Hemerodromia epsilutea, Plant, Adrian R., 2015

Plant, Adrian R., 2015, Diversity of Hemerodromia Meigen, 1822 (Diptera: Empididae) in Thailand, the tip of a tropical iceberg?, Zootaxa 4039 (1), pp. 1-56 : 24-26

Hemerodromia epsilutea sp. nov.

( Figs 34–36 , 83 )

Diagnosis. A species with thorax entirely yellow with only sutures in front of root of halter and about laterotergite blackish. Sct present. Cell bm+dm long. Abdomen with tergite 2 blackish. Male terminalia with hypandrium and epandrium clear yellow, surstylus broadly pointed emerging beyond tip of epandrium and bearing strong setae apically.

Description. Male: Body length 1.9 mm; wing length 1.8 mm. Head. Black, dusted greyish, frons slightly paler; antenna and mouthparts pale whitish yellow, all setae pale; one pair small reclinate ocl; postocular setae very small, becoming somewhat longer below, merging above with 1–2 pairs small vtl and a few fine hairs on vertex; frontal setulae apparently absent. Antenna with postpedicel ~2.5X long as wide, a few minute outstanding setulae subapically; stylus somewhat shorter than postpedicel; scape with distinct fine dorsal seta. Thorax. Dusted greyish. Ground colour clear yellow including mediotergite and prothoracic ‘collar’; only sutures in front of root of halter and about laterotergite blackish; anterior spiracle narrowly and faintly emarginated above with diagonal dark mark. All setae yellowish; minute apart from a pair of distinct sct and one smaller npl. Legs. Pale yellow. C1 ~1.1–1.2X longer than distance between C1 and C2, all setulae minute. F1 ~ 1.2X long as C1, ~ 6X long as wide, evenly inflated, hardly constricted on proximal 0.3; femoral formula ~ 6/15/16 +1/6, denticles black, rows converging apically; spines yellow, pv and av rows similarly very short and hair-like, becoming somewhat longer proximally. T1 ~ 0.6–0.7X long as F1, evenly curved, ventral face shallowly concave; with row of ~ 16 sharply pointed spinose setae ventrally (in the holotype T1 is tightly reflexed against F1 and it is uncertain if it bears 1 or 2 rows of setae); ventroapical spur small with distinct ventroapical erect black spinose seta arising from near its base. Mid and hind legs slender with only small pale setulae. Wing. Membrane faintly darkened by rather even covering of brownish yellow microtrichia but hyaline basally. Veins brownish yellow, somewhat darker about junction of R1 and C, base of R2+3, R4+5 and cell bm+dm, but paler near base. Marginal setulae pale. R2+3 almost linear, joining C ~ 0.6–0.7X distance between end of R1 and R4; length of C between ends of R2+3 and R4 ~1.8–2.0X long as R4; R4 slightly Sshaped, angle with R5 at extreme base ~ 85°, becoming ~70–80° thereafter, joining C at ~ 85°. R5 ~ 2.8X long as R4, slightly curved; R4+5 fork distal to M1+2 fork by ~ 1X length of R4. M1 almost linear beyond base, convergent distally with R5; cell bm+dm long, ending beyond tip of R1. Halter yellowish white. Squama with margin greyish. Abdomen. Yellow with tergites 2–5 blackish; all setae yellow, short but slightly longer on distal segments, especially sternites 6 and 7. Terminalia. Epandrium and hypandrium clear yellow, cercus and surstylus black. Cercus distinctly angulate in dorsal view ( Fig. 34 ), distal lobe incurved bearing numerous strong setae ( Fig. 35 ). Epandrium sub-trapezoid, without strong setae on external face. Surstylus present, broad bluntly pointed apically with strong apical setae, partly fused with and emerging beyond epandrial lamella. Hypandrium narrow, with distinct setae distally. Phallus with sharply pointed apical processes ( Fig. 36 ). Female: Unknown.

Type material. HOLOTYPE ♂, THAILAND: Chiang Mai Province, Doi Inthanon NP, Wachirathan trap 1, 662 m, 18.5408°N, 98.6001°E, 2–29.v.2014, MT, W. Srisuka R. Sawkord T. Somboonchai & S. Suriya [QSBG- 2014-134]( QSBG).

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

Remarks. The combination of male terminalia clear yellow and abdomen yellow with tergite 2 blackish serves to distinguish H. epsilutea sp. nov. from other yellow species of Hemerodromia occurring in Thailand although confirmation of identity requires more detailed examination of the male terminalia. The species is only known from a single lowland (662 m) site in dry evergreen forest during May in Chiang Mai Province, northern Thailand ( Fig. 83 ).

Figures

FIGURES 34 – 36. Male terminalia of Hemerodromia epsilutea sp. nov. 34, lateral view of terminalia; 35, dorsal view of cerci; 36, apex of phallus. Abbreviations: cer = cerci, epa = epandrium, hyp = hypandrium sur = surstylus.

FIGURES 82 – 90. Distribution of Hemerodromia spp. in Thailand at a resolution of 0.25 ° and symbols sized to 0.5 ° of latitude and longitude. 82, H. demissa sp. nov.; 83, H. epsilutea sp. nov.; 84, H. etalutea sp. nov.; 85, H. flaviventris Yang & Yang; 86, H. furcata Grootaert, Yang & Saigusa; 87; H. fusca Yang & Yang; 88, H. gammalutea sp. nov.; 89, H. isochita sp. nov.; 90, H. namtokhinpoon sp. nov.