Phalaena delia Cramer, 1780, Uitl. Kapell. 3:172.
Orsonoba rajada Walker, 1860, List Specimens lepid. Insects
Colln Br. Mus., 20: 219.
Diagnosis. In Borneo, the male of clelia is a uniform reddish tint rather
than pale cream marked with grey and ochre-yellow as in G. pallida Butler.
The females are much more similar but also generally redder in clelia. In
the male genitalia the processes of the tegumen are longer and slightly more
delicate in pallida. The aedeagus apex is strongly spined in clelia but
only weakly so in pallida. In the aedeagus vesica clelia has a
scattering of about six small peg-like cornuti, whereas pallida has two
or three larger cylindrical ones with several distal cusps, and often a few
smaller ones. Xylinophylla species can be distinguished readily in the
male by the ciliate (other than bipectinate) antennae, and in the female by the
straight fasciae cutting off the irregular margin of the hindwing.
Geographical range. Sri Lanka, S. India, Andamans, Singapore, Borneo.
Habitat preference. A series was taken by Major Tim Helps in an extensive
area of mangrove in the Bay of Brunei. No other Bornean material has been
Biology. The early stages were described by Bell (MS). The larva is cylindrical,
slender, tapering from T3 to the head and being thickest at A9. It is a light,
rather ochreous brown when mature, with a large dark brown, saddle-like patch on
AS, extending forward to the dorsolateral chalazae of A4; the venter is darker.
The setae are set on chalazae, the dorsolaterals of A2 more prominent than the
rest and set on erectile fleshy ovoid bags. Smaller bags occur on A3 and A4. In
the second instars these processes are most prominent, equal in size, on A2 and
A3, orange with a yellow tip, contrasting with the rest of the larva which is
velvety black. They are about as high as the body is broad. Setae and chalazae
in the first instar are white, but change to black in later instars. Subsequent
instars resemble the mature larva. The larva is illustrated by Murphy (1990).
The larva at rest holds itself at 45 degrees to the stem, petiole or
leaf edge which it grasps with its claspers. Early instars will fall off the
host-plant if alarmed, suspended on a silken thread. Pupation is in a cocoon
incorporating particles of substrate. It occurs in a crevice or other secluded
The adult resting posture was noted as unusual by Bell. The body only
touches the substrate posteriorly, with the thorax raised by the front legs.
Each hindwing is spread out horizontally with the dorsum touching the body, so
that the plane of the wings is oblique, following the line of the body. The
forewings are also held out horizontally but longitudinally downflexed centrally
such that anterior and posterior margins are directed upwards at an angle of 100
degrees to each other. The angle between the forewing dorsum and the hindwing
costa is also 100 degrees so the wings are well separated. The insect thus
resembles a withered dead leaf. The wings are fanned slowly up and down if the
moth is alarmed.
The eggs are laid in small crevices in any substrate. The long, narrow
structure of the ovipositor lobes is consistent with this.
Host-plants recorded were Eugenia (Myrtaceae), Olea (Oleaceae)
and Ricinus (Euphorbiaceae). The species has also been reared from Sonneratia
alba (Sonneratiaceae), Aegiceras (Myrsinaceae), Avicennia (Avicenniaceae),
and Allophylus (Sapindaceae) in mangrove in Singapore by Murphy (1990)
and from Excoecaria (Euphorbiaceae) in the Andamans.
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