Butterfly Biodata:
Genus: Deudorix Hewitson, 1863
Species: elioti Corbet, 1940
Wingspan of Adult Butterfly: 17-20 mm
Caterpillar Local Host Plant: Caryota mitis (Arecaceae [Palmae], common name: Fishtail Palm).
Physical Description of Adult Butterfly:
On the upperside, the male is yellowish-brown with a thick dark brown border on the forewing, and a series of obscure post-discal spots on the hindwing. The female is dark brown with faint brown markings in the tornal half of the hindwing. On the underside, both sexes are pale grey with cell-end bars and rounded post-discal spots edged with white striae. In the hindwing, there is a black tornal spot encased in a large yellowish oblong spot. The tornal area has bluish-green scales, and a filamentous white-tipped tail at the end of vein 2.
Underside view of a male Eliot's Cornelian.
Upperside view of a male Eliot's Cornelian.
An Eliot's Cornelian taking nectar from a flower of the Mile-a-Minute (Mikania micrantha).
Field Observations:
The Eliot's Cornelian is moderately rare in Singapore. Sightings of the species have been made in urban parks and gardens as well as the forested area of the nature reserves. It has also been observed with regularity on the offshore island of Pulau Ubin, and in the Lornie area in recent months. The adult is a rapid flyer and has been observed to visit flowers of various species for nectar.
An Eliot's Cornelian taking nectar from a flower of Bridelia tomentosa.
An Eliot's Cornelian taking nectar from a flower of Leea indica.
An Eliot's Cornelian taking nectar from a flower of Bidens alba.
Early Stages:
A video clip showing various stages of the life cycle of the Eliot's Cornelian.
For Eliot's Cornelian, only one larval host plant, Caryota mitis (Fishtail Palm), has been identified in Singapore. As is the case of other Deudorix spp., caterpillars of the Eliot's Cornelian bore into developing fruits of the host plant, and feed on the soft pulp and developing seed within the fruits. Moulting events between larval stages also take place solely within a partly eaten fruit.
Local host plant: Caryota mitis (Fishtail Palm)
A fruit bunch of the Fishtail Palm. An adult Eliot's Cornelian can be seen checking out the fruits.
A mating pair of the Eliot's Cornelian
Eggs are laid singly on the surface of a fruit or the bract of a fruit of the Fishtail Palm. Each egg resembles a bun with coarse polygonal reticulations. It is initially pale greenish when newly laid but darkens as it matures. Each egg has a basal diameter of about 0.8-0.9mm.
A female Eliot's Cornelian ovipositing on a fruit of the Fishtail Palm.
Two views of an egg of the Eliot's Cornelian, a few hours after it was oviposited..
Two views of a partially developed egg of the Eliot's Cornelian, two days after it was oviposited..
Two views of a fully developed egg of the Eliot's Cornelian, four days after it was oviposited.
The egg takes about 4-5 days to hatch. The caterpillar slowly nibbles away the top part of the egg shell to emerge. The newly hatched is about 1.5mm long. It has a black head and a pale yellowish brown body covered with long setae dorsally and laterally. There is a small black anal plate on the posterior segments, and a small dark brown prothoracic shield.
An animated sequence of the hatching process of a caterpillar of the Eliot's Cornelian.
Two views of an early 1st instar caterpillar of the Eliot's Cornelian, length: 1.5mm.
After emergence, the newly hatched does not eat the empty egg shell. Instead, it proceeds to find a spot on a fruit to bore into. Once inside the fruit, the caterpillar stays there and feeds on the soft contents of the developing fruit.
A newly hatched caterpillar in the early stage of boring into a fruit of the Fishtail Palm.
Two close-up views of a newly hatched caterpillar in the early stage of boring into a fruit of the Fishtail Palm.
A time-lapse sequence of the first entrance into a fruit by a newly hatched caterpillar of the Eliot's Cornelian.
