Life History of the Tailed Jay

Life History of the Tailed Jay (Graphium agamemnon agamemnon)

Butterfly Biodata:
Genus: Graphium Scopoli, 1777
Species: agamemnon Linnaeus, 1758
Subspecies: agamemnon Linnaeus, 1758
Wingspan of Adult Butterfly: 70mm
Local Caterpillar Host Plants: Annona muricata (Annonaceae, common name: Soursop), Michelia alba (Magnoliaceae, common name: White Champaca), Annona cherimola (Annonaceae), Polyathia longifolia var. pendula (Annonaceae, common name: Ashoka Tree), and two plants (to be identified) found in Central Catchment Reserve.

Physical Description of Adult Butterfly:
As with most Graphium species, the wings are produced at the forewing apex and hindwing tornus and the inner margin of the hindwing bends inwards. Above, the Tailed Jay has apple-green spots of various sizes on a black background. Underneath, the same green spotting can be found against a purple-brown background, and additional red spots are featured on the hindwing. Each hindwing has a short tail at vein 4, longer in the female than in the male.


The upperside view of a Tailed Jay perching on a flower.


A female Tailed Jay visiting flowers at the fringe of the nature reserve.


A male Tailed Jay puddling on a wet ground in the nature reserve.


A male Tailed Jay perching on a branch in the cool morning air.

Field Observations of Butterfly Behaviour:
The swift-flying adults are not uncommon, and can be observed regularly in both nature reserves and urban parks. The adults are often sighted visiting flowers such as ixora or lantana blossom. The males of this species can be found feeding on roadside seepages or urine-tainted sand.

Early Stages:
The early stages of the Tailed Jay feed on young leaves of several plants in the Annonaceae family. One recently recorded local plant is Polyathia longifolia var. pendula (Ashoka Tree). There are also two other yet-to-be-identified host plants in the nature reserves. Eggs and early stages of the Tailed Jay are typically found on saplings of the host plants at low heights.


Host plant : Ashoka Tree. Left: far view of one tall tree (growing in a housing estate);
right: close-up on young leaves.


Un-identified local host plant #1, commonly found in the Central Catchment Nature Reserve.


Un-identified local host plant #2, leaves are covered with hair.

The eggs of the Tailed Jay are laid on young leaves of a sapling. The spherical egg is creamy white with a diameter of about 1.1mm.


Left: fresh egg; right: mature egg. Diameter: 1.1mm

A time-lapse hatching sequence of a Tailed Jay caterpillar

The egg takes 3 days to hatch, and the newly hatched has a body length of about 2.7mm. Typically, the entire egg shell is consumed by the newly hatched as its first meal. The body is initially pale yellowish brown but turning dark brown hours later. There are rather broad and white dorsal patches on thoracic segments and the posterior abdominal segments. A pair of yellowish brown lateral spines can be found on each of the three thoracic segments, and another pair at the anal segment. The body also features rows of short dorsal-lateral tubercles with long setae. Between feeds, the Tailed Jay caterpillar of all instars rests on the upper leaf surface, usually alongside the midrib.


Two views of a newly hatched Tailed Jay caterpillar.
Almost done with the egg shell in top view. Length: 2.7mm


Two views of a 1st instar caterpillar, several hours old, length: 3mm

After about three days of feeding on young and tender leaves, the 1st instar caterpillar grows to a length of about 6mm. Now the body looks pumped up, and assumes a yellowish brown coloration. The white dorsal patches on thoracic segments have faded away by this time. The moult to the 2nd instar takes place after a period of inactivity.


1st instar caterpillar, late in this stage, length: 6mm.

In the 2nd instar caterpillar, the thoracic segments are much enlarged from the 2nd to 3rd segment. The thoracic spines and the anal spines are pale yellowish brown. As the body grows to a length of 10mm in 3-4 days for this instar, the yellowish brown body color darkens to purplish brown.


Two views of a 2nd instar caterpillar, newly moulted, length: 6mm.


