Life History of the Great Imperial v2.0

Life History of the Great Imperial (Jacoona anasuja anasuja)
An earlier version of the life history of the Great Imperial can be viewed by clicking this link.

Butterfly Biodata:
Genus: Jacoona Distant, 1884
Species: anasuja C & R Felder, 1865
Sub-species: anasuja C & R Felder, 1865
Wingspan of Adult Butterfly: 34-38mm
Caterpillar Local Host Plants: Dendropthoe pentandra (Loranthaceae), Scurrula ferruginea (Loranthaceae).

A sunbathing  Great Imperial  displaying its upperside.

A male Great Imperial.

Physical Description of Adult Butterfly:
Above, the male is dark brown with lower halves of both wings in shining blue. In the forewing, there is a short and oblique blue band in the apical area, and a black oval band in the outer part of the cell. The female is mainly brown. In its hindwing, the tornal area is white with embedded black spots in space 1b, space 2 and in the tornal lobe. Underneath, both sexes are mainly yellowish orange with the lower half of the hindwing white. Black post-discal striae are present in the tornal half of the hindwing. In the forewing, the basal part of vein 12 is black (this is a key characteristic for distinguishing the Great Imperial from the Grand Imperial). There are tails at the end of veins 1b and 2 in the hindwing. For the tail at end of vein 2, the one for the male is little more than a tooth, while that of the female is moderately long. As for the tail at end of vein 1b, the one for the male is long and sword-like, while that for the female is even longer and fluffy in appearance.

A newly eclosed male Great Imperial resting on its pupal case.

A male Great Imperial taking nectar from Syzygium flowers.

Field Observations of Butterfly Behaviour:
This species is rare in Singapore. The handful of sightings take place mainly in the Central Catchment Reserve, as well as small pockets of wooded area to its west and north. The Great Imperial appears to be a tree-top dweller. The fast flying adults typically perch with its wings closed upright between flights. In sunny weather, however, they have been observed to sun-bathe with wings fully open.

A female Great Imperial.

Early Stages: 
So far, two parasitic plants have been recorded as the host plant for the Great Imperial. The caterpillar feeds on the young leaves of both host plants, with the early instars mainly skimming the leaf surface while those in the later instars devouring the leaf lamina whole from the edge.

Local host plant #1: Scurrula ferruginea.

Local host plant #2: Dendropthoe pentandra.

The eggs are laid singly on the underside of a leaf of the host plant. Each egg is about 1-1.1mm in diameter, creamy yellow in color when freshly laid. The surface is covered with conical protrusions with blunted tip. The tiny and depressed micropylar sits at the pole.

Two views of an egg of the Great Imperial.

It takes about 3 days for the egg to hatch, with the young caterpillar nibbling away the upper portion of the egg shell to emerge. The newly hatched has a length of about 1.9mm. Its body has a white and pale yellowish ground colour with two sets of reddish patches on the sides. The pro-thoracic shield and anal plate are mainly brown in colour. Each of the segments from the 3rd thoracic segment to the 7th abdominal segment has a dorsal conical protrusion. Pale brown setae emanate from these protrusions. The body also features rather long whitish setae along the body rim, and a rectangle-shaped posterior end. After hatching, the infant caterpillar proceeds to devour the remnant of the egg shell.

A newly hatched caterpillar devouring the remnant of its egg shell.

Two views of a newly hatched caterpillar of the Great Imperial.

As the caterpillar grows the reddish patches on its body expand their reach and become darker and more intense red at the same time. After about 4 days of growth in the first instar, and reaching a length of about 3.3mm, the caterpillar moults to the next instar.

Two views of a 1st instar caterpillar, late in this stage, length: 3mm.

Two views of a 1st instar caterpillar, dormant before its moult.

The 2nd instar caterpillar has much shorter (proportionately) dorsal and lateral setae. It prothoracic shield is dark brown to black in colour. The previously rectangular posterior segment now has two small conical protrusions. The dorsal nectary organ on the 7th abdominal segment is now discernible. The 2nd instar caterpillar grows steadily and reaches a length of about 6-6.5mm. After about 4 days in this instar, it moults again.

