23 June 2019

The Bamboo Feeders (Part 1)

The Bamboo Feeders (Part 1)
Bamboo-feeding Butterfly Caterpillars


A Common Duffer (Discophora sondaica despoliata) whose caterpillars feed on Bamboo

It is relatively well known that many butterfly caterpillars are very plant-specific in their diet. Unlike moth caterpillars, which can feed on many different plants, butterfly caterpillars are picky eaters and often feed on only one or two particular plant species. These plants, on which the caterpillars feed, referred to as "host plants", support their respective butterfly species. Without these specific plants, the corresponding butterfly species may cease to exist in a particular habitat.



Plants can generally be classified into monocotyledons and dicotyledons. Whilst it is beyond the scope of this article to discuss plant taxonomy and biology, we take a layman's view of plants on which these caterpillars feed, and their correlation to the butterfly families. In general, monocotyledons feature long, narrow-leafed plants with parallel veined leaves, whilst dicotyledons are generally broad-leafed with net-veined leaves.



This blogpost deals with a specific group of monocotyledons - the bamboos. From online resources, there are over 1,600 species of bamboos, and broadly split into two groups that describe how they grow in nature - clumpers and runners. In southeast asian countries like in Singapore, the clumpers are the more dominant species. The diversity of bamboo species is amazing, and identifying the spectrum of species is best left to the experts. Bamboo, like the coconut tree, has a myriad of uses in construction, cuisine, ornaments, medicine and everyday utensils.


The parallel-veined elongated leaves of the monocotyledon Bambusa spp

Coming back to bamboo and butterfly correlation, it is noteworthy to mention that caterpillars of only two families of butterflies feed on bamboo leaves - Nymphalidae and Hesperiidae. And if we move one level deeper, only a few species from two subfamilies - Satyrinae and Hesperiinae, use bamboo as their caterpillar host plants.


Malay Dwarf Bamboo (Bambusa heterostachya)

Hedge Bamboo (Bambusa multiplex)

Common Bamboo (Bambusa vulgaris)

We take a look at a few examples of the species from these two subfamilies that use bamboo as their caterpillar host plants. As research and data are continuously being updated and new finds are discovered and documented, the information that we have are by no means final. The intent here is to highlight the similarities and differences amongst the species that use bamboo as a host plant.

1) The Bamboo Tree Brown (Lethe europa malaya)



The English common name of the butterfly already suggests that the species is somehow connected to bamboos. This medium-sized species is by no means common, but can often be found in the vicinity of bamboo clumps around Singapore. It is an elusive species, skittish and hard to approach. Its caterpillars feed on bamboo leaves although it is likely to use different species of bamboos as its host plant.




The Bamboo Tree Brown is predominantly brown above, with females having a wider subapical band on the forewing compared to the male. The undersides bear a number of cryptic patterns with thick lilac ocelli on the forewing. There is a short "tail" at vein 4 of the hindwing. The butterfly stays close to bamboo thickets and flies low amongst the shrubbery.


A Bamboo Tree Brown perched on the sign of the Tinwa Bamboo at the Singapore Botanic Garden's Bamboo Garden Collection

A caterpillar of the Bamboo Tree Brown with its "cat ear" feature

The caterpillar is green and resembles the related species amongst the Mycalesis (Bush Browns), Ypthima (Rings), and Elymnias (Palmflies) in that they feature "cat ear" heads and a twin-tailed posterior. The Bamboo Tree Brown is relatively widely distributed across Singapore, and can be found quite regularly on Pulau Ubin and in the bamboo garden of the Singapore Botanic Gardens near the Eco-Lake.

2) The Common Duffer (Discophora sondaica despoliata)



The second Satyrinae species featured in this article, the Common Duffer can hardly be described as 'common' in Singapore these days. However, at times, its caterpillars have been found in numbers, feeding on the leaves of bamboo. The adult butterfly is elusive and stays in heavily-shaded thick vegetation. Its cryptic undersides camouflage it well, and unless it is disturbed and flies off, it is hard to detect.



The male is dark purple brown above with a series of obscure pale blue spots on the forewing. The female is also brown but with a series of yellowish-white discal and post-discal spots on the fore and hindwings. The underside is ochreous brown and heavily striated. There are few post-discal eye-spots on the hindwing. The female has a more angular protrusion at vein 4 of the hindwing.


