29 November 2014

Lycaenid Butterflies and Ants

Lycaenid Butterflies and Ants

In many ways, ants are the greatest cooperators on earth. As eusocial insects, they are well known for their highly cooperative and coordinated societies, but they also cooperate with other organisms.  Ants engage in mutualisms—aka symbiotic, cooperative, or mutually beneficial interactions—with plants, fungus, and other insects. They serve as effective protectors, fertilizers, seed dispersers, tenders, cleaners, and farmers. Ants are such prolific cooperators, that an entire class of species interactions exists to describe cooperative associations with ants: myrmecophily (meaning ‘ant love’). But wait, this is a butterfly article, right?

A caterpillar of the Centaur Oakblue being attended by Weaver Ants.

A pupa of the Centaur Oakblue still getting the attention of a number of Weaver Ants.

A Centaur Oakblue adult.

Right: butterflies. As you well know, butterflies are a wonderful group to study for both scientific and artistic purposes. Butterflies are beautiful and fascinating, and as far as I'm concerned, the butterfly family Lycaenidae is the most beautiful and fascinating of them all. With more than 6,000 estimated species, the Lycaenidae is a huge family (second in number only to Nymphalidae), and lycaenid butterflies occur in nearly every habitat where a butterfly could conceivably occur. They exhibit an incredibly broad hostplant range, feeding on numerous plant families, as well as fungi, lichen, and yes, other insects. But what really makes them the most interesting butterfly group is their larval association with ants.

A Common Red Flash displaying its striking upperside.

Caterpillars of the Common Red Flash in the company of attending ants.

A Long Banded Silverline adult.

Caterpillars of the Long Banded Silverline interacting with ants eager to get a taste of its nectary excretion.

More than 75% of the world’s lycaenid species engage in highly specialized larval interactions with ants. In its most basic form, the interaction looks something like this: caterpillars produce nutritious secretions (honeydew) from specialized organs for the ants to eat, and in exchange the ants protect the caterpillars from predators and parasitoids. There are many aspects of this interaction that are tantalizing to a biologist, not least of which are the behavioural and communicative adaptations that must take place in order for the association to work. Caterpillars use a variety of mechanisms, including chemical mimicry and acoustic signaling, to elicit the favor to ants.

A 2nd instar caterpillar being tailed by an ant which is eyeing the nectary fluid excreted by the caterpillar.

A sequence of three pictures showing an ant receiving its pay packet of a nectary droplet from the 2nd instar caterpillar.

Moreover, the interactions can be highly variable, with different lycaenid species engaging in different ‘flavors’ of ant association. Some lycaenids do not associate with ants at all, and among those that do the interaction can range from generalist, facultative mutualism (meaning that the caterpillars don’t need ants to survive, but they’ll associate with them if they’re available) to species-specific, obligate associations (a caterpillar’s survival absolutely requires being adopted by the correct ant species).  The interaction is not always a truly cooperative one either: there are many species of lycaenids that have evolved to parasitize their ant partners. In these cases the ants still care for the lycaenid caterpillars, but instead of feeding on plants like the majority of lepidopteran larvae, the caterpillars switch to carnivorous food sources such as ant brood or other insects that are within the ants’ care. Amazing!

A Quaker adult.

A Quaker caterpillar being tended by an ant.

However, despite the fascinating life histories and the commonness of lycaenids worldwide, they remain some of the most mysterious butterflies in many places.  For example, if you look through the lycaenid section of a good butterfly field guide, you might be amazed to see how often the larval food source is unrecorded. Moreover, many times we think we know what a species eats, we're dead wrong! Hostplant records are often based on anecdotal field observations or on rearing experiments in captivity, but what a caterpillar will eat versus what is does eat are two different stories. Horace recently told me that he's successfully reared the Ciliate Blue (Anthene emolus), a species known to be carnivorous throughout SEA, on plants, and that he has also observed "known" herbivores munching on treehoppers. Go figure.

A mother Singapore Four-line Blue laying an egg on its host plant.

Several caterpillars of the Singapore Four-line Blue with ants in attendance.

Close-up view of one caterpillar (and one ant) in the picture above.

I suspect that carnivory is more widespread than we think. I often come across species descriptions that say something along the lines of "Lives in ant shelters, larval hostplant unknown," and my first suspicion is parasitism. Then again, there are also plenty of species that live inside ant shelters during the day when predators are active, but leave the nests at night to feed on plants under the watchful guard of their ant escorts. In order to describe species' diets and ant associations with confidence, we need systematic observations and study. In lieu of that, the life histories and diets of these species will remain mysterious.