Two views of a 2nd instar caterpillar, late in this stage, length: 10mm


Field shots of a Tailed Jay caterpillar on the same leaf over the course of 2 days.
Left: 1st instar; right: early 2nd instar.

There is no drastic change in appearance in the newly moulted 3rd instar caterpillar. Noticeable are the color change of the thoracic splines to black, and the change to completely white anal spines. This instar takes another 3 days to complete with body grown to about 10mm in length.


Two views of a 3rd instar caterpillar, early in this stage, length: 10mm

As growth proceeds in the 3rd instar, the white dorsal patch on the posterior abdominal segments gradually changes to yellow. This instar takes another 3-4 days to complete with the body grown to about 21mm in length. Numerous small markings, dark in color, appear on the body surface towards the end of this instar. At the same time, the thoracic and anal spines become black with a bluish sheen at the distal end.


Two views of a 3rd instar caterpillar, midway in this stage, length: 15mm


Two views of a 3rd instar caterpillar, late in this stage, length: 21mm

The body of the 4th instar caterpillar is mainly yellowish green and speckled with small dark green markings. The yellow dorsal patches on posterior abdominal segments have become less well defined in its boundary. Each thoracic spine on the 3rd thoracic segment now has an orange circular base. This instar lasts a further 3-4 days with body length reaching about 26mm.


Two views of a 4th instar caterpillar, length: 25mm

The 5th instar caterpillar resembles the late 4th instar caterpillar, but without the dorsal patch and with the body color in a more uniform colour of yellowish green to orchre-yellow. The 5th instar lasts for 5-6 days, and the body length reaches 40-43mm.


Two views of a 5th instar caterpillar, early in this stage, length: 26mm


Two views of a 5th instar caterpillar, late in this stage, length: 39mm


Field shots of Tailed Jay caterpillars. Top: 3rd instar; bottom: 5th instar

Toward the end of the 5th instar, the body gradually shortens in length. At the same time, the body turns completely yellow with all markings faded away. After doing some wandering around for a pupation site, the caterpillar eventually comes to rest on the surface of a leaf in an upright position and becomes a pre-pupatory larva. Here the caterpillar prepares a silk pad, and a silk girdle, both of which are critical for the success of the pupation event later on.


Two views of a pre-pupatory larva of the Tailed Jay.

Pupation takes place a day later. The pupa suspends itself with a silk girdle from the leaf surface, further secured with and a firm anchor at the posterior end. The pupa is yellowish green, about 33mm in length and has a slender and obtusely pointed thoracic process. The abdomen has two dorsal carinae. Reddish brown ridges run laterally to the tip of the mesothoracic horn which is directed forwards.

A time-lapse pupation sequence of a Tailed Jay caterpillar

Two views of a fresh pupa.

The pupal period lasts for 12-13 days, and the pupa turns black in the wing pads the night before eclosion. The apple-green spots on the forewings also become visible through the pupal skin at this stage. The adult butterfly emerges the next morning to commence the ``high-flying'' phase of its life cycle.


Two views of a mature Tailed Jay pupa.

A time-lapse eclosion sequence (partial) of a Tailed Jay adult

A newly eclosed Tailed Jay resting on the pupal case.

References:

• The Butterflies of The Malay Peninsula, A.S. Corbet and H.M. Pendlebury, 4th Edition, Malayan Nature Society.
• The Butterflies of Hong Kong, M. Bascombe, G. Johnston, F. Bascombe, Princeton University Press 1999

Text by Horace Tan, Photos by Anthony Wong, Mark Wong, Henry Koh, Tan Ben Jin, Sunny Chir and Horace Tan

The Grass Yellows of Singapore (Part 2)

The Grass Yellows of Singapore (Part 2)

Part 2 of this article on the Grass Yellows of Singapore features the remaining three species of the genus Eurema, all of which have either two or three cell spots on the underside of their forewings. (Refer to the ID Key in Part 1 of the article).

