21 July 2018

Butterfly of the Month - July 2018

Butterfly of the Month - July 2018
The Purple Bush Brown (Mycalesis orseis nautilus)

The month of July 2018 will probably be most remembered for the 2018 FIFA World Cup in Russia, a miraculous cavern rescue in Chiang Rai, Thailand, and the major cybersecurity breach of personal data in Singapore. We live in interesting times, and there are often outcomes that are still unpredictable, like who would win the World Cup, despite all means (including cats, birds and anything that can be believed!) of soothsaying by those who gambled away small fortunes.

A Purple Bush Brown found in southern Thailand - same subspecies as the one in Peninsular Malaysia and Singapore

So France won the 2018 World Cup. Along the way, the usually successful Latin American teams dropped like flies, and so did defending champions Germany. Asian teams didn't make it far into the games, with only Japan remaining in the last 16 before bowing out to Belgium despite leading 2-0. The next World Cup in 2022 will be held in Doha, Qatar, and the games shifted to the end of the year to avoid the 40+ degrees summer heat in the Middle Eastern nation.

Then over in the sleepy provincial town of Chiang Rai in northern Thailand, a group of 12 teenagers and their football coach decided to take an excursion into the cave complex at Tham Luang. As this is the monsoon season in northern Thailand, the torrential storms caused flash floods that cut off the group's exit as rain water flooded the passages. A search-and-rescue operation commenced and it was only after more than 10 days of searching that they were found on a ledge more than 3km into the cave complex.

The rescue operation that followed was described as nothing short of a miracle, as the personnel involved took great risks to bring a group of boys out through the treacherous labyrinth, many parts of which were totally submerged. All in all, it was a successful rescue operation with all the boys and their coach making it out with much difficulty. Sadly, there was one casualty, a Thai Navy SEAL diver who ran out of air whilst playing a crucial support role of bringing oxygen tanks and placing them along the route for the rescuers.

The Purple Bush Brown is often encountered flying low amongst the undergrowth, in deep forest shade, perching on the top of a leaf or blade of grass.  

Back home in Singapore, hackers infiltrated the government's health database and stole the confidential records of over 1.5 million patients, including the Prime Minister's drug prescriptions. Whilst the government had to soothe alarmed patients whose personal data had been compromised, the government's Cyber Security Agency will be busy patching up vulnerabilities and weaknesses in the IT system. In this cyber age and the era of connectivity, I cannot imagine having to go back to the paper and filing systems of the last millennium. Hence it is a risk that the government and any private company will have to face and resolve, moving forward.

We move back to our butterfly world with our feature butterfly of the month of July 2018. This month's butterfly is the Purple Bush Brown (Mycalesis orseis nautilus). The species is adorned with ocelli (or eye spots) on the margins of both wings and is one of many similar-looking species in the Mycalesis genus, often referred to as Bush Browns.

In Singapore, the Purple Bush Brown is the rarest species amongst the six species found here. However, the ocelli are distinctive and identification of the Purple Bush Brown is less challenging when compared to separating a few of its other close cousins. The Purple Bush Brown has prominent and distinct yellow-ringed ocelli that are rather uniform in size.

Individuals of this species have a full complement of ocelli on both wings with rather crisp colours and distinct outlines on the ocelli. The relatively uniform post-discal band is broad and faintly violet-washed in pristine individuals. There is a thin dark brown sub-basal line on both wings.

The butterfly is rather local in distribution and is considered rare in Singapore. It is a forest-dependent species and is not encountered beyond the sanctuary of heavily shaded forested areas in the nature reserves. It is usually observed singly, flying low amongst the undergrowth and grasses in heavy shade.

The Purple Bush Brown has also been observed to feed on overripe fallen fruits on the forest floor. The life history of this species has not been recorded yet in Singapore, although its caterpillars are likely to feed on a type of grass, like many of its other closely related species in the sub-family Satyrinae.

Text by Khew SK : Photos by Antonio Giudici, Federick Ho, Khew SK, Koh CH, Loke PF, Billy Oh, Tan CP and Benjamin Yam.