Two views of a 2nd instar caterpillar, early in this stage, length: 3.6mm..

Two views of a 2nd instar caterpillar, later in this stage, length: 5.2mm..

Two views of a 2nd instar caterpillar, late in this stage, dormant prior to its moult.

The 3rd instar caterpillar resembles the 2nd instar caterpillar, but with various features (such as dorsal and posterior conical protrusions, body outline) becoming more pointed or angular. Numerous setae covering the body are now proportionately shorter and uniform in length. The dorsal nectary organ is also rather large and more prominently featured than in the 2nd instar. The pair of tentacular organs found on the 8th abdominal segment is now easily observed as well. The 3rd instar takes about 5 days to complete with the body length reaching about 9-10mm.

Two views of a 3rd instar caterpillar, length: 7.2mm.

Two views of a late 3rd instar caterpillar, dormant prior to its moult, length: 9mm.

Initially, the 4th instar mostly resembles the late 3rd instar caterpillar closely in coloration and most features. One obvious change is that the dorsal conicao protrusions from the 3rd thoracic segment to 3rd abdominal segment are now fused together to form a contiguous dark brown ridge. As growth progresses, the body color becomes uniformily purplish brown, and the anterior end becomes pointed with two tips closely spaced. The 4th instar takes about 3 days to complete with the body length reaching about 19-20mm. As it lays dormant prior to its moult, the body colour is mostly greyish brown.

Two views of a newly moulted 4th instar caterpillar, eating its exuvia.

Two views of a 4th instar caterpillar, later in this stage, length: 19mm.

Two views of a late 4th instar caterpillar, dormant prior to its moult.

The 5th instar caterpillar is initially reddish brown in body colour, but becoming darker as growth progresses. By day 4 of this instar, the body base colour is almost black to dark chocolate. At the same time, pale beige brown markings appear in mid-abdomen and posterior segments, and wavy markings flank the dorsum of the abdominal segments.

Two views of a newly moulted 5th instar caterpillar, eating its exuvia.

Two views of a 5th instar caterpillar, early in this stage, length: 18mm.

Two views of a 5th instar caterpillar, length: 27mm.

Two views of a 5th instar caterpillar, length: 29mm.

After about 6-7 days of feeding and reaching a length of about 32mm, the caterpillar stops food intake, and its body gradually shortened and body base colour decolorised to a dull shade of greyish green. The caterpillar would wander around in seek of a pupation site which is typically a spot on a stem or branch. At this site, the pre-pupatory caterpillar prepares for pupation by spinning a silk pad to which it attaches itself via its anal claspers. After 1 day as a pre-pupa, pupation takes place. The pupa has two prominent dorsal protuberances. It is predominantly pale to dark greyish brown with powdery green patches decorating its surface. There are also cryptic markings in orange, white and green to add to the concealment effect. Pupal length: 18-20mm.

Two views of an immobile pre-pupa of the Great Imperial.

Two views of a pupa of the Great Imperial.

7-8 days later, the pupa turns rather dark, first in the wing pad and thorax, then progressively in the abdomen. The next day, the pupal stage comes to an end with the emergence of the adult butterfly.

Two views of a mature pupa of the Great Imperial.

A newly eclosed  Great Imperial waiting for its wings to expand fully near its pupal case.

References:

• [C&P4] The Butterflies of The Malay Peninsula, A.S. Corbet and H.M. Pendlebury, 4th Edition, The Malayan Nature Society.
• Butterflies of Thailand, Pisuth Ek-Amnuay, 1st Edition, 2006.

Text by Horace Tan, Photos by Ben Jin Tan, Federick Ho, Sunny Chir and Horace Tan

Down Memory Lane - Burmese Caerulean

Down Memory Lane
The Burmese Caerulean (Jamides philatus subditus)

This species, referred to as the Burmese Caerulean, was recorded in Singapore by the early authors. Both the reference books, Butterflies of the Malay Peninsula by Corbet & Pendlebury and Butterflies of West Malaysia and Singapore by WA Fleming listed this species as extant in Singapore in the checklists found in the books. It is described as uncommon.

