18 August 2018

Butterfly of the Month - August 2018

Butterfly of the Month - August 2018
The Banded Yeoman (Cirrochroa orissa orissa)

A Banded Yeoman puddling on the ground 

Just over a week ago, the Republic of Singapore celebrated its 53rd birthday on 9 Aug 2018 - 53 years of independence after it broke away from Malaysia in 1965. Back then, post-separation, Singapore was not expected to survive long on its own. A small island nation of only 580 sq km in 1965, it had no natural resources, a resident population of about 1.9m people, scant financial resources, virtually no army and a host of political and internal security issues to deal with.

A Banded Yeoman hides under a leaf with its wings folded upright

In just over five decades, the little country punched well above its weight, grew its economy and physical size - it has a land area of about 720 sq km today, physically expanding, through reclamation, by nearly 25% since 1965. Today, Singapore ranks amongst the top 10 countries in terms of Gross Domestic Product per capita according to the International Monetary Fund.

A Banded Yeoman sunbathes with its wings opened flat

Looking forward, stormy skies loom ahead. Singapore's past successes cannot be taken for granted, as the nation struggles with high cost of living, a more demanding and vocal citizenry and business competition from other emerging economies in the region. However, Singapore still has a number of things going for it, and it has to leverage on these pluses to leap ahead in the coming decades. This is where the government is focusing on, to re-invent Singapore and restructure the economy in the face of uncertain and rapid-changing global environment.

It is also in August that the Chinese Hungry Ghost month (7th month of the Lunar Calendar) starts. An annual Chinese tradition for the spirits of the afterlife, there are many do's and don't's that have been passed from generation to generation. The Hungry Ghost Month is, generally speaking, a bad time to do anything. Many significant milestones are avoided at this time, as people believe it's simply bad luck - from renovations, to moving house or buying an apartment, to getting married.

One of the interesting no-no's is "killing a moth" (or a butterfly for that matter). The Chinese believe that spirits are reincarnated as insects, especially moths. And the souls of the dear departed are in the moths (and butterflies) that visit your homes in the wee hours of the night. So stay away from killing any moths and butterflies during the month, lest it is the soul of a loved one visiting you!

A Banded Yeoman feeding on the flower of the Bandicoot Berry (Leea indica)

Our feature Butterfly of the Month for August 2018 is the Banded Yeoman (Cirrochroa orissa orissa). This is a moderately rare species in Singapore and is forest-dependent. It is rather local in distribution, and regularly sighted at its favourite sites in the Central Catchment Nature Reserves where its caterpillar host plant, Ryparosa scortechinii, grows.

The Banded Yeoman is ochreous brown on the upperside of its forewing, with a yellow post-discal band and a black apical border. The hindwing is also ochreous brown above with a series of marginal and sub-marginal lines and black spots that is typical of species of the genus Cirrochroa (collectively called the Yeoman butterflies).

The underside is much paler, and generally reflects the patterns and markings on the upperside. The broad apical area on the forewing has two white apical spots. The post-discal silvery band is a diagnostic feature to separate the species in the genus. In flight, the Banded Yeoman resembles another species that flies in Singapore - the Rustic. Indeed, both species are often seen together when feeding at flowering plants like the Bandicoot Berry (Leea indica) along forest paths.

The Banded Yeoman is skittish and is always on the move. It has a habit of flying and hiding on the underside of leaves with its wings folded upright. The species is relatively more common in Malaysia, often seen in secondary forests and nature parks, where several individuals can be observed together.

A Banded Yeoman puddling on a damp footpath

The species is also often observed to puddle at muddy footpaths near forest streams. Even when puddling, it has a habit of opening and closing its wings as it twists and turns whilst probing its proboscis in search of nutrients in the damp mud or sand.

