Genus: Ariadne Horsfield, 1829
Species: ariadne Linnaeus, 1763
Subspecies: ariadne Linnaeus, 1763
Wingspan of Grownup Butterfly: 38-45mm
Caterpillar Native Host Plant: Ricinus communis (Euphorbiaceae, widespread identify: Castor Oil Plant)
An Angled Castor puddling on a moist floor.
A feminine Angled Castor perching on a leaf of the Castor Oil Plant.
A newly eclosed feminine Angled Castor resting within the neighborhood of its pupal case.
Bodily Description of Grownup Butterfly:
On the upperside, the wings are orangey to reddish brown and traversed by 5 – 6 slender and sinuate black strains. A single black discal line lies simply past the cell-end on each wings. On the underside, the wings are pale crimson brown and crossed with a number of irregular bands in darker coloration. Small whitish wing scales are featured dotting the wing floor, in a lot larger abundance within the feminine than the male. A distinguished white sub-apical spot is featured within the forewing on each under- and uppersides.
The upper- and underside views of each female and male adults of the Angled Castor.
A male Angled Castor perching on the underside of a leaf.
A male Angled Castor perching on a flower of the Coat Buttons plant.
A sun-bathing Angled Castor perching on a grass blade.
Subject Observations of Butterfly Behaviour:
Angled Castor was re-discovered in Singapore in 2013 when a single particular person was noticed in an space throughout the Central Catchment Reserve on mainland Singapore. Extra lately, in late 2018, a small colony of this species was discovered in a location on Pulau Ubin, in an space the place its host plant, the Castor Oil Plant, grew in abundance. The sluggish flying adults might be seen feeding on grass flowers in that location, and puddling on damp muddy areas at that website.
An Angled Castor taking nectar from flowers of a grass species.
One other Angled Castor taking fluid from grass flowers.
A male Angled Castor perching on a twig.
An Angled Castor sunbathing on a leaf.
A feminine Angled Castor displaying its lovely wing underside.
Throughout the areas the place Angled Castor happens, the popular larval host plant is the Castor Oil Plant (Ricinus communis) from the Euphorbiaceae household. That is additionally true in Singapore. In India, a number of Tragia species, additionally belonging to the Euphorbiaceae, have additionally been recognized as larval host crops. Caterpillars in all instars of the Angled Castor feed on leaves of the Castor Oil Plant.
Native host plant: Ricinus communis (Castor Oil Plant).
A mom Angled Castor ovispositing on the leaf underside of the Castor Oil Plant.
Eggs of the Angled Castor are laid singly on the floor of a leaf of the host plant. The yellowish inexperienced egg is oval-shaped with a flat base, and a small flat high with the micropylar sitting within the center. The floor is marked with rows of lengthy, whitish hairs. Every egg has a peak of about 0.8mm.
Two views of an egg of the Angled Castor, peak: 0.8mm.
Two views of a mature egg of the Angled Castor. Observe the head capsule and physique setae now clearly seen by way of the egg shell.
The egg takes about 2.5 to three days to hatch. The younger caterpillar emerges by consuming a sufficiently giant a part of the egg shell. The newly hatched is about 1.6mm in size and it has a cylindrical and pale yellowish brown physique lined with rows of lengthy black setae (hair) dorsally and dorso-laterally, and white setae laterally. The physique can be marked with a number of reddish brown patches laterally. The top capsule is pale brown to darkish brown.
Two views of a newly hatched Angled Castor caterpillar quickly after its emergence.
The first instar caterpillar feeds on the leaf lamina. Because it feeds and grows, the lateral darkish patches and the pinnacle capsule flip darkish brown. After reaching about 3.5mm in 2-2.5 days, the caterpillar moults to the 2nd instar.
Two views of 1st instar caterpillar, size: 3.2mm.
Two views of 1st instar caterpillar, late on this stage, dormant previous to its moult, size: 3.5mm.
The physique of the 2nd instar caterpillar is yellowish brown with darkish brown lateral patches on most physique segments. Reasonably lengthy tubercles, every of which is endowed with dendritic spines and setae, run alongside the size of the physique. On both sides of the physique, there are three sequence of such tubercles: one happens dorso-laterally, one other laterally and the final sub-spiracularly. The color of the tubercles on the metathorax, third, fifth and seventh stomach segments are darkish brown, whereas these on the remaining physique segments are yellowish brown. The top capsule is darkish brown with two brownish cephalic horns, every of which can be endowed with dendritic spines and setae. This instar lasts about 1.5 days with the physique size reaching about 5.5mm.
Two views of a 2nd instar caterpillar of the Angled Castor, early on this stage, size: 3.3mm.
Two views of a 2nd instar caterpillar of the Angled Castor, size: 4.5mm.
Two views of a late 2nd instar caterpillar of the Angled Castor, dormant previous to its moult, size: 5.5mm.
