Life History of the Baron

Life History of The Baron (Euthalia aconthea gurda)

A male Baron basks in the early morning sunshine

A female Baron foraging on damp ground on rotting fruit

Butterfly Biodata :
Genus : Euthalia Hubner, 1819
Species : aconthea Fruhstorfer, 1906
Subspecies : gurda Fruhstorfer, 1906
Wingspan of Adult Butterfly : 70mm

Caterpillar Host Plant : Mangifera indica

Physical Description of Adult Butterfly : The wings are dark brown above with a broad but obscure post-discal band on both wings. A few small white spots define the inner edge of this band. The spots are larger and most distinct in the female than the male. The underside is a paler brown than the upperside. The proboscis of this species is a bright yellow-green.

Field Observations of Butterfly Behaviour : The Baron is relatively common and is often seen in urban parks and gardens. The species is also observed in residential estates where its preferred host plant, the Mango, is cultivated. As the Mango tree is a favourite fruit tree found in many gardens, the Baron is often attracted to these urban areas. It is a flighty butterfly, and a strong flyer, alert and difficult to photograph. Both males and females can sometimes be found feeding on overripe fruits.

Host plant of the Baron - Mangifera indica

Early Stages : The eggs are laid singly, usually on the undersides of the broad leaves of the host plant. The appearance of the egg is very similar to its related species in the genera of Tanaecia and Lexias, being dome-like in shape, about 2mm in diameter, and covered with hexagonal segments from which whitish hair-like protuberances emerge.

"Spiky" green egg of the Baron

After about 3-4 days, the 1st instar caterpillar emerges, eating the eggshell as its first meal. The caterpillar is yellow in colour, and sports white-edged black spines from its body. It grows to about 4mm long, before moulting into its 2nd instar.

1st instar caterpillar of the Baron

The 2nd instar caterpillar has complex branched spines and is predominantly green, with a light yellow dorsal stripe, edged with purple-brown spots, corresponding with the base of the spines.

2nd instar caterpillar of the Baron with its branched spines

The 3rd instar caterpillar is similar in appearance to the 2nd instar, but the spines have grown much longer. It feeds on the younger leaves of its host plant, and reaches about 16mm before moulting again.

3rd instar caterpillar

The 4th instar caterpillar reaches a length of about 22mm and its branched spines make it appear to be much larger than it actually is. When resting on the mid-rib of its host plant, the branched spines give the caterpillar some measure of camouflage from predators.

4th instar caterpillar reaching a length of 22 mm

The 5th instar caterpillar is medium green, and the yellowish-white dorsal stripe loses the earlier purple-brown spots along the edge of the stripe. The branched spines appear almost like a bird's feather, with the secondary spines arranged neatly perpendicular to the main spine. It reaches a mature length of about 45mm before shortening and adopting its pre-pupation pose.

Final instar caterpillar with its prominent yellowish-white dorsal stripe

Pupation takes place on the underside of a leaf of the host plant, with the cremaster firmly attached to the mid-rib of the leaf. The light green pupa has a series of brownish spots arranged symmetrically. The pupa of the Baron appears very similar to the related species in the genus, and also the related Tanaecia and Lexias species.

Two views of the Baron's pupa

The adult butterfly ecloses in the early morning hours and stays for about an hour as it dries its wings, before taking off to feed, find a mate and continue the circle of life and propagation of the next generation.

Newly eclosed female Baron showing the undersides of its wings

Newly eclosed female Baron showing the uppersides of its wings

Text by Khew SK ; Photos by Goh LC and Khew SK

A new Riodinidae species for Singapore?

Is there a new Riodinidae species in Singapore?

Some time back in mid 2004, a small colony of what was first thought to be the Malayan Plum Judy (Abisara saturata kausambioides) was discovered at several locations at Singapore's urban hill parks known as the "Three Ridges".

A side shot of the mystery Abisara sp.

After taking many shots of the species, ButterflyCircle member Sunny Chir noticed that the behaviour of the individuals of this species to be rather unique. As the individuals spotted had a much stronger flight and engaged in "dog-fighting" activity - quite uncharacteristic of the behaviour of females of the Malayan Plum Judy, which these individuals resemble, Sunny continued to observe their behaviour over a period of several months, and highlighted the possibility of a different Abisara species to me.

