Type species: textilis
Synonyms: Desmonaxa Prout
(type species angustaria Leech, China); Psilonaxa Warren (type species taicoumaria
This genus contains a
number of Oriental species all with very similar translucent white, rounded
wings with rows of dark greyish spots on the veins marking the course of the
postmedials and, on the forewing only, the antemedial. On both wings there is a
similar row of marginal spots set in the spaces. Both male and female antennae
are narrowly bipectinate. The frenulum is weak or absent. There is a large
areole formed by the radial system of the forewing; M1 arises independently from
this. In the male genitalia
the valves are simple, with the costa more stongly sclerotised; the juxta is
strap-like, apically asymmetrically bifid; gnathus and socii are absent. The
aedeagus is slender, the vesica without cornuti but finely scobinate.
The female has the
ovipositor lobes and eighth segment simple. The bursa is ovate-spherical with an
irregular signum of ennomine type, though not the stellate mushroom form. The
ductus is long slender, the basal half more sclerotised, expanding but towards
Bell (MS) described the
biology of the type species.
The egg is ovoid with
broad ends, shining dirty yellow with irregular purplish blotches. The surface
is covered with minute, shallow, hexagonal cells.
The larva is
cylindrical, the surface smooth, velvety, the setae long, white, conspicuous,
arising from tubercles. The colour is pinkish brown, with white dorsolateral
lines broken by black dorsal patches on the posterior halves of segments A1-4,
the patch bordered posteriorly by white on A3 and A4. There is a subspiracular
white line and a dorsal dark one. The larva of the Japanese N. seriaria Motschulsky,
illustrated in Sugi (1987), is similar in appearance.
The pupa is claviform,
the cremaster having eight shaftlets. It is a creamy ivory colour, streaked and
dotted with black in a similar manner to the Japanese species.
The larvae are found
colonially, sometimes in hundreds, suspended in extensive webs among the leaves
of the host. They feed on the leaves within the web and also pupate there, the
pupae exposed, suspended by anterior hooks and tubercles as well as by the
cremaster. The eggs are laid in masses amongst the silks of the old larval web. N.
seriaria has similar biology and behaviour.
N. textilis is recorded from Olea (Bell), N. seriaria from Ligustrum
(Nakajima & Sato, 1979; Sugi, 1987), both Oleaceae.
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