Life History of the Cruiser

Life History of the Cruiser (Vindula dejone erotella)

Butterfly Biodata:
Genus: Vindula Hemming, 1934
Species: dejone Erichson, 1834
Sub-species: erotella Butler, 1879
Wingspan of Adult Butterfly: 80-90mm
Caterpillar Local Host Plants: Adenia cordifolia (Passifloraceae), Adenia macrophylla var. singaporiana (Passifloraceae, common names: Singapore Adenia, 大叶蒴莲).

A male Cruiser puddling on wet ground.

A female Cruiser sunbathing on a leaf perch.

A female Cruiser on a leaf perch with host plant Adenia cordifolia in the background.

Physical Description of Adult Butterfly:

The Cruiser is sexually dimorphic. On the upperside, the male is coloured rich fulvous orange. It has a broad post-discal band of paler coloration on both wings. The wings are marked with dark sub-marginal lines, and there are orange-ringed ocelli on the hindwing. The female is coloured pale greenish-grey with a white post-discal band. The orange ringed ocelli on the hindwing are large and distinct. On the underside, the male is pale orange and the female is pale ochraceous. Both sexes have a short pointed tail at vein 4 of the hindwing.

A male Cruiser puddling on wet ground.

A female Cruiser puddling on wet ground.

A male Cruiser taking nectar from an inflorescence of Pagoda flower.

Field Observations of Butterfly Behaviour:

The Cruiser is common in Singapore but confined to the forested area in the nature reserves. Males are often attracted to decomposing organic matter. Both males and female are observed to puddle on damp paths in the nature reserve. Both sexes are strong flyers, and are attracted to blooming flowers of plants such as Ixora, Lantana, Bidens alba and Pagoda flower.

A female Cruiser visiting Ixora flowers for nectar.

A female Cruiser taking nectar from a flower of Bidens alba.

Two male Cruisers checking out some animal waste.

Early Stages:

The local host plants are Adenia cordifolia and Adenia macrophylla var. singaporiana. Both are vines in the Passifloraceae family. Caterpillars of the Cruiser feed on leaves, tendrils, petioles and stems of the two plants.

Local host plant #1: Adenia cordifolia showing the trilobate leaf form.

Local host plant #2: Adenia macrophylla var. singaporiana.

A mating pair of the Cruiser found on the side of a forest trail.

Typically eggs of the Cruiser are laid singly or in small groups on tendrils (young or old) of the host plants. At times, the mother butterfly might opt to oviposit on the tip of a twig of other plants and even on fiber bundles in the vicinity of the host plant. Each egg is coloured beige, barrel-shaped with a ribbed surface. Height: ~1.6mm.

A female Cruiser laying eggs on the end of a dry twig.


A short video clip of a female Cruiser laying eggs on the end of a dry twig.

A cluster of 8 eggs of the Cruiser laid on the tip of a dry twig (as seen in the above video).

A pair of eggs of the Cruiser laid on an old and damaged tendril of the host plant.

A composite showing Cruiser eggs (one-day old to two-day old) of varying numbers laid on young and old tendrils of Adenia cordifolia.

A pair of eggs of the Cruiser laid on the end of a fiber bundle.

Each egg takes about 3 days to mature. The egg becomes adorned with small reddish patches from the second day onwards, and turn dark reddish towards the end of the third day. The young caterpillar nibbles away sufficiently large portion of the egg shell to emerge, and then proceed to eat the remnant of the egg shell.

The cluster of 8 eggs of the Cruiser at the end of the 3rd day, with hatching to take place soon after.

The pair of two eggs at the end of 3rd day, with hatching to take place soon after.

Two newly hatched caterpillars of the Cruiser, length: 3mm.


A Cruiser caterpillar hatches from its egg.

The newly hatched has a cylindrical body in pale reddish color, and an initial body length of about 3mm. The body is covered in a grid of tubercles and numerous long setae. The head is black. When feeding, the young caterpillar either skims the lamina on a young leaf or nibbles away at the surface of a tendril or young stem. As growth progresses, the body base color turn reddish brown, with some of the body segments (1st and 2nd thoracic segments, 2nd, 4th, 6th, last abdominal segments) becoming whitish.

