Thylacosceles Meyrick, 1889

Thylacosceles Meyrick, 1889: 171 . Type species: Thylacosceles acridomima Meyrick, 1889, by monotypy.

Generic characters. Adults small sized. Head (Fig. 1) smooth, vertex with a transverse fillet; occiput broad and flat, about 1.3 times length of eyes' diameter, with longitudinally lined scales. Antenna shorter than forewing; scape elongately clubbed; flagellum filiform, stouter in male than in female, with extremely short cilia. Labial palpus (Fig. 2) ascending, third palpomere usually shorter than second, pointed apically. Maxillary palpus extremely short. Forewing lanceolate, more or less uniform in color, costal margin usually with a large distal spot. Venation (Fig. 8): R1 arising from basal 3/4 of upper margin of cell, R4 and R5 stalked for basal 2/5, R5 reaching costa before apex, CuA1 arising from lower angle of cell, CuA2 from basal 2/3 of lower margin of cell, 1A+2A not furcate basally. Hindwing narrow lanceolate; cilia about six times width of wing, Rs and M1 approximated at base, M2, M3, CuA1 and CuA2 subparallel. Hindleg (Fig. 3) upturned and arched, forming a right angle in lateral view when in rest; hind tibia with mid spurs located at basal 1/3, dorsally with a tuft of long bristles from basal 1/3 to near apex, forming a triangular shape in lateral view, with whorls of dark bristles at apex. Abdominal tergites II–VII in male and II–VI in female with spines arranged in a slightly arched line along posterior margin (Fig. 9).

Male genitalia: Gnathos slightly shorter than uncus. Tegumen branched from posterior portion and gradually narrowed to pointed anterior end. Valva usually with ampulla. Aedeagus stout; cornutus present or absent.

Female genitalia: Antrum developed. Ductus bursae usually shorter than antrum. Corpus bursae with signum.

Diagnosis. This genus is similar to Thylacosceloides Sinev, 1988 superficially by sharing a broad and flat occiput, but can be distinguished by the occiput having no deep longitudinal groove in male; in Thylacosceloides, the occiput has a deep longitudinal groove in male medially.

Distribution. Australian and Oriental regions.