30 September 2026

Butterfly of the Month - September 2026

Butterfly of the Month - September 2026
The Banded Flitter (Quedara monteithi monteithi)

A mating pair of Banded Flitter - Left : Female, Right : Male

We are on the threshold of the final quarter of 2026 as we bid farewell to September. This month, we celebrated the Mid-Autumn Festival (中秋节, Zhōngqiū Jié) which is one of the most important traditional Chinese festivals, often described as a celebration of family reunion, gratitude and the full moon. It falls on the 15th day of the eighth lunar month, when the moon is traditionally considered at its fullest and brightest. The round full moon represents completeness, which is why families traditionally gather for dinner, drink tea, admire the moon and share mooncakes. Their round shape also symbolises reunion.

A male Banded Flitter perches on a leaf
A female Banded Flitter feeding on the flower of Mussaenda bush

September was also a month when the dreaded haze returned to Southeast Asia, triggered primarily by the slash-and-burn agricultural practice amongst Singapore's neighbours. Whilst the air quality deteriorated into the unhealthy range on several days in the month, seasonal rains eased the smoggy air somewhat and made the haze less severe than previous years.  It is a wonder that such burning occurs almost annually in large areas of Sumatra and Kalimantan, but with such large expanses of forests and difficult access, fighting such fires during the dry season proves very challenging.


Speaking of rain, the city of Bangkok was inundated with heavy storms. Rainfall over the past three days has caused heavy flooding in the Thai capital. A state of disaster has been declared in all 50 districts in Bangkok. A symptom of climate change? Or poor city planning and management? Perhaps a bit of both? But livelihoods, and often even lives are at stake from such natural disasters. Infrastructure planning in congested urban cities can, to a certain extent, mitigate extreme weather phenomenon but a lot depends on what the authorities and governments are willing to do.


This month, we feature a Hesperiidae or Skipper, which I refer to as the Banded Flitter. Although a more frequently used name for this species is Dubious Bar Flitter or Dubious Flitter, the common name thus given makes no sense. What is so dubious about this Flitter? Dubious means doubtful, questionable, or not entirely trustworthy. It usually suggests that there is a good reason to hesitate before believing, accepting, or approving something. For a butterfly? If someone is trying to justify the cryptic nature of this species with many lookalikes, then why only this species? There are tens of other species that are often "dubious" in their identifications!


The rationale for referring to this Flitter as Banded Flitter is that the female of the species resembles another similar looking species - the Banded Demon (Notocrypta paralysis varians) and other similar looking and related Notocrypta species. One question that may be asked would be "why name the species after only the female's physical characteristics?" This is because the male of this species is brown and unmarked. But then again, so is the Striped Blue Crow (Euploea mulciber mulciber) where only the female is striped and the males have no sign of any stripes whatsoever.

A female Banded Flitter feeding on the flower of a Spanish Needle (Bidens alba)

Hence, giving the common name for Quedara monteithi monteithi as Banded Flitter is a more reasonable and logical name rather than calling it "Dubious". As there is no international naming authority for common names of butterflies, it is through common usage that the common names stick over time. Taxonomic specialists will always refer to this species as Quedara monteithi monteithi and there is never a doubt (or anything "dubious" about it!) as to what this species is known, by its Latin name.

A female Banded Flitter feeding on the flower of Lantana camara
A female Banded Flitter sunbathing with half-opened wings showing the extent of the white band on the forewing

The male Banded Flitter is dark brown and unmarked on the upperside and underside of its wings, which sometimes have lighter shades along the wing margins. The female is more distinctive and has a broad oblique white band across the forewing. The eyes are a solid dark brown whilst the antennae are generally brown throughout.


A female Banded Flitter reacts to the camera flash and shows its white forewing band more completely.

The species is a forest-dependent butterfly and often found where its caterpillar host plant, the Water Rattan Palm (Daemonorops augustifolia) grows wild.  The Banded Flitter shares this host plant with some other skippers like the Tree Flitter (Hyarotis adrastus praba) and White Palm Bob (Suastus everyx everyx).


