Deltoplastis causidica (Meyrick, 1910)

(Figs. 2 d, 4c, 7b)

Onebala causidica Meyrick, 1910: 451. TL: Assam, India.

Deltoplastis causidica (Meyrick, 1910): Meyrick, 1925: 228; Gaede, 1937: 506; Clarke, 1965: 36.

Material examined. China: Hainan Province: 1♀, Qixianling, 10.XI.2009, coll. Bingbing Hu & Jing Zhang; 1♀, Jianfengling Nature Reserves, Ledong County, 770 m, 7.VII.2014, coll. Peixin Cong, Linjie Liu & Sha Hu; Sichuan Province: 1♀, Mabian Yonghong, 1500 m, 23.VII.2004, coll. Yingdang Ren. Thailand: 1♂, Nakhon Nayok, Khao Yai, 800 m, 23.IX.1987, coll. S. Moriuti, T. Saito, Y. Arita & Y. Yoshiyasu; 1♀, Nakhon Nayok, Khao Yai, 800 m, 19.VI.1983, coll. S. Moriuti, T. Saito, Y. Arita & Y. Yoshiyasu; 1♀, Loei Province, Phuluang Wildife Sanctuary, 700–900 m, 8‒14.X.1984, coll. O. Karsholt, O. Lomholdt & E. Nielsen; Nakhon Nayok Province, Khao Yai, 700 m, 29.IX‒6.X.1984, coll. O. Karsholt, O. Lomholdt & E. Nielsen. O. Lomholdt & E. Nielsen.

Male genitalia (Fig. 4 c): Uncus relatively broad at base, gradually narrowed to blunt apex, slightly curved toward ventral surface. Gnathos wide at base, slightly narrowed to about 3/5, then curved ventrad by a right angle, distal 2/5 sharply narrowed to a point tip. Valva broad at base, about twice as broad as its median part; costa with basal 1/4 obliquely straight, then deeply concave in an arch; ventral margin with basal half straight, concave beyond end of sacculus; sacculus triangular, reaching about middle of ventral margin; cucullus obliquely upturned, triangular, narrowed to rounded apex, ventro-distal corner bluntly rounded, obliquely straight on outer margin. Juxta nearly quadrate, with a horizontal sub-semicircular ridge on posterior 1/3, anterior margin convex medially, caudal margin nearly straight; caudal lobe short, digitate, slightly curved inwardly, about 1/4 length of juxta. Vinculum narrowly banded. Aedeagus stout, as long as valva, curved at basal 1/4, straight distally; cornuti consisting of a number of variably sized spinules spreading from near base to before apex.

Diagnosis. Adult (Fig. 2 d) with wingspan 17.0– 22.5 mm. This species is superficially similar to the new species D. acutiprocessa sp. nov., but can be distinguished by the juxta bearing a horizontal sub-semicircular ridge on posterior 1/3, the digitate caudal lobes about 1/4 length of the juxta, and the aedeagus with cornuti consisting of numerous unequally sized spinules spreading from near base to before apex and without denticles on the ventral surface in the male genitalia (Fig. 4 c). In D. acutiprocessa, the juxta has one triangular process on the caudal margin at middle and the caudal lobes are papillate, and the cornuti of the aedeagus consist of numerous spinules in distal half and the aedeagus bears denticles on the ventral surface (Fig. 6 a).

Distribution. China (Hainan, Sichuan), India, Thailand, Vietnam.

Note. This species is recorded for the first time from China and Thailand; and the male is described for the first time.