The Burmese Caerulean has distinctive black wedge-shaped submarginal spots on the underside of the hindwing and sets it apart from the other lookalike species of the Jamides genus. The upperside is a pretty light sky blue. It has a filamentous white-tipped tail at vein 2 of the hindwing.

These shots, taken this year in Malaysia, show the Burmese Caerulean puddling at a sandy streambank. It would be awesome to see this species again in Singapore. Will it be back here again one day? Or will it remain only in our memories and is gone forever from Singapore?

Butterflies Galore! : Tree Yellow

Butterflies Galore!
The Tree Yellow (Gandaca harina distanti)

The Tree Yellow resembles the "Grass Yellows" from the genus Eurema. Although there are at least six species from the Eurema, the Tree Yellow, the sole representative of its genus, is slightly larger and lighter yellow in appearance. The absence of any markings on the underside of this species will easily distinguish the Tree Yellow from its commoner relatives. The Tree Yellow is mainly a forest denizen and rarely seen in urban parks and gardens. The butterfly is unmarked except for a narrow black border on the upperside of the wings.

In Singapore, the Tree Yellow is often seen puddling at moist footpaths and sandy streambanks. However, it is very skittish and not easily approached. There are occasions, however, when the butterfly is more cooperative and allows a photographer to sneak up close to it for a good shot. This individual was photographed in the nature reserves by ButterflyCircle member Nelson Ong.

It's a Bird! No, it's a Butterfly!! Part 2

It's a Bird! No, it's a Butterfly!! Part 2
Crows and Tits


A Dwarf Crow feeding on the flower of the Indian Heliotrope (Heliotropium indicum)

Following up from my earlier article about bird-butterfly name sharing, this second article looks at two more groups of butterflies which bear the same collective name as birds.  Obviously, the authors who coined the names for these butterflies probably captured the physical attributes of the butterflies that resemble their avian namesake.  

The Crows

The first group deals with predominantly dark coloured butterflies of the Danainae subfamily. The characteristic black or blue butterflies with prominent white spots and streaks belonging to the genus Euploea are collectively called "Crows". In the avian world, Crows are members of a widely distributed genus of birds, Corvus, in the family Corvidae.


A screen capture of images after googling "Crows"

Here in Singapore, crows are considered pests that are unhygienic, tearing apart rubbish bags and leaving a mess. They are also known to pinch food and leftovers from hawker centres and even homes. There have been reports of crows attacking passers-by in housing estates. It is also a common sight to see crows chasing after the local refuse trucks and scavenging scraps of anything edible from the truck. When the crow population spiralled out of control, the local gun clubs were recruited to cull the large birds. The population of these unwelcomed birds reached a peak of 120,000 individuals in 2001 before regular culling dropped their numbers to a more manageable 10,000 in 2007. Although they are still quite evident in the local environment, their numbers appear to be under check.

Local superstitions put the crow as a bringer of bad luck. Their loud "caws" are also considered undesirable and whenever they appear in human habitations, they are rarely accepted as a welcome visitor. However, crows are known to be amongst the most intelligent of birds, being able to use their resourcefulness to get at their food.


A female Striped Blue Crow feeds on the flowers of a Syzygium tree, shot against the blue sky

In our butterfly world, Crows belong to the genus Euploea.  There are eight extant species of Crows in Singapore, of which one species is very rare. The known species of Crows that exist in Singapore are :

• Striped Blue Crow (Euploea mulciber mulciber)
• Striped Black Crow (Euploea eyndhovii gardineri)
• Blue Spotted Crow (Euploea midamus singapura)
• Spotted Black Crow (Euploea crameri bremeri)
• King Crow (Euploea phaenareta castelnaui)
• Malayan Crow (Euploea camaralzeman malayica)
• Magpie Crow (Euploea radamanthus radamanthus)
• Dwarf Crow (Euploea tulliolus ledereri)

A male Striped Blue Crow perches on a leaf

Amongst these species, the Striped Blue Crow is the commonest species. It is found in urban areas as well as in the nature reserves. The species is named after the female, which features a striped hindwing. The upperside of the males is a deep iridescent blue that is attractive when it flies slowly past an observer.


