20 September 2020

Butterfly of the Month - September 2020

Butterfly of the Month - September 2020
The Malay Staff Sergeant (Athyma reta moorei)

A typical male Malay Staff Sergeant with the twice-constricted forewing cell streak

The month of September 2020 is well into its second half, and this year, the first half of the month coincided with the Chinese Hungry Ghost Festival. In Chinese folk legend, the seventh lunar month is the Ghost Month. It is said that every year on the first day of the seventh lunar month, the Gates of Hell will be wide open and the ghosts will come out until the gates are closed on the 30th day of the month, which fell on the 16 Sep this year. So we are now into the 8th month of the Lunar Calendar, and looking forward to delicious moon cakes.

The COVID-19 situation in Singapore appears to be improving, with low double digit infection cases in the recent few days, and few or no cases at all in the community. This is a good sign that the pandemic is well under control, and Singaporeans from all walks of life look forward to further relaxation of the controls that were put in place to manage the spread of the virus. But all these controls have been at the expense of the economy - and a valid trade-off.  Even so, Singapore's estimated Gross Domestic Product (GDP) for the full year is expected to land somewhere between -6% to -7% - its worst economic contraction since its independence in 1965!

As the economy takes a severe beating, the spectre of increased unemployment, job losses and salary cuts loom over the horizon. There is little cheer in the atmosphere, as our island state braces itself for the stormy seas ahead. Even as the government rolls out various measures to ease the pain of businesses and individuals, such schemes are not sustainable in the long term, and various sectors are compelled to craft new strategies to adapt to the new norm and reinvent their businesses to stay afloat.

The race is on, for a vaccine to eliminate the never-ending outbreaks and recurrence of the virus. Optimistically such a vaccine is hoped to wipe out the COVID19's effect across the globe. The current estimate of infections globally has already passed 30.8M with over 958,000 fatalities due to the virus.  The numbers continue to climb every day, with the US, India and Brazil taking the top three spots for total infections. And the world continues to search for a solution to end one of the most deadly pandemics in modern history.

Our Butterfly of the Month for September 2020 is a species that has recently made the news in taxonomic circles. The female of the Malay Staff Sergeant (Athyma reta moorei) had eluded many taxonomists and butterfly experts all this time. The discovery that the species is actually sexually-dimorphic was only made this year, after years of careful research and life history documentation. It is now confirmed that there is unlikely to be a black-and-white female of the Malay Staff Sergeant, and that the female is orange and black all along.

A puddling male Malay Staff Sergeant

The Malay Staff Sergeant is considered a rare species in Singapore, and is a forest-dependent butterfly. It is usually spotted singly feeding on flowers or puddling on damp sandy footpaths or streambanks.  The ripened fruits of the Singapore Rhododendron is also a favourite with this species. Interestingly, in Singapore, the females are more often encountered than the males. 

The diagnostic feature of the Malay Staff Sergeant is the twice-constricted white cell streak on the upperside of the forewing.  This streak is also well separated from the triangular spot beyond. The white bands in the males show a slight bluish tint at certain angles, but not as prominently as those in the related male Colour Sergeant.

The female is now known to be orange and black, and the differences between the female Malay Staff Sergeant and the lookalike female Colour Sergeant form-neftina are depicted in the annotated photo shown here. The female Malay Staff Sergeant is regularly observed singly, usually feeding at flowering plants or on the ripened fruits of the Singapore Rhododendron (Melastoma malabathricum)

Newly eclosed male (left) and female (right) Malay Staff Sergeant

The caterpillar host plant where it has been successfully bred on in Singapore, is Glochidion zeylanicum. The complete life history is recorded here.

Text by Khew SK : Photos by Huang CJ, Khew SK and Horace Tan

13 September 2020

Mistletoes and Butterflies

Mistletoes and Butterflies
Ecological importance of Parasitic Plants

A female Banded Royal opens its wings to sunbathe. A recent addition to the number of butterfly species whose caterpillars feed on mistletoe

A parasitic plant is a plant that derives some or all of its nutritional requirement from another living plant. All parasitic plants have modified roots, called haustoria, which penetrate the host plant, connecting them to the conductive system – either the xylem, the phloem, or both. This provides them with the ability to extract water and nutrients from the host. Parasitic plants which derive water/nutrients from the hosts and are photosynthetic are known as "hemiparasites".

The large leaves of the Malayan Mistletoe are able to support the big numbers of the common urban species like the Painted Jezebel.