Two views of a 1st instar caterpillar of the Cruiser, several hours after hatching, length: 4mm.

Two views of a 1st instar caterpillar of the Cruiser, one day after hatching, length: 5.5mm.

As the 1st instar comes to an end, the whitish markings turns prominently white as the caterpillar lies dormant to moult. After 2-2.5 days in the 1st instar and reaching a length of about 6mm, the caterpillar moults to the next instar.

Two views of a 1st instar caterpillar of the Cruiser, dormant prior to its moult.

The 2nd instar caterpillar has a dark reddish brown colour, and those rows of fine setae in the 1st instar are now replaced by longitudinal rows of long and pointed black spines. Furthermore, a pair of long black cephalic spine appear on the head, which also has a pair of lateral white stripes. A prominent white saddle is featured on the 6th abdominal segment. Small white patches are also found on the 1st, 2nd thoracic segments, 2nd, 4th, and the terminal abdominal segments. A few whitish spots also adorn the dorsum of other segments. This instar lasts about 2-2.5 days with the body length reaching about 9.5-10mm before the next moult.

Two newly moulted 2nd instar caterpillars of the Cruiser found at the end of a young shoot.

Two early 2nd instar caterpillars of the Cruiser resting on a leaf.

Two views of a 2nd instar caterpillar of the Cruiser on a developing tendril, length: 7.5mm.

Two views of a 2nd instar caterpillar of the Cruiser, length: 10mm.

Two views of a late 2nd instar caterpillar of the Cruiser, dormant prior to its moult.

The 3rd instar does not bring along any drastic change in physical appearance. Two colour forms, one pale yellowish brown and the other dark reddish brown, are observed in this instar. Both forms features black body spines and cephalic spines. This instar takes 2.5-3 days to complete with body length reaching about 16mm.

Two views of a 3rd instar caterpillar of the Cruiser, newly moulted, dark brown form.

Two views of a 3rd instar caterpillar of the Cruiser, newly moulted, yellow form.

Two views of a 3rd instar caterpillar of the Cruiser, dark brown form, length: 12mm.

Two views of a 3rd instar caterpillar of the Cruiser, yellow form, length: 13.5mm.

Two views of a 3rd instar caterpillar of the Cruiser, yellow form, length: 16mm.

Two views of a late 3rd instar caterpillar of the Cruiser, yellow form, dormant prior to its moult.

The next moult brings the caterpillar to its 4th instar. The caterpillar retains the same body features and colour forms as in the 3rd instar. This instar lasts for 3-4 days with the body length reaching up to 31-32mm.

Newly moulted 4th instar caterpillars of the Cruiser. Top: dark brown form; bottom: yellow form.

Two views of an early 4th instar caterpillar of the Cruiser, dark brown form, length: 14.5mm.

Two views of a 4th instar caterpillar of the Cruiser, yellow form, length: 21mm.

Two early 4th instar caterpillars of the Cruiser, dark brown and yellow forms, resting after a feeding session.

Two views of a 4th instar caterpillar of the Cruiser, dark brown form, length: 27mm.

Two views of a 4th instar caterpillar of the Cruiser, yellow form, length: 30mm.

Two views of a late 4th instar caterpillar of the Cruiser, dark brown form, colour changed to dark wine red, dormant prior to its moult.

Two views of a late 4th instar caterpillar of the Cruiser, yellow form, dormant prior to its moult.

The 5th (and final) instar caterpillar retains the same body features as in the 4th instar. Again two main colour forms exist, a black form and a yellow form. The black form resembles the dark brown form in the earlier instars but with much darker body colour and more distinct white saddle mark on the 6th abdominal segment and the second thoracic segment. In the yellow form, the body spines, except for the ones on the saddle mark, are no longer black but yellowish. The saddle mark and other white markings in the yellow form can be much reduced in some individuals.

