Stictoptera illucida Walker,
1865, List Specimens lepid. Insects Colln. Br. Mus. 33: 918.
Lophoptera illucida Walker;
Holloway, 1976: 19.
species is recognised by the dark brown, almost black semicircle at one third on
the forewing dorsum; only rarely is this obscured with rufous in Bornean
specimens which might lead to confusion with leucostriga (with a much
more developed lenticular submarginal) or ferrinalis (with a more
elongate rufous zone). The semicircle is often associated with a white patch,
slightly distal and anterior to it (illustrated). Other forms, rare in Borneo,
have the central zone of the forewing longitudinally paler or a purplish tone to
the forewing with pale patches at the tornus and centre of the margin (both
Taxonomic note. A
closely related, undescribed species with a striking hyaline base to the
hindwing flies in New Guinea.
tropics to Peninsular Malaysia and Borneo.
G. Kinabalu it was frequent at 1200m. During the Mulu survey it was frequent in
upper montane forest on G. Mulu but rare at lower altitudes, common at Long Pala
where the trap was set on a limestone outcrop overlooking alluvial forest
canopy, and frequent all over the transect of G. Api. A singleton was taken at
1620m in upper montane forest on Bukit Retak, Brunei.
Biology. The larva has been described by both Bell (MS) and Gardner (1948a). The
descriptions differ slightly. The following is taken from Bell with Gardner's
observations in square brackets.
The larva is cylindrical, narrowing somewhat towards the head. The head
is pale yellow [brown] with a black crescent from the antennal bases that curves
towards the clypeus. The body is green [yellow], marked variously with dull,
dark purple [black], sometimes only in an irregular lateral patch, sometimes
extending broadly down the flanks and, at the anterior of each segment, over the
dorsum. The first thoracic segment is always pure green above the lateral line
and has a narrow black anterior margin. [The legs and prolegs are pale, the
latter brownish apically, and the spiracles have fine brown rims.]
Bell's larvae were brought in moulting to the final instar in cells
formed by folding young leaves of the host-plant, the folds fixed by regular
walls of dense, pure white silk. The larva feeds in the young leaves, often
within a loose cell of the same nature. It turns pink prior to pupation which is
in the soil in an ovoid cocoon of grey silk coated with earth particles and
fitting the pupa closely. The pupation time is about two weeks.
Both recorded host-plants are in the Dipterocarpaceae: Shorea robusta
(Sevastopulo, 1941; Gardner) and Hopea wightiana (Bell).
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