05 July 2008

Life History of the Hieroglyphic Flat

Life History of the Hieroglyphic Flat (Odina hieroglyphica ortina)

Butterfly Biodata:
Genus: Odina Mabille, 1891
Species: hieroglyphica Butler, 1780
Sub species: ortina Evans, 1941
Wingspan of Adult Butterfly: 32mm
Caterpillar Host Plants:
Erycibe tomentosa (Convolvulaceae)

Physical Description of Adult Butterfly:
Male is yellow-orange, with yellow-orange markings framed by thick black lines on both wings. Female is paler yellow.
The underside markings are similar in pattern but paler. The abdomen of the butterfly is stripped in orange and black. The Hieroglyphic Flat is a very distinctive-looking skipper, with the cryptic patterns reminiscent of the camouflage paint of a German Messerschmitt fighter plane in World War II.

Field Observations of Butterfly Behaviour:
This species is rarely encountered in Singapore. Over the last few years, it has been sighted in a dozen times in various areas in the Central Catchment Area, Southern Ridges and in an abandoned farm land in the west. It is a fast-flyer and can only be observed when the adults stop to feed on flowers and bird dropping, or when the females are carrying out oviposition routines of leaf hopping. When resting, as with other "flat" skippers, the adults have the habit of perching on leaf undersides.

The Hieroglyphic Flat feeding on bird dropping on a board walk (left),
and taking nectar in an open wasteland (right).

Early Stages: The host plant, Erycibe tomentosa, is a woody climber, and locally can be found on hedges, edges of forests and sides of forest trails, in areas such as the Central Catchment Area and Southern Ridges. On one occasion, Sunny Chir, an active Buttercircle member, chanced upon a female laying eggs on the host plant at the edge of the nature reserve, close to a row of private houses.

Host plant : Erycibe tomentosa

The eggs are laid singly at the leaf tip of a young leaf or mid-age leaf. Each egg is white and almost spherical with vertical ridges, and has a diameter of 0.8mm. As with other "flat" (such as the Chestnut Angle) skippers, the mother rubs the tip of her abdomen over the freshly laid egg, resulting in the egg being concealed in a mess of fine brown hairs.

Two views of the hairy eggs of the Hieroglyphic Flat.

Empty egg shell of the Hieroglyphic Flat.

It takes 3 days for the egg to hatch. The young caterpillar eats just enough of the shell to emerge, and has a length of about 2mm. It has the typical cylindrical shape for skipper caterpillars. It body is yellowish orange with a transverse black line right behind a black bilobed head.
After leaving the egg shell, the 1st instar caterpillar makes its way to the leaf edge to construct its first leaf shelter. It rests within the shelter and ventures out to eat the leaf surface nearby. The intake of this diet gives the caterpillar a greenish undertone.

1st instar caterpillar, length: 2mm

A view of the leaves of the host plant, showing the location of an
empty egg shell, and small leaf shelter for the 1st instar caterpillar.

As with some other skipper species, the Hieroglyphic Flat caterpillars have been observed to ballistically eject their somewhat sticky faecal pellets (frass) at speed. In a home breeding environment, this also results in a splatter of frass on the inner side of the container wall next to the leaf shelter.
After 3 days in 1st instar and reaching a length of about 4mm, the caterpillar moults to the next instar within the shelter. It still has the same light yellowish body with a green undertone, but now numerous tiny whitish speckles become apparent. It reaches a length of about 6mm after 5 days of growth in this instar.

2nd instar caterpillar, 4mm

2nd Instar caterpillar, 6mm.

A 2nd Instar caterpillar almost done with the cut of the leaf blade in the construction of its leaf shelter.

The 3rd instar caterpillar has a similar appearance as in the previous instar. The 3rd instar lasts about 3-4 days with the body length reaches 10-11mm. The leaf shelters for the larger caterpillars in 3rd and later instars are made from bringing two edges of the leaf together with sinuous cuts and silk threads, resulting in a ``curry puff'' appearance.

3rd instar caterpillar, early in this stage, length: 7mm

3rd instar caterpillar, late in this stage, length: 10mm
The 4th instar caterpillar looks similar to the earlier instars with the only visible difference being the much more distinctive speckle pattern on its body, and two rows of small black spots dorsally on the first seven abdominal segments, with two spots to each body segment. The 4th instar takes about 4 to 6 days to complete with the body length reaching 17-18mm.

4th instar caterpillar, early in this stage, length: 10mm

4th instar caterpillar, ready to moult to the next stage, length: 15mm.

The head capsule of the final and 5th instar caterpillar has a brown or dark brown base color with pale brown to orange patches. The surface of the head capsule is covered with a layer of short fine hairs. Growth in this stage is rather slow and it takes about 14-15 days to complete with the body length reaching about 24mm.
5th instar caterpillar, newly moulted to this stage, 15mm

5th instar caterpillar, late in this stage, length: 24mm

At the end of 5th instar, the body of the caterpillar gradually shrinks in length. Soon it becomes dormant in its leaf shelter and enters the prepupatory phase which lasts for one day.

Two views of a pre-pupatory larva of the Hieroglyphic Flat.

Pupation takes place within the leaf shelter. The pupa secures itself with its cremaster attached to a short transverse band on the leaf surface, and has a silk girdle. The pupa is mostly green in base colour. It has a short thorax, a rather long abdomen and a pointed rostrum. Length of pupae: 16-18mm.

Two views of a fresh pupa of the Hieroglyphic Flat.

After 9 days, the pupa becomes mostly black in color with the cryptic patterns on the forewing somewhat distinguishable through the now transparent pupal skin. Eclosion takes place the next day.

Two views of a mature pupa of Hieroglyphic Flat.

A newly eclosed Hieroglyphic Flat.

  • The Butterflies of The Malay Peninsula, A.S. Corbet and H.M. Pendlebury, 4th Edition, Malayan Nature Society.
  • The Butterflies of Hong Kong, M. Bascombe, G. Johnston, F. Bascombe, Princeton University Pres 1999
Text and Photos by Horace Tan