24 April 2010

Life History of the Knight

Life History of the Knight (Lebadea martha parkeri)

Butterfly Biodata:
Genus: Lebadea C.&R. Felder, 1861
Species: martha Fabricius, 1787
Subspecies: parkeri Eliot, 1978
Wingspan of Adult Butterfly: 60mm

Caterpillar Host Plants: Ixora congesta (Rubiaceae), I. javanica (Rubiaceae) and one un-identified plant in the nature reserve.

A male Knight showing us its underside.

A sunbathing male Knight displaying its upperside.

Physical Description of Adult Butterfly:
The forewing is falcate at vein 6, and is long and narrow, more so in the male than in the female. The upperside is ochreous brown and marked with a rather complex pattern. A prominent white discal band is seen on the forewing for both sexes, and in male this band is more prominent and continues onto the hindwing where it tapers towards the tornus. The forewing has a series of white post-discal lunules in spaces 2-6, lying on the outer margin of the white discal band. The apical area of the forewing is strongly whitened in the male. As a characteristics of the subspecies parkeri, the distal part of the hindwing is broadly laved with varying extent of pale mauve.

A female Knight on a leaf perch showing us its upperside.

A newly eclosed female Knight giving a view of its underside.

Field Observations of Butterfly Behaviour:
This species is not uncommon in Singapore and has a rather wide distribution. Adults have been sighted at multiple locations such as areas within nature reserves, several urban parks and even outlying islands. In sunny weather, both sexes can be found flying in the vicinity of flowering shrubs and having energy intakes from nectar and ripened fruits.

A female Knight enjoying the ripened fruit of the Singapore Rhododendron.

Early Stages:
Thus far, two Ixora species and one un-identified plant in the catchment reserves have been identified as local host plants.

Host plant: Ixora sp. found in the Southern Ridges.

The unidentified host plant in the catchment reserve.

The mother lays an egg singly at the leaf tip on the host plant. The yellowish green egg is globular-shaped and has its surfaces marked with hexagonal pits and short spines at pit corners. The micropylar sits atop. Diameter of the egg is about 1.1-1.2mm.

A female Knight laying an egg on the tip of an Ixora leaf in the Southern Ridges.

Two views of an egg of the Knight. Diameter: about 1.1mm.

Two views of a mature egg of the Knight.

The egg takes about 3-4 days to hatch. The young caterpillar emerges by eating away the upper portion of the egg shell. The rest of the egg shell is typically consumed soon after. The newly hatched is about 2.5mm in length and has a cylindrical yellowish green body covered with many small tubercles and short setae. Tubercles running dorso-laterally and sub-spiracularly are larger in size and appear paler in coloration. The pale brown head capsule is round, relatively smooth and sporting a few short setae.

Two views of a newly hatched caterpillar of the Knight, length: 2.5mm.

Two views of a 1st instar caterpillar of the Knight. Length: 3mm.
Note the frass pallets stuck to its body surface.

The caterpillar feeds on the lamina in a rather systematic manner. At a short distance from the tip, it makes a cut on the lamina from the edge to the midrib, creating an isolated leaf fragment which it then dines on. Two to three such fragments can be present at one time. As existing leaf fragments are exhausted, new ones are made further away from the tip.

A view of the leaf tip where a 1st instar caterpillar had taken up residence.
Note cut-off leaf fragments, frass bundles and the intact midrib.

Frass pallets are gathered by Knight caterpillars to make rather large bundles near the receding edge of the feeding site. In particular, the first instar caterpillar has the habit of adhering frass pallets to its body, possibly for the purpose of enhancing its disguise/concealment when resting in close proximity to the frass bundles.

Two views of a 1st instar caterpillar of the Knight. Length: 5mm.

After reaching about 5.0mm in 3-4 days, the caterpillar moults to the 2nd instar. The body color of the 2nd instar caterpillar is pale brown with a yellow undertone. Besides tiny tubercles covering most of its body surface, the 2nd instar caterpillar also features short (but distinct) branched spines dorso-laterally and sub-spiracularly. A small lateral dark patch sitting atop a light patch can also be found below each dorso-lateral spine. The head capsule is dark brown and dotted with a small number of conical tubercles. This instar lasts about 3-4 days with the body length reaching 7-8mm.

