Life History of the Malay Lacewing

Life History of the Malay Lacewing (Cethosia hypsea hypsina)
An updated version of the life history of the Malay Lacewing can be viewed by clicking this link.


Butterfly Biodata:
Genus: Cethosia Fabricius, 1807
Species: hypsea Doubleday, 1847
Subspecies: hypsina C. & R. Felder, 1867
Wingspan of Adult Butterfly: 80mm
Caterpillar Host Plants: Adenia macrophylla var. singaporeana


A Malay Lacewing resting on a perch in the wild.


A male Malay Lacewing visiting flowers of Leea indica.

Physical Description of Adult Butterfly:
Above, the forewings are black with a white subapical band beyond the cell; the basal area is orange-red for the male (with the red confined to the base of the wings) and black for the female (with a yellowish-white patch in mid space 1b). The hindwing upperside is entirely orange-red except for the scalloped black distal border. Underneath, the wings are orange-red with white fasciae and are spotted with black, and the forewing cell has several black-edged, pale blue transverse stripes. The wing borders are dark coloured and deeply indented with lace-like pattern of white markings. One distinguishing feature to separate Malay Lacewing from other Cethosia species is the absence of a white submarginal band on the hindwing underside.

Field Observations of Butterfly Behaviour:
Locally the occurrence of this species is restricted to the forested nature reserves, possibly due to its preferred host plant being found only in such areas. It is not uncommon in the reserves, and adults can be spotted visiting flowers of flowering plants such as Leea indica in forest clearings or alongside trekking trails. At appropriate times, females can also be seen checking out leaves in search of an ovipositing site. More about the adult behaviour can be found in an earlier blog article in the Butterfly of the Month series.


Early Stages:
The local host plant is a member of the Passifloraceae family. Also known as Singapore Adenia, it is a botanical variety of Adenia macrophylla which occurs only in Johor and Singapore. One prominent feature of this tendrillate climber is the pair of spatulate glands at the leaf blade base. This plant is a forest dweller and can be found in the Central Catchment Nature Reserves and Pulau Ubin.


Host plant : Adenia macrophylla var. singaporeana

The eggs of the Malay Lacewing are laid in large clusters on the underside of a youngish or middle-aged leaf, around a stem or a tendril. Each egg is pale yellow, cylindrical and ribbed, taller than broad (1.5mm versus 1mm).


A female Malay Lacewing flying near an ovipositing site.


A cluster of fresh eggs of Malay Lacewing laid on a stem

Each egg takes about 6 days to mature. The young caterpillar pushes its way through the cracked egg shell, and does not bother to eat the empty egg shell. The newly hatched has a cylindrical body in yellowish brown, and an initial body length of about 3mm. The body is covered in a grid of dark tubercles, each with a single long seta. The head is black and there is a pair of short black spines on the first thoracic segment. The young caterpillar either skims the lamina on a young leaf or nibbles away at the tip of a young stem. The Malay Lacewing caterpillars are gregarious throughout all five instars, often eating (leaves and stems) and moulting together in groups.


Eggs in various stages of development, including mature eggs and empty egg shells.


Newly hatched 1st instar caterpillar, length: 3mm


1st instar caterpillar, day 2 in this stage, checking out the spatulate
glands of the Adenia leaf; length: 4mm

As the 1st instar caterpillar grows to a length of 5mm, the body color changes gradually to pinky red, and a faint white saddle mark appears on the 4th abdominal segment. After about 2.5 days in 1st instar, the caterpillar moults to the next instar.


1st instar caterpillar, day 3 in this stage, ready to moult; length: 5mm

The 2nd instar caterpillar has a wine-red body colour, and the rows of tubercles in the 1st instar are replaced by 6 longitudinal rows of dark fine-pointed spines, 3 to each side of the body. The spines in uppermost two rows are the longest. A pair of short and black coronal spine appears on the head. The white saddle is now more prominently marked, and carries black-tipped white spines. This instar lasts 2.5 days with the body length reaching about 9mm before the next moult.


2nd instar caterpillar, early in this stage, 5.5mm

In the 3rd instar, there is no drastic change in physical appearance except for proportionately longer coronal spines (now about the same length as the height of the head capsule), and the larger and more distinct white saddle mark. This instar takes 3 days to complete with body length reaching about 16mm.


3rd instar caterpillar, early in this stage, length: 9.5mm


3rd instar caterpillar, late in this stage, length: 16mm

The coronal spines in the 4th instar caterpillar are again longer proportionately with the length of each spine about equal to the 1.5x height of the head capsule. The 4th instar lasts about 2-3 days with body length reaching about 24mm.


4th instar caterpillar, early in this stage, length: 16mm


A group of 4th instar caterpillars, with one subgroup ringbarking a young stem.



A group of caterpillars just moulted to 5th instar on the underside of a leaf

The next moult brings the caterpillar to its 5th and final instar. Now the coronal spines are about 2x the height of the head capsule. The upper half of the body is bright wine red, while the lower half is dark red. This phase lasts for 4 days before the caterpillar stops eating, and at this time the body length is 38-40mm.


5th instar caterpillar, early in the stage, 30mm


A group of 5th instar caterpillars sharing an Adenia leaf

Toward the end of 5th instar, the caterpillar moves about restlessly between feeds. Finally the caterpillar finds a spot on the underside of a leaf, stalk or stem to secure itself at the anal end, from which it hangs vertically as a pre-pupa. The pupation site needs not be on the host plant itself. In the wild, Malay Lacewing pupae have been found on other plants several metres from the Adenia host plant.


Left: A pre-pupatory larva of Malay Lacewing
Right: Pupa, newly pupated, still reddish to reddish brown on most parts.

Pupation takes place a day later. The pupa hangs vertically. It has two pairs of pointed white processes at the middle of its body and a number of less prominent dorsolateral processes. A pair of black foliaceous processes adorn the head. Body color is pale brown mottled with white and black patches, and several dorsal spots of bright gold. When disturbed, the body could jerk sideways through the movement of the posterior abdominal segments. Length of pupae: 28-29mm.


Pupa of Malay Lacewing; fresh on left and mature on right

After 7 days of development, the pupa becomes darkened. The next day the adult butterfly emerges to kick-start the next cycle in its lineage.


A newly eclosed Malay Lacewing dryig its wings on the pupal case

In one particular field visit, a newly eclosed adult was observed to mate right next to its empty pupal case. It was apparently the target of the older mate who had been seen flying in and out of the bush earlier.



A newly eclosed Malay Lacewing becomes part of a mating pair

Acknowledgments:

I would like to express my gratitude to Samsuri Ahmad and Ali Ibrahim of NParks, and botanist Joseph Lai for generous assistance in the identification of the host plant (Adenia macrophylla var. singaporeana).

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 Pres 1999

Text and Photos by Horace Tan