Two early instar caterpillars of the Ciliate Blue (Anthene emolus) with Weaver ants in attendance.

A late instar caterpillar of the Dark Tit (Hypolycaena thecloides).

A final instar caterpillar of the Vinous Oakblue (Arhopala athada).

So, what exactly would we like to know about lycaenid-ant interactions, and why don’t we know it already? For closely ant-associated species, it can be difficult to access lycaenid larvae. Excavating ant nests to search for caterpillars is tough work, and not many people are so inclined to spend their leisure time being attacked by ants. Imagine spending your days opening up weaver ant nests to look for caterpillars--no thank you! But there is some really good stuff in there! The caterpillars of the Moth Butterfly (Liphyra brassolis), one of the coolest lycaenid species in the world, are found only inside weaver ant nests, and a few other lycaenid species have been found in these nests as well. My gut feeling tells me that if more crazy people were out there opening up weaver ant nests we'd be fascinated to find what other animals they host inside. We'd also have a lot of ant bites….

A final instar caterpillar of the Copper Flash (Rapala pheretima sequeira).

A final instar caterpillar of the Pale Mottle (Logania marmorata damis).

But luckily we don’t need to scour every ant nest to answer important questions about lycaenid ecology. We can answer many outstanding questions simply through careful observation - something members of ButterflyCircle truly excel at. By documenting and keeping records of observed associations, we can start to fill in the gaps in our current knowledge. Below is a preliminary list of some easy ways in which the members of ButterflyCircle can contribute important ecological data about Singapore’s lycaenid (and even non-lycaenid) butterflies:

A Branded Imperial adult sipping fluid from the young shoot of its host plant.

Three Branded Imperial caterpillars caught the attention of a large black ant.

  • Photograph interactions between ants and lycaenid larvae whenever possible. These photographs can be considered data, and with enough data we can start to understand fundamental aspects of ant-lycaenid interactions: How often do different lycaenid species associate with ants in the wild? Are certain ant species (or genera) preferred over others? What hostplants do these interactions take place on? Are specific behaviours observed?
  • Note the habitats that these interactions occur in. Do you only find certain species in certain habitats? How might ant distributions affect lycaenid distributions?
  • Photograph ants and hostplants so that they can be identified later.
  • Record GPS coordinates along with photos. This goes for non-lycaenid butterflies as well. Having reliable location data can be useful for understanding butterfly dispersal, population dynamics, and habitat use.
  • Collect DNA material. Many modern zoological museums are shifting their collections away from dried, pinned specimens toward DNA and tissue collections. Rather than donating spread adults to museums like the Raffles Museum of Biodiversity Research, consider donating larvae, pupae, or adults preserved in ethanol instead. Specimens preserved in this way provide a valuable resource for understanding evolutionary relationships, population genetics, and species delineations of Singapore’s butterflies (and moths too!). While I understand and appreciate that collecting is not an important component of ButterflyCircle’s work, if anyone is interested in learning more about DNA collections please feel free to contact me.

About the author:
Dr. Melissa Whitaker is a postdoctoral fellow at the Harvard Museum of Comparative Zoology, where she studies the evolution and ecology of ant-lycaenid associations. She recently visited Singapore to collaborate with Horace Tan on research focusing on Singapore's lycaenid fauna (funded by the Wildlife Reserves Singapore Conservation Fund). She is a huge fan of the ButterflyCircle’s approach to butterfly study and appreciation. For more information about Dr. Whitaker's research, or to contact her, please visit www.melissawhitaker.net.

Text by Dr Melissa Whitaker; Photos by Khew SK, Horace Tan; Videos by Horace Tan.

22 November 2014

Butterfly of the Month - November 2014

Butterfly of the Month - November 2014
The Malayan Eggfly (Hypolimnas anomala anomala)

"It's beginning to look a lot like Christmas..." as the song goes. The eleventh month of 2014 is upon us, as shopping malls and office buildings in Singapore get decorated in anticipation of the year-end holidays and Christmas season. Many shopping malls are getting in on the act early to take advantage of the end of school season and people who would like to do their Christmas shopping early. Even the theme at our Gardens by the Bay already feature Christmas decor and lights to mesmerize its visitors with the colours of the season.

