Butterfly of the Month - September 2025

Butterfly of the Month - September 2025

The Malay Dartlet (Oriens paragola)

A Malay Dartlet perches on a Coat Button flower

September 2025 is almost over as Asia struggles with destructive tropical cyclone Bualoi sweeping across Philippines, Vietnam, Hong Kong and southern China. Occurring with alarming regularity in this era of climate change, these destructive cyclones and typhoons bear across Asia, usually with fatalities and severe damage caused to property. The low-pressure front has also brought wet weather to Singapore and Southeast Asia.

Locally, the inauspicious Hungry Ghost month ended on 21 Sep and in shopping malls and online, mooncakes are being pre-ordered and sold as the Chinese community look forward to Mid-Autumn Festival with lanterns and mooncakes. It is also a month where many Chinese couples prefer to tie the knot, and hotels will usually be fully booked for weddings.

Singapore has also taken a tough stance on "vaping". For quite some time now, vaping was tolerated as a "safer" alternative to smoking. Despite being illegal in Singapore, enforcement was low on these devices that use heat to create an aerosol that is inhaled by the vaper. However in recent months, the use of Kpods containing etomidate, normally used as an anesthetic or sedation drug. The effects of a vaper using etomidate may cause symptoms like drowsiness, confusion and loss of consciousness.  What is more alarming is that vaping equipment have been found in primary school premises, implying that some users may even be well underaged.

So vaping with Kpods containing etomidate and other potential hallucinatory drugs is now considered as a Class C drug under the Misuse of Drugs Act, and punishable under Singapore law. Visiting foreigners whose countries allow vaping are advised to surrender their vaping devices upon entering Singapore. The public has also been informed to report vape-related offences to the authorities.

A Malay Dartlet feeding on bird dropping and excreting fluid through its abdomen at the same time

Our feature butterfly for the Month of September 2025 is the recently-discovered Malay Dartlet (Oriens paragola). First sighted at Sg Buloh Wetland Reserve in 2011, this diminutive Hesperiid has since spread across the island to our urban parks and nature reserves. One of the reasons of its rapid distribution may be because its caterpillar host plant is a common grass species - Ottochloa nodosa which grows quite abundantly across a wide variety of habitats.

A Malay Dartlet falls prey to a Crab Spider whilst it is distracted when feeding at a Leea indica bush

As it was not listed in the early authors' checklists, the Malay Dartlet is still considered an exotic species on the Singapore Red Data List. Until the time of its discovery, the genus Oriens was only represented by a single species, the Common Dartlet (Oriens gola pseudolus) in Singapore. There is a third species, Oriens goloides which has not been reliably seen in Singapore yet.

Malay Dartlets feeding on the flowers of the Bandicoot Berry (Leea indica)

The Malay Dartlet is distinctive in having undersides which are dark chocolate brown with a contrasting bright orange-yellow discal patch on the hindwing. The upperside of the wings are dark brown with orange-yellow post-discal bands on both the fore- and hindwings. There are orange-yellow cilia on the hindwing termen in pristine individuals. The post-discal bands are sharply defined and not edged with black spots.

When the Malay Dartlet perches on a leaf, it usually folds its forelegs and stands on the remaining four legs giving the perception that it only has 4 legs instead of 6!

This species is quick on the wing and often observed feeding on small flowering plants in various habitats. In recent years, it can be considered more commonly seen than when it was first discovered 14 years ago. It has spread across to park connectors, urban parks and various other habitats where its host plant grows in abundance. It is highly likely that its caterpillars feed on other species of grasses.

A female Malay Dartlet ovipositing on a leaf of its host plant

The Malay Dartlet has been successfully bred locally on its caterpillar host plant, Ottochloa nodosa (Slender PanicGrass) after its discovery in 2011.  The species is now quite well distributed across Singapore and is not considered rare today.  

Text by Khew SK : Photos by  David Ho, Federick Ho, Khew SK, Koh CH, Ong LM, Michael Soh and Horace Tan

Life History of the Malay Dartlet

Life History of the Malay Dartlet (Oriens paragola)

Butterfly Biodata:
Genus: Oriens Evans, 1932
Species: paragola de Nicéille, 1896
Wingspan of Adult Butterfly: 22-27mm
Caterpillar Local Host Plant: Ottochloa nodosa (Poaceae).

Physical Description of Adult Butterfly:

Above, both sexes are dark chocolate brown with amber-coloured post-discal bands on both fore- and hindwings, and amber-coloured cilia on the hindwing termen. The forewing band stretches from the dorssm to almost touching the costa, and is deeply excavate at vein 5. The lower cell spot fuses with this band at space 2. The hindwing post-discal band is shorter, stopping well short of the costa.   Underneath, the wings are dark brown  with  post-discal bands mirroring those on the uppersides. These bands are sharply defined and not edged by black spots (as is the case of the Oriens gola, the Common Dartlet).

