Life History of the Lime Butterfly v2.0

Life History of the Lime Butterfly (Papilio demoleus malayanus)

Butterfly Biodata:
Genus: Papilio Linnaeus, 1758
Species: demoleus Linnaeus, 1758
Subspecies: malayanus Wallace, 1865
Wingspan of Adult Butterfly: 60-80mm

Caterpillar Local Host Plants:  Citrus microcarpa (Rutaceae), Citrus maxima (Rutaceae, common name: Pomelo), Citrus aurantifolia (Rutaceae, common name: Lime) and other Citrus spp., Ruta graveolens (Rutaceae, common name: Herb-of-grace).


A male Lime Butterfly.


A female Lime Butterfly.

Physical Description of Adult Butterfly:

Above, both sexes are black with yellow spots and markings, some of which forming  an  irregular and intermittent macular band running across the forewing to the mid-dorsum of the hindwing.  A submarginal series of smaller yellow spots can be found on both wings. In space 1b on the hindwing, there is a red spot in both sexes. In the male, this spot is capped with a narrow blue lunule with a very narrow intervening black gap. In contrast, the red spot and the blue lunule in the female have a  rather large black spot between them.  Underneath, both sexes are mostly yellow with black streaks and irregularly-shaped spots.  On the hindwing, several black spots are lined with blue striae. There is  a series of orange post-discal bars on both hind- and forewings.

Field Observations of Butterfly Behaviour:

Lime Butterfly is rather common in Singapore and can be found in both forested and urban areas in Singapore. The fast flying adults are frequently seen in flights in and around residential areas, often  visiting flowers growing in gardens and  potted plants  in common areas outside houses/flats.  The females can also be seen making ovipoisiting visits to the many Citrus plants, cultivated or wild, in the residential neighbourhood. The hyper-active adults are easier to approach for photographic captures during the cooler hours in the morning and late afternoon, when they retire to rest among the foliage. 

Early Stages:

The local host plants include a number of species in the Rutaceae family, with majority belonging to the Citrus genus.   The caterpillars of the Lime Butterfly feed on the young to middle-aged leaves of the host plants.

Host plant : Citrus aurantifolia.


A mating pair of the Lime Butterfly.

The eggs of the Lime Butterfly are laid singly on the young stem, the petiole or the underside of leaves of the host plant. The egg is pale creamy yellow with a finely roughened surface. It is nearly spherical with a diameter of about 1.1-1.2mm.

A mother Lime Butterfly about to oviposit on a lime plant.


Two views of an egg of Lime Butterfly, diameter: 1.1-1.2mm


Two views of a mature egg of the Lime Butterfly.

The egg takes about 2.5-3 days to hatch. The young caterpillar eats its way out of the mature egg, and then proceeds to finish up the rest of the egg shell. The newly hatched has a body length of about 2.75mm and has a rather spiky appearance caused by bands of spiky processes which are longer dorso-laterally and much shorter laterally. Overall the body  is yellowish brown dorsally and darker brown laterally. The head is dark brown.

Two views of a new hatched caterpillar nibbling at the egg shell.

The first 4 instars of the Lime Butterfly  resemble bird droppings with the resemblance in the 3rd and 4th instars being closer due to  the body  taking on  a slimy appearance. As the 1st instar caterpillar grows up to a length of about 5mm, the  whitish saddle patch on the 3rd-4th abdominal segments become more evident. After about 2.5-3 days in 1st instar, the caterpillar moults to the next instar.

Two views of a 1st instar caterpillar, late in this stage,  length: 4.8mm

The 2nd instar caterpillar has a similar appearance to the late 1st instar caterpillar except for the more prominent whitish saddle. As the caterpillar grows, small whitish patches appear laterally on the first two thoracic segments. This instar lasts about 2 days with the body length reaching up to  10mm before the next moult.

Two views of a 2nd instar caterpillar, newly moulted, length: 4mm


Two views of a 2nd instar caterpillar, late in this stage, length: 7mm

The 3rd instar caterpillar has whitish lateral patches on the anterior and posterior body segments. The white saddle is  more extensive and prominent than in the two previous instars.  This instar takes about 2 days to complete with the body length reaching up to 16mm.

Two views of a 3rd instar caterpillar, early in this stage, length: 10.5mm


Two views of a 3rd instar caterpillar, late in this stage, length: 16mm

The 4th instar caterpillar resembles the late 3rd instar caterpillar initially but with a more slimy appearance and a ground colour which is in darker brown.  This penultimate instar lasts about 2-2.5 days with body length reaching about 25mm.