It's been an interesting year of ups and downs, both in the local and global scenes, as Singapore looks ahead towards celebrating its 50th year of independence since 1965. The year 2015 looks like it's going be a pretty busy year for Singapore with many commemorative celebrations and events planned by numerous organisations, both from the public and private sectors. Even ButterflyCircle is also planning on a special 'present' for Singapore's 50th birthday, but let's leave that for later. ;)

On the butterfly conservation and research front, we are encouraged to see more people interesting in butterflies - setting up butterfly gardens and sanctuaries, as well as learning more about butterflies through observing them and photographing them. As the Lee Kong Chian Natural History Museum, one of the region's first custom-designed building for a natural history museum readies itself for completion, several exciting initiatives and projects, in collaboration with ButterflyCircle, are in the works.

A typical example of form-nivas of the Malayan Eggfly

ButterflyCircle members have continued to contribute to conservation initiatives and promoting butterfly-friendly projects in collaboration with the National Parks Board. In support of Ubin Day, ButterflyCircle will be conducting a butterfly watching and photography session next Sunday, 30 Nov 2014. The registration for participants is now closed, and we thank all the interested parties for registering and joining us. Weather permitting, we hope that you will have an enjoyable morning at Butterfly Hill on Pulau Ubin!

Upperside of a form-anomala of the Malayan Eggfly

This month, our feature butterfly is the Malayan Eggfly (Hypolimnas anomala anomala). This low-profile and relatively sombre coloured butterfly doesn't usually create much excitement amongst butterfly watchers, when compared to its more colourful and attractive cousins. In fact, it is often mistaken for one of the drab "Crows" from the Danainae family, due to its close resemblance to its distasteful models.

A form-anomala of the Malayan Eggfly feeding on the flowers of the Red Leea

The Malayan Eggfly displays mimetic behaviour, in that it mimics the Crows for protection against predators. It also flies in an unhurried and slow manner, copying the flight of the Crows to fool predators to avoid them as they would for the distasteful Danainaes. From the number of mis-identifications of this species by beginners and casual nature enthusiasts, we can almost conclude that the Malayan Eggfly is a passable mimic of the Crows (at least from the human perspective!).

The Malayan Eggfly is relatively common in Singapore. Seasonally, several individuals can be observed together at various locations, particularly in the vicinity of its caterpillar host plant, Pipturus argenteus, a secondary forest bush that grows quite commonly in the forested areas of Singapore.

A form-nivas with reduced white markings on the hindwing

The species is observed to display territorial behaviour - particularly the males. Individuals select favourite perches amongst shrubbery and low foliage, and perch with wings held upright. Whenever an 'intruder' breaches its domain, it will fly out and try to 'attack' the newcomer. At other times, it returns repeatedly to its favourite perches even when disturbed.

In the typical form, the Malayan Eggfly is reddish brown on the upperside, with a series of post-discal and submarginal white spots on both wings. The underside is usually darker and bears the white spots as on the upperside. The species is subject to considerable variation in the extent of additional white markings on the hindwings, although two distinct forms are documented for this species.

Form-anomala is the typical brown form where the hindwing post-discal area is unmarked, both on the upper- and undersides. This form is the more commonly observed one, and is quite widespread in distribution, from urban parks and gardens to the forested sanctuary of the nature reserves.

Typical form-nivas with prominent white post-discal patches of varying degrees on the hindwing on both the upper and undersides

The other form, which is slightly less encountered, features a series of white post-discal streaks on the hindwings. This is form-nivas. Between the two forms, is a wide spectrum of variations from totally no postdiscal markings, to a few obscure streaks, to a prominent white patch on the hindwings.

A female variant with iridescent blue forewings resembling a Striped Blue Crow

The two forms are passable mimics of the Danainae species that are also found in Singapore - Striped Blue Crow (for form-anomala) and Lesser Striped Black Crow (for form-nivas). However, not infrequently, a third "form", with iridescent blue forewings on the upperside, is seen. This variant is usually female, featuring the attractive blue forewings and we believe it mimics the male Striped Blue Crow. Ecologically, it also makes sense that the female has a series of alternative mimetic strategies to ensure a higher chance of survival to prolong its lifespan to be able to lay as many eggs as possible before it falls prey to a predator or dies of natural causes. However, why this is not considered a different form or documented in any research paper as such, is still not fully understood.