Field Observations of Butterfly Behaviour:

This species was not listed by early researchers as extant in Singapore. It was  discovered about one year ago and added to the Singapore checklist as species #297. According to C&P4, the Malay Dartlet frequents  lowland forests. However, adult sightings in Singapore  have so far been very infrequent and only confined to one grassland adjacent  to a forested area. The species has a preference for perching in semi-shady areas, and visiting flowers in the grassland for nectar. Given that the larval host plant is a common grass species, there is a possibility that Malay Dartlet exists elsewhere in Singapore. Even if this is not so now, this species  has the potential of spreading beyond the currently known location.

Early Stages:

The host plant, Ottochloa nodosa, is a common grass species which can be found in many locations in Singapore and is utilized by several other common skipper spp. (Common Dartlet, Chestbut Bob, and one Caltoris sp.) as larval host plant. The caterpillars of the Malay Dartlet feed on leaves of this plant, and live in shelters made by joining edges of a grass  blade together with silk threads.

Host plant: Ottochloa nodosa.

A female Malay Dartlet resting between oviposition runs.

A female Malay Dartlet laying an egg on the underside of a grass blade.

The eggs are laid singly on the underside of a leaf of the host plant. Between each oviposition run, during which one or two eggs are laid on separate leaves, the mother butterfly has the habit of  perching on a sunny spot  to re-energise  This could go on for a few rounds before the mother decides to retire altogether.  Each tall hemispherical egg is milky white and is finely recticulated.  The base diameter is about 0.75mm.

 

An egg of the Malay Dartlet.

A maturing egg of the Malay Dartlet.

A mature egg with the young caterpillar already nibbled away the polar part of the egg shell.

It takes about 5 days for the egg to hatch. The young caterpillar eats just enough of the shell to emerge, and will devour the rest of the egg shell after emergence. The newly hatched has a length of about 1.7-1.8mm. Its has a cylindrical body shape, very short dorso-lateral and sub-spiracular setae and a tuff of long setae at the posterior end. The body is creamy white with a prominent black collar on the dorsum of the prothorax. The head capsule is entirely black.

A newly hatched 1st instar caterpillar in the process of nibbling away its egg shell.

Two views of a newly hatched 1st instar caterpillar, soon after devouring the egg shell.

The body color changes to pale yellowish green after a few feeding sessions on the leaf. The newly hatched constructs its leaf shelter near the tip of a grass blade soon after it is done with the egg shell. Between feedings on the nearby leaf lamina, the caterpillar retreats to its shelter for rest and security. By the time the caterpillar lies dormant in its shelter for the moult to the 2nd instar, its length has reached about 4-4.5mm. The 1st instar takes about 4-4.5 days to complete.

Two views of a 1st instar caterpillar, early in this stage, length: 2.4mm.

Two views of a 1st instar caterpillar, late in this stage, length: 4mm.

The 2nd instar caterpillar is again whitish, but appears to be yellowish green with its "stomach" contents showing through the translucent cuticle.  The anal plate still carries a few setae but these are not as long and prominent as in the 1st instar. Although the prothoracic collar is still present, it appears to lose lighter in its black coloration. The head capsule is still black in colour. This instar lasts about 3-4 days with the body length reaching about 6.5-7mm.

Two views of a 2nd instar caterpillar, early in this stage, length: 4.2mm.

Two views of a 2nd instar caterpillar, length: 5.2mm.

The 3nd instar caterpillar resembles the 2nd instar caterpillar closely in body markings except for the diminishing black prothoracic collar.  Two faint whitish dorso-lateral bands, first appears in the 2nd instar but less obvious, are now discernible. This instar lasts about 2-3 days with the body length reaching about 8.5-9mm.

A newly moulted 3rd instar caterpillar, the head capsule is yet to turn black.

Two views of a 3rd instar caterpillar,  length: 7.2mm.

 

Two views of a 3nd instar caterpillar, later in this stage. length: 8.2mm.

The 4th instar caterpillar resembles the 3rd instar caterpillar closely but with the black prothoracic collar almost completely  diminished. As in the earlier instars, the head capsule is completely black and there is no markings on the anal plate.  This penultimate instar lasts 3-4 days with the body length reaching up to about 15.5-16mm.

Two views of a 4th instar caterpillar, early in this stage, length: 12mm.

 
Two views of a 4th instar caterpillar, late in this stage, length: 15.8mm.

The 5th (and final) instar caterpillar loses the black coloration of its head capsule seen in the earlier instars. The head is  now pale neutral yellow to neutral green. The body colour has a strong tone of yellowish white, with two broad and whitish dorso-lateral bands and two narrow pale yellowish lateral bands.  This instar takes about 6-8 days to complete with the body length reaching up to about 24-25mm.

Two views of a  newly moulted 5th instar caterpillar.

 
Two views of a 5th instar caterpillar, late in this intar, length: 24mm.

Towards the end of the 5th instar, the the body of the caterpillar shortens and its base coloration changes to a translucent pale green. Tyipcally it picks the underside of a grass glade for its pupation site. It becomes dormant in this shallow leaf shelter and enters the prepupatory phase which lasts for one day.  During this time period the caterpillar spins a silk pad with a transverse band for the grapers in its anal prolegs to attach to, and a silk girdle across the dorsum of the 2nd-3rd abdominal segments.

