Life History of the Elbowed Pierrot

Life History of the Elbowed Pierrot (Caleta elna elvira)



Butterfly Biodata:
Genus: Caleta Fruhstorfer, 1922
Species: elna Hewitson, 1876
Sub-species: elvira Fruhstorfer, 1918
Wingspan of Adult Butterfly: 22mm
Caterpillar Local Host Plants: Ziziphus sp. (Rhamnaceae)

Physical Description of Adult Butterfly:
Above, the Elbowed Pierrot is dark brownish black with a broad white band spanning both wings. Beneath, the Elbowed Pierrot is yellowish white with a number of black spots and markings. In particular, the basal streak in the forewing is right-angled, and appears to link up with the basal streak in the hindwing. Each hindwing has a slender white-tipped filamentous tail at the end of vein 2.


An Elbowed Pierrot visiting flowers in the nature reserve.


An Elbowed Pierrot puddling on wet grounds.


An Elbowed Pierrot resting on a perch.

Field Observations of Butterfly Behaviour:
This small-sized species is rather common in the nature reserves of Singapore. The adults are often found flying close to the ground and settled at moist spots on the forest floor. On sunny days, they can be found to visit flowers, and the males have been observed to puddle on bird droppings.

Early Stages:
The local host plant, a Ziziphus sp., is a thorny straggling shrub with simple, alternate and ovate-lanceolate leaves, each of which has three prominent nerves and finely toothed along the edge. Young leaves are light brown to reddish brown, and turning green when mature. All four instars of the immature stages of the Elbowed Pierrot feed on the young brownish leaves, and the green leaves when they are still relatively young and tender.


Host plant:a Ziziphus sp. Young shoots.


Host plant: a Ziziphus sp. Close-up shots of young and mature leaves.


A mating pair of the Elbowed Pierrot.


Elbowed Pierrot mothers' attempts to lay eggs on the leaves of the host plant.

Eggs of Elbowed Pierrot are typically laid on young shoots or leaves of the host plant. The small egg is disc-like (about 0.5mm in diameter) with a depressed micropylar. When freshly laid, the egg is yellowish green. The color soon decolorizes to light green within the next few hours, and then to white overnight as it matures. The surface is covered with a reticulated pattern of intersecting ridges.


Two views of an egg of the Elbowed Pierrot. Diameter: 0.5mm.



Left: mature egg showing the caterpillar eating away the egg shell for its exit.
Right: empty egg shell.

Each egg takes 2-2.5 days to hatch. The young caterpillar emerges after nibbling away sufficiently large portion of the egg shell. Measured at a length of about 0.9mm, its pale yellow body is cylindrical in shape, sporting long fine setae (hairs) and a brown head capsule.


Top: a newly hatched caterpillar, length: 0.9mm.
Bottom: 1-day old caterpillar, length: 1.2mm.

The newly hatched grazes on the surface of young leaves. As it feeds and grows, its body takes on a greenish undertone. After 2 to 3 days of growth, it looks pumped up at a length of about 2mm. After a period of immobility of about half a day, it moults to the 2nd instar.


1st instar caterpillars. Top: 2-day old, length: 1.5mm.
Bottom: late in this stage, length: 2mm.

Covered with numerous setae, the body of the 2nd instar caterpillar could in either light yellowish green or pale pinkish coloration. Setae found at the dorsal and lateral margins are longer and stiffer. The body is flatter compared to the 1st instar caterpillar, and faint dorsal bands whitish in color are discernible.


2nd instar caterpillars. Top: newly moulted, length:2mm.
Bottom:late in this stage, length: 3.5mm.


Top: late 2nd instar in pre-moulting dormant state.
Bottom: newly moulted 3rd instar caterpillar.

The 2nd instar caterpillar reaches a length of about 3.5-4mm, and after about 3 days in this stage, it moults again. The 3rd instar caterpillar has numerous short and fine body setae. The two whitish parallel dorsal bands, flanked by two thin and deep green bands, are now rather pronounced, The 3rd instar takes 3-4 days to complete with the body length reaching about 6.0-7.0mm. There is no obvious sign of any nectary organs, which are common in many other lycaenid species, on the 7th and 8th abdominal segments,


3rd instar caterpillars. Top: early in this stage, length: 4mm.
Bottom: late in this stage, length: 6mm.

The 4th (and final) instar caterpillar is similar in appearance to the 3rd instar caterpillar with one main difference being the apparent merging of the two dorsal bands into a single broad band. The body segments appear to be translucent, in either light green or pale pinkish coloration. The body shape deviates from the usual onisciform shape in being much flatter with a large prothorax.


4th instar caterpillars. Top: middle-aged, pink form, length: 9.5mm.
Bottom: late in this stage, green form, length: 12mm.

While some members of the Caleta genus (such as Caleta roxus) do not carry any nectary organs in any instar, the Elbowed Pierrot has a slit-like structure on the 7th abdominal segment in the final instar. With no ant attendance observed in the field, it is likely to be a non-functional dorsal nectary organ. In addition, no tentacular organs can be found on the 8th abdominal segment.