A female Malayan Eggfly standing guard over her eggs

Speaking of egg-laying, the Malayan Eggfly displays a very unique behaviour where the female, after ovipositing from anything between 50 to 100 eggs on the underside of the leaf of its host plant, "stands guard" over the eggs. This behaviour has been documented by researchers and papers have been written about it, but it is not really known why the female does that, because a butterfly does not possess the means nor arsenal of offensive weaponry to fend off any potential predators of her eggs.

Another shot of a form-anomala female Malayan Eggfly standing guard over her future babies

In some instances, the female stands guard over her eggs until the first instar caterpillars hatch and start eating the leaf. The adult butterfly, in at least two of our observations, died in that position, "protecting" her eggs till her last breath. In a controlled environment on one occasion, we physically removed the female butterfly from her perch, only to see it fly back the moment it was released, back to stand guard over her progeny!

The Malayan Eggfly is partial towards human sweat as can be seen here, feeding on a sweaty camera body and a sweaty finger.  The top photo shows the species puddling at sandy streambanks

The Malayan Eggfly has also been observed puddling at sandy streambanks and muddy footpaths. It also has a liking for human sweat and there have been instances where it stays on the hands and arms of ButterflyCircle members, sipping sweat.

A mating pair of form-anomala Malayan Eggfly

The life history of the Malayan Eggfly has been fully documented here in Singapore, feeding on the caterpillar host plant, Australian Mulberry (Pipturus argenteus). The detailed life history of this species can be found here.

Text by Khew SK : Photos by Sunny Chir, Goh EC, Huang CJ, Koh CH, Khew SK, Loke PF, Jonathan Soong, Horace Tan, Nelson Ong and Anthony Wong.

15 November 2014

Life History of the Full Stop Swift

Life History of the Full Stop Swift (Caltoris cormasa )

Butterfly Biodata:
Genus: Caltoris Swinhoe, 1893
Species: cormasa Hewitson, 1876
Wingspan of Adult Butterfly: 32-34mm
Caterpillar Local Host Plants: Ottochloa nodosa (Poaceae), Panicum maximum (Poaceae, common name: Guinea Grass), Ischaemum ciliare (Poaceae, common name: Smut Grass).

Physical Description of Adult Butterfly:
On the upperside, the wings are dark brown with hyaline spots in spaces 2,3 and 4, subapical spots in spaces 6 and 7 and two cell spots in the forewing. The upper cell spot is typically either absent or small in comparison to other Caltoris spp. On the underside, the wings are ferruginous brown, usually with a purplish tinge.

A close-up view of the forewing upperside, showing two small cell spots of a Full Stop Swift.

The upperside view of a newly eclosed Full Stop Swift. The upper cell spot is absent  while the lower cell spot is small.

A Full Stop Swift visiting flower in a wasteland.

Field Observations of Butterfly Behaviour:
The Full Stop Swift is moderately common in Singapore. The adults have been sighted in multiple locations including forested areas, wastelands, urban parks and gardens across the island. The adults fly with a swift, strong and darting flight.

08 November 2014

Butterflies of Pulau Ubin

Butterflies of Pulau Ubin
Butterfly Hill @ Pulau Ubin

Aerial view of Butterfly Hill @ Pulau Ubin - © National Parks Board

Pulau Ubin, an offshore island of Singapore of about 10.2 sqkm, is often considered the "last frontier" of rural ambience and rich biodiversity in Singapore. Local Malays once called it "Pulau Batu Ubin" or Granite Stone Island. In the past this small island supplied the local construction industry with granite and sand, from which coarse aggregates and the sand were used to construct roads, manufacture concrete and other building materials. The granite was also used to make floor tiles, or Jubin as it was called in Malay.

A map of Pulau Ubin - © National Parks Board

Today, the 7km long by 2km wide island is a favourite weekend destination for adventure lovers and nature enthusiasts taking a short bumboat ride from the Changi Ferry Terminal. The island is known for its rich biodiversity and rustic environment to which many weekend visitors flock to get away from Singapore's hectic urban lifestyle.

On the bumboat back from Ubin with senior government officials and nature enthusiasts

In early 2014, the Ministry of National Development, led by Minister of State Desmond Lee, visited Pulau Ubin with a group of nature enthusiasts, heritage experts and community leaders. The visit was part of the wider plan to initiate a conversation with Singaporeans on how we can all play a part to sensitively enhance the natural environment of Pulau Ubin, which was announced by Mr Desmond Lee in Parliament in March 2014.