The mystery Abisara with half-opened wings, perched on a leaf

That initial "gut-feeling" resulted in a long period of observing this species in their natural habitat - the times during which the species is most active, and their frolicking behaviour when two or three other individuals of the species were around in the same place. Thus far, no mating pairs were observed yet.

The mystery Abisara with half opened wings. In a side light, the upper wings show a purple-blue sheen.

Upon closer scrutiny of the photos taken, and by a process of elimination, we came to a tentative conclusion that this species may not be the Malayan Plum Judy (Abisara saturata kausambioides).

Taking reference from Corbet & Pendlebury's "Butterflies of the Malay Peninsula" 4th Edition, in the key for separation of the three extant Abisara species in Singapore we have :

Abisara savitri - Upperside paler, more reddish brown; forewing with inner band diffuse, sullied and from beyond mid-costa to the dorsum before the tornus. Hindwing with a long, white-tipped tail at vein 4.

Abisara geza - Underside of forewing inner postdiscal fascia bent basad above vein 4. Underside of hindwing discal band dislocated at vein 4. Male upperside with ovate paler subapical area on forewing and submarginal spots in spaces 1b, 4 and 5 of the hindwing.

Abisara saturata - Underside of hindwing discal band not dislocated, but may be angled at vein 4. Male upperside dark crimson brown and unmarked.



Male and Female Abisara saturata kausambioides

The first Abisara species - A. savitri can be eliminated due to its very distinct and different appearance from the other two species.

Hence, the unknown species :

• cannot be Abisara geza as the hindwing discal band is not dislocated at vein 4.
• cannot be a male Abisara saturata as the males of A. saturata are distinctly difference in appearance.
• is not a female A. saturata as all the shots taken of this species so far, show clearly that it uses only 4 legs for walking, and this is consistent with the genus that the adult forelegs are non-functional in the male, but functional in the female.
• is not likely to be female A. saturata due to the observation of the individuals' more robust and speedier flight, as well as "dog-fighting" behaviour - usually typical of males of this genus.

More views of the unknown Abisara sp


So the conclusion up to this point would be that this is a :

• male specimen of an unknown Abisara sp.
• is not an Abisara geza as it does not have the dislocated discal band at vein 4 of the hindwing
• is not a male Abisara saturata as that species' male is distinctly marked.

So what species is this?

Voucher specimens captured of this species suggest that, from the visual inspection of the end of the abdomen of the specimens, that these individuals are males. These specimens have been sent to expert lepidopterists in Japan and Malaysia for a full-fledged dissection to ascertain the identity of this species. We are waiting patiently for the conclusion of these experts. A journal paper has been prepared to this effect, for the purpose of recording this strange and unknown Abisara as well as other discoveries by ButterflyCircle members.

A possible ID of this species flying around the hilltops of Singapore's urban parks could be Abisara kausambi kausambi. The characteristic of "Underside of forewing inner postdiscal fascia straight" and "Male upperside forewing with narrow, obscure, paler subapical area" seems to suggest that this mystery Riodinid matches the description of Abisara kausambi kausambi. However, as this species has not been recorded in Singapore by the early authors, the ID of this species remains a mystery for the time being.

Could our mystery Riodinid be Abisara kausambi? Could it be an endemic sub-species which is hitherto unrecorded in Singapore? Or perhaps a totally new Abisara species which is not even recorded in the region?

Whilst the status of this species remains uncertain in Singapore, and we wait in anticipation for the experts' advice, we would like to place on record this observation which was first made by Sunny Chir.

Who am I???

Text by Khew SK ; Photos by Khew SK, Sunny Chir, Tan CP

Life History of the Suffused Flash

Life History of the Suffused Flash (Rapala suffusa barthema)

Butterfly Biodata:
Genus : Rapala Moore, 1881
Species : suffusa Moore, 1879
Subspecies : barthema Distant, 1885
Wingspan of Adult Butterfly: 15-19 mm
Caterpillar Local Host Plant: Bridelia tomentosa (Phyllanthaceae, common name: Pop-gun Seed, 土蜜树).

A male Suffused Flash.

Another male Suffused Flash.