14 July 2018

Interpretative Signage in Butterfly Gardens

Butterfly Gardens
Importance of Interpretative Signage

In recent times, there has been a greater interest in setting up free-ranging butterfly gardens (not the enclosed gardens in a zoo-like environment) in both private and public premises. Over the years, our local knowledge about butterflies and their caterpillar host plants has increased through field observations and breeding efforts by amateur butterfly enthusiasts. Hence, if an individual or organisation wishes to set up their own butterfly garden, it is a simple case of cultivating the right caterpillar host plants, nectaring plants and creating a butterfly-friendly habitat, and then waiting for the winged jewels to appear!

Well, maybe not that overly simple! In creating a free-ranging butterfly garden, one has to look at the chosen site in relation to the surroundings, the catchment areas nearby, a quick baseline survey of the butterfly species in the vicinity, and then choose the right plants to attract the butterflies. A very important critical success factor of butterfly gardens is that there should be minimal or no spraying of pesticides at or near the site.

Interpretative sign in front of Pomelo bush at Butterfly Hill @ Pulau Ubin

And so there have been quite a few butterfly gardens and trails created all around Singapore. Some are, of course, more successful than others, depending on the people who are maintaining the butterfly garden (usually Town Council, NParks, other government agencies and volunteers) and the sustained interest of key leaders in the community. However, creating a butterfly garden does not just end there. Whilst there may be butterflies fluttering around, it would be a missed opportunity if there were no interpretative and educational signage to educate the general public about butterflies. Otherwise, visitors who are less acquainted with butterflies, caterpillars, host plants and so on, will be none the wiser after visiting the butterfly garden.

Interpretative sign in front of a bamboo grove at Butterfly Hill @ Pulau Ubin, showcasing some butterfly species whose caterpillars feed on bamboo

This is where interpretative signage becomes an important element for education and creating a better awareness of the ecological requirements of butterflies and plants. Two years ago, ButterflyCircle had the privilege of working together with the National Parks Board to put up a series of interpretative signs for the Butterfly Hill at Pulau Ubin.

Butterfly's eye view of Butterfly Hill @ Pulau Ubin

The creation of the Butterfly Hill at Pulau Ubin started way back in 2005 when a barren knoll just next to the Jelutong Campsite on Pulau Ubin was cultivated with butterfly attracting plants as an initial experiment to create a butterfly-friendly habitat. It was almost a decade in the making, when the hill became a very successful butterfly garden and is often teeming with butterflies on an ideal sunny day. Today, it is definitely a 'must-go' destination for butterfly watchers.

NParks then decided to work on a series of interpretative signs to create awareness about butterflies, showcase the butterfly species that can be regularly seen on Butterfly Hill, and their close association with plants. This blog article is a narrative of the 15 educational signs, mounted on pedestals and scattered around strategic spots at Butterfly Hill.

The introductory sign located at the entrance of Butterfly Hill tells the story of how this butterfly garden came to be

The introductory sign tells the story of how Butterfly Hill at Pulau Ubin came about and how many species of plants are cultivated at the football field sized butterfly garden. The sign is strategically located at the primary entrance to Butterfly Hill where visitors can stop by to learn about this conservation project that started with a collaborative effort between NParks and ButterflyCircle more than 10 years ago.

The next couple of signs give an overview about butterflies in general, their ecological role in nature, biology and differences between butterflies and moths. The language is kept as simple as possible so that readers do not find it too difficult to understand the educational message that is being conveyed. Both these signs are located at the top of the knoll near the shelter.

The next 12 signs describes the butterfly species that are found in the vicinity of Butterfly Hill and their relationship to plants of particular interest e.g. nectaring plants, caterpillar host plants and other feature plants. Often, where possible, the signs are located strategically next to where these plants are cultivated. Each sign also features a QR code, which brings you to NParks FloraWeb where you can learn even more details about the plant featured on the sign.

The interpretative sign about the Crown Flower, and the location of the sign in front of a clump of Crown Flower plants educates the visitor about the butterfly-plant relationship of the Plain Tiger and Crown Flower

For example, where the Crown Flower (Calotropis gigantea), the caterpillar host plant of the Plain Tiger is grown, the interpretative sign that describes the plant and butterfly is located just in front of a clump of the Crown Flower plants. Often, as one reads the sign, the Plain Tiger will be fluttering in full sight of the visitor, and frequently ovipositing on the leaves of the plant. If one looks a bit closer, one may even find the caterpillars feeding on the plant. This makes the information on the sign very effective if the visitor can connect immediately, the butterfly and its host plant from field observations.