There are currently 10 known species of parasitic plants extant in Singapore. Quite a few of these species, commonly referred to as "mistletoes", can be seen attached to a variety of host plants - from shrubs to large trees all around Singapore. Mistletoes are believed to have medicinal properties and used in traditional medicine to cure a variety of ailments like cough, diabetes, hypertension, cancer and as a diuretic.

In the popular Asterix and Obelix comics, the druid Getafix adds mistletoe as a key ingredient in his magic potion 

In the popular comic series Asterix and Obelix, the mistletoe is a key ingredient in the magic potion that endows our two heroes with superhuman strength. The druid Getafix, who makes the concoction, is often depicted in the comics cutting mistletoe, hidden amongst the lush treetops with a golden sickle that preserves the magical properties of the mistletoe.

The hemiparasitic Chinese Mistletoe attached to the host

Parasitic plants are not the most welcomed plants amongst arborists, tree maintenance personnel and gardeners. This is because, by virtue of the parasitic nature of these plants, they anchor themselves to a host shrub or tree and extract nutrients from the host. In very severe infestations, the parasitic plants may stunt the growth of the host or even kill it. However, in most cases, a host can support these parasitic plants for decades without significant adverse effect on the host. Nevertheless, these under-appreciated and misunderstood parasitic plants are often pruned and removed from the host.

The shiny leaves of the Rusty Mistletoe are reddish brown when young, but turn a deep green when mature

What then, are the ecological functions of these "parasites" of other plants? Plants research has shown that mistletoes are keystone species in forests and woodlands. A keystone species is one which has a very significant influence in an ecosystem, and if removed may cause undesirable impact to the ecology. Many birds, insects and aboreal mammals build their nests among mistletoes. A wide variety of animals and insects feed on the leaves, shoots, fruits, flowers and nectar of mistletoes.

The Singapore Mistletoe Story by Francis Lim - a book about the parasitic plants in Singapore

Amongst the species of mistletoes in Singapore, three are of particular importance to butterflies. They are host plants to a variety of common to very rare species of butterflies. This article explores these species of mistletoes which are hosts to the caterpillars of these butterflies. It is also likely that the remaining 7 species of mistletoes may be caterpillar host plants for other species of butterflies, but this has yet to be discovered and hopefully recorded in time to come.

1. Malayan Mistletoe (Dendrophthoe pentandra)

The lush green leaves of the Malayan Mistletoe with flowers on its stem

The Malayan Mistletoe is by far the most common mistletoe in Singapore. It is a familiar site on roadside trees and in urban gardens, especially where plants are neglected or unkempt. It is quite often seen on plants like the Shui Mei (Wrightia religiosa) in private gardens, as well as any urban trees where birds spread the seeds of this parasitic plant, ranging from fruit trees like mango and chiku, to a wide variety of other roadside trees.

This common parasitic plant is a caterpillar host plant to at least five different species of butterflies across three families. These are :
  1. Painted Jezebel (Delias hyparete metarete)
  2. Green Baron (Euthalia adonia pinwilli)
  3. (Tajuria dominus dominus)
  4. Peacock Royal (Tajuria cippus maxentius)
  5. Great Imperial (Jacoona anasuja anasuja)

The distasteful Painted Jezebel's caterpillars have somehow managed to sequester the chemicals from the Malayan Mistletoe to make itself unattractive to predators

Amongst these species, it is interesting to note that the aposematic Painted Jezebel is believed to be distasteful to birds and has somehow managed to sequester the chemicals in the Malayan Mistletoe as a protection against predators. This is something that the other 3 species that feed on the same host plant are not able to do so, or at least the adult butterflies are not known to be distasteful to predators.

The flowers of the Malayan Mistletoe

The Malayan Mistletoe is most likely dispersed mainly by the birds that feed on its fruits, and then transporting the seeds to other trees where the bird droppings, which contain the seeds, are deposited on the branches of other plants. As the seeds ripen, it will extend its haustoria (specialised roots) and penetrate into the host as it takes grip and grows. The haustoria of the Malayan Mistletoe tends to grow into a ball-like form as the plant matures.

2. Chinese Mistletoe (Macrosolen cochinchinensis)

A healthy growth of the Chinese Mistletoe

The next most common species of our local parasitic plants, is the Chinese Mistletoe, which, like the previous mistletoe, is also a stem hemiparasite. It attaches itself to the branches of its host and grows into a large bush that can span 1m-2m across. Depending on the size of the host, the growth of the Chinese Mistletoe can sometimes overwhelm and smother the entire host.

