Butterfly of the Month - September 2019

Butterfly of the Month - September 2019
The Common Duffer (Discophora sondaica despoliata)


A portrait of a butterfly : A freshly eclosed Common Duffer perched on flowers of Lantana camara

We tread into the 9th month of 2019 as the summer heatwave begins to ease off slightly. Already, there have been reports of torrential rains and floods affecting certain countries around the world. As the monsoons bear upon countries like India and parts of Indo-China, the intensity of rainfall and volumes have changed over the decades, making predictions and flood-mitigating measures difficult.

Singapore prepares for climate change, as outlined in Prime Minister Lee's National Day Rally speech last month, by (1) understanding the issue (2) take measures to mitigate it and (3) adapt to it. As a low-lying city state near the equator, Singapore is more vulnerable to sea level rise than most countries.

As it is, various pilot projects have been tested to prevent local infrastructure from being affected by rising sea levels. Platform levels for new infrastructure is being raised, and new developments are required to be built at least 4m above mean sea level. Research on polders and dikes are being carried out on the offshore island of Pulau Tekong and these experiments are likely to be implemented in a large scale on the main island of Singapore in time to come.

A Common Duffer typically lurks in dark shady vegetation 

In the meantime, the Cross Island MRT Line is back in the news. The future Cross Island MRT Line that will stretch from Tuas to Changi can either run under the Central Catchment Nature Reserve or go around it. Generating controversy for the past few years, nature groups continue to be up in arms against the MRT line cutting across the nature reserve. The initial feasibility studies have shown that both options can be made to work. Furthermore, the MRT line that cuts across the CCNR will now be planned to be 70m deep under the nature reserve, instead of 40m as originally intended.


A Common Duffer feeding on some nutrients on a twig

The decision of the alignment of the MRT line will be made some time next year. Both nature groups and the public, particularly the homeowners whose properties may be affected by the option to skirt the MRT line around the nature reserve, say their piece for or against either option. The two options obviously have their respective pros and cons, and the government will make a final decision soon.



We come back to our feature butterfly for the month of September 2019, the elusive Common Duffer (Discophora sondaica despoliata). The species is anything but common, as what its English common name suggests. Adults are rarely seen in Singapore, although it is quite widely distributed across the island. It can be found in the vicinity of its host plant, bamboo (Bambusa spp.)


Two female Common Duffers

The butterfly has been observed, usually singly in heavily shaded forested areas. But it can also be found in areas around bamboo groves, like the Singapore Botanic Gardens and even on Pulau Ubin. The Common Duffer lurks amongst heavily vegetated areas, staying quite still unless disturbed. It is skittish and is hard to approach when disturbed from its hiding places.



The Common Duffer is dark brown with a series of obscure pale blue spots on the apical half of the forewing in the male. The female is also a similar shade of brown on the upperside, but with a series of mauve post-discal spots and sub-marginal spots on the forewing and orange post-discal and sub-marginal spots on the hindwing. The female has a more pronounced protrusion at vein 4 on the hindwing making the hindwing appear slightly more angular.


A female Common Duffer perches on palm leaves



The underside is ochreous brown and heavily striated with the distal half of the wings a lighter shade. There are a few post-discal eyespots on the hindwing. In a sidelight, there is a purplish wash on parts of both wings.


A Common Duffer from Hong Kong feeding on some organic matter


Two Common Duffers from North Thailand

Males of the species have regularly been observed to puddle on decomposing organic matter and along damp footpaths that have been tainted with animal excretion. Females are more often seen feeding on overripe fruits and in particular the fruits of the Singapore Rhododendron (Melastoma malabathricum)


The hairy caterpillars of the Common Duffer resemble moth caterpillars

Occasionally, its caterpillars can be found in small numbers on its caterpillar host plant, bamboo. The caterpillars are typical of the genus in the sub-family Satyrinae and are hairy and moth-like. Early instar caterpillars are gregarious and often feed in a group.

Text by Khew SK : Photos by May Chan, Antonio Giudici, Federick Ho, Khew SK, Loh MY, Jonathan Soong and Liyana Zolpakar

Special thanks to Foo Jit Leang for discovering several clutches of caterpillars on the bamboo plants near his home to allow us a chance to observe and photograph the Common Duffer more easily

The Fruit Feeders

The Fruit Feeders
Fruit-feeding butterflies in Singapore


A Saturn (Zeuxidia amethystus amethystus) feeding on a fermenting fruit on the forest floor in the nature reserves

Butterflies' liquid diet can vary from nectar to carrion and sodium-rich puddles to fermenting fruits on the forest floor. This weekend's blogpost takes a look at some encounters of various species of butterflies that feed on overripe fruits and fruits of forest trees that are decomposing on the forest floor.