Previously considered a rare species in Singapore, the Banded Flitter is no longer as rare as before and the females are more regularly spotted along forest edges and amongst the shrubbery next to the nature reserves in Singapore. Both sexes are often photographed feeding on flowering plants. A rarer cousin, Quedara singularis looks very similar and should be looked out for in Singapore.

Text by Khew SK : Photos by Billy Goh, Khew SK, Koh CH, Henry Koh, Low JK, Aaron Soh, Horace Tan and Art Toh.


26 September 2026

Life History of the Jewel Fourline Blue

Life History of the Jewel Fourline Blue (Nacaduba sanaya elioti)


Butterfly Biodata:
Genus: Nacaduba  Moore, 1881
Species: sanaya   Fruhstorfer, 1916
Subspecies: elioti   Corbet, 1938
Wingspan of Adult Butterfly: 30-34mm
Caterpillar Local Host Plants: Agelaea macrophylla (Connaraceae), Rourea mimosoides (Connaraceae), Agelaea sp. (Connaraceae).


A Jewel Fourline Blue perching on a leaf.

A female Jewel Fourline Blue perching on a stem.

Physical Description of Adult Butterfly:
Above, the male is shining violet blue with a thread-thin border; the female is pale silvery blue with broad border. Underneath, both sexes are greyish brown with two bands in the forewing (post-discal and discal) each composed of a double series of whitish striae. Forewing postdiscal band curved in towards base and dislocated at vein 6. On each hindwing, there is an orange-crowned black tornal spot in space 2 with no presence of bluish-green metallic scales. Next to the tornal spot, a pair of filamentous white-tipped tails occurs at end of vein 2. The female has more rounded forewing termen than the male.

A close-up view of the hindwing of a Jewel Fourline Blue. Note the absence of bluish-green metallic scales in the black tornal spot.

A male Jewel Fourline Blue visiting flowers of Elephantopus scaber (Elephant’s Foot).

A Jewel Fourline Blue puddling on wet ground.

Field Observations of Butterfly Behaviour:
The Jewel Fourline Blue was re-discovered in 2008 and is moderately rare in Singapore. The adults are found in various forested areas of the central catchment reserve, visiting flowering plants, puddling on wet grounds and performing oviposition rituals at young leaves of the host plants.

A mating pair of the Jewel Fourline Blue perching on a stem.

A Jewel Fourline Blue puddling among fallen leaves.

An aberrated Jewel Fourline Blue ovipositing on a young leaf of an unidentified plant.

Early Stages:
The Jewel Fourline Blue is polyphagous. Thus far, three plants in the Connaraceae family have been identified as the larval hosts in Singapore. They are Agelaea macrophylla, Rourea mimosoides and another Agelaea plant with the species id yet to be finalized. All three plants are common in the catchment reserves. Caterpillars of the Jewel Fourline Blue mainly feed on young leaves of the host plant. As in the case for most lycaenid species, the caterpillars of the Jewel Fourline Blue are tended by ants.

Local host plant #1: Agelaea macrophylla.

Local host plant #2: Rourea mimosoides.

Local host plant #3: Agelaea sp..

Eggs are laid singly on a young leaf or stem of the host plant. Each egg is whitish with a green undertone. It has a thick discoid shape, and features a depressed micropylar on top. The egg surface is finely reticulated, slightly raised at the intersections of cris-crossing ridges. The egg has a diameter of about 0.5mm.

A mother Jewel Fourline Blue ovipositing on a young leaf of Agelaea sp. .

A mother Jewel Fourline Blue ovipositing on a young leaf of Agelaea macrophylla.

Two newly laid eggs of the Jewel Fourline Blue on a stem of an Agelaea sp.

Two views of an egg of the Jewel Fourline Blue laid on leaf surface of an Agelaea sp.

It takes about 2 days for the egg to hatch. The young caterpillar consumes part of the egg shell to emerge. With a length of about 1mm, it has a pale yellowish body with long setae (hairs) dorsally and sub-spiracularly. The body color changes gradually to a darker shade of yellow as growth progresses. The first instar lasts for 2-2.5 days and the body length reaches about 2mm before the moult to the 2nd instar.

A newly hatched caterpillar of the Jewel Fourline Blue, resting next to its empty egg shell.

