Hemerodromia gammalutea Plant, 2015, sp. nov.

Hemerodromia gammalutea sp. nov.

(Figs 48–50, 88)

Diagnosis. A yellow species with mediotergite with variably brownish marking narrowing posteriorly to a broad point on posterior margin leaving posterolateral margins yellow. Sct present. Cell bm+dm long. Wing vein forks R4+5 and M1+2 rather close together, separated by less than length of R4. Tergites 2–5 blackish, 6 yellow. Male terminalia with cercus of complex and characteristic structure.

Description. Male: Body length 2.5 mm; wing length 2.1 mm. Head. Black, dusted greyish, frons slightly paler; antenna and mouthparts pale yellowish white, all setae pale; one pair reclinate ocl; postocular setae uniseriate, becoming biserial below, merging above with 1–2 pairs small vtl hardly distinguishable from fine setulae on vertex and upper occiput; frontal setulae apparently absent. Antenna with postpedicel ~1.8–2.0X long as wide, stylus about as long as postpedicel; scape with distinct fine dorsal seta. Thorax. Dusted greyish. Ground colour yellow; mediotergite with variably brownish marking narrowing posteriorly to a broad point on posterior margin leaving posterolateral margins yellow; prothoracic ‘collar’ vaguely brownish medially; sutures between prothoracic ‘collar’ and anterior margin of scutum and lateral margins of scutellum very narrowly black. All setae yellowish; minute apart from a pair of distinct sct and one smaller npl. Legs. Whitish yellow. C1 ~1.2X longer than distance between C1 and C2, all setulae minute excepting a few slightly longer apicals and a posterior ciliation of fine proclinate hairs ~0.2X long as limb is deep. F1 ~ 1.2X long as C1, ~ 6X long as wide, evenly inflated, almost indiscernibly constricted on proximal 0.2– 0.3; femoral formula ~ 6– 7 /18–20/15+1/5, denticles black, rows converging apically; spines yellow, pv and av rows similarly long, becoming somewhat longer proximally. T1 ~ 0.7–0.8X long as F1, evenly curved, ventral face shallowly concave; with one row of ~ 16 sharply pointed spinose setae ventrally; a small yellow ventroapical spur with distinct ventroapical erect black or yellowish black spinose seta arising from near its base; a short ciliation of distinct proclinate hairs dorsally on distal 0.2. Mid and hind legs slender with only small pale setulae, somewhat longer on front metatarsus proximally and dorsally on distal 0.3 of T3. Wing. Membrane slightly darkened by rather even covering of yellowish brown microtrichia but hyaline basally. Veins brownish yellow, somewhat darker about base of R2+3, R4+5 and distal part of cell bm+dm but pale yellowish near base. Marginal setulae pale. R2+3 almost linear, gently curved, joining C ~ 0.6X distance between end of R1 and R4; length of C between ends of R2+3 and R4 ~ 2X long as R4; R4 almost linear, only very vaguely Sshaped; R5 ~ 2.2–2.5X long as R4, almost linear; R4+5 fork distal to M1+2 fork by ~ 0.5–0.8X length of R4. M1 very gently curved beyond base, convergent distally with R5; cell bm+dm moderately long, ending distinctly beyond tip of R1. Halter yellowish white. Abdomen. Yellow with tergites 2–5 brown; all setae yellow, short but longer on sternites 6–7 and posterior margins of sternites 7 and tergite 8. Terminalia. Cercus of complex structure; about as long as epandrium (Fig. 48); a basal subtriangular to quadrate lobe bearing numerous short spinose setae along inner margins; an elongate lobe, apparently originating beneath basal lobe, projecting posteriorly with extreme tip reflexed anteriorly and bearing 3–4 short black spines; a narrow process originating from outer margin just beyond 0.5 from base, curving dorsally and inwardly, with 2 short twisted spines at tip; apical lobe rather broad, slightly incurved, bearing short but distinct setae on outer face, almost bare on inner face (Fig. 49). Epandrium slightly concave dorsally in lateral view; a short pointed posterodorsal process bearing numerous fine setae behind; a fan of closely spaced fine setae emerging from behind posterior margin (probably arising from surstylus hidden beneath epandrium). Hypandrium rather triangular in ventral view (Fig. 50) distally rounded with pointed tip; fused ventroapically where covered with strong setae; divided ventrobasally, bare. Female: Unknown.

Type material. HOLOTYPE ♂, THAILAND: Chiang Mai Province, Doi Phahompok NP, Kiewlom1/ montane forest, 2,174 m, 20°3.549'N, 99°8.552'E, 7–14.v.2008, MT, P. Wongchai [T6098](QSBG). PARATYPE: ♂, Chiang Mai Province, Doi Inthanon NP, Kew Maepan Trail, 2,200 m, 18°33.162'N, 98°28.81'E, 8–15.v.2007, MT, Y. Areeluck (QSBG).

Etymology. The specific epithet is a concatenation of the Latin luteus and the third letter of the Greek alphabet (gamma). It is used as a noun in apposition.

Remarks. Hemerodromia gammalutea sp. nov. is only known from moist hill evergreen forest at around 2,200 m on the mountains Doi Phahompok and Doi Inthanon in Chiang Mai Province, northern Thailand (Fig. 88). Adults were captured in May at the start of the Southwest Monsoon.