The hairy caterpillars of the Common Duffer resemble moth caterpillars

The caterpillar of the Common Duffer may be mistaken for a moth caterpillar at first glance. It is hairy and features cryptic stripes and markings on its body. However, unlike similar-looking moth caterpillars, the hairs on its body are not urticaceous and do not result in rashes or any skin irritation if one were to touch them. The caterpillar feeds on a type of broad-leafed bamboo and the butterfly can sometimes be found in the same localities as the Bamboo Tree Brown.

3) The Bamboo Paintbrush Swift (Baoris farri farri)



Like the Bamboo Tree Brown, this species' common name instantly suggests its association with bamboos. The Bamboo Paintbrush Swift (and its close cousin, the Paintbrush Swift (Baoris oceia)) are regularly found in the vicinity of bamboo thickets in Singapore. They are skittish, but are often observed to rest on the uppersides of leaves with their wings folded upright in shaded areas in the undergrowth.




On the upperside, the wings of the Bamboo Paintbrush Swift are dark brown. The forewing has hyaline spots in spaces 2-4, 6-8 and 2 cell spots. The female is usually fully spotted and has an additional non-hyaline spot in space 1b on the forewing. The hindwing does not bear any spot, but the male has a black hair tuft in the cell on top of a scent pouch (hence "Paintbrush" in its common name). On the underside, the wings are pale brown and similarly ``spotted'' as per the upperside.


The caterpillar of the Bamboo Paintbrush Swift with its unique head pattern

The caterpillar has a green body, usually covered with a whitish waxy powder. It folds the bamboo leaf as a shelter in which to conceal itself. In its later instars, the black head transforms into a unique black-and-white patterned 'face' that helps to distinguish the species from other lookalikes. The caterpillars use several species of bamboos as their host plants, of which two - Bambusa multiplex and Bambusa vulgaris have been identified.

4) The Common Redeye (Matapa aria)


A Common Redeye with its prominent bright red eye perches on a leaf

The Common Redeye is widespread in its distribution across Singapore. Although the adult butterfly is not as common as its name suggests, it makes its appearance regularly in parks and gardens, as well as in the fringes of the nature reserves. Again, bamboo, being its caterpillar host plant, indicates that the species is usually not far from where bamboos grow.




The Common Redeye's wings are a buff-brown above and unmarked. The underside is a more orangey-brown with the hindwing cilia prominently yellowish-white. The eyes of the butterfly are a deep red and stands out prominently. It is a fast-flying species, although more often spotted at rest with its wings folded upright in shaded undergrowth.


The caterpillar of the Common Redeye constructs a leaf shelter to conceal itself

The caterpillar uses several bamboo species as its host plant and is more often spotted, than the adult butterfly. The 5th instar caterpillar has a head which is orange-coloured with no markings, and its body much more whitish in appearance with a slight hint of a yellow tone. The anal plate does not bear any marking.



And so, bamboos, an easily cultivated plant used for horticultural use in landscaping, but which also grows wild in various areas in Singapore, belong to group of plants that butterfly caterpillars use as their host plant. These species depends on bamboos for their continued survival in our environment. In the next part of our bamboo-feeding butterfly caterpillars, we will take a look at four other skippers whose life history depends on bamboos.

Text by Khew SK : Photos by Foo JL, Huang CJ, Khew SK, Loh MY, Jonathan Soong, Horace Tan, Bene Tay and Anthony Wong

References :

15 June 2019

Bobs of Singapore

The Bob Skippers of Singapore
Featuring Skippers with the English name Bob



This weekend's blogpost looks at a number of butterflies from the Hesperiidae family that have been given the English common name of "Bob". Common names of butterflies have always been intriguing in that it is hard to say for sure what were the thoughts of the early authors who coined these names for the butterflies.



Think of the name "Bob" and probably the first thing that comes to mind would be the name of a person. However, a quick search on the internet would give "Bob" a series of different meanings that can range from a hairstyle to a coin used in the UK to a short abrupt motion, amongst many other definitions. The English language is rather complex in this instance, where a single word carries many different meanings.



But the subject of this article focuses on our butterflies, and the several species that carry the name "Bob". Interestingly, the majority of species that I have come across that are called "Bob" are in the family Hesperiidae (or Skippers). It would be interesting to find out what the intent of the origins of the name "Bob" for these skippers. Was it because of the way they fly? Or perhaps their size? We will never know for sure. Nevertheless, in Singapore, we have 4 species of skippers with the name Bob.