Another plant of interest is the Rattle Weed (Crotalaria retusa). Whilst the plant is neither a host nor a nectaring plant, the Rattle Weed contains alkaloids which many Danainae butterflies love. This unique plant attracts these Crow and Tiger butterflies and the relationship of this plant to the butterflies is immediately evident to visitors.

Interpretative sign with information about nectaring plants for butterflies

And then there are signs that depict the butterflies' favourite nectaring plants like the Snakeweed (Stachytarpheta indica) and the String Bush (Cordia cylindristachya). Again, the plant details are described so that the visitor can learn more about these plants, as well as the butterflies that visit them to feed on the nectar from the flowers.

Various caterpillar host plants that support their respective butterfly species at Butterfly Hill @ Pulau Ubin

The remaining interpretative signs depicting host plants of specific butterflies like the Bamboo, Chinese Violet, Batoko Plum, Lime and Pomelo and others are also carefully located where these plants are cultivated. To attract the butterflies whose caterpillars feed on these host plants, various nectaring plants are planted nearby so that visitors can chance on these butterflies when they feed on the flowers.

Caterpillar host plant Seven Golden Candlesticks (Senna alata) are cultivated behind the interpretative signage displaying information about the plant and the butterflies that are associated with it 

In conclusion, whilst designing and creating a butterfly garden is not difficult with the correct information on plants and the myriad of information available on the internet, it is also important not to miss the opportunity to create awareness and promote the conservation of butterflies through the use of interpretative and educational signage that help to spread the knowledge about our butterflies. So the next time you visit Butterfly Hill @ Pulau Ubin, do take some time and learn more about butterflies and the plants that are associated with the butterflies.

Text by Khew SK ; Photos by Khew SK and Robert Teo

08 July 2018

The Butterfly Labial Palps

The Butterfly Labial Palps
Labial Palps of the Butterfly - Its Olfactory Sensory System

The exceptionally hairy labial palps of a Common Three Ring

Every butterfly possesses labial palps (or palpi) - a pair of hairy, moustache-like scaly appendages on the head of the butterfly. These palps are covered with sensory hairs and are believed to help a butterfly "taste" food sources and identify what is potentially edible and what is not. The labial palps are multi-segmented external organs and vary in size and shape across the different families of butterflies.

There are also other theories that suggest that the labial palps of a butterfly serves other functions. For example, one theory suggests that the pair of palps, given their symmetrical location on both sides of the proboscis, could offer some form of physical protection for the proboscis. It would appear to be highly plausible in some species, where the proboscis is completely hidden by the labial palps until the proboscis is uncoiled for feeding. However, in other species, the size of the labial palps is not adequately large enough to cover even half of the coiled proboscis, leaving the proboscis exposed.

© Encyclopedia Britannica (left) and © NC State University (right)

Another suggestion of the function of the labial palps would be that the long hairs covering the palps act as some form of filters and protect the eyes from being contaminated as the butterfly feeds at flowers or when puddling. Again, the extent to which this may be true or not, varies from species to species, from the extremely hairy labial palps of a Satyrinae butterfly, to the smooth and more robust labial palps of some of the Nymphalidae.

In field observations, one can observe the movement of the labial palps when the butterfly uncoils its proboscis to feed. The muscles in the head of the butterfly appears to be able to control the antennae, proboscis and the labial palps independently but yet at the same time, coordinated enough to allow maximum efficiency for the butterfly to fulfil its primary objective to extract as much food source as possible when it feeds.

The physical appearance of the labial palps varies quite a bit across the different families of butterflies. In some cases, the palps are short and plump and held closely to the head of the butterfly. In other examples, the palps are extremely hairy, whilst some are stubby and smooth. Some species have the last segment of the palps modified and stick out like a pair of horns, and some examples show the palps sticking rigidly and extending beyond the head of the butterfly like a snout.

The labial palps of the Club Beak butterfly (Libythea sp.) gives it an appearance of  a face with a snout

A unique example of the labial palps evolving into something remarkable in a butterfly would be the "Club Beak Butterflies" or "Snout Butterflies". Although these species do not fly in Singapore, they are distinctive enough to be mentioned and shown here as an example of butterflies where the extended labial palps gives them an appearance of having a long snout.