A likely non-functional dorsal nectary organ on the 7th abdominal segment of
a final instar Elbowed Pierrot caterpillar.

After 5-6 days of growth and reaching a maximum length of around 12-13mm in the final instar, the body of the caterpillar gradually shrinks, and finally takes on a pale reddish brown coloration. All bred specimens chose to enter their pre-pupatory phase on a spot on the leaf surface. At the chosen site, the caterpillar readies itself for pupation by spinning a silk girdle and a silk pad. The caterpillar secures itself to the silk pad via claspers on its posterior end.



Two views of an immobile pre-pupatory larva of the Elbowed Pierrot.
The silk girdle can be easily seen.

Early stages of the Elbowed Pierrot.

Pupation takes place after one day of the pre-pupal stage. The hairy pupa has the typical lycaenid shape, being somewhat flatter and having a broader abdomen. It is pale brown in the abdomen, dark brown on the thorax and beige in the wing pad areas. The pupa has a length of about 8-9mm.


Two views of a pupa of the Elbowed Pierrot, length: 8mm

Six days later, the pupa becomes darkened in color signaling the imminent emergence of the adult. The prominent white bands on the forewing uppersides become visible through the pupal skin in the wing pads. The next day the adult butterfly emerges from the mature pupa.


Two views of a mature pupa of the Elbowed Pierrot.


A newly eclosed Elbowed Pierrot


A newly eclosed Elbowed Pierrot perching near its empty pupal case.


References:

• The Butterflies of The Malay Peninsula, A.S. Corbet and H.M. Pendlebury, 4th Edition, The Malayan Nature Society.
• The life history of Caleta roxus, Konrad Fiedler, Nachr. entomol. Ver. Apollo, N.F. 14 (4): 371-384, Jan. 1994.

Text by Horace Tan, Photos by Anthony Wong, Benedict Tay, Sunny Chir and Horace Tan

We Are One!

We Are One! - Butterfly Lodge is One Year Old

It has been a year since the launch of the Butterfly Lodge at Oh’ Farms on 9 Aug 2008. Last Sunday, on the day when Singapore was celebrating its 44th National Day, our friends at Butterfly Lodge, members of Butterfly Circle and a few invited guests also had a gathering to celebrate Butterfly Lodge’s first birthday!

We spent the evening in a very casual and carefree setting, chatting and sharing stories about butterflies (of course!). Amidst the laughter and bantering, we could hear the low-frequency throb of helicopters in the nearby skies, returning from the National Day Parade at Marina Bay. With the constant supply of good wine, drinks, beer and delicious food, all of us were so engrossed in our conversations and eating that we did not remember to snap even a single shot. What a pity !

Yeok Keong, the owner of Butterfly Lodge at Oh’ Farms also presented tokens of appreciation to members of ButterflyCircle who had helped in the initial planning and setting up of Butterfly Lodge. The pictures below show some of the A1 size posters outside the butterfly flight cage (photos on the posters were contributed by ButterflyCircle members).

Being the only one of its kind here, Butterfly Lodge features only common local butterfly species with the main aim of promoting butterfly appreciation and awareness amongst school children. We are proud to report that within a year, about 5000 visitors (mainly from Child Care Centres, Pre-schools and Primary Schools) have visited Butterfly Lodge and attended an introductory lesson related to the life cycles and behaviour of butterflies.

We are glad to say that ButterflyCircle and Butterfly Lodge have created opportunities for kids here to observe the activities in a typical day in the life of a butterfly, such as feeding, sunbathing, performing courtship dance, mating, and laying eggs, up close and personal, creating lasting learning interactive experiences for the kids.

How many students these days have the chance to see mating butterfly ? At Butterfly Lodge, visitors can very often observe a live scene of what mating is all about. This presents a very good teachable moment of explaining how a new life begins to our young children.



In the enclosure, students may be lucky enough to witness a weird behavior of how a female would reject mating by pointing her abdomen upwards as shown in the picture here.

Indeed, we are delighted to learn that some of our young visitors are now able to recognize and identify the butterfly species flying around in their neighbourhoods after their visit to Butterfly Lodge.

While playing the role of supporting Butterfly Lodge in various areas, ButterflyCircle members also gained valuable learning experiences and insights on the biology and ecology of butterflies during the past one year. Here are some examples :

One whole batch of Plain Tiger (Danaus chrysippus chrysippus) larvae were found dead overnight after they were fed with Crown Flower (Calotropis gigantea) leaves supplied from a neighbouring country. We suspected that the leaves might have been contaminated with chemicals that we were not aware of . Butterfly larvae are very susceptible and vulnerable to toxins - even a trace amount of toxin is enough to kill all of them.

