TRIBE ORTHOSTIXINI
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Naxa Walker

Type species: textilis Walker, Bangladesh.

Synonyms: Desmonaxa Prout (type species angustaria Leech, China); Psilonaxa Warren (type species taicoumaria Orza, Japan).

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 the ostium.

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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