21 November 2009

Life History of the Glistening Caerulean

Life History of the Glistening Caerulean (Jamides elpis pseudelpis)

Butterfly Biodata:
Genus: Jamides Hübner , 1819
Species: elpis Godart, 1824
Sub-species: pseudelpis Butler, 1879
Wingspan of Adult Butterfly: 30mm
Caterpillar Local Host Plants:
Saraca cauliflora (Leguminosae, common name: Yellow Saraca); Lepisanthes amoena (Family: Sapindaceae).

A Glistening Caerulean sampling a water droplet on a leaf bud.

Physical Description of Adult Butterfly:
Above, the male is pale shining sky blue, with thread-thin forewing border and absence of submarginal markings on the hindwing. The female is pale blue with forewing border ending at mid costa. Beneath, the narrow striae are white and straight, or nearly so. Being a member of the elpis subgroup (of the celeno group), the Glistening Caerulean also has the post-discal band on the forewing underside completely dislocated at vein 3. On the hindwing, the second white stria from the base in space 7 is about mid-way between the second and third striae from the base in the cell. Each hindwing features a black-centred orange-crowned tornal spot, rather large submarginal orange markings along veins 1b and 4, and a white-tipped filamentous tail at the end of vein 2.

A male Glistening Caerulean giving us a full view of its glistening blue upperside.

A Glistening Caerulean perching on a leaf of the Yellow Saraca.

Field Observations of Butterfly Behaviour:
This species is rarely encountered in Singapore. It is re-discovered in the early part of this year in an urban garden where a small colony was found to be breeding on the two host plants present. At this site, the males were observed to be flying around in sunny weather, and puddling on wet ground. A number of females were also with sighted carrying out their oviposition routines on flower buds of both host plants.

A Glistening Caerulean perching on a broken twig.

Early Stages:
The 1st local host plant, Lepisanthes amoena (Kayu Matahari) is a small to medium-sized tree with imparipinnate (pinnate with a terminal leaflet) leaves. Leaf-like pseudo-stipules are present. The whitish flower buds are globular and occur in terminal panicles. Fruits are tri-lobular and turn reddish brown when ripened. Early stages of the Glistening Caerulean feed on flower buds and flowers of this plant.

Host plant: Lepisanthes amoena: Flower buds (left); Fruits (right).

A mother Glistening Caerulean laying her eggs on flower buds of Lepisanthes amoena.

The 2nd local host plant, Saraca cauliflora (Yellow Saraca) is a small to medium-sized tree with pinnate leaves in 4-6 pairs. The flowers are orange-yellow in large clusters on trunk or branches. Early stages of the Glistening Caerulean feed on flowers parts of this host plant.

Yellow Saraca: cauliflorous flowers (left); pinnate leaves and seed pod (right).

A mother Glistening Caerulean laying her eggs within a cluster of Yellow Saraca flowers.

Eggs of Glistening Caerulean are laid singly on flower buds or flower parts of the host plant. The small pale green egg is disc-like and about 0.4-0.5mm in diameter. Its surface is covered with a reticulated pattern of intersecting ridges.

Eggs of the Glistening Caerulean laid on flower parts. Left: on Lepisanthes amoena;
Right: on Yellow Saraca.

The egg takes 2-3 days to hatch. The young caterpillar emerges after nibbling away sufficiently large portion of the egg shell. Measured at a length of about 0.8-0.9mm, its pale yellow body is cylindrical in shape, sporting long fine setae (hairs) and a dark head capsule. There is also a dark prothoracic shield and an anal plate.

Bottom: A newly hatched caterpillar of the Glistening Caerulean, length: 0.8-0.9mm.
Top: A late 1st instar caterpillar, 1.9mm.

The newly hatched grazes on the surface of flower petals or bores into a flower bud for the goodies within. After about 2 days of growth and reaching a length of about 2.5mm, the caterpillar moults to the next instar.

Boring into flower parts. Left: a newly hatched on Yellow Saraca flower.
Right: a 2nd instar caterpillar on a flower bud of Lepisanthes amoena.

The 2nd instar caterpillar has numerous short setae with dark base and this gives the pale yellow body surface a heavily dotted appearance. From this instar onwards, the small diamond-shaped prothoracic shield takes on a pitch black coloration.
This instar lasts about 2 days with the body length reaches up to 4.5mm.

2nd instar caterpillars, late in this stage, length: 4mm.

The 3rd instar caterpillar resembles the 2nd instar caterpillar with body color pale to dark yellow. Both the dorsal nectary organ (on the 7th abdominal segment) and tentacular organs (on the 8th abdominal segment) are barely discernible.
The 3rd instar takes 2.0 days to complete with the body length reaching about 7.0mm.

3rd instar caterpillars. Top: newly moulted, 4.3mm. Bottom: 5.5mm.

Still covered with numerous fine setae on the body surface, the 4th (and final) instar caterpillar has taken on a darker shade of yellowish brown. The dorsal nectary organ is now prominently marked with an encircling dark brown patch. Another noticeable change is in the diamond shaped prothoracic shield which now has a vertical split.

4th instar caterpillar feeding on Yellow Saraca flowers.
Top: early in this stage, length: 7.5mm. Bottom: late in this stage, length: 12mm.

After 4-5 days of growth and reaching a maximum length of around 11-12mm in the final instar, the body of the caterpillar gradually shrinks, and finally takes on a dark pinkish to reddish brown coloration. All bred specimens chose to enter their pre-pupatory phase in tight pockets of space within leaf debris. At the chosen spot, 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 Glistening Caerulean.

The girdled down pre-pupa still has the ability to evert its tentacular organs, indicating that
ant-larva association does continue into the pre-pupal stage.

Pupation takes place after one day of the pre-pupal stage. The pupa has the typical lycaenid shape. It is pale yellow to beige in base color with a number brown and black specks. of various sizes. The pupa has a length of about 8-9mm.

Two views of a pupa of the Glistening Caerulean, length: 9mm

Eclosion takes place after 6 days in the pupal stage. The mature pupa gradually darkens in colour the day before. Bluish patches on forewing uppersides become clearly visible in the wing pads of the mature pupa. The extent of these bluish patches reveals the gender of the soon-to-emerge adult.

Two views of a mature pupa of a female Glistening Caerulean.

A newly eclosed male Glistening Caerulean

  • 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 Bobby Mun, Sunny Chir, Khew SK and Horace Tan