A newly moulted 5th instar caterpillar of the Cruiser, with body splines and cephalic spines yet to turn black.

Two views of an early 5th instar caterpillar of the Cruiser, black form.

Two views of an early 5th instar caterpillar of the Cruiser, yellow form.

Two views of a 5th instar caterpillar, black form, length: 31mm.

Two views of a 5th instar caterpillar, yellow form, length: 36mm.

Two views of a 5th instar caterpillar of the Cruiser, yellow form, with saddle mark absent, length: 42mm.

Two views of a 5th instar caterpillar of the Cruiser, black form, length: 53mm.

Two views of a 5th instar caterpillar of the Cruiser, yellow form, body taking on a purplish undertone, length: 46mm.

A yellow form 5th instar caterpillar of the Cruiser observed in the field, resting on a leaf at the fringe of the nature reserve.

The 5th instar lasts up to 4-5 days, with the body length reaching up to 53mm. Toward the end of the instar, the caterpillar stops feeding and moves around in search of a pupation site. The body is shortened and body colour changed. In the black form, the body colour usually changes to dark purplish brown, while those in yellow form can turn reddish/purplish brown to even totally purplish. Finally the caterpillar finds a spot on the underside of a leaf, stalk or stem to spin a silk pad to which it secures itself with the claspers at its posterior end. Now the caterpillar is an immobile pre-pupa, hanging vertically from this pupation site.

A late 5th instar caterpillar of the Cruiser, black form.

A late 5th instar caterpillar of the Cruiser, yellow form, with colour changed.

A late 5th instar caterpillar of the Cruiser, yellow form, with colour changed drastically.

A late 5th instar caterpillar of the Cruiser, yellow form, with colour changed drastically.

Three pre-pupatory larvae of the Cruiser taking up the J-position on the underside of a leaf or a stem.

Pupation takes place half a day later. The pupa hangs vertically. It has two pairs of long and pointed processes at the middle and the posterior end of the body. Each of these processes has a fin-shaped basal section. A pair of short processes also adorn the head. Body color is in varying shades of pale reddish/yellowish brown. In some cases, the pupa can be almost entirely yellowish. There are also pairs of silvery spots on the dorsum of anterior segments and green spots on the dorsum of posterior segments. The dorsum is prominently keeled at the thorax. Length of pupae: 30-36mm.

A Cruiser caterpillar moults to its pupal stage.

Three views of a pupa of the Cruiser. Pale brownish. Left: lateral view; Middle: ventral view; Right: dorsal view.

Three views of a pupa of the Cruiser. Pale yellowish. Left: lateral view; Middle: ventral view; Right: dorsal view.

The dorsal view of a yellowish Cruiser pupa.

Five pupae of the Cruiser, showing varying coloration.

The pupa takes about 6-7 days to develop fully. About 0.5 day before eclosion, the pupa becomes darkened in the wing pad, and the absence/presence of a whitish band reveals the sex of the soon-to-emerge adult butterfly. When the adult body in the pupa is fully detached from the pupal skin, the eclosion takes place soon after.

Fully developed pupae of the Cruiser, minutes before eclosion. Left: female; right: male.


A Cruiser emerges from its pupal case.

Newly eclosed female Cruiser clinging on to its pupal case.

Newly eclosed male Cruiser clinging on to its pupal case.

References:

• [C&P5] The Butterflies of The Malay Peninsula, A.S. Corbet and H.M. Pendlebury, G. and N. van der Poorten (Eds.), 5th Edition, Malayan Nature Society, 2020.
• Butterflies of Thailand, Pisuth Ek-Amnuay, 2nd Edition, 2012.
• A Field Guide to the Butterflies of Singapore, Khew S.K., Ink On Paper Communications, 2nd Edition, 2015.

Acknowledgment:
I would like to express my gratitude to Hanpeng Lim for sharing information on the host plant and early stages of the Cruiser.

Text by Horace Tan, Photos by Koh Cher Hern, Hanping Lim, Lumin Ong, Khew SK, Zick Soh and Horace Tan.