There was an initial success of breeding the Blue Pansy (Junonia orithya wallacei) in captivity, resulting in good numbers of Blue Pansys in Butterfly Lodge. However, they did not proliferate further after one or two generations. Subsequently, despite a few times of introductions of both male and female Blue Pansys into the enclosure, we have not seen caterpillars yet. We suspect that certain unknown factors in the enclosure environment may have prevented Blue Pansys from mating or laying eggs.

Both the male and female Blue Pansy are very pretty and attractive. We will continue to monitor the breeding progress for this species.

One pair of Jacintha Eggfly (Hypolimnas bolina jacintha) was introduced into the enclosure in Aug 08. The species was doing very well during the first few generations. But, again the number of Jacintha Eggfly larvae dropped drastically over a period of 2 to 3 months. Since late March 2009, there was not a single Jacintha Eggfly left. So we suspect that inbreeding may have a role in causing infertility in the species.

A new female form of Jacintha Eggfly?

Furthermore, we also observed that a small number of female Jacintha Eggfly in the last one or two generations displaying unusual markings as shown in the picture. Was it due to inbreeding or is there really such a new form that has not been observed before?

It was a pleasant discovery that Peacock Pansy utilizes Strobilanthes cubia as a preferred larval host plant in the enclosure despite the presence of Red Flame Ivy (Hemigraphis alternate) and Ruellia repens which are its known host plants in the wild.


A Peacock pansy caterpillar in its pupation position and the newly discovered host plant, Strobilanthes cubia

In addition, it was also observed that without enhancing the gene pool with new introductions from outside the flight cage, low fertility rate also affected the population of the Peacock Pansy (Junonia almana javana).



Lastly, we also discovered that the life span of some species such as Common Mime (Chilasa clytia clytia ) and Common Birdwing (Troides helena cerberus) was very short (less than a week) in captivity. So these species are not suitable for captive breeding unless the flight cage is high and big enough for them to roam freely.

Apart from some minor setbacks, generally, it has been a very successful year for Butterfly Lodge. Looking forward, Butterfly Circle and Butterfly Lodge will continue working together to educate more children and the public in butterfly appreciation. With more people being butterfly-literate, many flying jewels should soon be fluttering in our natural environment for our next generation to appreciate. We are also confident that what we have learnt in captive breeding will help in the conservation of some butterfly species in the future.

Text by Federick Ho ; Photos by Neo Ai Ling & Federick Ho

Butterfly of the Month - August 2009

Butterfly of the Month - August 2009
The Dingy Bush Brown (Mycalesis perseus cepheus)

A female Dingy Bush Brown perches on a blade of grass in the nature reserves

This month, we feature a species from the sub-family Satyrinae. This sub-family, referred to by its common collective English name of "Browns and Arguses", consists of many drab coloured and inconspicuous butterflies. Many are common and their caterpillars feed mainly on monocotyledons, e.g. grasses, padi & bamboos.

Another female Dingy Bush Brown lurking on the forest floor

The Dingy Bush Brown (Mycalesis perseus cepheus) is one of several species of the genus Mycalesis found in Singapore. The butterflies are small, drab brown with a pale post-discal band on the underside of both wings, often with a wingspan not exceeding 50mm, and have multiple ocelli on both the upperside and underside of the wings. They tend to fly in semi-shaded environments, amongst grasses and undergrowth along the fringes of wooded areas. They are not fast-flyers, preferring to remain low in the undergrowth and stop with their wings folded upright. However, they are skittish, and not easy to photograph properly.

The Dingy Bush Brown can be separated from its closely related species in the Mycalesis genus by the hindwing ocellus in space 2 on the hindwing moved in and well out of line with those adjacent to it.

A courting pair of Dingy Bush Browns. Left : Male, Right : Female

In Singapore, the species is local in distribution, but not rare. Where it is found, several individuals can often be seen, fluttering in the low shrubbery and feeding on organic material on the forest floor. It often flies in the company of its relatives the Dark Brand Bush Brown (Mycalesis mineus macromalayana) and the Long Brand Bush Brown (Mycalesis visala phamis) with which it could be confused, as well as the Nigger (Orsotriaena medus cinerea). The Dingy Bush Brown males are of a much darker brown in colouration than the females. The post-discal band on the underside of the females' hindwings is usually broader.

A unique specimen of the Dingy Bush Brown with only two ocelli on the underside of the forewing instead of the usual four

The forewing ocelli on the underside of the forewing in spaces 3 to 6 are not equal, and some usually absent. Where present, the size of the ocelli can be rather variable.

A male Dingy Bush Brown perching on a leaf

The Dingy Bush Brown is, more often than not, unappreciated by most observers, as it is considered "unattractive" and unremarkable. Its drab brown and low-profile behaviour in the field also tend to keep it much ignored by most butterfly watchers. However, upon looking closely at its ocelli and shape of the wings, one can say that Beauty is often in the Eyes of the Beholder, and one needs to look closer to see that the Dingy Bush Brown can also be considered a pretty butterfly in its own right!

Text & Photos by Khew SK