22 June 2013

Life History of the Banded Demon

Life History of the Banded Demon (Notocrypta paralysos varians)


Butterfly Biodata:
Genus: Notocrypta de Nicéville, 1889
Species: paralysos Wood-Mason & de Nicéville, 1881
Sub-species: varians Plötz, 1882
Wingspan of Adult Butterfly: 33-36mm
Caterpillar Local Host Plant: Costus lucanusianus (Costaceae, common name: African Spiral Flag).




Physical Description of Adult Butterfly:
Above, the wings are dark brown. The forewing has a large white band consisting of conjoined spots in spaces 1b, 2 and the distal end of the cell. There is usually a small white hyaline spot in space 4 of the forewing. The hindwing is unmarked. Underneath, the wings are brown and dusted with purplish scales next to the termens. The purplish hue is more readily observed in pristine specimens. The antenna has a pale whitish band just below the club.



Field Observations of Butterfly Behaviour:
Banded Demon is moderately common in Singapore. The adults are rather localized and are typically found in the vicinity of its host plant in the fringe of the nature reserve. The adults are fast fliers among the ground cover and shrubbery. They visit flowers for nectar, and at times perch on sun-bathing spots with half-open wings.





Early Stages:
Thus far the early stages of Banded Demon are found to utilize only one local host plant in the Costaceae family. It is likely that other plant species in the Zingiberaceae and Costaceae families are utilized as well. The caterpillars feed on leaves of the host plant, and live in leaf shelters constructed by cutting and folding and securing leaf fragments with silk threads. As the caterpillar grows in size, it will abandon the current shelter and proceed to construct a bigger one.

Local host plant: Costus lucanusianus (African Spiral Flag).

Leaf shelters for various instars of the Banded Demon found on its host plant in the field.

The eggs of the Banded Demon are laid singly on the upper surface of a leaf of the host plant. The hemispherical egg is wine-red mottled with milky white patches. It has a base diameter of about 1.25-1.30mm.

Two views of an egg of the Banded Demon.

Two views of a mature egg, with the caterpillar's head visible through the hole in the shell in the right view.

The egg takes about 4.5 days to hatch. The newly hatched has a length of about 2.8-3.0mm and has a black head capsule and a orange-colored body. A black collar mark lies just behind the head on the dorsum of the prothoracic segment. A few relatively long setae are present at the posterior end.

Two views of 1st instar caterpillar, early in this stage, length: 3mm.

After hatching, the young caterpillar eats the empty egg shell for its first meal, and then moves on to construct its first leaf shelter, typically at the leaf tip. From the shelter, it then ventures out to eat the nearby leaf lamina for subsequent meals. The body takes on a green undertone as a result. The growth in this first instar is moderately paced and the body length reaches about 5mm in about 3-3.5 days before the moult to the 2nd instar.

Two views of a 1st instar caterpillar, late in this stage, length 6.2mm.

A late 1st Instar caterpillar, dormant before its moult.

The 2nd instar caterpillar is yellowish green in body colour. The head capsule is still black, but the black collar mark on the prothorax is now absent. At the posterior end, the relatively longer setae are longer present, and the anal plate is unmarked. This instar lasts about 3 days with the body length reaching 8-9mm.

Two views of a 2nd instar caterpillar, early in this stage, length 5.8mm.

A late 2nd instar caterpillar, dormant prior to its moult, length: 8.8mm.

The 3rd instar caterpillar is pale yellowish green. Otherwise it resembles the 2nd instar caterpillar closely. The anal plate is still unmarked, and the head is still entirely black. This instar takes about 3 days to complete with body length reaching about 14-15mm.

Two views of a 3rd instar caterpillar, early in this stage, length 9mm.

Two views of a 3rd instar caterpillar, length 10.5mm.

A late 3rd instar caterpillar, dormant prior to its moult, length: 14mm.

The 4th instar caterpillar is little changed from the 3rd instar in terms of body markings and coloration. This instar takes about 3 days to complete with body length reaching about 23-24mm.

Two views of a 4th instar caterpillar, early in this stage, length 14mm.

Two views of a 4th instar caterpillar, late in this stage, length 22mm.

A late 4th instar caterpillar, dormant prior to its moult, length: 23mm.

The 5th and final instar caterpillar is mainly pale yellowish to whitish green. The black head capsule has pale brown patches on the two sides of the coronal sulcus. These pale brown patches vary in size and can reach as far down as to the mandibles. The 5th instar lasts for about 5 days, and the body length reaches up to 37-39mm.

Two views of a 5th instar caterpillar, early in this stage, length 25mm.

Two views of a 5th instar caterpillar, late in this stage, length 35mm.

The heads of two 5th instar caterpillars, showing the pale brown patches in two variations.

On the last day of the 5th instar, the body of the caterpillar shortens and changes to a milky shade of yellowish green. It ceases feeding and comes to a halt on the surface of a leaf of the host plant. Here the caterpillar spins a short transverse silk band and a silk girdle. At the same time, a moderate amount of white waxy substance is secreted by the caterpillar and spread over the pupation site. With its posterior end secured to the silk band via claspers and the body secured at the mid-section with the girdle, the caterpillar enters its immobile pre-pupatory stage.

A pre-pupatory larva of the Banded Demon.

Pupation takes place about 1.5 day later. The yellowish green pupa secures itself with the same silk girdle as in the pre-pupal stage, but with the cremaster replacing claspers in attaching the posterior end to the transverse silk band. The long and slender pupa has a long rostrum and is unmarked. Length of pupae: 28-30mm..

Two views of a pupa of the Banded Demon.

Two views of a mature pupa of the Banded Demon.

After about 7 days of development, the pupa turns black as its skin turns translucent with the development within the pupal case coming to an end. The white band in the forewing are now discernible in the wing case. The following day, the adult butterfly emerges from the pupal case.

A newly eclosed Banded Demon clinging onto its empty pupal case.

References:
  • [C&P4] The Butterflies of The Malay Peninsula, A.S. Corbet and H.M. Pendlebury, 4th Edition, Malayan Nature Society.
  • Butterflies of Thailand, Pisuth Ek-Amnuay, 2nd Edition, 2012
  • A Field Guide to the Butterflies of Singapore, Khew S.K., Ink On Paper Communications, 2010.

Text by Horace Tan, Photos by Jonathan Soong, Lemon Tea Yi Kai, EC Goh, Anthony Wong and Horace Tan.

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