Flight of the Imperials

Flight of the Imperials

Featuring Singapore's Imperial Butterflies


A Branded Imperial perches on a leaf in the shaded forest understorey

The English word "imperial" is usually used to refer to things or people that are or were connected with an empire or pertaining to an emperor or empress. When the early collectors coined the name Imperial for some species of the Lycaenidae family, it is highly likely that they were using the word to describe these majestic butterflies that awed them with their breath-taking colours and beauty.


A Green Imperial stops to rest on the flower of the Javanese Ixora

In the world of butterflies, the Imperials are pretty, colourful and usually long-tailed species belonging to the sub-family Theclinae of the Lycaenidae family. Singapore is home to five of these Imperials, all of which are forest-dependent and usually found only in the heavily forested nature reserves. Of the five, only one is considered common and regularly seen by nature enthusiasts.


A female Great Imperial feeding on the flower of the Javanese Ixora

This blogpost takes a look at these five Imperial butterflies found in Singapore. Interestingly, each one of the five belongs to a different genus. All have orange with white undersides and black tornal markings. Their long tails are remarkable features on these species, and two of them probably sport the longest tails amongst the extant butterflies in Singapore.

1. The Branded Imperial (Eooxylides tharis distanti)


A Branded Imperial shares the sweet sap of the Bandicoot Berry with some ants

The first of the Imperials is the Branded Imperial. This species is by far the commonest of the five species and is regularly found along forest paths in the shaded understorey of our nature reserves. At times, several individuals can be seen together, particularly when they are feeding on the young shoots of the Bandicoot Berry (Leea indica).



A male Branded Imperial opens its wings to sunbathe.  Note the prominent brands on its forewings

The wings are black above with blue-dusted tornal area on the hindwing. In the male, a prominent "brand" can be seen on the upperside of the forewing. This could be why the butterfly is named Branded Imperial. The underside is reddish-orange with the hindwing bearing black sub-marginal spots on the white tornal area. There are 3 tails on the hindwing, of which the one along vein 2 is the longest.



The species' caterpillar feeds on the invasive weed Smilax bracteata which it shares with another Lycaenid, the Yamfly. As this non-native weed is very widespread in the nature reserves (despite efforts to remove the weed), the Branded Imperial has become a common species in Singapore.

2. The Common Imperial (Cheritra freja friggia)



The Common Imperial is a moderately rare species but is quite widespread across the island. Although found in the forested nature reserves, it can sometimes be found in urban parks and forested ridges in Singapore. It is usually observed singly and prefers to stay at treetops. It has a habit of perching on favourite leaves and returns time and again to the same perches as it flies around.


A male Common Imperial sunbathing with its wings opened to show the purple-blue uppersides

The male Common Imperial has purple-blue forewings on the upperside, whilst the female is dark brown. There are large black spots on the tornal area of the hindwing. Te underside is mainly white, with part of the forewing and the apical area of the hindwing shaded a light orange. The tornal spots on the hindwing are overlaid with metallic blue-green scaling. It has 3 tails of which the one at vein 2 is the longest.



The species' caterpillars feed on two species of common roadside trees, the Wild Cinnamon and the Red Saga. It has also been bred on other forest plants that are mainly found in the nature reserves. The species is observed to sunbathe with open wings at certain hours of the day at sunlit spots.

3. The Green Imperial (Manto hypoleuca terana)



The Green Imperial is considered rare in Singapore. It is usually seen at the forest edges of the nature reserves, feeding on the nectar of flowering plants. It is a fast-flying species that probably prefers to stay at the treetops.



The male of the Green Imperial is a shining bluish-green above, with broad black apical area on the forewing. The underside is largely orange and unmarked on the forewing, whilst the hindwing has black sub-marginal spots and streaks. The female is dark blackish-brown above with the usual black spots on a white tornal area on the hindwing. The underside of the dorsal area of hindwing is white, whilst the other areas of the forewing and hindwing are orange. The species has 2 tails - a relatively long tail and vein 2 and a short stubby one at vein 3.



Female Green Imperial. Top : Underside Bottom : Upperside

The species is one of several rare Lycaenidae that feeds on the parasitic plant, Macrosolen cochinchinensis, that can be found growing on large trees and bushes all around the island. The females have been observed ovipositing on the leaves of the host plant in the early afternoon and lays her eggs on the young shoots of the plant.