Physical Description of Adult Butterfly:
On the upperside, the female is entirely brown whereas the male is orange-red with broad dark brownish borders which are purple-shot in a side light on the forewing, while the hindwing is largely unmarked. As with other Rapala spp., the male has an oval-shaped brand in space 7 on the hindwing. On the underside, both sexes are ochreous to pale buff brown. The markings are typical for Rapala spp, with cell-end bars on both wings, and brown postdiscal lines edged with white on the side nearer to the termen. The hindwing carries a white-tipped tail at the end of vein 2 with a tornal lobe between veins 1a and 1b. In addition, there is a black tornal spot, a bluish green patch in space 1b, a round black sub-marginal spot in space 2, and black post-discal striae in spaces 1b and 2.

A comparison of the hindwing underside of Scarlet Flash, Suffused Flash and Malay Red Flash.

Of the four members of the R. suffusa group, three species, namely, R. dieneces (Scarlet Flash), R. suffusa (Suffused Flash) and R. damona (Malay Red Flash), are often challenging to differentiate due to their similar colorations and markings. One way to tell them apart is to examine the underside hindwing for the following two features (as provided by Dr Seow TL).

In space 1b (marked in pink oval in the picture above)

• R. dieneces (Scarlet Flash), speckled patch occupies about 50% to 60% of space.
• R. suffusa (Suffused Flash), speckled patch occupies about 50% or less of space.
• R. damona (Malay Red Flash), speckled patch occupies about 80% to 100% of space.

In space 2 (marked in blue oval in the picture above)

• R. dieneces (Scarlet Flash), black spot has an orange crown.
• R. suffusa (Suffused Flash), black spot does not have an orange crown or yellow and merged with ground colour.
• R. damona (Malay Red Flash), black spot has a crown which is orange or yellow and obscure.

A female Suffused Flash.

A male Suffused Flash.

Field Observations:
The Suffused Flash is moderately rare in Singapore. Sightings of this species have mostly been confined to a few locations within the catchment nature reserve and the landward edge of mangrove swamps. The fast-flying adults have been sighted taking nectar at flowering plants and perching on leaves to sunbathe occasionally.

A female Suffused Flash.

Another female Suffused Flash.

Early Stages:
In Singapore, thus far only one larval host plant has been identified. This local larval host is Bridelia tomentosa, a plant typically found along forest edges and popular as a larval host plant and nectary plant for a number of butterfly species. On this plant, caterpillars of the Suffused Flash feed mainly on flower buds and flowers, as well as developing young fruits.

Local host plant: Bridelia tomentosa.

Eggs are laid singly on a part of a flower or flower bud of the host plant. Each egg is about 0.6mm in diameter, greenish in colour when freshly laid. It is bun-shaped with a depressed micropylar at the pole and a surface reticulated with very fine ridges.

Two views of a fresh egg of the Suffused Flash.

Two views of a two-day old egg of the Suffused Flash.

Two views of a fully developed egg of the Suffused Flash with the caterpillar ready to emerge.

It takes about 3 days for the egg to hatch. The young caterpillar consumes just enough of the egg shell to emerge. It is pale yellowish brown in base colour, and has a length of about 1mm. Long setae (hairs) run along the length of the body dorsally as well as sub-spiracularly. A dark brown prothoracic shield is present, and the dorsum of the metathorax and the posterior segments from the 6th are brown to dark brown in colour. Pairs of dorsal tubercles are featured from the thorax to the 5th abdominal segments, and they turn whitish as growth progresses. The 1st instar lasts about 2-2.5 days with the body length increased to about 2.1mm.

A newly hatched caterpillar of the Suffused Flash next to its empty egg shell, length: 1mm.

Two views of a newly hatched caterpillar of the Suffused Flash, length: 1mm.

A 1st instar caterpillar of the Suffused Flash feeding on flower parts of Bridelia tomentosa.

Two views of a 1st instar caterpillar, late in this instar, length: 2mm.

In the 2nd instar caterpillar, the dorsal tubercles are larger and the long dorsal setae seen in the 1st instar are now absent. Instead, proportionately shorter dark setae occur in greater numbers on the body surface. Similar tubercles also appear subspiracularly on body segments from mesothorax to the 8th abdominal segment. The caterpillar still features a dark brown prothoracic shield and a dark brown head capsule. The metathorax is reddish brown and the posterior abdominal segments from the 6th are dark brown. The 2nd instar lasts about 2-2.5 days, with the body length reaching up to 5mm.