A pair of Archdukes feeding on rotting fruit

Not all species of butterflies feed on fruits that have dropped on the forest floor. These fruits that are produced by a variety of trees in the nature reserves of Singapore, either ripen and drop on the forest floor, or have been eaten by birds, macaques and other animals and the remains of the uneaten fruits fall onto the ground and ferment over time.

Four butterflies - Dark Blue Jungle Glory and Common Faun feasting on rotting fruit on the forest floor

When fruits start to rot, the main product of the fermentation process is likely to be acetic acid. Whilst the flesh of many fruits contain several types of sugars, the concentration of lactic acid during the fermentation process is an indicator of a just-ripe fruit with maximum sugar content. This is why when a fruit is not ripe enough or too ripe, butterflies are not attracted to them. Hence there appears to be an optimal period during the fermentation process where butterflies can be found feeding on the fruits.


Three Saturns feeding on discarded overripe pineapples on the forest floor

A Dark Blue Jungle Glory foraging amongst fallen fig fruits

So, do all butterflies feed on rotting fruits? The answer, as with many things to do with butterflies, is "it depends". Not all species of butterflies feed on fruits, and there are cases where certain fruits only attract some species, whilst other fruits attract different other species. Generally, the forest-dependent fruit-feeding species are largely from the sub-families Satyrinae, Limenitidinae, Charaxinae and Nymphalinae. Even so, not all species in the sub-families mentioned above are fruit feeders. Field observations show that quite a number of the fruit-feeders are those that prefer low-light conditions and keep low on the ground in the shaded forest understorey.


The ripened fruit of the Singapore Rhododendron (Melastoma malabathricum) attracts a Bush Brown and an Arhopala - a rare sight in itself, as Arhopalas are rarely seen to feed 

Amongst the six families of butterflies, the Papilionidae, Pieridae, Riodinidae, Lycaenidae and Hesperiidae species are very rarely observed feeding on fruits. With some exceptions of some Lycaenidae, which have been observed feeding on the ripened fruits of the Singapore Rhododendron (Melastoma malabathricum), it is pretty rare to see a Lycaenidae feeding on rotting fruits on the forest floor.



The Common Faun feeding on fallen fruits



Amongst the fruit feeding species that are regularly observed on fermenting fruits on the forest floor, are species like the Common Faun (Faunis canens arcesilas), Saturn (Zeuxidia amethystus amethystus) and Dark Blue Jungle Glory (Thaumantis klugis lucipor). It is also likely that the recently confirmed Dark Jungle Glory (Thaumantis noureddin noureddin) would also be attracted to such fermenting nectar source.




Amongst the Limenitidinae, the Malay Viscount and Malay Baron are often observed to feed on fallen fruits along forest footpaths

Amongst the species of Euthalia and Tanaecia/Cynitia we have observed the Malay Viscount (Tanaecia pelea pelea) and the Malay Baron (Euthalia monina monina), feeding on rotting fruits on the forest floor. Other species in these two genera have not been so often observed to display this behaviour and more field observations can be made to validate this.





The Archdukes, Rajahs and Nawabs are often "customers" of overripe fruit on the forest floor

All three species of the Lexias have been encountered to feed on rotting fruits on the forest floor. Both males and females of the species are equally attracted to the fruits when the sugar content from the fermentation process is optimal. Amongst the Charaxes and Polyura species, some have also been observe to like feeding on rotting fruits.


A sample of the type of fruits that, when ripened and fall on the forest floor, attract butterflies

In Singapore's forests, fruits of various species of figs (Ficus spp) that have fallen on the floor are the most popular source of sugars for these fruit-feeding butterflies. There are many species of figs growing in our forests, and these are a good source of sugars for these species of butterflies, besides being food for the animals and birds.


A Common Evening Brown feeding on overripe Jambu Air at Sg Buloh Wetland Reserve


And then there are other cultivated fruits like the pink Jambu Air or Water Apple, tends to also attract some species like the Common Evening Brown (Melanitis leda leda) and the Bamboo Tree Brown (Lethe europa malaya). There are also several species of the jambu (Syzygium spp) where the fruits attract butterflies. On Pulau Ubin and Sg Buloh Wetland Reserve, we have observed butterflies feeding on the fruits when the trees drop their overripe fruits on the floor. Other species like the Bush Browns (Mycalesis spp) and Common Palmfly (Elymnias hypermnestra agina) are also attracted to some of these fruits.


