Erosia mutans Butler, 1887, Ann. Mag. nat. Hist. (5),
Erosia conscripta Lucas, 1894, Proc. Linn. Soc. N.S. W.
Dirades annulifer Warren, 1896, Novit. zool., 3: 274.
Dirades seminigra Warren, 1896, Novit. zool., 3: 346, syn.
Diagnosis. As with the previous two species, the forewing postmedial enables the
sexes to be associated and the species distinguished. It is strongest across the
apical half, weakly concave distad, and delineated paler. In other species it is
convex and usually darker, except in erosioides and acutilinea. The
hindwings are purplish brown in both sexes, the postmedial straight in the male
but right-angled in the female. The female has a longitudinal pale streak to the
hindwing that bisects this angle. The female genitalia are unusual in lacking a
signum, the bursa being generally finely scobinate. The base of the ductus and
ostium are broadened, shaped somewhat as in a wine glass.
Taxonomic notes. P. lugens Warren comb. n. (Samoa) appears to be closely
related to mutans but with a straighter forewing postmedial. The
Australian 'male' in the original description of lugens has female
hindwing facies, venation and frenulum, lacks a head and has a damaged abdomen,
so it would thus be advisable to designate the Samoan specimen as LECTOTYPE. The
Australian specimen may well be mutans. P. seminigra Warren (Queensland;
based on females only) is conspecific with mutans, having the typical
genitalic features mentioned above. P. rhombifera Warren comb. n. (Timor)
appears to be distinct, based on a female with a much less strongly angled
hindwing postmedial. These observations are somewhat at odds with the systematic
arrangement in Nielsen, Edwards & Rangsi (1996), and further revision of
this group of taxa may be necessary.
Geographical range. Sundaland to Queensland and Solomons.
Habitat preference. The only Bornean material seen is from Bidi in the
lowlands of Sarawak.
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