Nyssia vetusta Walker, 1862, J. Linn. Soc. Lond. (Zool.)
Nyssia biguttata Walker, 1862, Ibid 6: 145.
Thosea vetusta Walker; Hering, 1931: 713, Holloway, 1976: 91,
Barlow, 1982: 38.
Diagnosis. This species is sexually dimorphic as illustrated. The postmedial is
more oblique than in other species and marks a greater contrast between the
ground colour on each side. The genitalia, illustrated by Holloway (1976), have
a lobe subcostally on the valve and the sacculus is stepped out from the valve
in an angular manner.
Geographical range. Sundaland, Sulawesi.
Habitat preference. The species has been recorded mainly in the lowlands
but one was taken at over 1000m on G. Kinabalu.
Biology. The larva has been illustrated by Wood (1968) and in above. In shape
and ornamentation it is typical of the genus. It is pale blue-green with a
narrow yellow dorsal stripe that is broken, broader in the two posterior
fragments. The breaks are at one third from the front and over a slightly longer
interval, at two fifths. The dorsal yellow band is edged laterally by
fluctuating thin dark blue lines, replaced by deep orange centrally on the
middle, rather oval fragment. Some variants have the dorsal yellow line unbroken
but still edged with blue dashes and with orange lenses centrally. (M.J.W. Cock,
photo). It has been reared from oil palm (Elaeis), Musa (Musaceae), tea (Camellia;
Theaceae) and Acorus (Araceae) (Wood; Kalshoven, 1981 ; CIE records).
on oil palm in Peninsular Malaysia (M.J.W. Cock)
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