The third instar caterpillar resembles the 2nd instar caterpillar carefully, with the identical three sequence of tubercles. These tubercles and related dendritic spines are proportionately longer (than these within the 2nd instar) and uniformly darkish brown in coloration. The physique is usually darkish brown dorsally and laterally, aside from the prothorax, the posterior phase and decrease portion of every phase, that are yellowish brown. Tiny, whitish specks could be seen on the darkish dorsum. The cephalic horns are additionally for much longer proportionally and have a variety of lateral spines. The top capsule is totally darkish brown to black. This instar takes about 2 days to finish with physique size reaching about 8-9mm.
A newly moulted third instar caterpillar of the Angled Castor.
Two views of a third instar caterpillar of the Angled Castor, size: 7.3mm.
Two views of a late third instar caterpillar of the Angled Castor, dormant previous to its moult, size: 8.8mm.
The 4th instar caterpillar carefully resembles the third instar caterpillar, however with darkish coloration on the dorsum way more intense than within the third instar, and the cephalic horns longer proportionately as effectively. The 4th instar lasts about 2.5-3 days with the physique size reaching about 17-18mm. In late 4th instar, a band of small greyish white patches could be seen on the dorsum.
Two views of a 4th instar caterpillar, early on this stage, size: 9.6mm.
Two views of a 4th instar caterpillar of the Angled Castor, size: 15mm.
A 4th instar caterpillar of the Angled Castor discovered within the subject on a leaf of the Castor Oil Plant.
Two views of a late 4th instar caterpillar, dormant earlier than its moult, size: 16mm.
The fifth (and remaining) instar caterpillar is just like the 4th instar caterpillar. As within the late 4th instar, a band of small whitish patches seem on the dorsum of the first to the seventh stomach segments. The robust distinction between the white patches and darkish coloration of the dorsum makes this band a hanging and straightforward identifiable characteristic of the fifth instar. A noteworthy level: The bottom of the dorsal and dorso-lateral tubercles on the mesothorax, metathorax, and the first to eighth stomach segments could be pink in some people, or black in others.
A fifth instar caterpillar of the Angled Castor, newly moulted. Observe the exuvia behind the caterpillar. The tubercles and cephalic horns nonetheless within the stage of enlargement.
A fifth instar caterpillar of the Angled Castor, newly moulted. The tubercles and cephalic horns totally fashioned.
Two views of a fifth instar caterpillar, early on this instar, base of tubercles reddish, size:18mm.
Two views of a fifth instar caterpillar of the Angled Castor, base of tubercles reddish, size: 28mm.
Two views of a fifth instar caterpillar of the Angled Castor, base of tubercles black, size: 30mm.
A fifth instar caterpillar (base of tubercles pink) discovered within the subject on a leaf of its host plant, after a rain swept by way of the realm.
The fifth instar lasts for 3-3.5 days, and the physique size reaches as much as 30-31mm. On the final day, the physique turns into shortened and the caterpillar ceases feeding and wanders round. Finally it stops at a spot on the underside of a leaf or a stem and spins a silk pad from which it hangs vertically to tackle the pre-pupatory pose.
A pre-pupa of the Angled Castor.
The pupation occasion of a Angled Castor caterpillar.
Pupation takes place about 0.5 day later. The pupa suspends itself from the silk pad with no supporting silk girdle. It happens in two coloration kinds, with the brown kind showing pale yellowish brown with darkish brown spots and patches on the dorusm, and the inexperienced kind showing pale yellowish inexperienced with darkish inexperienced spots and patches on the dorsum. The dorsum of the thoracic segments are raised to tall ridge on the mesothorax. On the anterior finish, there are two quick cephalic horns. Size of the pupa: 20-22mm.
Three views of a pupa of the Angled Castor, brown kind.
Three views of a pupa of the Angled Castor, inexperienced kind .
Three views of a mature pupa of the Angled Castor.
After about 5 days of growth, the pupal pores and skin of the mature pupa turns translucent and the entire pupa turns into principally darkish brown at this stage. The eclosion occasion takes place the following day.
The eclosion occasion for each female and male Angled Castor.
A newly eclosed feminine Angled Castor resting on its pupal case
within the subject.
A newly eclosed male Angled Castor resting on its pupal case.
A newly eclosed feminine Angled Castor resting on its pupal case.
An fascinating truth. All 5 instars of the Angled Castor larval stage have the behavior of forcefully ejecting their frass pellets. This isn’t a typical characteristic amongst butterflies. Beforehand, we have now solely noticed this behaviour in members of the Ypthima and Mycalesis genera, in addition to Discophora sondaica (Widespread Duffer).
Forceful ejection of frass pellets by caterpillars of the Angled Castor.
[C&P5] The Butterflies of The Malay Peninsula, A.S. Corbet and H.M. Pendlebury; G. and N. van der Poorten (Eds.), fifth Version, Malayan Nature Society (2020).
Butterflies of Thailand, Pisuth Ek-Amnuay, 2nd Version, 2012.
- Okay. Saji, H. Ogale and M. Bhakare. 2021. Ariadne ariadne (Linnaeus, 1763) – Angled Castor. Kunte, Okay., S. Sondhi, and P. Roy (Chief Editors). Butterflies of India, v. 3.06. Indian Basis for Butterflies.
Textual content by Horace Tan, Photographs by Loh Mei Yee, Khew S Okay and Horace Tan, Movies by Horace Tan.