Hemerodromia demissa, 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 : 23-24

Hemerodromia demissa sp. nov

( Figs 31–33 , 82 )

Diagnosis. A reddish black species with preapical abdominal segments contrastingly yellow. 2 pairs of apical sct present. Distinguished from H. curvata Grootaert, Yang & Saigusa, 2000 primarily by differences in male terminalia with inner margin of cercus distally not serrate and a prominent apical downwardly directed process narrower with stronger serrations on its posterior margin.

Description. Male: Body length 2.5 mm; wing length 2.0 mm. Head. Black, dusted greyish. Antenna pale whitish yellow, scape and pedicel slightly darker, Mouthparts yellowish white. Vertex with only minute setulae (ocl apparently lost in types); postocular and lower occipital setulae minute. Antenna with postpedicel ~2.5X long as wide, stylus ~0.5X as long; scape with small dorsal seta. Thorax. Dark reddish brown to reddish black, slightly paler in postpronotal area, dusted greyish. All setae yellowish; minute apart from one small npl (anterior of which are a few very fine hairs); 4 very small apical sct.

Legs. Ground colour yellow including apical tarsomeres. C1 ~1.1X longer than distance between C1 and C2; all coxae with only minute setulae except for a few distinctly longer anteroapicals. F1 ~1.1X long as C1, rather strongly inflated ~ 3.5–4.0X long as wide, distinctly constricted 0.15 from base; femoral formula ~ 6– 7 /15–18/12– 18+1–2/7; denticles black, rows converging apically, basal denticle of pv series stronger, positioned basal to constriction of limb; spines yellow, av spines longer than pv series. T1 ~ 0.8X long as F1, evenly curved, ventral face shallowly concave; with 2 rows of ~16 sharply pointed spinose setae ventrally; ventroapical spur weakly developed; a strong ventroapical erect black spinose seta present. Mid and hind legs slender with only small setulae. Wing. Membrane usually slightly but distinctly darkened with brownish microtrichia but hyaline near extreme base. Veins brownish but paler near base. Marginal setulae brownish. R2+3 linear, joining C ~ 0.8X distance between end of R1 and R4; length of C between ends of R2+3 and R4 ~1.2X long as R4. R4 almost linear, only slightly S-shaped, angle with R5 at extreme base ~ 75–80°; R5 ~ 2.X long as R4; R4+5 fork distal to M1+2 fork by ~ 1.5X length of R4; R5 and M1 almost linear, convergent distally; cell bm+dm short, ending at level of R1. Halter entirely dirty whitish. Abdomen. Black dusted greyish but tergite 7 and sternites 7 and 8 contrastingly yellow or sometimes yellowish brown; all setulae black, small except some long yellow bristles posteriorly on sternites 7 and 8 and darker yellowish bristles on tergites 7 and 8. Terminalia. Black with dark setae. Cercus rather broad in lateral view ( Fig. 31 ), extending to tip of epandrium; a large broad (in lateral view) terminal process curved downwards bearing distinct serrations on posterior margin ( Fig. 33 ); an inwardly directed rather pointed apical process (in dorsal view) ( Fig. 32 ); inner margin of cercus otherwise lacking serrations or denticles. Epandrium bilobed distally; upper lobe short and blunt, bearing a few strong setae apically; lower lobe elongate, narrow with slightly expanded tip (surstylus?) incurved and bearing a few short spinose setae on inner margin. Hypandrium narrow and short, reaching only as far as tip of upper lobe of epandrium; aedeagus short, with hook-like lateral projection. Female: Unknown.

Type material. HOLOTYPE ♂, THAILAND: Chiang Mai Province, Doi Inthanon NP, Wachirathan trap 1, 662 m, 18.542°N, 98.600°E, 2–29.v.2014, MT, W. Srisuka and R. Sawkord [QSBG-2014-134[( QSBG). PARATYPES: 2♂, 1♀, same data as holotype, 3–31.iii.2014; Chiang Mai Province, Queen Sirikit Botanic Garden, deciduous forest, 620 m, 18.9007°N, 98.8551°E, 31.1.– 2.ii.2007, flight interception trap, N. Buawangpong, J. Phasuk et al. ( QSBG & NMWC).

Etymology. The specific epithet demissa (Latin) meaning dwelling in lowlands, refers to the lowland habitat in which this species has been found. It is used as a noun in apposition.

Remarks. Hemerodromia demissa sp. nov. is clearly closely related to H. curvata from Yunnan China, differing mostly in the shape of the distal processes of the cercus and small differences in shape of the tip of the lower epandrial process. Hemerodromia demissa sp. nov. lacks a deeply serrate margin on the inner face of the cercus distally (see Grootaert et al. 2000, fig. 11 and Yang & Yang 2004, fig. 113) but instead has a single strong rather pointed, incurved process at the apex ( Fig. 32 ). Additionally the downcurved apical process of the cercus in H. curvata is rather quadrate in lateral view (see Grootaert et al. 2000, fig. 10 and Yang & Yang 2004, fig. 112) whereas in H. demissa sp. nov. it is more elongate, has stronger serrations on its posterior margin and its extreme apex is not produced dorsally ( Figs 31, 33 ). The thorax of H. curvata is apparently black ( Grootaert et al. 2000) whereas it is more reddish brown or reddish black in H. demissa sp. nov. The preapical abdominal segments of H. demissa sp. nov. are distinctly yellow, contrasting with much darker segments on the rest of the abdomen. The species is known from lowland (620–662 m) deciduous and dry evergreen forest biotopes in Chiang Mai Province, northern Thailand ( Fig. 82 ). Adults were captured in February, March and May, coincident with the cool dry season.

Figures

FIGURES 31 – 33. Male terminalia of Hemerodromia demissa sp. nov. 31, lateral view of terminalia; 32, dorsal view of cerci; 33, apex of right cercus, inner surface viewed in slightly anterior aspect. Abbreviations: cer = cerci, epa = epandrium, hyp = hypandrium.

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.