1) Chestnut Bob (Iambrix salsala salsala)



The Chestnut Bob is a common butterfly that is quite widespread in distribution across Singapore. It is more often found in urban parks and gardens flying low but rapidly around open grassy patches, but can also be found at the fringes of nature parks amongst the low shrubbery. It often stops to sunbathe in the typical skipper pose with the hindwings opened flat whilst the forewings are held open at an angle.





The species is dark brown on its uppersides with a paler post-discal band in the male, and white spots in the female on the forewing. The underside is a reddish brown with a series of silvery-white spots on both wings. The butterfly is small, with a wingspan of about 25-30mm and flies rapidly. The caterpillar of this species feeds on the Common Cow Grass (Axonopus compressus) amongst other varieties of grasses.

2) Starry Bob (Iambrix stellifer)



The Starry Bob (or Malayan Chestnut Bob) superficially resembles the Chestnut Bob. It is, however, a forest-dependent species and is rarely found outside the forested nature reserves in Singapore. It flight and habits also mirrors its more common cousin. Within the nature reserves, it is regularly found feeding on the flowers of the Bandicoot Berry (Leea indica).





The upperside of the Starry Bob is dark brown and unmarked. On the underside, it appears reddish brown but has an orange-speckled appearance, particularly on the forewing apical area and the basal area of the hindwing. Like the Chestnut Bob, both wings feature a series of silvery-white spots except for the diagnostic white spot in space 5 of the hindwing, which is placed between the cell end and termen.

3) Palm Bob (Suastus gremius gremius)



The Palm Bob (or Indian Palm Bob) was recorded as a new discovery for Singapore when it was added to the checklist of butterflies in Singapore in the 1990's. Back then, reference books described the species as "very rare" and confined to only mangrove areas in northern Malaysia. Perhaps in those years, the species had just made its appearance from India through Thailand and was uncommon.





Today, the species is widespread and common in parks and gardens. A medium brown butterfly, there are a few large yellowish-white spots on the wings on the forewing above. The underside is a paler brown, and overlaid with buff scaling with a number of sharply defined discal black spots. The caterpillars of this species feeds on a variety of palms, a few of which are ornamental palms that are commonly used in urban landscaping.

4) White Palm Bob (Suastus everyx everyx)



Again another new discovery to Singapore when it was recorded, the White Palm Bob is rare and confined to the forested areas of our nature reserves. Being a small and insignificant species, usually spotted hiding amongst undergrowth in heavily shaded forests, the White Palm Bob may have been missed by the early authors. It is skittish and a fast-flyer, but often stops to rest with its wings folded upright. It has been observed to puddle at damp muddy areas and also on bird droppings.






The species is dark brown above and unmarked, except for a narrow whitened area at the tornus of the hindwing. The underside is a lighter brown and the hindwing is largely whitened. There are a few black spots on the hindwing of which there is one large submarginal spot at space 2 of the hindwing. The caterpillars of this species feeds on a type of thorny palm that is normally found in forested areas.

Text by Khew SK : Photos by Huang CJ, Khew SK, Koh CH, Loh MY, Jonathan Soong, Horace Tan, Anthony Wong and Benjamin Yam

This article is dedicated to one of ButterflyCircle's veteran member, "Uncle" Bob Cheong, who is taking a break from butterfly photography due to a personal domestic issue. We hope that Bob will return soon to our beloved butterflies and share his awesome photos that have been a source of enjoyment for many of his fans.

09 June 2019

Buffer Parks to Nature Reserves

Buffer Parks to Nature Reserves
An Effective Means of Conserving Biodiversity?


A mating pair of Common Posy shot at Dairy Farm Nature Park

Recently, the Gardens Bulletin Vol 71 (Supplement 1) was launched. This special issue features the Comprehensive Biodiversity Survey of Bukit Timah Nature Reserve - a survey that spanned over two years. The section on butterflies, titled "Butterflies of the Bukit Timah Nature Reserve, Singapore, and its vicinity" covered five transects featuring various habitats. In my discussion, I made reference to the usefulness of green buffer parks to BTNR and how these buffer parks play an important role in sustaining butterfly populations through judicious planting of nectaring sources for butterflies.