A group photo of Friends of Ubin Network taken at Singapore Botanic Gardens

Subsequently, the Friends of Ubin Network (FUN) was set up to continue to engage the stakeholders whilst a public feedback portal and even an Ubin Symposium was organised to openly discuss possible options for Ubin. There have been numerous media articles and blog articles discussing what different groups of people want for Ubin.

Blue Glassy Tiger (Ideopsis vulgaris macrina) - a "resident" species at Butterfly Hill

On 30 Nov 2014, a public event to celebrate Pulau Ubin, will be resurrected by Ria Tan and Grant Pereira.  The event, known as Ubin Day, was previously held in 2002 and 2003, and this will be the 3rd instalment of this event, featuring different activities by various groups in many parts of the island. The event's objective is to introduce the diversity of activities that can be enjoyed by the general public on this little island, and to showcase the amazing biodiversity that we have on Ubin.

A peep at the Butterfly Hill during earthworks back in 2005

Let's come back to Pulau Ubin's Butterfly Hill. In 2005, the Jelutong Campsite was created out of a piece of wasteland reclaimed from the sea during past granite quarrying operations. Within the campsite sits Butterfly Hill – a knoll created specially to conserve and showcase butterflies. Back then, I worked with NParks' staff, Robert Teo, Choi Yook Sau, Jacky Soh and How Choon Beng to build up Butterfly Hill from scratch. I remember vividly when the hill was completely wiped clean except for a solitary tree, and the hill was just covered with red earth.

Black Veined Tiger (Danaus melanippus hegesippus) - a regular visitor at Butterfly Hill

Fast forward to 2014, it's been almost 10 years in the making, and the Butterfly Hill continues to be a good place to observe butterflies, yielding the occasional surprise in terms of rare species. Over the period since the Butterfly Hill was designed and planted with butterfly host and nectaring plants, we have recorded over 150 species (and counting!). On a typical day, one can expect to be greeted by the resident Plain Tigers, Blue Glassy Tigers, Pea Blues, Great Eggflies, Common Birdwings and others. A half day butterfly watching outing should easily yield about 20 different species.

Common Line Blue (Prosotas nora superdates) feeding on Bidens flower at Butterfly Hill

Amongst the uncommon butterflies that have been spotted and photographed at Ubin's Butterfly Hill are :

Mangrove Tree Nymph (Idea leuconoe chersonesia) - This large Danainae is very rare, previously known only from Pulau Tekong. This individual was photographed at Butterfly Hill recently.

Malayan Birdwing (Troides amphrysus ruficollis) - A large and showy Birdwing, this species was first recorded in Singapore from a caterpillar discovered at Alexandra Hospital's Butterfly Trail. This species was seen on Butterfly Hill and there have been subsequent sightings in the past year.

Great Mormon (Papilio memnon agenor) - This large swallowtail frequents Butterfly Hill because its caterpillar host plant, Pomelo (Citrus grandis) is cultivated here.

Lesser Striped Black Crow (Euploea eyndhovii gardineri) - This Crow is uncommon and often encountered singly. Butterfly Hill is one location where this species is observed quite regularly.

Dwarf Crow (Euploea tulliolus ledereri) - The Dwarf Crow is thus far known reliably only from Pulau Ubin. Whilst it was previously seen regularly at Butterfly Hill, it has become rarer and not often seen in the past two years.

Bamboo Tree Brown (Lethe europa malaya) - A shy and skittish shade lover, this species is regularly seen amongst the bamboo clumps at Butterfly Hill.

Forest Hopper (Astictopterus jama jama) - This elusive skipper has regularly been spotted at Butterfly Hill usually flying rapidly amongst the low shrubbery.

Conjoined Swift (Pelopidas conjunctus conjunctus) - This large and fast-flying skipper has been observed at Butterfly Hill on several occasions by ButterflyCircle members.

Plain Palm Dart (Cephrenes acalle niasicus) - This skipper, though not often spotted, has been seen several times at Butterfly Hill, particularly when there are flowering Syzygiums.

So when you visit Pulau Ubin's Butterfly Hill, do look out for some of these rarities, and we hope that you can also add more to the checklist of butterflies on Butterfly Hill by spotting other new species!

On 30 Nov 2014's Ubin Day, ButterflyCircle members will be on site to share tips on butterfly watching and photography. For those who are keen to join us, please sign up here.  We look forward to an enjoyable morning with nature's flying jewels!

Text by Khew SK : Photos by Brian Goh, Khew SK, Simon Sng, Jonathan Soong, Anthony Wong, Yong Wei Hoong