A Magpie Crow feeding on a fallen fruit

The Magpie Crow is the next most common species. This species is often observed puddling in the nature reserves and on damp timber structures like shelters and railings. The Magpie Crow is the model that is mimicked by the Courtesan for protection against predators.


A Blue Spotted Crow feeding on the flowers of a Syzygium tree

The Spotted Black Crow and the Blue Spotted Crow are quite similar in appearance. Both are black with almost identical white spots on both the fore and hindwings. However, the spots on the Spotted Black Crow are more elliptical, and on the forewing apical area, it has an extra spot when compared to the Blue Spotted Crow.


A Spotted Black Crow feeding on the flower of a String Bush

The King Crow is the largest member of the genus, and is a moderately rare species. It can be quite local, and is regularly seen in back-mangrove areas where its caterpillar host plant, the Pong-Pong tree (Cerbera odollam) grows. It can be seen in urban parks and gardens, as well as in well-vegetated areas in the vicinity of its host plant


A King Crow feeding on the flowers of a Syzygium tree

The Striped Black Crow is rare, but occasionally appears at urban parks when flowering trees are in full bloom. The hindwing features a series of white submarginal streaks. It has been observed puddling on concrete floors and structures in the vicinity of the nature reserves in Singapore.


A Striped Black Crow feeding on a Bidens sp flower

The Dwarf Crow was first discovered on the offshore island of Pulau Ubin in Singapore, and was regularly observed, sometimes in numbers in the mid-2000's. However, in recent years, it has almost completely disappeared from Pulau Ubin, and has not been reliably spotted for several years after 2010.


A puddling Dwarf Crow

The Malayan Crow is the rarest of the species in the genus in Singapore. This fairly large black butterfly with white marginal and submarginal white spots, has only been seen on a few occasions in Singapore. Thus far, the observations of this species has been in the forested areas of the nature reserves. Although its known host plant is available in Singapore, it is curious as to why the species is not found more often, and whether the earlier observations of the individuals were of non-resident migrants or not.


A male Malayan Crow resting on a leaf in the nature reserves

The Tits

If one innocuously googles the word "tits" with well-meaning intention, looking for pictures of birds or butterflies, the result may not be as expected. Doing so usually brings forth pictures of well-endowed women and in particular featuring a part of the female anatomy that men tend to admire. Coming back to our avian variety of "tits", we find birds belonging to the Paridae, a large family of small passerine birds which occur in the northern hemisphere and Africa.


A screen capture of images after googling "Tits Birds"

These birds are mainly small stocky woodland species with short stout bills. Some have crests. They range in length from 10 to 22 centimetres. They are adaptable birds, with a mixed diet including seeds and insects. They are found in urban areas and around human habitation.


A male Common Tit displays its spectacular ultramarine blue uppersides

In the world of butterflies, the Tits are small tailed butterflies from the Lycaenidae family. In Singapore, there are three extant species - The Fluffy Tit (Zeltus amasa maximinianus), the Dark Tit (Hypolycaena thecloides thecloides) and the Common Tit (Hypolycaena erylus teatus). It is not apparent why these butterflies are called "Tits" as they generally bear very little resemblance of any sort to their avian friends.


A female Common Tit perches on a leaf

Of the three species, the Common Tit is the most often seen in urban parks and gardens. The caterpillars of this species are polyphagous, with at least five different host plants. The caterpillars display a symbiotic relationship with the weaver ant. The male Common Tit features an attractive deep ultramarine blue on the upperside of its wings. The hindwing features a pair of tails and a large orange-crowned black tornal spot and another black spot at the lobe.