The Chinese Mistletoe is a caterpillar host plant to an even wider variety of butterfly species (some of which also feeds on the Malayan Mistletoe). These are :
  1. Green Baron (Euthalia adonia pinwilli)
  2. Centaur Oakblue (Arhopala centaurus nakula)
  3. Peacock Royal (Tajuria cippus maxentius)
  4. Banded Royal (Rachana jalindra burbona)
  5. Felder's Royal (Tajuria mantra mantra)
  6. Green Imperial (Manto hypoleuca terana)
  7. Great Imperial (Jacoona anasuja anasuja)
  8. Semanga superba deliciosa.

The flowers and fruits of the Chinese Mistletoe, on which the caterpillars of the Green Imperial and Banded Royal feed

The leaves of the Chinese Mistletoe are pinkish to red when young, turning light green and finally dark green as they mature. The mature leaves are stiff and slightly waxy. It should be noted, however, that several of the butterfly species' caterpillars actually feed on the flower buds and fruits of the Chinese Mistletoe, rather than the leaves.

A young shoot of the Chinese Mistletoe attached to its host via its specialised roots called haustoria

Like the Malayan Mistletoe, the Chinese Mistletoe is also mainly propagated by birds. Birds feed on the ripened globular fruits of the Chinese Mistletoe and once digested, the bird droppings are deposited on other plants as the bird moves in search for food. This gives a chance for the seeds to germinate and grow if a suitable host is found.

3. Rusty Mistletoe (Scurrula ferruginea)

The Rusty Mistletoe has a layer of fine brown hairs on the undersides of its leaves - giving it a "rusty" look

The last and slightly rarer species of mistletoe that plays host to butterfly caterpillars, is the Rusty Mistletoe. The leaves of this parasitic plant are green on top, but covered with a layer of fine brown hairs on the underside of the leaves, giving it a "rusty" appearance. As it grows, the main stem of the Rusty Mistletoe attaches to the host rather seamlessly, with a few side roots extending along the sides of the branch, growing the many little haustoria into the host.

The White Royal's caterpillars feed on the young shoots and leaves of the Rusty Mistletoe

This species of mistletoe is the caterpillar host plant for at least two species of Lycaenidae. These are:
  1. Great Imperial (Jacoona anasuja anasuja)
  2. White Royal (Pratapa deva relata
Both are rare species in Singapore. The White Royal was only recently re-discovered in 2007 but subsequently successfully bred on the Rusty Mistletoe.  The Great Imperial, which has been bred on all three mistletoes mentioned in this article, is the most versatile and its caterpillar accepts all three host plants.

A female White Royal perched on a leaf of the Rusty Mistletoe after ovipositing on the young shoots of the plant

Where it grows, the Rusty Mistletoe is not difficult to spot, as the brownish red appearance of its foliage sets it apart from its host. It grows into a relatively large bush that can measure 1-2m across. The flower of the Rusty Mistletoe has an interesting appearance of a brownish coloured hairy paw, whilst the fruit is a small hairy pseudo berry of about 1cm long.

Again, like the other mistletoes mentioned here, the Rusty Mistletoe is probably dispersed by birds that eat the fruits and then propagated by the bird droppings as the birds forage for food around the area. The seeds are also likely to stick onto branches of the host and then the haustoria anchoring the the plant to the host after the seed germinates, typical of the like the other species of stem hemiparasites.

In closing, we have taken a look at the more common mistletoes found in Singapore, and it is through keen observations with a dose of luck that we have discovered the range of species of butterflies that are dependent on these specific mistletoes for survival. If there is overzealous management of these "parasites" and their removal from their hosts, then it will critically threaten the existence of these species of butterflies (many of them rare) in Singapore. So the next time you see these parasitic plants around, leave them alone. The butterflies will thank you for that!

Text by Khew SK : Photos by Huang CJ, Khew SK, LohMY, Jonathan Soong and Horace Tan

References and Further Reading :

05 September 2020

Butterfly Photography at Our Local Parks - Telok Blangah Hill Park

Butterfly Photography at Our Local Parks
Featuring : Telok Blangah Hill Park

The Terrace Garden which leads up to the highest point of Telok Blangah Hill Park

In our earlier blogpost on the Southern Ridges Parks, we explored the 47 Ha Kent Ridge Park. Starting from west and moving towards east, the Southern Ridges comprises Kent Ridge Park, Hort Park, Telok Blangah Hill Park and Mount Faber Park. All the four parks are interconnected via walkways and overhead bridges. This weekend, we take a look at the next elevated park, Telok Blangah Hill Park.