The Common Grass Yellow (Eurema hecabe contubernalis)

The Common Grass Yellow is described as the "commonest butterfly in the eastern tropics" and has a range that extends from Sri Lanka to Australia. This species, and the Three Spot Grass Yellow, has been observed to have seasonal 'breakouts' where large numbers of the same species can be found flying at many locations across Singapore. There was a year when the species was observed flying across one of the expressways, and a large number of roadkills was recorded as the butterflies were smashed by the speeding oncoming traffic.

The Common Grass Yellow is as frequently observed in urban parks, gardens and wherever there is a patch of greenery, as well as in the forested areas. It is widespread, and the caterpillars feed on a variety of Leguminosae plants.

The butterfly, with its bright lemon yellow wings with black bordering on the upperside and dark brown markings on the underside, is often very variable, particularly in the underside markings. The female is larger and a paler yellow, with broader black but diffused markings on the uppersides of both wings, particularly on the black marginal border on the hindwings.

(Eurema simulatrix tecmessa)

This species, which can be considered the rarest of the Grass Yellows, is also the largest amongst the 6 species in the genus found in Singapore. The characteristic cleft subapical reddish-brown marking on the underside of the forewing distinguishes it from the other species.

Whenever encountered, they are usually observed singly, either feeding at flowering plants, or puddling on sandy mudbanks. It is never abundant, and rarely, if ever, seen in large numbers unlike the Common Grass Yellow or the Three Spot Grass Yellow.

A rare threesome puddling shot of E. simulatrix

The Three Spot Grass Yellow (Eurema blanda snelleni)

This species probably rivals the Common Grass Yellow for the title as the most common Grass Yellow. As widespread as its cousin, the Three Spot Grass Yellow is unique in having three cell spots on the underside of the forewing. Males tend to have reduced upperside black marginal borders, although the females bear the typically broader and diffused borders.

Found in urban locations as well as in the nature reserves, the Three Spot Grass Yellow is also known to puddle in numbers along forest trails and sandy banks of streams which have been contaminated by decomposing organic material.

Females of the Three Spot Grass Yellow have been observed to lay large clutches of eggs on the host plant Falcataria moluccana (Albizia). In a single sitting, a female was seen to have laid at least 103 eggs on a leaf of the host plant!

How many E. blanda eggs can you count on the leaf?

Besides the six species which have been reliably identified in the Singapore Checklist, it is very likely that several other species, primarily those that occur in the Malay Peninsula, may appear in Singapore one day. Two of the species have not been observed since the early records of their presence is Singapore, and may eventually appear again. Thus far, our records have shown that these two species, Eurema ada iona and Eurema lacteola lacteola have not been reliably sighted (or may have been missed), and effort should be made to establish their status in the Singapore checklist.

Text by Khew SK ; Photos by Khew SK & Federick Ho

The Grass Yellows of Singapore (Part 1)

The Grass Yellows of Singapore (Part 1)

This blog article features the genus Eurema which comprise comparatively small, deep-lemon yellow butterflies with black borders. The Eurema, often referred to as the "Grass Yellows" are relatively common in Singapore, although there are actually six distinct species occuring on the island, and one of the species is a recent re-discovery and its habitat is threatened with development.

The more common species are found throughout the island, from urban areas to the forested nature reserves. At times, they can be abundant, where hundreds can be seen fluttering in an almost 'migratory' fashion in certain parts of the island. However, these rare 'break-outs' are seasonal, and could have been triggered by a variety of factors - from abundance of host plants, to the absence of predators and parasitic insects which keep the population in check and maintains a balance in nature.

The Grass Yellows are generally weak flyers, fluttering low around bushes and flowers. The caterpillars of the species feed on Leguminosae and it is known that various species have various alternative host plants. Amongst the favourite genera are Cassia (Senna), Caesalpinia, Paraserianthes (Albizia), Acacia and many others.

The identification of the species of Eurema is often not easy, particularly when the butterflies have a rather restless flight, and are alert when approached. The main identifying characteristics rely on certain distinguishing markings, particularly the number of spots at the cell on the underside of the forewing. The following is an identification key to the separation of the species in the genus :

Eurema species with no cell spots on the underside of the forewings

Eurema brigitta senna (No Brand Grass Yellow) - Upperside forewing black apical border serrated but not more deeply excavated in spaces 2 & 3. Male has no brand.