Two views of a pre-pupa of the Malay Dartlet.

The pupa  secures itself to the substrate with a cremastral attachment to the silk pad and the previously constructed silk girdle. It is yellowish green throughout and has  dorsal, dorso-lateral and lateral whitish to yellowish bands. There is a long and pointed snout, and the abdomen is relatively long.  Length of pupae: 18.5-21.5mm.

A Malay Dartlet caterpillar molts to its pupal stage.

Two views of a pupa of the Malay Dartlet.

On the last day of the pupal period, the pupa becomes mostly dark brown. Yellowish orange  markings against a dark brown background are now visible in the wing cases. Finally after about 7-8 days of pupal phase, eclosion takes place with the adult emerging from the pupal case.

Two views of a mature pupa of the Malay Dartlet.

A Malay Dartlet emerges from its pupal stage.

A newly eclosed Malay Dartlet.

References:

• [C&P4] 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 by Horace Tan, Photos by Koh Cher Hern, Loke PF, Chng CK, Sunny Chir, Khew SK and Horace Tan

Butterfly of the Month - January 2026

Butterfly of the Month - January 2026

The Common Dartlet (Oriens gola pseudolus)

A Common Dartlet perched on a blade of grass

A new year starts and we are already almost at the last day of the first month of 2026. Time waits for no one. Procrastinators will be left behind in the dust if opportunities are not grabbed quickly. All over Singapore, Lunar New Year decorations have already been put up, delicious seasonal goodies being sold and festive songs being played at shopping malls and other public venues, all waiting to herald the lunar new Year of the Fire Horse.

Globally, world powers are raising concerns about the overtures that the US has made towards Greenland. The US President has made it clear that he intends to acquire the world's largest island with a total of 2,166,000 square kilometres, by military force, if necessary. Also known as the "ice island", about 80% of Greenland is covered in ice. The US wants Greenland for its "geostrategic importance and sees the island as crucial to protect the US from Russia or China by having direct command of the Arctic approaches".

A quick check with ChatGPT shows that Greenland has only 5 regularly recorded butterfly species - one Pieridae, two Nymphalidae and two Lycaenidae, with a country checklist that records 8 species overall inclusive of the occasional migratory species. The climate is extremely cold with only a short summer hence only cold adapted species can survive there. Certainly not a preferred destination for butterfly watchers and enthusiasts!

Back in Singapore, January was an exceptionally windy month - far more windy than I can remember in recent years. The northern winds are still cold, lowering the average temperatures around the island. The north-easterly winds also brought a "burnt smell in the air" over a few days. The National Environment Agency reported that the potential haze could be due to peat fires burning in Johor and the smell carried over by the north-easterly winds. However, air quality remains in the good to moderate range, so there is no cause for alarm at the moment.

Our first feature butterfly for 2026 is the small and relatively common Hesperiidae, the Common Dartlet (Oriens gola pseudolus). It is one of two species from the genus Oriens that can be found in Singapore so far. The other one being the newly-discovered Malay Dartlet (Oriens paragola). The butterfly is a bright orange with an average wingspan of about 25mm. At various locations, it flies in the company of the other "Darts" from the Potanthus genus and can sometimes be mistaken for the other species that are more common.

Common Dartlet feeding on Bidens alba

The Common Dartlet is small and fast-flying like most species of the family Hesperiidae, and generally found in open sunlit areas, usually in the early morning hours. As the day heats up, if prefers to rest in shaded areas amongst the grassy patches. Its distribution in Singapore is quite widespread and it can be found in habitats ranging from urban parks and gardens as well as in the forested nature reserves. 

The Common Dartlet is dark brown with yellowish orange post-discal bands on both fore- and hindwings. The forewing band stretches from the dorsum to almost touching the costa and is deeply excavate at vein 5.  The eyes are solid and dark brown.

Common Dartlets feeding on flowers - top : Syzygium sp. bottom : Asystasia gangetica

On the underside, the wings are yellowish-orange with post-discal bands mirroring those on the upperside. The veins are barely dark-dusted across the orange-yellow markings. The hindwing bands are roughly bordered by varying degrees of black shading. The antennae are typical of Hesperiidae and ends with an apiculus at the tip.

A Common Dartlet puddling and using its own pee to extract the nutrients from the ground

The adults can be seen frolicking in sunlit areas and typically amongst grassy areas or low shrubs. They visit flowers for nectar and puddle on wet ground or even bird droppings for mineral intake. The caterpillars have been successfully bred on Ottochloa nodosa (Creeping Forest Grass) (Poaceae), Axonopus compressus (Cow Grass) (Poaceae), Centotheca lappacea (Sefa) (Poaceae).

Text by Khew SK : Photos by Alan Ang, David Chan, Federick Ho, Huang CJ, Khew SK, Loh MY, Richard Ong and Horace Tan.