An overview of Telok Blangah Hill Park which is connected to Hort Park at the western end at Alexandra Road, and to Mount Faber at the eastern end at Henderson Road

A view along the elevated Forest Walk, which connects Alexandra Arch to Telok Blangah Hill Park.

Telok Blangah Hill Park is bounded by Alexandra Road on its western boundary, and Henderson Road on its eastern boundary. This elongated park is about 34 Hectares in area, and covered with lush greenery over most of its area. It is connected to the Hort Park via the Alexandra Arch overhead bridge at its western boundary. A visitor entering from this end of the Park will trek the Forest Walk – a 1.3-kilometre-long elevated metal walkway that links Hort Park to Telok Blangah Hill Park.

Below the elevated Forest Walk is the Earth Trail.

A certain locations, the Earth Trail is connected to the elevated Forest Walk via staircases

Both the Earth Trail and Forest Walk end at the little metal shelter which then leads you onto Telok Blangah Green road

An alternative route along the same direction is the Earth Trail that brings you closer to the forest understorey. The Earth Trail is below the elevated Forest Walk and connects to the elevated walk at certain places via staircases. Both trails will lead a visitor to Telok Blangah Green. At the start of the Forest Walk is a shelter at which you can take a quick rest before proceeding to the other parts of this hill park.

A the top of Telok Blangah Hill Park, where a visitor gets a 360deg view of the surroundings

A view across the horizon of the Singapore skyline

A view downwards from the top at the Terrace Garden

Be prepared for lots of staircases and steps at Telok Blangah Hill Park!

The entrance to the Terrace Garden

Telok Blangah Green winds around the hillock which overlooks the Terrace Garden. The Terrace Garden consists of a series of semi-circular terraces situated at the top of the park. The top of this hillock is the highest point of the park and from here, you will be able to enjoy a breath-taking 360-degree view of Singapore.

Alkaff Mansion with its commanding view of the surroundings

Alkaff Mansion and more steps!

The forecourt at Alkaff Mansion

Walking along Telok Blangah Green will take you past the historic Alkaff Mansion, an elegant colonial bungalow built by a family of Arab Traders, which used to host grand parties for the social elite and who's who in 19th century Singapore. Situated on top of a knoll with a commanding view of the lush greenery around, Alkaff Mansion is now an F&B outlet today.

Some of the red-brick paths winding through the forested areas in the park

Brick path in the forested area.  There are stone tables/seats where one can take a good rest or even have a picnic under the shaded understorey.

As you continue to walk towards the east, you will pass a public rest room on the left, and the Therapeutic Garden on the right. The lush greenery all around the garden creates a restorative environment to engage the senses and to uplift both mental and emotional well-being while serving as complementary habitat for native biodiversity. Walk towards the Therapeutic Garden and take a short detour downhill towards the Stream Garden which brings you to the foot of the hill and the main road Telok Blangah Heights.

A pavilion to take shelter from the hot sun or pouring rain

And more steps!

Back up at the Therapeutic Garden, and on the left of Telok Blangah Green is a hilly patch of lush forested area with a network of quiet paths complete with stone tables and seats and a shelter from the elements. There are the occasional butterfly surprises around this area, and one should look carefully at the shrubbery that may attract some rarities.

Paved road leading towards the Henderson Waves

If you stay on the main trails, there are ample signages

One of the older trails that lead you to the hillock that connects to Mount Faber Park.

On the right side is Car Park 1, and another network of paths winding around the greenery, leading to another knoll which is connected to the Henderson Bridge. There is a shelter and seats at this hilltop area where one can take a short rest and a cold drink from the vending machine before crossing the distinctive Henderson Waves overhead bridge to Mount Faber Park.  This forested hillock was also the location where the body of Huang Na was found after her tragic murder back in 2004.

Butterflies of Telok Blangah Hill Park

As far as butterflies are concerned, the Southern Ridges is a location where occasional rare species may appear. This is related to one of the habits of "hill topping" by butterflies - whereby many species, particularly the males, indulge in the activity of choosing their favourite perches and patrol the area for eligible females.  The list of butterflies featured here is not exhaustive.

Two examples of butterflies that are normally found in the forested nature reserves, but can be spotted at Telok Blangah Hill Park.

Over the years, some of the species that have been observed at Telok Blangah Hill Park include some of the rarest Lycaenidae species that have been observed in Singapore. As some of the vegetation have evolved over the years, certain species that have been spotted between 2000 and 2010 are no longer seen today. Interestingly, some forest-dependent species like the Branded Imperial and Malayan Lascar were "regulars" at TBHP in the past.