4. The Great Imperial (Jacoona anasuja anasuja)



Another rare Imperial, the Great Imperial has been observed only in the forested nature reserves of Singapore. The adult butterfly appears to be another tree-top dweller but occasionally can be seen to descend to low level shrubbery to feed or oviposit. When disturbed, it can fly rapidly up the treetops.



Top : Female Great Imperial Bottom : Male Great Imperial

The male of the Great Imperial is a deep shining blue on the upperside with an oblique band running across the apical area of the forewing. The female is predominantly brown above with a white tornal area on the hindwing. The underside is mainly orange with the forewing apical area a darker shade. The dorsal area of the hindwing is white with the tornal black streaks and spots. Both sexes have tails, where the males have a shorter sword-like tail at vein 2 whilst the female's tail is much longer.



The caterpillar host plant of the Great Imperial is the common Malayan Mistletoe. However, the species is not usually found in urban parks and gardens. It is found along the forest fringes and where it is observed, it is perched on the uppersides of leaves with its wings folded upright. Both sexes also descend from the treetops to feed on flowering plants.

5. The Grand Imperial (Neocheritra amrita amrita)



The last of the Imperials is also a rare forest-dependent species that is quite local in distribution. Its caterpillar host plant is found in the nature reserves and is quite rare. The plant has yet to be positively identified. However, the Grand Imperial was seen in numbers on the military-training island of Pulau Tekong in the early 2000's during a period of biodiversity surveys. It is not known if they are currently still as common.


A male Grand Imperial feeding on flowers

The male Grand Imperial has a royal blue upperside, with the apical areas of both wings black bordered. The female is dark brown and largely unmarked, except at the white tornal area where there are black spots. The underside of the forewing and costal half of the hindwing is dark orange whilst the remaining part of the dorsal area of the hindwing is pure white.


A female Grand Imperial sunbathing

The Grand Imperial has the longest tails of any Lycaenidae found in Singapore. It has 3 tails, of which the longest tail is at vein 2, whilst there are two shorter tails at veins 1b and 3 of the hindwing. The male has a prominent raised 'disc' on the underside of the forewing.

Text by Khew SK : Photos by Huang CJ, Khew SK, Simon Sng, Jonathan Soong, Horace Tan and Tea Yi Kai

Butterfly of the Month - February 2019

Butterfly of the Month - February 2019
The Common Imperial (Cheritra freja frigga)

Chinese communities all over the world welcomed the Year of the Pig on 5 Feb 2019. The pig is the the twelfth animal in the 12-year cycle of Chinese zodiac sign and 2019 completes the cycle that started in 2006. This year's pig is the "Earth" pig according to the Chinese almanacs.




According to the Chinese astrology , 2019 is a great year to make money, and a good year to invest! 2019 is going to be full of joy, a year of friendship and love for all the zodiac signs; an auspicious year because the Pig attracts success in all the spheres of life. Sounds generally good enough for me! :)



It is always a nice feeling to shed the old and bring in the new, especially when 2018 wasn't a particularly good year on many fronts. It was heartbreaking when my mom left us at the age of 87 in early January. That month was just a total blur of sadness, grief and pain - combined with a flurry of activities.



But thankfully, our family support and well-wishes of friends helped us tide over that period. Mom would have wanted us to carry on and be happy that she no longer had to endure the suffering that she had to go through in the last 4 months of her life. To all the relatives and friends who were there for us, I thank you from the bottom of my heart. My apologies if I could not thank each of you individually, but you know who you are, and you have my humble gratitude that you reached out in my family's moments of darkness.



So life goes on for those of us, as we ponder our own mortality, and what we plan to leave behind us in the time that we have left in this world. Whatever little good that we can contribute to the world around us, we should. And we move on to do our little bit to make the world a better place in our own ways.



And we continue to bring cheer during this Chinese New Year period and look forward to better times that we have to work hard for. Our world is changing rapidly in many tangible and intangible ways. Disruptions of all sorts and sizes abound, and we have to face new challenges all the time. But that's what makes life 'colourful' and less mundane, even though we struggle to maintain order and stability around us.