Two views of a newly hatched caterpillar of the Jewel Fourline Blue, length: 0.9mm.

Two views of a 1st instar caterpillar of the Jewel Fourline Blue, length: 2mm.

Two views of a late 1st instar caterpillar of the Jewel Fourline Blue, dormant prior to its moult.

In the second instar, dorsal setae are much shortened proportionately compared to those in the first instar. Moreover, there are numerous short setae present all over the body surface. The body color is variable, whitish to yellowish or pale reddish brown. The 2nd instar lasts about 3 days and the caterpillar grows to a length of about 3.5mm before the moult to the 3rd instar.

Two views of a 2nd instar caterpillar of the Jewel Fourline Blue, length: 2.6mm.

Two views of a 2nd instar caterpillar of the Jewel Fourline Blue, length: 2.8mm.

Two late 2nd instar caterpillars of the Jewel Fourline Blue, dormant prior to their moult to the 3rd instar.

The 3rd instar caterpillar has similar body coloration as in the 2nd instar. The dorsal nectary organ and tentacular organs are now easily discernible. After about 3 days in this instar with the body length reaching about 6-5.5mm, the next moult brings the caterpillar to its final instar.

Two views of an early 3rd instar caterpillar of the Jewel Fourline Blue, length: 3.8mm.

Two views of a 3rd instar caterpillar of the Jewel Fourline Blue, length: 6.2mm.

Two views of a late 3rd instar caterpillar of the Jewel Fourline Blue, dormant prior to its moult.

A well-concealed caterpillar of the Jewel Fourline Blue observed with attending ants on young leaves of Rourea mimosoides.

The 4th instar caterpillar has the same pale yellowish to reddish brown ground color as in the 3rd instar. As in the 3rd instar, the dorsal nectary organ and tentacular organs are prominent on the posterior segments. Tentacular organs are readily everted when the caterpillar are disturbed or when attending ants are present.

An early 4th instar caterpillar of the Jewel Fourline Blue.

Two views of a 4th instar caterpillar of the Jewel Fourline Blue, length: 12.5mm.

Two views of a 4th instar caterpillar of the Jewel Fourline Blue, length: 14mm.

A 4th instar caterpillar of the Jewel Fourline Blue found in the field, feeding on a young leaf of an Agelaea sp., with ants in attendance.

The 4th instar lasts for 4-5 days and the body grows up to a length of about 14mm. On the last day of this instar, the caterpillar ceases food intake and its body shrinks in length and its body colour changes to orangy to pinky brown. The fully grown caterpillar finally chooses a spot on a leaf surface where it readies the site for pupation by spinning a silk pad and a silk girdle to secure itself.

A 4th instar caterpillar of the Jewel Fourline Blue, late in this stage, with color change taken place.

Two views of a girdled-down pre-pupa of the Jewel Fourline Blue.

About 1 day later, pupation takes place. The pupa has the typical lycaenid form, and is 8-8.5mm in length. It is mostly pale yellowish brown and speckled with black spots of various sizes and shapes.

Two views of a freshly pupated pupa of the Jewel Fourline Blue, with colour yet to change to yellowish brown.

Two views of a pupa of the Jewel Fourline Blue.

Five days later, the pupa becomes darkened in color signaling the imminent emergence of the adult. The markings on the forewing upperside becomes increasing obvious through the pupal skin. The next day the adult butterfly emerges from the mature pupa. Pupal period: 6 days.

Two views of a mature male pupa of the Jewel Fourline Blue, showing extensive purplish blue coloration in the wing pad.

Two views of a mature female pupa of the Jewel Fourline Blue, showing much less extensive bluish coloration in the wing pad.

A newly eclosed male Jewel Fourline Blue resting near 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.
  • A Field Guide to the Butterflies of Singapore, Khew S.K., Ink On Paper Communications, 2nd Edition, 2015.
  • Butterflies of Thailand, Pisuth Ek-Amnuay, 2nd Edition, 2012.
Text by Horace Tan, Photos by Koh Cher Hern, Low Jian-Kai, Lumin Ong, Sebastian Ow and Horace Tan.