When excreting frass pellets, it does so by backing up to the hole with just the posterior segment exposed. These frass pellets quickly pile up around the hole. The caterpillar rarely exits the fruit. On a few occasions when it does, it wanders around the fruit it is feeding on. The first instar sees the body length reaches up to about 3.5mm, and lasts about 3-4 days before the moult to the next instar.
A time-lapse sequence showing the disposal of frass pellets by a caterpillar of the Eliot's Cornelian.
A time-lapse sequence showing the return of a 1st instar caterpillar after wandering around in the vicinity of the hole.
Two views of a 1st instar caterpillar of the Eliot's Cornelian, length: 2.6mm.
A time-lapse sequence showing the return of a late 1st instar caterpillar after wandering on the fruit surface.
The second instar caterpillar is pale reddish brown in base colour. The dorsum of the 1st, 2nd and 6th abdominal segments are darker than the other body segments. Numerous white and dark brown setae adorn the body surface. On the side of the body, there is an obscure whitish lateral band running across most segments. The head capsule has changed to pale reddish brown in color and will remain so for the next instar. The prothoracic shield is now larger and broader proportionately and black in colour. The 2nd instar lasts about 3 days with the body length reaches up to 5.5-6mm.
An early 2nd instar caterpillar, looking for a new fruit to dine in.
Two views of a second instar caterpillar of the Eliot's Cornelian, early in this stage, length: 4.3mm.
Two views of a second instar caterpillar of the Eliot's Cornelian in the early stage of boring into a fruit.
Close-up view of a fruit bunch of the Fishtail Palm with some fruits being "attacked" by the caterpillars of the Eliot's Cornelian. Can you tell which ones?
The fruit being eaten by a caterpillar usually detaches easily from the rachis/rachillae of the fruit bunch. The caterpillar works to prevent the fruit from falling by spinning threads at the base of the fruit during a number of ventures out of its feeding chamber within the fruit.
A time-lapse sequence of a 2nd instar caterpillar checking out the threads securing the now-detached fruit.
Two views of a second instar caterpillar of the Eliot's Cornelian, length: 5mm.
A time-lapse sequence showing a second instar caterpillar returning to its feeding chamber within the fruit.
The third instar caterpillar closely resembles the 2nd instar caterpillar in body features with the exception of having a denser coat of short brown setae on body surface. The colour of all spiracles are pale brown in this penultimate instar. With a larger body and greater appetite, the 3rd instar caterpillar can be seen to change fruit more frequently than the 2nd instar caterpillar. The third instar lasts about 3-4 days and the body length reaches up to about 8.5-9mm before the moult to the 4th (and last) instar.
Two views of a third instar caterpillar of the Eliot's Cornelian, early in this instar, length: 6mm.
Two views of a third instar caterpillar of the Eliot's Cornelian, length: 7.5mm.
Two views of a third instar caterpillar of the Eliot's Cornelian in the early stage of boring into a fruit.
An animated sequence of frass disposal by a 3rd instar caterpillar (inside fruit) of the Eliot's Cornelian. .
The 4th instar caterpillar is largely similar to the 3rd instar caterpillar but with some noticeable differences. The prothoracic shield is now dark reddish brown with black patches at the edges, and the head capsule is reddish brown with two black lateral patches. The spiracles are now all black with the exception of the last one which is beige brown in color.
Two views of a 4th instar caterpillar of the Eliot's Cornelian, early in this instar, length: 8.3mm.
Two views of a 4th instar caterpillar of the Eliot's Cornelian, late in this instar, length: 12.5mm.
The 4th instar lasts about 4-5 days with the body length reaches up to 14-16mm. On the last day, the body color darkens in the anterior and posterior segments, and the front edge of the prothorax and the mesothorax turn orangy brown.
Two views of a 4th instar caterpillar of the Eliot's Cornelian, length: 16mm.
