby stem. All dorsal spots disappear at this juncture and a bi-color saddle mark can be seen on the 2nd abdominal segment.

A pre-pupa of the green Baron

After 1 day of the pre-pupal stage, pupation takes place with the pupa suspended with its cremaster firmly attached to the silk pad on leaf surface. The pupa is smooth and tapers steeply towards each end from a high transverse dorsal ridge. The light green pupa has a series of brownish spots arranged symmetrically. Length of pupae: 20-21mm.

Two views of a fresh pupa of the Green Baron with its old coat caught dangling


Two views of a pupa of the Green Baron

Ten days later, the pupa has developed to the point of revealing the upperside wing markings in the wing pad area. The next day, the adult butterfly ecloses in the morning hours. It stays on the empty pupal case for an hour or two before taking off to feed, find a mate and continue the circle of life and propagation of the next generation.


Left: mature pupa on a branch; Right: a newly eclosed male Green Baron

Another newly eclosed male Green Baron



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 Pres 1999

Text by Horace Tan, Photos by Tan Ben Jin, Federick Ho and Horace Tan

Butterflies of the Month - December 2008

Butterflies of the Month - December 2008
A White, White Christmas



It has been a year since the Butterflies of Singapore BLOG started the Butterfly of the Month series in December 2007! Time really flies, and it's been really great featuring a special butterfly each month, researching each species, and collecting the excellent photos from members of the ButterflyCircle community.

With the global economic crisis (yes, it even affects butterflies, well, actually the photographers, not the butterflies!), it's been a tumultuous year for the world as we cross the threshold of the final month of 2008. All around the world, the 'winter' of the financial storm has hit home to many countries, and it will be a time of prudence and belt-tightening in many parts of the world. But there will always be time to stop and appreciate our beautiful butterfly friends, who are totally oblivious to our human material world.

However, winter and white, no matter how depressing they are, often have their beauty and grace. Even in the most adverse of cold weathers, Mother Nature always presents her beauty in the seasons, and white winters are no exception. Butterflies are always admired for their colour and diversity. But, there are plain white butterfly species as well - but they are no less attractive, for there is beauty to behold in even the plainest and commonest of these species.

This month, we feature not one, but two white butterflies. Small, unassuming and plain, these butterflies are found very often in urban parklands and secondary growth, fluttering feebly and going about their business of feeding and enjoying their freedom in the natural world.

The Psyche (Leptosia nina malayana)

The first butterfly is the Psyche. I've often wondered why the common name of this butterfly is such, and a little googling turned up this romantic definition, which I liked best :

In Roman mythology, Psyche was a beautiful girl who was visited each night in the dark by Cupid, who told her she must not try to see him. When she did try, while he was asleep, she accidentally dropped oil from her lamp on him, and he awoke and fled. After she had performed many harsh tasks set by Cupid's mother, Venus, Jupiter made her immortal, and she and Cupid were married. Her name Psyche is Greek for both “soul” and “butterfly.”

Learn how to pronounce Psyche

The Psyche is a small and delicate butterfly. It is usually seen fluttering feebly, close to the ground, stopping only to feed on flowers. A favourite flower which it likes to feed on is the white bloom of the Common Asystasia (Asystasia gangetica). The upperside is white, with a black tipped apex and a black oblong subapical spot. The underside carries greenish lines and streaks. It can be found in both urban areas as well as forests.

When observing this feeble flying butterfly, one has to be extremely patient to wait for it to alight to feed on a flower, or to take an occasional rest on a nearby leaf. Though it has a weak flight, it can go on flying for long periods of time without taking a rest stop - butterfly photographers will find it a challenge to take a shot of this butterfly!

The Cabbage White (Pieris canidia canidia)

The 2nd white butterfly featured this month, is the Cabbage White. Another small inconspicuous butterfly, it occurs in mainly urban areas where its host plant, Cleome rutidosperma, which it shares with the Psyche, grows.

The Cabbage White has predominantly white wings, with usually a few black post-discal spots and a black apical border on the forewings above. The females are more heavily black-dusted, and possess a distinct double spot in space 1b of the forewing. In pristine specimens, there is a distinct yellow streak at the basal area of the hindwing below.

This species occurs in open grassy areas and flies in the company of the Striped Albatross and Psyche. It is a weak flyer, and keeps close to the ground, looking for the flowers of common weeds to feed on. On a sunny day, it has a restless flight, and rarely stops for long.

It occurs in urban areas as well as parklands and can sometimes be common where it occurs. Often, several individuals are seen at one time, especially in the vicinity of its host plant.

Text by Khew SK : Photos by Tan BJ, Federick Ho, Sum CM, Sunny Chir & Khew SK

Acknowledgments :

* Merriam-Webster Online Dictionary

Life History of the Dot-Dash Sergeant

Life History of the Dot-Dash Sergeant (Athyma kanwa kanwa)

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


A Dot-Dash Sergeant resting on a perch in the nature reserve, showing us its undersides


A Dot-Dash Sergeant resting on a leaf in the nature reserve


A Dot-Dash Sergeant puddling on a trail in the nature reserve

Physical Description of Adult Butterfly:
Above, the Dot-Dash 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. On the forewing, the white post-discal spot in space 2 is roughly oval and well separated from the spot in space 1b. Usually there is no post-discal spot in space 3. The forewing cell-streak is entire and separated from the triangular spot beyond. 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. The underside is greyish brown with markings as on the upperside.

