Type species: semifascia Hampson
This genus, along with Ceratonema Hampson, has Darna-type forewing
venation and filiform male antennae. The species assigned to these two genera
are a miscellaneous assemblage sharing the two characters just mentioned. They
need revision. The generic description here is restricted to characters of the
The forewing is divided by an oblique white line running from the apex
to the centre of the dorsum, gently curved in the female, more sinuous and
broken in the male. Basal to it is a pale ochreous zone and distal to it a
darker brown zone.
The male genitalia of Ceratonema retractata Walker, the type
species, are as in the ground plan. In Trichogyia the uncus and gnathus
are invested apically with setae that oppose each other. The valve is adpressed
to the vinculum in the saccular zone, with the slender apical process free,
splaying slightly. The sacculus has a spur. This incipient division of the valve
may be homologous with the more extreme condition in Limacosilla; the
valve of Olona Snellen is of intermediate development.
The female genitalia have the ductus spiralled, thus relating the Darna
group to the three generic groupings already discussed; Ceratonema
caustiplaga Hampson also has the ductus spiralled. The signum is a single
circular scobinate patch of sclerotisation as in Limacosilla; in C.
caustiplaga there is a sparse subbasal ring of short, broad spines. The
lateral ampullae of the eighth segment (see family
Limacodidae) are sclerotised, and acute
rather than flexible, blunt and membraneous. The distal part of the eighth
segment is produced on each side into a triangular process bearing setae
The larva is described in the specific account.
Trichogyia gateri West (Peninsular Malaysia, Sumatra) is congeneric with Olona
albistrigella Snellen (Java) and is therefore combined with Olona comb.
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