Two views of an early 2nd instar caterpillar of the Suffused Flash, length: 2.8mm.

Two views of 2nd instar caterpillar of the Suffused Flash, late in this stage, length:5mm.

Two views of a 2nd instar caterpillar of the Suffused Flash, dormant prior to its moult.

In the 3rd instar, the caterpillar bears strong resemblance to the 2nd instar caterpillar but with body base colour turning more greenish, and the dorsal and subspiracular tubercles more yellowish. The dorsal nectary organ on the 7th abdominal segment and the tentacular organs on the 8th abdominal segment are now easily discernible. The 3rd instar lasts about 3 days, with the body length reaching up to 10mm.

Two views of a newly moulted 3rd instar caterpillar of the Suffused Flash, eating its old skin.

Two views of an early 3rd instar caterpillar of the Suffused Flash, feeding on flower buds of Bridelia tomentosa, length: 6mm.

Two views of a 3rd instar caterpillar of the Suffused Flash eating flower buds of Bridelia tomentosa, length: 9mm.

Two views of a 3rd instar caterpillar of the Suffused Flash, length: 10mm.

Two views of a late 3rd instar caterpillar of Suffused Flash, dormant prior to its moult to the final instar.

The 4th instar caterpillar resembles the 3rd instar caterpillar in most body features/markings but with several changes. The body base colour now varies from dull green to brownish green and the dorsal/subspiracular tubercles varies from pale yellow to lemon yellow. Small dark spots appear in the dorsal/subspiracular tubercles. In addition, spiracles are now prominently black in colour, and the prothoracic shield is whitish with dark brown fringes. The 4th (and final) instar lasts about 4 days with the body length reaching up to 21-22mm.

Two views of a newly moulted 4th instar caterpillar of the Suffused Flash, eating its old skin.

Frontal view of a 4th instar caterpillar of the Suffused Flash, showing the prothoracic shield and black spiracles.

Two views of a 4th instar caterpillar of the Suffused Flash, length: 11.5mm.

A final instar caterpillar of the Suffused Flash with ants in attendance.

Two views of a 4th instar caterpillar of the Suffused Flash, length: 17mm.

A 4th instar caterpillar of the Suffused Flash feeding on a young fruit of Bridelia tomentosa.

Two views of a 4th instar caterpillar of the Suffused Flash, length: 20mm.

As it enters the pre-pupatory phase of its life cycle, the caterpillar ceases its feeding activity. Its body gradually shrinks in length and the base colour turns dark brownish. The pre-pupatory caterpillar wanders around for a suitable pupation site. Typically it settles for a spot on a surface which is partially concealed. At the chosen pupation site, it stays dormant for about 0.5 day or so before spinning a silk girdle and a silk pad to which it attaches itself via claspers at the posterior end.

Two views of a late 4th instar caterpillar of the Suffused Flash.

Two views of a pre-pupa of the Suffused Flash.

About 1 day after the pre-pupatory caterpillar secures itself to the pupation spot, pupation takes place. The pupa is held firmly to the pupation spot with the silk girdle and cremastral attachment to the silk pad. It is 11.5 to 12.5mm in length, with the typical shape for a lycaenid pupa. It is yellowish brown with dark brown speckles and patches dotting the pupal surface.

Two views of a pupa of the Suffused Flash.

Two views of a mature pupa of the Suffused Flash.

Seven 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.

A newly eclosed Suffused Flash resting next to its pupal case.

References:

• [C&P5] The Butterflies of The Malay Peninsula, A.S. Corbet and H.M. Pendlebury, G. and N.  van der Poorten (Eds.), 5th Edition, Malayan Nature Society, 2020.
• Butterflies of Thailand, Pisuth Ek-Amnuay, 2nd Edition, 2012.
• A Field Guide to the Butterflies of Singapore, Khew S.K., Ink On Paper Communications, 2nd Edition, 2015.

Acknowledgment:
I would like to express my gratitude to Mr Foo Jit-Leang for sharing information on early stages of the Suffused Flash.

Text by Horace Tan, Photos by Koh Cher Hern, Khew SK, Jonathan Soong, Ellen Tan and Horace Tan.