 

Two views of a 4th instar caterpillar, newly moulted, length: 15.5mm


Two views of a 4th instar caterpillar, late in this stage, length: 25mm

The next moult brings the caterpillar to its 5th and final instar with a drastic change in appearance. There are two lateral eye spots near the leading edge of the  third thoracic segment with a   milky brown transverse band linking them. Another transverse band can be found at the posterior edge of the same body segment. A long oblique bar, dark brown in colour, stretches from the base of the 4th abdominal segment to the dorsum of the 5th abdominal segment. A much shorter  bar can be found in the 6th abdominal segment. Round dorso-lateral marks, variable in size, can be found on the 6th to the 8th abdominal segments.  After the moult to 5th instar, the body ground color is initially mottled  yellowish green, but this changes gradually to a uniform green or yellowish green after about 0.5 day.

Two views of a 5th instar caterpillar, freshly moulted, length: 23mm.


Two views of a 5th instar caterpillar, late in this stage, length: 41mm


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

As in the case of all Swallowtail butterflies, the Lime Butterfly caterpillars in all instars possess a fleshy organ called osmeterium in the prothoracic segment. Usually hidden, the osmeterium can be everted to emit a foul-smelling secretion when the caterpillar is threatened.

The 5th instar lasts for about 3.5-4  days, and the body length reaches up to 41mm. Toward the end of this instar, the body gradually shortens in length. Eventually the caterpillar comes to rest on the under surface of a stem or a leaf. Here it stays dormant for a while before performing a purge of  loose and wet frass pellets. It then spins a silk pad and a silk girdle to become an immobile pre-pupatory larva.

A pre-pupatory larva of the Lime Butterfly.
 

A Lime Butterfly caterpillar molts to its pupal stage.

Pupation takes place a day later. The pupa suspends itself with a silk girdle from the substrate. There are two color forms. In the green form, the pupa is is mainly green with a large yellowish diamond-shaped patch on the dorsum of the abdominal segments.. In the brown form, the pupa is mainly greyish  brown with dark patches. Each pupa has a pair of cephalic horns, a dorsal thoracic hump and is angled in side view. Length of pupae: 30-32mm.

Two views of a Lime Butterfly pupa, brown form.


Two views of a Lime Butterfly pupa, green form.

After 9 days of development, the pupa turns black as the development within the pupal case comes to an end. The yellowish spots and band on the forewing becomes visible through the pupal case. The next day the adult butterfly emerges from the pupal case. The beautiful undersides of its wings are fully displayed as it dries its wings for the first one to two hours after eclosion.

Two views of a mature pupa.

A Lime Butterfly adult emerges from its pupal case.


Another Lime Butterfly emerging from its chrysalis.


A newly eclosed Lime Butterfly clinging onto its pupal case.

References:

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

Text by Horace Tan, Photos by Tan Keyang, Bobby Mun, Loke PF,  Sunny Chir, Khew SK and Horace Tan

Butterfly of the Month - November 2011

Butterfly of the Month - November 2011
The Malayan Bush Brown (Mycalesis fusca fusca)

The month of November is the 11th month in the Gregorian calendar, although its original name in Latin, novem, means nine, as it was the ninth month of the Roman calendar.  The two Zodiac signs of Scorpio and Saggitarius fall in the month of November. 

In western traditions, the premier holiday of November is Thanksgiving. It is held on the 4th Thursday in November. The first Thanksgiving was given by the pilgrims in 1623. It did not become an official holiday until President Lincoln declared it in 1863. The holiday was created to give thanks for the plenty of the harvest. Today it is celebrated by family gatherings.

Over in Asia, the Muslim community celebrated Hari Raya Haji on 7 Nov this year.  Hari Raya means festival, while Haji simply means that of pilgrim, or pilgrimage. This is the day when Muslim pilgrims from all over the world end their journey to the sacred Mecca in Saudi Arabia. Fellow Muslims celebrate and honour those who have successfully completed this long and hard pilgrimage.

The month of November in 2011 is special for the unique date of 11 November 2011 or written in short, "11-11-11".  This comes once in a lifetime for most of us, and it is a special date on which many couples tie the knot.  Geomancers claim that the string of 11's signify a date of good fortune and is an auspicious date for significant milestones in one's life, like marriage, moving house or having a ground breaking ceremony for projects.

The birthstone for November is the topaz.  Topaz is a silicate mineral of aluminium and fluorine that crystallizes in the orthorhombic system and its crystals are mostly prismatic terminated by pyramidal and other faces.  Orange topaz, also known as precious topaz, is the traditional November birthstone, the symbol of friendship.