Two views of a newly moulted 2nd instar caterpillar, length: 4.5mm

2nd instar caterpillar, late in this stage, length: 7mm

The 3rd instar caterpillar resembles the 2nd instar caterpillar but with noticeably longer dorso-lateral spines, with the pair on 3rd thoracic segment much longer than the rest., and the pair on the 8th abdominal segment moderately longer. Its head capsule is dark brown to black irorated with a few tubercles and short peripheral spines. A fine line beige to pale brown in coloration runs along the dorsum. Faint markings with diamond-shape outline appear dorsally with the one on the 2nd abdominal segment half marked in beige. This instar takes about 3-4 days to complete with body length reaching 11-12mm.

3nd instar caterpillar, early in this stage, length: 8.5mm

A 3rd instar Knight caterpillar found on its resident leaf on the unknown
host in the nature reserve.
Note the neatly cut leaf fragments.

Two views of 3rd instar caterpillar, late in this stage, ready for the moult to the 4 instar.

The 4th instar caterpillar resembles the 3rd instar caterpillar in most features. The various dorsal and lateral markings are now more strikingly presented with the body being dominated in black. The spines on the head capsule are now proportionately longer, and there are two whitish to yellowish line flanking the lateral halves of the head capsule. This instar lasts 3-5 days with body length reaching 17-18mm.

Two views of a newly moulted 4th instar caterpillar, length: 9mm.

Two views of 4th instar caterpillar, length: 10mm.

In the 5th (final) instar, the newly moulted caterpillar resembles the 4th instar caterpillar closely. The branched dorso-lateral spines are now very well developed on all body segments, and those on the 3rd thoracic and the 8th abdominal segment the longest and thickest.

Two views of a new moulted 5th instar caterpillar, length: 18mm.

In about a day, the body color soon changes drastically to yellowish brown on the anterior portion and dark brown to black in the posterior portion. The new appearance is dominated by two large lateral patches, in bright lime green, on the 2nd-4th abdominal segments. There is a large saddle mark, beige and meshed in appearance, nearly covering the entire 5th abdominal segment. Large markings oval to diamond in shape also appear on the dorsum with the one on the 2nd abdominal segment prominently colored in beige. The yellowish brown head capsule has much longer and pointed spines.

Two views of a 5th instar caterpillar, later in this stage, length: 31mm.

As with other members of the Limenities subgroup, when disturbed, the caterpillar adopts a characteristic posture with the anterior body arched and the head tucked beneath the thorax.

A 5th instar caterpillar adopting an on-guard stance when sensing the presence of an intruder.

A 5th instar caterpillar tending to its frass bundle.
Note an egg was mistakenly laid by a mother butterfly at the bundle.

The 5th instar lasts for 4-7 days, and the body length reaches up to 31-33mm. On the last day, the base body decolorizes rather dramatically. The lime green lateral patches changes to pink/beige, and the other pale markings become now almost whitish in appearance.

Two views of a 5th instar caterpillar preparing its pupation site, length: 32mm.
Note the color changes in various markings.

The caterpillar eventually ceases feeding and wanders around. It chooses a spot on the underside of a branch/stem and spins a silk pad from which it hangs vertically to take on the pre-pupatory pose.

A pre-pupatory larva of the Knight.

Pupation takes place a day later. The pupa suspends itself from the silk pad with no supporting silk girdle. It is almost entirely pale coffee brown in color with segments and parts outlined in a darker shade of brown. Pink to white patches also adorn the pupal surface at the head region. The abdominal segments are slender, and the thoracic portion being larger and expanded laterally. Dorsally, there are two short processes curved towards each other. Length of pupae: 23-24mm.

Three views of a pupa of the Knight.

After about 7 days of development, the pupal skin turns translucent as the development within the pupal case comes to an end. The markings on the forewing upperside also become discernible. The next day, the adult butterfly emerges from the pupal case.

Three views of a mature pupa of the Knight.

Newly eclosed adults drying wings on the pupal case.
Left: male; Right: female.

A newly eclosed male Knight. Note the narrower forewings.

A newly eclosed female Knight. Note the broader forewings.

  • 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 Ellen Tan, Bobby Mun, Federick Ho, Sunny Chir and Horace Tan.