A newly eclosed Banded Yeoman clinging on to its pupal case

The caterpillar has been successfully bred on the forest plant Ryparosa scortechinii in Singapore. The host plant is uncommon and is primarily found in the forested nature reserves of Singapore. At certain hours of the day, the Banded Yeoman can be observed to sunbathe on the tops of leaves and opening its wings flat to capture the heat of the sun.

Interestingly, this is the 888th article to be posted on this blog, as we feature our Butterfly of the Month today at exactly 18:08 on 18/08/18. That's a lot of auspicious 8's and will hopefully bring everyone lots of luck for the remaining months of this year!

Text by Khew SK : Photos by Antonio Giudici, Goh LC, Federick Ho, Khew SK, Loke PF, Tai LA, Tea Yi Kai, Horace Tan and Anthony Wong

11 August 2018

Book Review : Butterflies of Vietnam

Book Review : Common Butterflies of Vietnam
Dedicated books on Vietnam Butterflies

A recent business trip to Ho Chi Minh City (formerly Saigon) in South Vietnam led me to a local bookshop near the hotel where I stayed. Whilst browsing around the nature section, I wondered how many books I would find about the local butterfly fauna of Vietnam. The shop did not stock any, although there were quite a few other books about birds, flora and landscapes of Vietnam.

Of the 10 ASEAN countries, relatively comprehensive hardcopy literature on butterflies can be found for Malaysia, Thailand, Philippines, Laos and Singapore. The remaining ASEAN countries are Myanmar, Cambodia, Brunei Darussalam, Indonesia and Vietnam. There are basic guidebooks and many work-in-progress books for the majority of these countries. Amongst all the books available, Pisuth Ek-Amnuay's 944-page Butterflies of Thailand Vol 2 stands out as the largest comprehensive work on Thai butterflies.

A quick search online for books on the Butterflies of Vietnam showed that there are a couple of basic 'illustrated checklist and field guide' type of books, and a few more comprehensive work in progress. Most were authored by Dr Alexander Monastyrskii, a Russian entomologist, in collaboration with several other co-authors.

A basic Field Guide on the Common Butterflies of Vietnam, published in 2002 is touted as the "first illustrated field guide to the Butterflies of Vietnam". This 63-page field guide, featuring 105 of the common butterfly species in Vietnam, showcases hand-drawn illustrations of butterflies. These drawings by artist Wendy Gibbs, are very accurate drawings of the actual butterflies from a set collection.

The book opens with a foreword penned by Mr Nguyen Minh Thong, the IUCN Country representative, and Prof Vu Quang Con, the Director of the Institute of Ecology and Biological Resources in Hanoi.

Like the majority of butterfly books, the first six pages dwell with some basic information on classification, morphology, life cycle, behaviour, ecology and conservation. Having probably been worked on in the late 1990s and early 2000's the authors used the old taxonomic classification prior to the more recent consolidation of several families into Nymphalidae., this does not really detract from the value of this basic field guide in helping to identify common butterflies found in Vietnam.

The species pages are organised in a very simple format with the scientific names stopping at the species level. English common names are also given, and are generally quite consistent with many of the books available on ASEAN butterflies. For example the Neptis species are called "Sailors" in this book, as opposed to "Sailers" that are used by other authors.

Each species has a short write-up, describing the butterflies' behaviours, differences between the sexes, favourite nectaring plants and geographical range where the butterfly occurs. For some of the species, upper and underside or male/female illustrations are shown, using the half-butterfly depiction that is used in WA Fleming's Butterflies of West Malaysia and Singapore.

Given the small number of butterfly species featured - 105, which is less than 10% of the total number of species found in Vietnam, a reader will quickly look for more comprehensive books about Vietnam's butterflies. The good news is that there are several updates by the same author available. An example is the 114-page 2nd edition of the Butterflies of Vietnam: An Illustrated Checklist published in 2016.

