(Figures 2G–I; 3G–I)
Holotype. ♂, Cambodia, Prov. Pursat (Osam), 3 May 2010 (Bae, Chae and Vi), gen. slide no. CIS-6066 / Park.
This species is superficially similar to T. aritai Park, but the basal part of the forewing is darker than that of the latter, and the distance between R 1 and R 2 is about 1.5 times that between R 2 and R 3, whereas in T. aritai, the distance of R 1 –R 2 is about twice that of R 2 –R 3, It can be easily distinguished by the male genital structure as follows: the valva more elongate, without conic particles on ventral surface, with a crescent sclerite separating basal part and cucullus, and the aedeagus nearly straight.
Adult (Figure 2G–I). Wingspan 17 mm. Head, tegula, and thorax dark fuscous dorsally. Basal segment of antenna orange white, densely speckled with dark fuscous scales dorsally; flagellum orange white, with distinct brownish annulations beyond four-fifths of length. Second segment of labial palpus thickened, dark brown in basal two-thirds length on outer surface with orange-white apex, orange white on inner surface; third segment slender, as long as second segment, dark brown on ventral surface. Forewing evenly covered with dark brown scales throughout, with blackish reniform stigma at end of cell; costa gently arched before quarter of length, then nearly straight medially, slightly arched beyond three-quarters of length, with a small triangular orange-white costal patch at three-quarters of length; apex obtuse; termen oblique, sinuate, with blackish scales along margin; fringe the same colour throughout. Venation with R 1 arising before middle of cell; R 1 arising before middle; R 2 close to R 3 at base; R 3 and R 4 stalked for half their length; R 4 and R 5 stalked beyond two-thirds of length; R 5 to termen; M 2 close to M 3; M 3 and CuA 1 stalked for half length. Hindwing brownish grey, broader than forewing; venation with Rs and M 1 short-stalked; M 3 and CuA 1 also short-stalked. Hind tibia with dark-brown scales dorsally, with orange-grey apex.
Male genitalia (Figure 3G–I). Uncus heavily sclerotized, stout, gently bent downward, with round apex. Gnathos relatively short, strongly bent median process. Valva broad basally; costa gently concave beyond one-fifth; ventral margin with slightly expanded median lobe; cucullus elongate, slightly upturned before apex; apex more or less acute. Juxta with semiovate free flap in distal part. Saccus rounded anteriorly. Aedeagus nearly straight, as long as valva, with more than 10 short spines in vesica.
Cambodia (Pursat Prov.).
The species name is derived from the Latin, occidental, meaning “western”.