A Dark Tit shows off its uppersides whilst sunbathing

The Dark Tit, usually found on the landward side of mangrove areas, is much rarer. Unlike its commoner cousin, its caterpillars feed on a monocotyledon Flagellaria indica. The upperside of the Dark Tit is predominantly dark brown, except for the orange tornal area of the hindwing. Both the Common and Dark Tits are fast-flying butterflies, but often perch on the tops of leaves. During certain times of the day, both species have been observed to sunbathe with their wings opened flat.


A male Fluffy Tit feeds on bird droppings

The last species of the three to bear the name "Tit", is the Fluffy Tit. Belonging to a completely different genus, the Fluffy Tit is a pretty long-tailed Lycaenid. There are two pairs of white tails with the pair at vein 1b rather long, about twice as long as the pair at vein 2. The species is skittish, and flies rapidly, with its long white tails prominently trailing behind. Males are often observed to puddle on bird droppings and sandy banks of forest streams.

And so we have two more groups of butterflies that share the same English common name as birds.

Text by Khew SK : Photos by Sunny Chir, Khew SK, Henry Koh, Loke PF, Bobby Mun & Jonathan Soong

Butterflies Galore! : Blue Nawab

Butterflies Galore!
The Blue Nawab (Polyura schreiber tisamenus)

The Blue Nawab is a moderately rare species in Singapore. It is, however, widely distributed and is as often seen in urban parks and gardens as well as the forested nature reserves. Its caterpillars feed on a variety of host plants that include the Rambutan, Red Saga, and even the invasive non-native tree, Australian Wattle. Usually alert and skittish, the Blue Nawab is a strong flyer and is not easy to photograph.

Featuring two pairs of thick pointed tails, the Blue Nawab is a dark velvety black above with a light blue band across both wings. The underside is silvery white, marked with brown and purple-blue patterns. This rare open winged shot of a recently eclosed individual was photographed by ButterflyCircle member Koh Cher Hern.

Butterflies Galore! : Black Tipped Archduke

Butterflies Galore! 
The Black Tipped Archduke (Lexias dirtea merguia)

This shot of a female Black Tipped Archduke was shot in the shaded forested area in the nature reserves. The genus Lexias is represented by three species in Singapore. The Black Tipped Archduke is so called, as its antennae tips are black compared to the Archduke (Lexias pardalis dirteana) which has prominently orange-tipped antennae. Males are dark velvety black with broad blue margins on both wings, whilst females are dark brown with yellow spots.

All the species of this genus are forest-dependent species that rarely, if ever, leave the sanctuary of the forests. It is not observed in urban parks and gardens. Several individuals of all three species may be found feeding greedily on rotting fruits on the forest floor. The shot shown above depicts the typical feeding behaviour of the Archdukes foraging for decomposing fruits or organic matter amongst a bed of leaf litter. Under normal conditions, the Archdukes are skittish and fast-flying, usually gliding rapidly no more than a metre above the forest floor.

Butterflies Galore! : Horsfield's Baron

Butterflies Galore! 
The Horsfield's Baron (Tanaecia iapis puseda)

The Horsfield's Baron is a species that exhibits sexual dimorphism, in that the appearance of the male and female is markedly difference. The male has dark velvety black wings above, with a broad bright blue marginal border across both wings. The underside is a pale buff brown with light brown markings. The female is brown with markings resembling a Malay Viscount or a female Malay Baron. Males are territorial and return to their favourite perch again and again. Whenever an "intruder" enters its airspace, it will dive to attack it.

ButterflyCircle member Koh Cher Hern shot this pristine male in the forested area of a reservoir park last weekend. The typical behaviour of the male Horsfield's Baron is that it flaps and glides rapidly and stops on the upper surface of a leaf with its wings opened flat. Females prefer to fly amongst shrubbery, especially amongst bushes of the Singapore Rhododendron (Melastoma malabathricum) which is its caterpillar host plant.