A Palm King feeding on discarded watermelon

The large Palm King (Amathusia phidippus phidippus) is another species that can be found feeding on fruits. We have had a couple of observations of several individuals of this species feeding at discarded fruits from a roadside fruit vendor in Malaysia. In the picture above, the Palm King was photographed feeding on a half-eaten watermelon that had been thrown away along a footpath at Chestnut Nature Park.



Butterflies feeding on fruit servings in commercial butterfly parks.  A Yellow Barred (now extinct in Singapore) feeding on overripe banana and a Palm King feeding on pineapple at Entopia, Penang

In commercial butterfly parks, one can often see many species of butterflies feeding on rotting banana, papaya, mango, pineapple and many other sugar-laden domestic fruits that are left to ferment on artificial feeders. There are also many websites that teach butterfly gardeners how to use fruit hangers to attract butterflies to their gardens.

Text by Khew SK : Photos by Khew SK and Loke PF

Flying Tigers 2.0

Tiger Refresh!
An Update of the Flying Tigers of Singapore

Some time back in January 2008, our weekend blogpost featured the Flying Tigers of Singapore. More than 11 years ago, there were 5 extant Danainae species that were referred to as "Tigers". Their common names probably originated from their striped appearance, and in some of the cases, the orange colour and/or stripes, reminiscent of the Malayan "Pak Belang".

Over the years, at least three other species appeared in Singapore and were spotted by eagle-eyed butterfly watchers and photographers. All these species have been classified as vagrants as sightings of them have been infrequent, and in some cases, only from a single chance encounter.

The Tigers belong to the subfamily Danainae, relatively large and slow-flying butterflies that are usually distasteful to predators. This is due to their caterpillar host plants that are lactiferous and in most cases, contains toxic substances which the caterpillars sequester to give themselves a "chemical protection" against predators.

The majority of species in the subfamily Danainae also display aposematic colouration, which is nature's way of communicating to would-be predators that the butterfly should be avoided, unless the predator is asking for some trouble. The characteristic stripes, iridescent colours or bright and showy colours of the Danainae are good examples of aposematic warning colouration that other butterflies and moths mimic to provide some measure of protection for themselves.

Today, the 5 extant species of Tigers that we featured in the 2008 blogpost are still doing fine, and over the past decade, where urban parks and gardens have cultivated more Tiger-friendly host and nectaring plants, they have become more common. These five species - The Plain Tiger, Common Tiger, Black Veined Tiger, Blue Glassy Tiger and Dark Glassy Tiger are still often seen feeding at the flowers in parks and gardens.

In Oct 2014, another species of the genus Ideopsis, the Grey Glassy Tiger (Ideopsis juventa sitah) was observed at Pulau Ubin, and then subsequently in the same year, at the Singapore Botanic Gardens. This species is not uncommon up north in Johor, and has been seen in numbers at the Desaru area on the eastern coastal areas of Johor.




It is possible that an outbreak of the species has sparked off some strays into Singapore. It has not been reliably seen in recent years after the sightings in 2014, but added to the Singapore Butterfly Checklist as a vagrant species appearing in Singapore.

In 2016, a free-ranging Dark Blue Tiger (Tirumala septentrionis septentrionis) was photographed in the field. The Dark Blue Tiger has been sighted previously but no photographic evidence of a Singapore field-shot individual was recorded so far. Also, at that time, the butterfly aviaries in Sentosa, Hort Park (now closed) and Changi Airport also imported this species from Malaysia and there may have been escapees.

In Jan 2019, another wild shot individual was posted from Pasir Ris Park. Although still considered a vagrant species, the Dark Blue Tiger was added to the Singapore Checklist and 'adopted' as one more flying tiger in Singapore.

Also in 2016, a single individual of the Blue Tiger (Tirumala limniace) was spotted at a suburban garden feeding on Crotalaria retusa. The Rattlebox Weed is a favourite plant of the Danainaes where they feed on the sap of the stem and seedpod of the plant. A rare species even in Malaysia, it was therefore a surprise that a pristine vagrant appeared in Singapore.

Perhaps, as the author suggested, the Blue Tiger shot 5 years ago was a stowaway on a plant that was imported to Singapore as a pupa, and then eclosed here. Other than this individual, so far no other sighting of the Blue Tiger has been made in Singapore since.



This is the latest inventory of "Tigers" in Singapore, with a total of eight sighted and recorded over the years.  Let us hope that there will be other Tigers that will make their way to Singapore in the coming years.  

Text and Photos by David Chan, David Ho, Mei Hwang, Khew SK and Loke PF