Leucophenga flavicosta Duda, 1926

(Figs. 2 B, 3C, 3D, 7C, 11)

Leucophenga subpollinosa var. flavicosta, Duda, 1926: 53 .

Leucophenga flavicosta Bächli, 1971: 59; Lin & Wheeler, 1972: 245; Okada, 1987: 679.

Diagnosis. This species differs from the other species of the subpollinosa group by having the wing fuscous along R1 only (Fig. 2 B), the halter yellow at base and stem, mostly dark brown at knob (Fig. 3 C, D), and the aedeagus slightly concaved on posteroventral 1/3, ventrolaterally with a thin process bearing a sensillum at tip (Fig. 11 D).

However, the only male specimen shows distinctly difference from the latest and most relevant descriptions about L. flavicosta (from Taiwan, China in Lin & Wheeler 1972; from Palau in Okada 1987) in the color patterns of abdominal tergites (Fig. 7 C), while the aforementioned characters of wing (Fig. 2 B) and halter (Fig. 3 C, D) are consistent with their descriptions (Lin & Wheeler 1972; Okada 1987), which are unique in the subpollinosa group. Therefore, the only male specimen was identified as L. flavicosta to avoid further confusion.

Description. Ocellar triangle brown, with ca. 2 setae above ocellar setae. Frons brownish yellow, with three indistinct, brownish, longitudinal stripes medially and laterally. Pedicel and first flagellomere brownish yellow. Clypeus brownish yellow medially, brownish laterally. Palpus brownish yellow. Mesonotum brownish yellow, with three brown, longitudinal stripes medially and sublaterally (Fig. 3 C). Postpronotal lobe yellow (Fig. 3 D). Acrostichal setulae in ca. 10–12 irregular rows (Fig. 3 C). Scutellum entirely brown (Fig. 3 C). Pleura, katepisternum and meron mostly brown above (Fig. 3 D). Wing (Fig. 2 B): Costal vein between R2+3 and R4+5 distally with ca. 5 peg-like spinules on ventral surface. Abdominal tergites dark brown (Fig. 7 C), with a pair of yellow patches submedially between 2nd to 3rd tergites. Male terminalia: Epandrium with ca. 1 seta near posterior margin per side (Fig. 11 A). Surstylus rounded apically (Fig. 11 A). Paramere with ca. 7 sensillum submediodorsally (Fig. 11 C).

Measurements. BL = 2.53 mm, THL = 1.07 mm, WL = 2.10 mm, WW = 0.97 mm, arb = 6/3, avd = 0.83, adf = 1.71, flw = 1.86, FW/HW = 0.40, ch/o = 0.02, prorb = 0.59, rcorb = 0.59, vb = 0.33, dcl = 0.46, presctl = 0.54, sctl = 1.42, sterno = 0.87, orbito = 1.80, dcp = 0.32, sctlp = 1.09, C = 1.89, 4c = 1.31, 4v = 2.14, 5x = 1.54, ac = 2.38, M = 0.69, C3F = 0.89.

Specimens examined. CHINA: 1♂ (SCAU, No. 128964), Haoping, Ziyang, Shaanxi, 470m, 16.viii.2003, ex tussock, JJ Gao.

Distribution. China (Shaanxi, Taiwan), India, Palau, Micronesia, Borneo, New Guinea (Madang), Indonesia (Java, Sumatra).