Dr Monastyrskii also expanded his work into a work-in-progress series :
Butterflies of Vietnam, Volume 1: Nymphalidae: Satyrinae in 2005
Butterflies of Vietnam, Volume 2: Papilionidae in 2007
Butterflies of Vietnam, Volume 3: Nymphalidae: Danainae, Amathusiinae in 2012
These are more comprehensive books showing a wider collection of the species found in Vietnam and I am sure that more volumes will be available in due course.

For the more serious students, a scientific paper on The Biogeography of the Butterfly Fauna of Vietnam With a Focus on the Endemic Species (Lepidoptera), by A.L. Monastyrskii and J.D. Holloway, is also available. This paper discusses the biogeographic distribution of Vietnamese butterflies, featuring several key endemics found in Vietnam.

So for butterfly watchers who visit Vietnam, do check out these books for your reference to help you to identify what you have seen in various parts of this biodiversity-rich ASEAN country. Vietnam is a large country covering a total of 331,230.8 km2 of land mass and has a long coastal line. The current number of species recorded is 1,181 and counting.

Text by Khew SK

Photo plates from the books are copyrighted property of their respective authors and publishers, and samples of the pages from the books are featured here under the principles of fair use.

05 August 2018

Butterfly Survey @ Zoo

Butterfly Biodiversity Project
Butterfly Survey at Mandai Zoo

WRS Invertebrate team and ButterflyCircle members

The Singapore Zoo, previously known as the Singapore Zoological Gardens, but often referred to by locals as the Mandai Zoo, was first opened in mid 1973. Sitting on a site of about 28 Hectares, the Singapore Zoo was one of the first to feature "open zoo" exhibits in the region, where animals are displayed in natural habitats without the use of cages.

Over the years, the success of the Singapore Zoo, under the stewardship of Wildlife Reserves Singapore (WRS) continued. WRS also manages the popular Night Safari (the world's first nocturnal wildlife park), River Safari and the Jurong Bird Park.

The future Mandai Nature Precinct © Mandai Park Holdings

In 2015, Singapore investment company Temasek partnered the Singapore Government to spearhead the rejuvenation of Mandai into an integrated wildlife and nature heritage precinct in Singapore. Within the next decade or so, the Singapore Zoo, Night Safari and River Safari will be joined by two new cousins, the new Bird Park and the Rainforest Park, creating an integrated nature and wildlife experience for all visitors to Mandai.

A quick discussion before the survey commenced

This weekend, ButterflyCircle members were invited to assist the WRS Invertebrate Team to conduct baseline surveys on butterfly biodiversity at the Singapore Zoo. The WRS Team intends to enhance butterfly biodiversity through its Butterfly Biodiversity Project in the coming months. This project aims to improve the butterfly fauna in the Mandai precinct by planting host and nectaring plants for local butterflies within the parks.

Looking up for the butterflies!

Our morning survey started with a short briefing by Delvinder Kaur, the coordinator of the project, and explaining the survey methodology. When we commenced the survey just past 10am in the morning, the Saturday morning crowd had already begun streaming in. The transect-based survey took us on a trail starting near the white rhino exhibit and ending at the Fragile Forest aviary.

The overcast morning was not the most ideal weather for butterfly watching, but there were a few Lemon Emigrants, Grass Yellows and a lone Striped Albatross flying about. Delvin also explained that the trails that we were surveying were no longer fogged with pesticides and hence more butterfly-friendly.

At the Tropical Crops patch.  The waters of the Upper Seletar Reservoir can be seen on the left of the photo

Our walk brought us to the tropical crops area of the Zoo, which was just adjacent to the shores of Upper Seletar Reservoir Park. I recall this area from past visits to the Zoo, and where a trellis of Aristolochia acuminata, the host plant of the Common Birdwing and Common Rose, was cultivated. Both these species did not make an appearance this morning, though.

Pupa of the Autumn Leaf

We spotted a Leopard fluttering restlessly about, and a few more Lemon Emigrants trying to puddle at the freshly-tilled soil on the plant beds. I also noticed that the host plant of the subspecies pratipa of the Autumn Leaf still lined some of the trails around the area. We first spotted this subspecies, which is different in appearance from the subspecies bisaltide which is the more commonly observed subspecies all around Singapore, at the Zoo.