The Colour Sergeant was once found quite commonly at the grounds of Alkaff Mansion.  It is no longer seen there today.

At the grounds of the Alkaff Mansion, there once were a few host plants of the Colour Sergeant growing at the periphery of the forecourt. I recall that we often found the caterpillars of the Colour Sergeant on this host. Today, these plants have not survived and the species is rarely seen at this location.

Three Spot Grass Yellows eclosing on their host plant, Albizia

The common urban species are found at TBHP, and interestingly, three species of the Eurema or Grass Yellows, have been observed around the park. There was a time when the Albizia trees (Paraserianthes moluccana) had large congregations of the Three Spot Grass Yellow (Eurema blanda snelleni) breeding on them. The Common Grass Yellow (E. hecabe contubernalis) and the Chocolate Grass Yellow (E. sari sodalis) are also spotted here.

Look out for the distinctive dragon-headed Plain Nawab caterpillars on the Red Saga shrubs

If you look amongst the low shrubs of the Red Saga, there are often caterpillars of the Plain Nawab (Polyura hebe plautus) feeding on the leaflets of this common tree. The adults are often frolicking at tree top level, flying rapidly from one perch to another, and returning repeatedly to their favourite perches.

The Malayan Plum Judy was first recorded from the Southern Ridges

Examples of the Miletinae found at Telok Blangah Hill Park

This park was one of the first places where the Malayan Plum Judy (Abisara saturata kausambioides) was spotted. It can still be observed hopping from leaf to leaf in recent years. At least four species of the Miletinae are regularly observed at TBHP, the most often seen is the Biggs Brownwing (Miletus biggsii biggsii) flying restlessly amongst the shrubbery. The Apefly, Blue Brownwing and Pale Mottle have also been spotted here.

The rare Silver Royal was feeding at the flower of Syzygium sp. at Telok Blangah Hill Park when it was sighted in 2005

The very rare White Fourline Blue was observed at Telok Blangah Hill Park for a period of about a month in 2009.  It can no longer be found there and has not been seen since.

Amongst the Lycaenidae recorded here is the very rare Silver Royal, which was photographed whilst feeding on the flowers of a Syzygium tree where it was first recorded as a re-discovery in 2005. Another very rare Lycaenidae, the White Fourline Blue (Nacaduba angusta kerriana) was first observed at TBHP. Subsequent to that sighting in 2009, where it was documented as a re-discovery, a female was observed ovipositing and its life history successfully recorded on the host plant Entada spiralis. However, it has not been seen since that short period in 2009.

Various other Line Blues from the genus Nacaduba are often sighted at Telok Blangah Hill Park

The other confusing lookalike Sixline and Fourline Blues can also be found here, usually frolicking on bright sunny days. They fly rapidly, and then select a perch onto which to land and they have a unique habit of flattening themselves to the angle of the sun to maximise their exposure to the warm sunshine.

A variety of skippers observed at Telok Blangah Hill Park

Amongst the Hesperiidae found at TBHP are the various Palm Darts, Common Redeye, Chequered Lancer, Plain Banded Awl and the Orange Awlet (where its caterpillar host plant, Arthrophyllum diversifolium, is commonly found at TBHP). The variety of caterpillar host plants that can be found at TBHP supports these species. Some examples are Spatholobus ferrugineus, Caryota mitis, Cocos nucifera and various grasses and bamboos.

A Copper Flash feeding at the flowers of the Mile-A-Minute at Telok Blangah Hill Park

All in all, the butterfly diversity at TBHP is above average. However, the park cannot be considered as an ideal butterfly-shooting location for beginners due to its topography and vegetation - some areas of which are not easily accessible. As nectaring plants are not as widespread, it is challenging to photograph butterflies that are actively flying about. Nevertheless, it is a good place to do butterfly-watching, due to its variety of habitats and environments.

A map of Telok Blangah Hill Park

How to Get There :

By bus :

(57, 145, 175, 176, 195, 195a, 272, 273) stop at Bus stop 14241, along Henderson Road and walk up along Telok Blangah Green.

(120, 124) stop at Bus stop 14331, along Telok Blangah Heights.

By car :

Drive along Henderson Green and turn into Telok Blangah Green. There are three carparks 1, 2 and 3, but on weekends, it may be challenging to find carpark lots during the peak hours. Parking is free.

Note that, due to the terrain, accessibility is challenging and there is no wheelchair access to many of the attractions mentioned above.

Text and Photos by Khew SK

References : NParks Website : Telok Blangah Hill Park