Let us come back to our colourful friends, the butterflies. This month, we feature the Common Imperial (Cheritra freja frigga), a delicate long-tailed beauty of the Lycaenidae family. It is always a breath-taking experience to see this butterfly flutter amongst the shrubbery with its elegant white tails trailing behind.


Upperside of a male Common Imperial

The Common Imperial is more often seen in urban parks and gardens than within the forested nature reserves in Singapore. This may be because the species' caterpillars depend on a variety of host plants that are more commonly found in urban areas. The caterpillars of the Common Imperial have been successfully bred on Callerya atropurpurea, Duabanga grandiflora, Adenanthera pavonina (Red Saga) and Cinnamomum iners (Wild Cinnamon). The last two host plants are common roadside trees.




The upper wing surfaces of the butterfly is a deep purple-blue in the male, and dark brown in the female. The tornal area on the upperside features large black quadrate spots. The underside is mainly white on the hindwing with the forewing a shade of orange. The tornal spots on the hindwing is overlaid with iridescent greenish-blue scaling. The Common Imperial has white tails along veins 1a, 2 and 3 of which the one at vein 2 is the longest.




The Common Imperial has a rapid flight and is often skittish, preferring to stay high in the treetops. Where it is found amongst low shrubbery, males have a tendency to perch on a few favourite spots and 'attacks' any intruders into its space. Females descend to the lower levels to oviposit in the mid- to late afternoon hours of the day.


A Common Imperial sometimes displays a behaviour where it hides under a leaf

A Common Imperial puddling at a sandy streambank

At certain hours on hot humid days, males may be seen opening their wings flat to sunbathe. At other times, it displays a behaviour where it hides under a leaf with its wings folded upright. It is not often seen puddling at damp streambanks or muddy trails, but there have been occasions where males are observed puddling.


A mating pair of the Common Imperial

Sightings of this species have been more regular and often in the past decade. However, it appears to have become rarer in the recent few years, having been spotted mainly in the parks of Singapore's Southern Ridges. As with many of the English names of butterflies, those that carry the "common" prefix are often not as common as one is led to believe. The Common Imperial is a species that is considered moderately rare to rare, and is usually observed singly.

Text by Khew SK : Photos by Goh LC, Federick Ho, Khew SK, Jonathan Soong, Horace Tan, Tan Sze Siong and Anthony Wong

Taxonomic Classification in Butterflies

Taxonomic Classification in Butterflies
What is a Subspecies?

The Swedish naturalist, Carolus Linnaeus (Carl von Linne) pioneered the internationally recognised naming system for every creature and plant. Realising that every organism should be classified systematically according to its relationship with other organisms, he created the Linnaean system in his works, Systema Naturae in 1735 - a catalogue of the names of all known animals and plants. The 10th edition of Systema Naturae in 1758 is often adopted as the starting point for biological classification of animals and plants by family, genus and species.

According to the Linnaean system, all animals and plants are known by a combination of two names - the first indicating the genus, and the second, the species. This system, referred to as binominal nomenclature is also applied to the naming of butterflies. Furthermore, classification of butterflies used by many researchers and authors extend one more level to a rank below species. This is the subspecies. This method of naming the subspecies is known as the trinominal system and is now in general use for the scientific naming of butterflies.

A Pea Blue in Singapore is also known as a Long-Tailed Blue in Australia and Europe.  But its scientific name, Lampides boeticus, is consistent, wherever it is found.

I have sometimes been asked about what a subspecies is, and how a butterfly subspecies comes about. This blogpost discusses the definition of subspecies, and the way it is applied to the scientific naming of butterflies. Although most amateurs and hobbyists prefer to use English common names for butterflies, this can often be confusing, and common names tend to differ amongst different countries and published references. Scientific names, however, are adopted universally and Lampides boeticus is the name used for the species, whether in England or in Singapore. The English common name, however, may vary from Long-Tailed Blue to Pea Blue, depending on where the butterfly is sighted!

Before we examine the concept of subspecies, let's consider what makes a species. A species is a group of living things with very similar traits that can interbreed. For example, elephants can breed with each other, but not with hippopotamuses. Different species rarely interbreed. On the occasions when they do, either by human intervention or naturally, the offsprings of the interbreeding are typically sterile, and are unable to reproduce further.