Caterpillar and adult female of the Autumn Leaf subspecies pratipa

Caterpillar and adult female of the Autumn Leaf subspecies bisaltide

The caterpillar of subspecies pratipa is distinctly different from the more common bisaltide in that the spots on its body are white, instead of orange. Photographic records of subspecies pratipa dated back to Aug 2007 when we were on a survey at the Zoo. This subspecies has not been seen in Singapore in recent years. Hopefully, the caterpillars will appear at the Zoo again.

The survey ended just near the new Reptopia exhibit, where we called it a day. We spotted a couple of Common Palmflies frolicking around the bushes. We took the opportunity to visit the Fragile Forest and the new butterfly aviary. This butterfly aviary was a recent add-on, but is facing some issues with predatory ants and a bunch of unwelcome moth caterpillars. The Clipper (Parthenos sylvia) and the orange form-chrysippus of the Plain Tiger were the two most common species flying in the aviary.

The new butterfly aviary adjacent to the Fragile Forest

A quick tour of the back-of-house, and visiting the breeding facilities that were still very much the same as I remembered from over 10 years ago, we ended our butterfly survey for the day. I also recall that back in 2011, the Zoo was helping to translocate the Metallic Caerulean (Jamides alecto ageladas) from the Mandai Orchid Garden that was being demolished. It would be good to check if this species can still be found at the Zoo.

A female Autumn Leaf subspecies pratipa ovipositing on its host plant at the Singapore Zoo

It was an interesting re-visit to the Zoo and we look forward to the forthcoming butterfly surveys in the months ahead. With a more targeted strategy of planting more host and nectaring plants for butterflies under the Butterfly Biodiversity Project, we hope to see a greater diversity of species at the Zoo in the near future.

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

28 July 2018

Sergeants of Singapore

The Sergeants of Singapore
Featuring the 5 Athyma species in Singapore

A female form-neftina Colour Sergeant feeds on the ripened fruit of the Straits Rhododendron

The genus Athyma comprises of butterflies with rather robust bodies and are powerful fliers. They belong to the subfamily Limetidinae of the family Nymphalidae. The butterflies have a horizontal striped appearance, usually black and white in the males, and females in some species that have the white bands replaced with either orange or brown.

A Common Sergeant (Athyma perius perius) that is no longer found in Singapore today

The are currently five extant species of the Athyma species in Singapore - often referred to as "Sergeants" by their English common names. There was a sixth species recorded from Singapore by the early authors - Common Sergeant (Athyma perius perius), but this species has not been seen in the wild for almost five or more decades in Singapore, and no longer considered an extant species here.

A male Colour Sergeant (Athyma nefte subrata) perches on a leaf

The other five "Sergeant" species continued to be regularly observed in Singapore over the years, with some more common than others. They are medium-sized butterflies with wingspans averaging between 55mm to 65mm. This blog post features all the five species and compares their differences and diagnostic features to distinguish and identify them.

The Lance Sergeant (Athyma pravara helma)

A Lance Sergeant.  Note the cell streak on the forewing which is complete and unbroken

The Lance Sergeant is the most distinctive of these black-and-white Sergeants in Singapore. The cell streak on the forewing is unbroken and club-like and this sets it apart from all the other Athymas found in Singapore.

It was a recent new discovery to Singapore, recorded in the mid-1990's and added to the Singapore Checklist. It has made a regular appearance thereafter, usually spotted when feeding on the ripened fruits of the Straits/Singapore Rhododendron (Melastoma malabathricum) and at flowering Syzygium trees.

It can be occasionally observed puddling at damp muddy footpaths in the nature reserves. The full life history has been recorded on a species of Uncaria found in the forested nature reserves of Singapore. In terms of size, the Lance Sergeant is probably the smallest of the five Athymas found in Singapore.