A total of 8 nature parks designated as "green buffers" to our nature reserves, will be developed over the years © NPARKS

Since 2001, the National Parks Board of Singapore has been introducing these nature parks as "green buffers" to help to reduce visitorship pressure on the nature reserves by providing interesting alternative venues for the public to enjoy nature-related activities. The development of these nature parks is part of a holistic approach to strengthen the conservation of the biodiversity in Singapore’s nature reserves.




Some of the rarer forest-dependent Awl species found at our nature parks

By providing visitors with alternatives to the Bukit Timah Nature Reserve, these nature parks will help to alleviate issues such as soil compacting, littering, pollution and noise levels at the reserves. At the same time, nature parks serve as physical buffers against urban development for the nature reserves. NParks aspires to "boost the diversity of plants in the nature parks and create a landscape akin to a mature rainforest."


URA's land use plans showing the nature parks as green buffers around Bukit Timah Nature Reserve © Urban Redevelopment Authority

Around BTNR, the nature parks that buffer the nature reserves are Dairy Farm Nature Park (also includes the Singapore Quarry area), Hindhede Nature Park and the future Rifle Range Nature Park. Some of the areas covered by these buffer parks are designated as interim use until such time when the land is required for development. In the recent Draft Master Plan 2019, the areas covered by Nature Reserves, Nature Parks, Utilities and Reserve Sites are clearly demarcated.


© Urban Redevelopment Authority

Although BTNR is a gazetted Nature Reserve, the buffer parks have not been granted such a protected status as yet. However, the benefits of such buffer areas to the nature reserves cannot be understated. Both the Dairy Farm Nature Park and Rifle Range Nature Park are areas of amazing butterfly diversity. During the survey of BTNR, evidence showed that these buffer parks had more butterfly species sighted than within BTNR itself.




Some forest dependent species observed at Dairy Farm Nature Park - Blue Helen, Bamboo Tree Brown and Royal Assyrian

So how effective are these green buffer parks?  In just the past year, after Dairy Farm was "renovated" and the vegetation judiciously managed and native plant species cultivated along the trails and forest edges (in particular nectaring plants), many rare forest-dependent species have been sighted. These species would not have been so easily encountered within BTNR itself if not for the appropriate butterfly-attracting vegetation planted at the adjacent buffer parks along the forest edges and trails.



The Malayan Jester is now a resident species at Dairy Farm Nature Park

One species, the Malayan Jester (Symbrenthia hippoclus selangorana), once very rare, with only a couple of sightings when it was first recorded in Feb 2012 as a new discovery for Singapore, has become a "resident" species at Dairy Farm Nature Park. This species frequents the main trail at DFNP and at times, several individuals have been observed. From the frequency of sightings in 2018/2019 and the pristine condition of the individuals when sighted, it is obvious that there is a viable breeding colony of this species in the area.





Over at the Rifle Range area, which abuts BTNR (at its southern boundary) and which is connected to the Central Catchment Nature Reserves (CCNR), butterfly diversity is also relatively rich. Although BTNR is separated from CCNR by Bukit Timah Expressway, an eco-link was subsequently constructed and opened in 2013 in an effort to reconnect the two nature reserves.



Two uncommon species found at Dairy Farm Nature Park and Rifle Range Nature Park - Yellow Archduke and Hieroglyphic Flat

When the Rifle Range Nature Park (another green buffer to BTNR) is completed in 2020, it is likely to be a good area to spot rarer butterflies that inhabit the forests of BTNR and CCNR, when they come out to feed. The development of these nature parks is good on two counts - firstly, it relieves the pressure on the two nature reserves from visitors, and secondly, it provides for good access for surveys and nature observers to record our local forest-dependent butterfly species.



Two forest-dependent species found at Dairy Farm Nature Park and Rifle Range Nature Park - White Spot Palmer and Banded Yeoman

Some examples of the more notable species of butterflies spotted in the nature parks/buffer parks like Dairy Farm NP and Rifle Range NP are featured throughout this article. Taken by various photographers and butterfly watchers over the past few years, many of the species found in these areas are those that are forest-dependent, and not those that we are familiar with, in urban parks and gardens.






There is therefore an important function of these green buffer parks in the ecological conservation of our main nature reserves. These nature parks that buffer the nature reserves play a critical role in the conservation of our forest-dependent butterfly biodiversity that urban parks and gardens cannot replicate.

Text by Khew SK : Photos by Alan Ang, Goh YL, Khew SK, Michael Khor, Lim CA, Michael Soh, Jonathan Soong and Alson Teo