A time-lapse sequence showing a late 4th instar caterpillar boring into a fruit of the Fishtail Palm.
Towards the end of the last day, the body gradually shortens. The caterpillar stops feeding, wanders around for a pupation site. For this, the caterpillar typically does so within the hollowed-out chamber of a fruit, or at a concealed spot on the peduncle and rachis of the fruit bunch or in a leaf litter. At the pupation site, it spins a silk pad and a silk girdle to secure itself. Once this is done, the caterpillar becomes an immobile pre-pupa.
Two views of a pre-pupa of the Eliot's Cornelian.
The pre-pupal stage of the caterpillar lasts about one day. The ensuing pupation event turns it into a reddish brown pupa with the typical shape of a lycaenid pupa. The pupal skin is adorned with numerous irregularly-shaped brown to black patches. The pupa attaches itself to the silk pad via its cremaster end and the silk girdle. Length of pupa: 9.5-10mm.
Two views of a pupa of the Eliot's Cornelian, length: 9.5mm.
Two views of a pupa of the Eliot's Cornelian pupated within a hollow fruit. Left: the pupa partially seen through the hole. Right: the pupa revealed after half of the fruit skin is removed.
Animated sequence of the development of a pupa of the Eliot's Cornelian.
After seven days, the pupa gradually turns dark towards the end of the day, with the wing pads prominently black. In the case of the male, yellowish brown patches are vaguely visible in the wing pads. Next day, the adult butterfly emerges from the fully mature pupa. It rests on the pupal case or nearby stem surface to have its wings gradually expanded. A few hours later, the adult Eliot's Cornelian takes its first flight.
Two views of a mature pupa of the Eliot's Cornelian.
A newly eclosed Eliot's Cornelian resting near its pupal case.
Caterpillars of the Eliot's Cornelian have been observed to fall victim to a species of parasitoid wasp. A very high percentage of the caterpillars perish in the 3rd or 4th instar when the fully grown parasitoid larvae exit the caterpillar body.
A dying caterpillar of the Eliot's Cornelian and the newly emerged larva of a parasitoid wasp lying next to it.
A dying caterpillar of the Eliot's Cornelian with the cocoon of a parasitoid wasp lying next to it.
References:
On the upperside, the male is yellowish-brown with a thick dark brown border on the forewing, and a series of obscure post-discal spots on the hindwing. The female is dark brown with faint brown markings in the tornal half of the hindwing. On the underside, both sexes are pale grey with cell-end bars and rounded post-discal spots edged with white striae. In the hindwing, there is a black tornal spot encased in a large yellowish oblong spot. The tornal area has bluish-green scales, and a filamentous white-tipped tail at the end of vein 2.
Field Observations:
The Eliot's Cornelian is moderately rare in Singapore. Sightings of the species have been made in urban parks and gardens as well as the forested area of the nature reserves. It has also been observed with regularity on the offshore island of Pulau Ubin, and in the Lornie area in recent months. The adult is a rapid flyer and has been observed to visit flowers of various species for nectar.
Early Stages:
A video clip showing various stages of the life cycle of the Eliot's Cornelian.
For Eliot's Cornelian, only one larval host plant, Caryota mitis (Fishtail Palm), has been identified in Singapore. As is the case of other Deudorix spp., caterpillars of the Eliot's Cornelian bore into developing fruits of the host plant, and feed on the soft pulp and developing seed within the fruits. Moulting events between larval stages also take place solely within a partly eaten fruit.
Eggs are laid singly on the surface of a fruit or the bract of a fruit of the Fishtail Palm. Each egg resembles a bun with coarse polygonal reticulations. It is initially pale greenish when newly laid but darkens as it matures. Each egg has a basal diameter of about 0.8-0.9mm.
The egg takes about 4-5 days to hatch. The caterpillar slowly nibbles away the top part of the egg shell to emerge. The newly hatched is about 1.5mm long. It has a black head and a pale yellowish brown body covered with long setae dorsally and laterally. There is a small black anal plate on the posterior segments, and a small dark brown prothoracic shield.