Who first comes to this world below
In drear November's fog and snow,
Should prize the topaz's amber hue,
Emblem of friends and lovers true.
- Gregorian Birthstone Poems

Our Butterfly of the Month for November is the Malayan Bush Brown (Mycalesis fusca fusca).  The butterfly belongs to the genus Mycalesis which is often referred to as "Bush Browns".  The species of this genus is characterised by the evenly rounded wings, usually a drab brown and the undersides featuring a series of ocelli with usually a post-discal band across both wings. 

Many species of the Bush Browns are common, but irritatingly similar in appearance, making field identification challenging at times.  They are low-flying butterflies and stop to perch on grasses and leaves with their wings folded upright.  They prefer shady spots and fly amongst the forest undergrowth.  In the early hours of the morning, some individuals can be spotted opening their wings flat to sunbathe. 

The Malayan Bush Brown is essentially a forest butterfly and is found in areas along the fringes of the nature reserves amongst grasses and low bushes. In the vicinity of its host plant, Scleria bancana, a long grass, several individuals can often be found, flitting from perch to perch at low level and frolicking with each other.

The species is the most distinctive of the genus Mycalesis found in Singapore due to its orange-brown colour with a pair of reddish-brown longitudinal stripes on both wings. The orange submarginal ocelli are not ringed with white. On the upperside, the male is brown, with obscure ocelli, whilst the larger female has rounded forewings and is generally paler.

The caterpillar is known to feed on the Cyperaceae grass called Scleria bancana a tall grass that is relatively common in many parts of the nature reserves and even in urban parks.  The life history is recorded in detail on this blog here.

So as we look forward to December and the festivities, holidays and Christmas, let us spare a thought for the less fortunate amongst the people of the world, and say a lil' prayer for one and all for global peace.  :)

Text by Khew SK ; Photos by Sunny Chir, Khew SK, Koh CH, Loke PF, Jonathan Soong, Ellen Tan, Horace Tan, Tan BJ & Zhuang YY

Life History of the Singapore Four-Line Blue

Life History of the Singapore Four-Line Blue (Nacaduba pavana singapura)

Butterfly Biodata:
Genus: Nacaduba Moore, 1881
Species: pavana Horsfield, 1828
Subspecies: singapura Corbet, 1938
Wingspan of Adult Butterfly: 26-30mm
Caterpillar Local Host Plants: Derris trifoliata (Leguminosae), Andira inermis (Leguminosae), Allophylus cobbe (Sapindaceae)





Physical Description of Adult Butterfly:

As a member of the pavana group (the Four-Line Blues), the adult does not have a basal pair of lines in the underside forewing cell. Above, the male is greyish  blue with a thread-thin  border; the female is brown with a pale blue discal patch on the forewing and blue dusting on the basal part of the hindwing.  Underneath, both sexes are greyish brown with the bands (post-discal, discal and basal) composed of a double series of whitish striae inwardly lined with darker lines with the space between them appear to be paler than the ground colour.  On each hindwing, there is an orange-crowned tornal spot lightly speckled with bluish-green metalic scaling.  Next to the tornal spot, a pair of filamentous white-tipped tails occurs at end of vein 2. Marginal and submarginal spots are black and stand out against the ground color of greyish brown.

Field Observations of Butterfly Behaviour:

Early researchers for butterflies in the Malay Peninsula from the 60s and 70s [C&P4] noted that Nacaduba pavana "is seldom seen except in Singapore, where it is sometimes quite common on the landward edge of mangrove swamps."  This observation still holds true today as recent sightings of this species have been confined to the northern and  north-western corner of the Singapore island in an area covering Sungei Buloh Wetland Reserve, Kranji Nature Trail and the Mandai Mangrove. The adults have been seen flying in the vicinity of their host plants, which are common in these habitats, visiting flowering plants, puddling on wet ground and performing oviposition rituals.

A female laying an egg on a young leaf of Derris trifoliata.


Another female ovipositing on a young leaf of Allophylus cobbe.

Early Stages:

The Singapore Four-Line Blue is polyphagous and so far three plant species found in the back mangrove habitats have been recorded as its host plants. The caterpillars feed on young and tender leaves and sometimes young shoots of these plants. As in the case for most lycaenidae species, the caterpillars of the Singapore Four-Line Blue  are typically tended by a number of ant species.

Local host plant #1: Andira inermis.
 

Local host plant #2: Allophylus cobbe.
 

