Risoba obstructa Moore, 1881, Proc. zool. Soc. Lond., 1881: 328.
Bethune-Baker, 1906, Novit. zool., 13: 234,
Diagnosis. This species is a smaller, greyer version of the prominens/olivens
pair in the vialis group discussed below. The forewing apical brown patch
is narrower, with the section of the submarginal adjacent to it more oblique.
The postmedial meets the dorsum obliquely, with an acute angle distad and a
slight kink. In olivens this line curves round distad to meet the dorsum
with an acute angle basad; prominens is somewhat intermediate as
discussed below. See the generic introduction for distinctive features of the
male genitalia which are very different from those of members of the vialis
Taxonomic note. The male genitalia of obstructa and grisea
appear identical, with features described in the generic introduction and
Geographical range. Sri Lanka, India, Thailand, Borneo, Java, Philippines,
Sulawesi, New Guinea, Queensland, Solomons (Bougainville).
Habitat preference. The three specimens seen are from Brumas and Tampanuli
in Sabah, both lowland localities.
Biology. Bell (MS) and Gardner (1941, 1948a) recorded the larva in India,
and Moore (1883) illustrated it from Sri Lanka. It has a transverse hump on A8.
The body in Sri Lanka is purplish brown with dorsal and lateral broken white
lines and a sublateral row of whitish streaks. The banding in S.India (Bell) is
yellowish white to orange. Bell described the behaviour; it is similar to that
of basalis (see above).
Host plants recorded by these authors and others (Robinson et al., 2001)
are species of Quisqualis, Terminalia (Combretaceae), Xylia
(Leguminosae), Lagerstroemia (Lythraceae) and Sterculia
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