After emergence, the newly hatched does not eat the empty egg shell. Instead, it proceeds to find a spot on a fruit to bore into. Once inside the fruit, the caterpillar stays there and feeds on the soft contents of the developing fruit.
When excreting frass pellets, it does so by backing up to the hole with just the posterior segment exposed. These frass pellets quickly pile up around the hole. The caterpillar rarely exits the fruit. On a few occasions when it does, it wanders around the fruit it is feeding on. The first instar sees the body length reaches up to about 3.5mm, and lasts about 3-4 days before the moult to the next instar.
The second instar caterpillar is pale reddish brown in base colour. The dorsum of the 1st, 2nd and 6th abdominal segments are darker than the other body segments. Numerous white and dark brown setae adorn the body surface. On the side of the body, there is an obscure whitish lateral band running across most segments. The head capsule has changed to pale reddish brown in color and will remain so for the next instar. The prothoracic shield is now larger and broader proportionately and black in colour. The 2nd instar lasts about 3 days with the body length reaches up to 5.5-6mm.
The fruit being eaten by a caterpillar usually detaches easily from the rachis/rachillae of the fruit bunch. The caterpillar works to prevent the fruit from falling by spinning threads at the base of the fruit during a number of ventures out of its feeding chamber within the fruit.
The third instar caterpillar closely resembles the 2nd instar caterpillar in body features with the exception of having a denser coat of short brown setae on body surface. The colour of all spiracles are pale brown in this penultimate instar. With a larger body and greater appetite, the 3rd instar caterpillar can be seen to change fruit more frequently than the 2nd instar caterpillar. The third instar lasts about 3-4 days and the body length reaches up to about 8.5-9mm before the moult to the 4th (and last) instar.
The 4th instar caterpillar is largely similar to the 3rd instar caterpillar but with some noticeable differences. The prothoracic shield is now dark reddish brown with black patches at the edges, and the head capsule is reddish brown with two black lateral patches. The spiracles are now all black with the exception of the last one which is beige brown in color.
The 4th instar lasts about 4-5 days with the body length reaches up to 14-16mm. On the last day, the body color darkens in the anterior and posterior segments, and the front edge of the prothorax and the mesothorax turn orangy brown.
Towards the end of the last day, the body gradually shortens. The caterpillar stops feeding, wanders around for a pupation site. For this, the caterpillar typically does so within the hollowed-out chamber of a fruit, or at a concealed spot on the peduncle and rachis of the fruit bunch or in a leaf litter. At the pupation site, it spins a silk pad and a silk girdle to secure itself. Once this is done, the caterpillar becomes an immobile pre-pupa.
The pre-pupal stage of the caterpillar lasts about one day. The ensuing pupation event turns it into a reddish brown pupa with the typical shape of a lycaenid pupa. The pupal skin is adorned with numerous irregularly-shaped brown to black patches. The pupa attaches itself to the silk pad via its cremaster end and the silk girdle. Length of pupa: 9.5-10mm.
After seven days, the pupa gradually turns dark towards the end of the day, with the wing pads prominently black. In the case of the male, yellowish brown patches are vaguely visible in the wing pads. Next day, the adult butterfly emerges from the fully mature pupa. It rests on the pupal case or nearby stem surface to have its wings gradually expanded. A few hours later, the adult Eliot's Cornelian takes its first flight.
Caterpillars of the Eliot's Cornelian have been observed to fall victim to a species of parasitoid wasp. A very high percentage of the caterpillars perish in the 3rd or 4th instar when the fully grown parasitoid larvae exit the caterpillar body.
- [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.
- A Field Guide to the Butterflies of Singapore, Khew S.K., Ink On Paper Communications, 2nd Edition, 2015.
A fantastic video and an excellent account of the life history.
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