A mother ovipositing on a cluster of flower buds of Derris trifoliata.


Another mother ovipositing on the young shoot of Andira inermis.

Eggs are laid on the young shoots or inflorescence of the host plants. It is not uncommon for a number of eggs to be found in close proximity on the same shoot, however the eggs occur singly rather than in clusters. Each egg is pale yellowish green, discoid and has a depressed micropylar on top. The egg surface is finely reticulated, slightly raised at the intersections of criss-crossing ridges. Th egg has a diameter of about 0.4-0.45mm.

Eggs on young shoot of Andira inermis with a 1st instar caterpillar nearby.


Two views of an egg of the Singapore Four-Line Blue. Diameter: 0.4mm.

It takes about  2 days for the egg to hatch. The young caterpillar consumes part of the egg shell to emerge. With a length of about 0.7-0.8mm, it has a pale yellowish body with long setae (hairs) dorsally and sub-spiracularly. The caterpillar assumes the typical woodlouse body shape as it grows. The body color  changes gradually to a brighter shade of yellow or red depending on the color form the caterpillar assumes. The first instar lasts for 1.5-2 days and the body length reaches about 1.8mm before the moult to the 2nd instar. A faint reddish brown patch appears on the dorsum of the 7th-9th abdominal segment towards the end of the first instar.

Two views of a newly hatched caterpillar, length: 0.8mm.


Two views of a 1st instar caterpillar, late in this stage, length: 1.8mm.


A red-form 1st instar caterpillar, late in this stage.

The long dorsal setae are absent in the 2nd instar caterpillar but now there are numerous short setae present all over the body surface. The body color is mainly yellow  with a greenish undertone or mainly red. A large, diffused, bright red to reddish brown patch occurs on the dorsum stretching from the 7th to the 9th abdominal segments in both color forms. The 2nd instar lasts for 1.5-2 days and the caterpillar grows to a length of about 3.5mm to 4mm.

Two views of a 2nd instar caterpillar, freshly moulted to this instar, length: 4mm.


A red-form 2nd instar caterpillar.


A field shot of caterpillars of Singapore Four-Line Blue on a young shoot with ants in attendance,
How many caterpillars can you see?

The 3rd instar caterpillar resembles the 2nd instar caterpillar closely but with the dorsal patch on the 7th to 9th abdominal segments much more prominent. In some specimens,  faint intermittent markings in red to reddish brown also appear dorso-laterally, and on the dorsum of the 2nd thoracic segment.  After 2 days in this stage with the body length reaching a maximum about 6.5mm, the next moult  brings the caterpillar to its final instar.

Two views of a 3rd instar caterpillar, early in this stage.


Two views of another 3rd instar caterpillar, length: 6mm.

Two views of a 3rd instar caterpillar, dormant prior to its moult.


A 3rd instar caterpillar with an attending ant in the field.

The 4th instar caterpillar are similar to the 3rd instar caterpillar but with all red and reddish brown markings much more prominently marked and in sharp contrast to the ground color.  The prothorcic shield is whitish and the dorsal nectary organ and ventacular organs are distinguishable on the posterior segments.

Two views of a red-form 4th instar caterpillar, length: 8.5mm.


Two views of a yellow-form 4th instar caterpillar, length: 12mm.

The 4th instar lasts for 2-3 days and the body grows up to a length of about 12mm. On the last day of this stage, the caterpillar ceases food intake and its body shrinks in length and decolorises to a dull shade of pale brown. The fully grown caterpillar finally comes to  rest on a spot among leaves where it readies the site for pupation by spinning a silk pad and a silk girdle to secure itself.

Two vies of a 4th instar caterpillar, late in this stage, with color change taken place, length: 11mm.


Two views of a girdled-down pre-pupa of the Singapore Four-Line Blue

The next day, after 6-7 days of larval growth, pupation finally takes place. The pupa has the typical lycaenid form, and is 8-8.5mm in length. It is mostly yellowish brown and speckled with black spots of various sizes and shapes.


Two views of a pupa of the Singapore Four-Line Blue

Five to six days later, the pupa becomes darkened in color signaling the imminent emergence of the adult. The markings on the forewing upperside becomes increasing obvious through the pupal skin. The next day the adult butterfly emerges from the mature pupa.

Two views of a mature male pupa showing the extensive bluish coloration in the wing pad.


Two views of a mature female pupa showing the much less extensive bluish coloration in the wing pad.

References:

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

Text by Horace Tan, Photos by Federick Ho, Sunny Chir, Khew SK  and Horace Tan