By definition, a subspecies is an individual or a group within a species that has become somewhat physically different from the species. However, they are still biologically similar enough to interbreed with individuals of the same species. Now let's take a look at why some species branch into subspecies. One major reason for this is the geographic isolation of a particular population of that species e.g. by physical distance or geographical separation, like an island. They are still the same species, but the group that became isolated may take on some different physical features simply due to their location.


The southern Malaysian and Singapore subspecies malayana (left) has less dense striations on its wings than the northern Malaysian subspecies nina (right)

However, we need to understand that the science of taxonomy is ever-evolving. Scientists often find themselves in disputes about which genus a particular species belongs to, or whether two or more butterflies with very similar physical characteristics should be classified as separate species or as subspecies. With recent developments in microbiology, phylogenetics, DNA sequencing, and the study of the early stages of a butterfly often results in new insights on the relationships between species. This newfound knowledge regularly results in the necessity to make revisions to the adopted classifications of butterflies.

Scientific name of the Lime Butterfly is :
[Genus]Papilio [Species]demoleus [Subspecies]malayanus

In the trinominal system of naming of butterfly species, we have the [Genus] followed by the [species name] and then by the [subspecies name]. Hence for a Lime Butterfly, the scientific name would be Papilio demoleus malayanus. Note that only the genus name is capitalised. The species and subspecies name should never be capitalised.

Different subspecies of butterflies found in Singapore vs those found in Northern Thailand
Top : Moduza procris procis (Chiang Dao) vs Moduza procris milonia (Singapore)
Middle : Cheritra freja friggia (Singapore) vs Cheritra freja evansi (Chiang Dao)
Bottom : Lexias pardalis jadeitina (Chiang Dao) vs Lexias pardalis dirteana (Singapore)

For amateur observers (and even for the more knowledgeable enthusiasts), it is sometimes difficult to ascertain the physical differences between two subspecies of butterflies. Very often, purely due to geographical distances, a butterfly that shows very little perceptible physical differences is given a different subspecies name. Others, however, are more obvious where the physical differences are clear.

Examples of butterflies which has only the species name, suggesting that the physical appearance of these species have no significant differences irrespective of where they are found - Lampides boeticus (Pea Blue), Acreae terpsicore (Tawny Coster), Udaspes folus (Grass Demon) and Plastingia naga (Chequered Lancer)

Then what about butterflies with only species name given to it? This suggests that the species is consistent throughout its range and there are no discernible physical differences in its appearance, no matter where it is geographically found. Some examples of such butterflies that are extant in Singapore are the Pea Blue, Grass Demon, Tawny Coster and Chequered Lancer. Interestingly, quite a number of butterflies that have been described down to only species level are from the Lycaenidae and Hesperiidae families.

Left : Subspecies malayana and Right : subspecies parkeri are both found in Singapore

Left : Subspecies bolina and Right : subspecies jacintha are both found in Singapore

Left : Subspecies pratipa and Right : subspecies bisaltide are both found in Singapore. However, subspecies pratipa has not be reliably seen since 2007.

Left : Female subspecies bisalitide and Right : subspecies pratipa showing their differences on the upperside of their wings

In Singapore, there are 3 occurrences of butterflies of which there are two subspecies observed here over the years. These are the Knight (Lebadea martha parkeri and Lebadea martha malayana), the Great / Jacintha Eggfly (Hypolimnas bolina bolina and Hypolimnas bolina jacintha) and the Autumn Leaf (Doleschallia bisaltide bisaltide and Doleschallia bisaltide pratipa). Being an island separated from mainland Malaysia, it is likely that these subspecies' range overlap between Singapore and Malaysia and the evolution of the subspecies may continue until one is eventually eliminated.

Top : Caterpillar of the Autumn Leaf subspecies bisaltide and Bottom : subspecies pratipa

In the case of the Autumn Leaf, the subspecies pratipa which is usually found in Malaysia has a distinctively different caterpillar that is more obvious than the adult butterflies. However, subspecies pratipa was last seen in Aug 2007 at the Mandai Zoo and it is unknown if this subspecies still occurs in Singapore. The other two species continue to have sightings of their respective subspecies to this day.

As taxonomic science continues to evolve, technical methods and new knowledge are gained, it is inevitable that changes and updates to the scientific names of butterflies will continue.

Text by Khew SK : Photos by James Chia, Khew SK, Anthony Wong and Mark Wong