Field Observations of Butterfly Behaviour:
Locally the Dot-Dash 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 around flowering trees and puddling on trails within the nature reserves.

Early Stages:
Four species of Uncaria (see attached picture) growing in the nature reserves have been found to be host plants for Dot-Dash Sergeant. Species #3 is suspected to be U. lanosa. Species #4 was previously recorded as the host plant for Lance Sergeant and Commander. Dot-Dash Sergeant shares the same feeding routine and utilization of frass chain/bundles as described therein for these two species.

Local host plants: 4 Uncaria spp. found in the nature reserves.


A female Dot-Dash Sergeant ovipositing on a leaf tip of Uncaria #1

The eggs of the Dot-Dash Sergeant are laid singly at the tip of a leaf on the host plant. In a behavior typical of members of its genus (and some other genera), 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. 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.

A freshly laid egg of Dot-Dash Sergeant at the leaf tip of Uncaria #1. Diameter: 1mm.
In this case, the mother butterfly laid it next to a failed egg.

A mature egg with few hours to hatching

The egg takes about 3.5 days to hatch. The young caterpillar emerges by eating away part of the egg shell. After its emergence, it turns around and proceeds to finish up the every bit of the remainng egg shell. The newly hatched has a cylindrical pale greenish body covered with many small tubercles. The head capsule is orange in base color and speckled with dark brown patches.


Newly hatched Dot-Dash Sergeant caterpillars, length: 2mm.
Top: first taste of leaf diet; Bottom: constructing first frass chain

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. 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 5.5mm in about 3 days, the caterpillar moults to the 2nd instar.


One 1st instar caterpillar resting on the exposed mid-rib near its frass barrier, length: 5mm

The body color of the 2nd instart caterpillar is mainly dark brown decorated with small black patches. Besides tiny tubercles covering most of its body surface, the 2nd instar caterpillar also features short and branched spines dorso-laterally and spiracularly. The head capsule is now mostly dark brown and dotted with a few conical tubercles. This instar lasts about 3 days with the body length reaching 8-8.5mm.


2nd instar caterpillar, length: 8mm

The 3rd instar caterpillar has slightly longer dorsolateral spines, with the pairs on thoracic segments longer than the rest. Its head capsule is dark brown to black irorated with pale brown tubercles. This instar takes 4-5 days to complete with body length reaching about 12mm.


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


3rd instar caterpillar, late in this stage, length: 11mm


Top: A late 3rd instar caterpillar, dormant before the moult to the next instar.
Note the bulge behind the head capsule, this will become the new head.
Bottom: A newly moulted 4th instar caterpillar, lenght about 12.5mm.

The 4th instar caterpillar has much longer dorsolateral spines which are heavily branched. The body is still brown to dark brown in base color but dotted with rather regular and prominent small black patches on each body segment. Besides conical tubercles, the head capsule also carries some short spines. This instar lasts 4 days with body length reaching about 19mm-20mm.


4th instar caterpillar, length: 13.5mm

The 5th and final instar brings about a drastic change in appearance. The body surface still has the same regular dark patches set against a light brown base color, but now the branched dorso-lateral spines are very well developed on all body segments with those on the meso- and metathorax being the longest. Newly moulted caterpillar has biege to light brown translucent spines, but these will change to light green and then green as the caterpillar grows. Parts of the body surface will also change from brown to green in tandem.


5th instar caterpillar, early in this stage, length: 20mm.
The old 4th instar head capsule can be seen a short distance behind the caterpillar.

Two views of 5th instar caterpillar, early in this stage, length: 20mm.

There is no prominent saddle mark on the 5th abdominal segment as typical in many Athyma spp. Instead, the dark patches which occur on all body segments are enlarged and more prominent on the 5th abdominal segment. The black to dark brown head capsule has much longer and pointed spines. 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.

Two vlews of a 5th instar caterpillar, with spines turning green, length: 20mm


5th instar caterpillar, mostly green in appearance, late in this stage, length: 35mm

A sequence of a few bites taken by a Dot-Dash Sergeant

The 5th instar lasts for 7-9 days, and the body length reaches up to 35-40mm. On the last day, the color of the body and the spines changes with a gradual change to white with yellowish tinge. The caterpillar ceases feeding and wanders around for almost half a day for a pupating site which is typically a branch or a stem. 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. For the most part of this immobile pre-pupal phase, the caterpillar adopts a curled-up posture (see pic). When it is within a few hours to pupation, the caterpillar gradually relaxes to a more upright posture, and at this time, waves of contraction starts to ripple from the posterior to the anterior end, until the pupation event kicks in.


5th instar caterpillar, last day in this instar with color changes taking place


Two pre-pupatory larva (already attached to the silk pad) in curld-up posture.


Two vlews of a pre-pupatory larva as it gradually adopts an straightened posture as a
prelude to the pupation event.

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. Fresh from the pupation, it is almost silky white. Within the first one or two hours, certain segments and parts are darkened while the remaining parts will gradually take on a beige-silvery shine in hours ahead. The pupa has a pair of long and slight curved cephalic horns, about 4-5mm. Dorsally, there are two processes curved towards each other, with one larger and dark in color. Length of pupae: 25-30mm (counting the cephalic horns).

A pupation sequence of a Dot-Dash Sergeant

Three views of a pupa of the Dot-Dash Sergeant.

After about 6.5 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 Dot-Dash Sergeant

A newly eclosed Dot-Dash Sergeant


Another newly eclosed Dot-Dash 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