The labial palps of the Papilionidae are compact with short hairs

Let us now take a look at this examples of this morphological feature across the different species in the families that can be found here in Singapore. Amongst the large Papilionidae, it can be observed that the labial palps of the majority of the species in this family are compact and held close to the head of the butterfly. The hairs of the labial palps sometimes take on the bright colours of the butterfly's body, like in the Common Rose.

The labial palps of the Common Rose takes on red hairs and gives it a distinct appearance

Given the long and thick proboscis of the Papilionidae and the comparatively compact labial palps, it is obvious that the palpi does not cover nor protect the proboscis at all, unlike some other butterfly species that we will see in the later part of this article. The sensory hairs on the labial palps are also short and thick and does not in any way extend out in front of the head of the butterfly.

In the next family, the Pieridae, the labial palps are also compact but are generally covered with longer and thicker hairs. Species from the subfamily Pierinae have labial palps covered with longer hairs and the last segment of the palps ends in a sharp point. Species from the subfamily Coliadinae, however, have compact labial palps and do not have the last segment ending in a point.

The large butterflies in the subfamily Danainae of the Nymphalidae family have compact and rather indistinct labial palps covered in short hairs. The last segment of the palps ends in a short stubby tip. The compact labial palps do not cover the proboscis completely when coiled - the proboscis is partially exposed and extends beyond the labial palps.

The labial palps of this Malay Baron gives it a beak-like look when viewed from the top

The Tawny Coster's labial palps are covered with yellow-coloured hairs

There is a wide variety of shapes of the labial palps of the several subfamilies of the Nymphalidae. Some are covered in sparse and fine hairs, like the Malay Lacewing, whilst others, like the butterflies of the Baron genus, have short stubby labial palps that look like a beak when the butterfly is viewed dorsally.

The genera Ypthima and Mycalesis features butterflies with exceptionally hairy labial palps, giving them an appearance of an unshaven face.

Of special mention are some species from the subfamily Satyrinae that feature exceptionally long hairs on their labial palps, giving the butterfly an appearance of an unshaven face. These long hairs on the palps completely hide the proboscis from view.

The Riodinidae butterflies have very compact labial palps with short hairs that can conceal their thin and short proboscis completely

The Riodinidae butterflies have very compact labial palps with very short hairs covering them. The palps are held tightly against the head and completely hide the short thin proboscis of the majority of the species in this family of butterflies.

The labial palps of this Curetis sp. are speckled with red spots

Amongst the Lycaenidae, the labial palps of many species have sharp distinct terminal segments protruding beyond the head. In some species, the extended labial palps give the butterfly an appearance of having a snout. Species from the Curetinae subfamily have red spots on the palps and are diagnostic features for separating the species in the group.

This Biggs' Brownwing has long labial palps that look like horns on the butterfly's head

Species from the Miletinae subfamily have long, smooth labial palps making the butterflies appear to have a second set of short horn-like antennae from its face. The thin proboscis is hidden between the labial palps.

Labial palps of various shapes and sizes amongst the Lycaenidae butterflies

Other species amongst the Blues and Hairstreaks have labial palps extending way beyond its compound eyes and is prominently featured like pointed horns sticking out from the butterfly's head. In several species, the labial palps are coloured distinctly.

The labial palps of this Yellow Banded Awl are broad and covered with short hairs. The terminal segments end in two needle-like appendages sticking out from the face of the butterfly

Finally, amongst the Hesperiidae, the labial palps of many of these robust-bodied species of butterflies are wide and covered with short thick hairs. The terminal segment of the labial palps of several species from the Coeliadinae subfamily end in a short, smooth needle-like points emerging from the head of the butterfly.

The thick and wide labial palps in skippers can almost hide its long proboscis

This Yellow Chequered Lancer extends its labial palps away from its face, making it appear strange

This newly-eclosed Orange Awlet extends and adjusts its labial palps (left) before retracting them close to its face (right) 

A unique behaviour amongst the Hesperiidae is that the butterfly can extend the labial palps beyond its face, pushing the palps forward in a remarkable fashion, making the face of the butterfly appear strange. In newly-eclosed individuals, this behaviour is also sometimes observed, as the butterfly extends its labial palps. In the majority of species of Hesperiidae, the wide and significant labial palps are able to almost totally conceal the coiled proboscis.

When you are out in the field next, do take a much closer look for this unique morphological feature in butterflies and share any special observations that you may have of the labial palps of butterflies.

Text by Khew SK : Photos by Khew SK, Bobby Mun and Nelson Ong