The Colour Sergeant (Athyma nefte subrata)

A male Colour Sergeant sunbathing.  Note the blue sheen on the white bands

The Colour Sergeant is the most often seen species amongst the Athymas in Singapore. It can be observed at urban parks and gardens as well as in the nature reserves. The males are black and white striped in the usual Sergeant look, but the white stripes appear bluish when viewed with angled lighting.

A female Colour Sergeant - form-subrata

A female Colour Sergeant - form-neftina

The females of this species occur in two forms - the orange-and-black form-neftina and the brown-and-black form-subrata. The orange female form is the commoner of the two forms. The undersides are usually paler in colour with a more washed-out appearance.

A female Colour Sergeant form-neftina feeding on the ripened fruit of the Straits Rhododendron

Males are fond of perching on the top surfaces of leaves with wings opened flat, and 'attacking' intruders that wander into its space. Both sexes are often found feeding greedily on the ripened fruits of the Straits/Singapore Rhododendron.

The Dot-Dash Sergeant (Athyma kanwa kanwa)

The strange English common name of this Sergeant probably came from its cell streak which ends in a triangular 'dot'. The species is largely forest-dependent and is not often found outside the sanctuary of the nature reserves in Singapore. It is rare, and usually spotted singly.

A Dot-Dash Sergeant sunbathing with its wings opened flat.  Note the narrow cell-end streak and the sharp and angular spot at the end of the streak

A powerful flyer like its other cousins in the group, it sports the flap-glide flight characteristic of the other Sergeants. It is skittish and alert, making it a challenge to photograph it, as any slight disturbance will spook it to speed away and up to the treetops.

A puddling Dot-Dash Sergeant

The Dot-Dash Sergeant has the usual black-and-white stripes on its wings. The cell streak on the forewing above is separated from the triangular spot (which is sharp and angular). The underside is a greyish-brown.

The Malay Staff Sergeant (Athyma reta moorei)

A Malay Staff Sergeant.  Note the twice-constricted cell streak on the forewing

The Malay Staff Sergeant is probably the rarest of the genus in Singapore, and is usually observed within the forested areas in the nature reserves. As with most of its other cousins, it is usually spotted singly, either sunbathing on the tops of leaves, or feeding at flowering plants.

The species is also known to puddle at damp muddy footpaths. The distinguishing markings of the Malay Staff Sergeant is the twice constricted white cell streak and the triangular spot is separated from this streak. The triangular spot is also more rounded compared to the Dot-Dash Sergeant's sharper and angular shape.

The Studded Sergeant (Athyma asura idita)

A puddling Studded Sergeant.  Note the black centred submarginal white spots on the hindwings

The Studded Sergeant is the largest member of the Athyma genus found in Singapore. It is also a forest-dependent species but is also regularly spotted in the vicinity of mangrove areas at Pulau Ubin and Sg Buloh Wetland Reserve.

A Studded Sergeant with wings folded upright.  Note the black-centred apical spots on the forewing

The cell streak is narrow and the cell-end spot is small and rounded. The unique feature of the Studded Sergeant is the black-centred white spots at the submarginal band of the hindwing. In the local subspecies, the spots are sometimes indistinct. The apical spots on the forewing are also black-centred.

The colourful caterpillar of the Studded Sergeant

The Studded Sergeant has been locally bred on two host plants - Ilex cymosa (Aquifoliaceae), and another unidentified Ilex species in the nature reserve. The caterpillar is attractive, with bright blue spots on a green body amidst sharp spines.

A Studded Sergeant feeding at the flowers of the Mile-a-Minute weed

And there you have it, the five "Sergeants" that you can spot in Singapore. And the next time you encounter one, you can hopefully be equipped to identify which of these Sergeants that you have spotted!

Text by Khew SK : Photos by Khew SK, Koh CH, Loke PF, Nelson Ong, Jonathan Soong, Horace Tan and Anthony Wong