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Nagadeba Walker
Type
species: indecoralis Walker, Java, India, Burma,
Andamans.
The
type species has an external appearance like a smaller and more slender Chrysograpta Hampson (p.
324), though in a darker, duller colour without yellow highlights. It shares
with the previous genus and the next a conspicuously pale orbicular stigma on
the forewing undersides and reduction of the phragma lobes of the second
tergite. The male abdomen has the eighth segment unmodified. The genitalia have
a well developed saccus. The valves are divided into three distally, somewhat
as in Metaphoenia Hampson (p. 367). The aedeagus vesica contains one
long, slender cornutus. The female genitalia have the ostium and the ventral
part of the eighth segment pulled anteriorly into a deep cleft within the
seventh sternite, which is considerably reduced. This appears to be the only
feature that unites several rather disparate species currently within the genus
and, as stated above, is shared by the Throana group as a
whole.
Other
species associated with the genus (Poole,
1989) appear to differ considerably, though not all have been examined here.
The only Bornean species previously assigned to this genus, celenoalis Walker, has very different, pale facies
on much deeper wings that show sexual dimorphism as described below.
The
male abdomen has the eighth segment modified from the framed corematous
pattern, the tergite broadened and the sternite deeply cleft posteriorly,
rendering the anterior lacuna vestigial. The genitalia are unusual with short
valves that have rasp-like processes from the base of the costa and from the
sacculus. The aedeagus is short, and the anellus is voluminous; the vesica is
large, at right-angles to the aedeagus, with a large, slender cornutus.
The
female genitalia show the generic and wider group feature having the ostium and
ductus associated with the seventh segment, where the sternite appears to be
vestigial. The ductus is short, the corpus bursae spherical, with some
scobination and sclerotisation in its basal half. The position of the ostium
within the seventh segment is also one feature that transfers geminipuncta Hampson from Egnasia to Nagadeba.
The
type species was reared by Bell (MS) in India. The larva is a
spindle-shaped, semi-looper, fattest centrally. The prolegs on A3 are absent.
The head and body are green, the former with areas of brown dots, and the
latter with most setae except the subdorsals arising from black spots. There is
a darker dorsal line and a thin yellow or white one through the spiracles which
are small, yellowish, with shining black rims. The young larvae are very
active, flipping off the foliage if alarmed and dropping on a silk thread.
Pupation is on the ground in a cell of silk incorporating particles of
detritus.
The
host plant is Mussaenda (Rubiaceae). This host is also noted for N. cinerea Hampson in the
Andamans (unpublished IIE records).
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