Eurema species with one cell spot on the underside of the forewings

Eurema sari sodalis (Chocolate Grass Yellow) - Underside forewing apical area entirely dark brown.

Eurema andersonii andersonii (Anderson's Grass Yellow) - Underside forewing apical area not entirely darkened. Inner edge of black border in space 1a and 1b inclined slightly towards tornus. Upperside black distal border not more deeply excavated in space 2 than in space 3.

Eurema species with two cell spots on the underside of the forewings

Eurema hecabe contubernalis (Common Grass Yellow) - Upperside forewing black border in space 1a and 1b at right angles to dorsum or sloping towards base.

Eurema simulatrix tecmessa - Underside forewing has a large cleft reddish brown apical spot.

Eurema species with three cell spots on the underside of the forewings

Eurema blanda snelleni (Three Spot Grass Yellow) - Upperside of the male with reduced and narrower black borders.

In Part 1 of this article, we feature three of the six Eurema species extant in Singapore.


The No Brand Grass Yellow (Eurema brigitta senna)



This species is a recent re-discovery, after missing from the Singapore checklist for a number of years. In an earlier blog article, we featured this species in detail. The No Brand Grass Yellow is the only species where the underside forewings are without cell spots. Upperside forewing black apical border serrated, but not more deeply excavated in spaces 2 and 3. Females are slightly more unique in that the yellow colour of the hindwings are lighter than the forewings on the undersides. The males' undersides are unicolourous as with the other species of this genus.

Both sexes undersides are covered with small brown 'freckles' which give the wings a rather spotted appearance, as compared to the other species in the genus. In certain individuals, the freckles are distinctly pronounced as to give the butterfly a very uniquely heavily spotted appearance, almost obscuring the clean yellow background colour of the wings.

The host plant of the species, Cassia mimosoides has been cultivated and located to other parts of the island in the hope of allowing the species to be translocated from its current habitat, which is under the threat of development. The species is highly vulnerable, although it can be common where its host plant occurs, and its preferred habitat of open sunny wasteland.

The Chocolate Grass Yellow (Eurema sari sodalis)

The Chocolate Grass Yellow is amongst the easiest of the genus to identify, especially when the butterfly stops to feed or puddle. The species' distinct solid brown apex on the forewing beneath sets it apart from the other species amongst the Eurema. The species is locally common, in locations where its preferred host plant is available.

However, it is not as widespread as the more common species of the genus, preferring the sanctuary of the fringes of the nature reserves in forested areas. It is more often encountered in well-vegetated areas of the forested parts of Singapore than flying in urban parks and gardens.

Where it occurs, males of the Chocolate Grass Yellows are often observed to puddle at sandy banks which have been tainted with fermenting organic matter, carrion and the like. Once it settles down to puddle, it remains quite still as it feeds, and allows an observer to get quite close to it.

The Anderson's Grass Yellow (Eurema andersonii andersonii)

This is a species that almost exclusively remains in the forested areas of Singapore's nature reserves. It is probably one of the rarer species of the genus (though one can argue that none of the species can be considered 'rare'). Usually seen singly, the Anderson's Grass Yellow features only one cell spot on the forewing beneath, like the Chocolate Grass Yellow. However, it does not have the former's solid brown apical patch.

Like its close cousin, the species has also often been observed to puddle at forest paths and sand banks of streams. In the morning hours, it also visits various flowering bushes as it feeds. Favourites are the white flowers of the Common Asystasia (Asystasia gangetica), the purple flowers of the Common Snakeweed (Stachytarpheta indicus) and several other wildflowers found in the forests.

The wings of the species also appear to be more rounded than its close cousins, and it has a comparatively more robust flight. At times it tends to have a habit of fluttering around low bushes, and then settling on the undersides of leaves.

Text by Khew SK ; Photos by Khew SK

References:

• The Butterflies of The Malay Peninsula, A.S. Corbet and H.M. Pendlebury, 4th Edition, Malayan Nature Society.