Hemerodromia betalutea, 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 : 16-18

Hemerodromia betalutea sp. nov.

( Figs 20–22 , 78 )

Diagnosis. A species with yellow thorax bearing more or less distinct dark lateral stripes on the scutum posteriorly and mediotergite blackish brown with posterior margin paler; anatergite mostly blackish and katatergite yellow. Sct present. Cell bm+dm long. Epandrium with small quadrate process apically bearing a close ciliation of fine hairs. Surstylus emerging slightly beyond with three groups of feather-like highly coalescent setae apically.

Description. Male: Body length 2.7 mm; wing length 2.7 mm. Head. Black, dusted greyish, frons slightly paler; antenna and mouthparts pale whitish yellow, all setae pale; one pair reclinate ocl; postocular setae uniseriate, becoming biseriate below, merging above with 2–3 pairs small vtl hardly distinguishable from fine setulae on vertex and upper occiput (but anterior pair behind ocelli rather stronger); frontal setulae apparently absent. Antenna with postpedicel ~2.0X long as wide, a few minute outstanding setulae subapically, stylus shorter than postpedicel; scape with distinct fine dorsal seta. Thorax. Dusted greyish. Ground colour yellow; mediotergite blackish brown with posterior margin paler; laterotergite with anatergite mostly blackish and katatergite yellow; metanepisternum yellow with suture along anterior margin (in front of posterior spiracle) narrowly blackish. Scutum with more or less distinct lateral stripes on posterior 0.4–0.5; prothoracic ‘collar’ yellow, narrowly blackish medially with suture between it and anterior margin of scutum dark; anterior spiracle narrowly emarginated above with elongate black mark more or less continued posteriorly along extreme lateral margin of scutum where weak but strengthening just in front of root of wing, forming a small dark spot below notopleural seta. Scutellum yellow, sutures at anterior and lateral margins dark. All setae yellowish; minute apart from a pair of distinct sct and one 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 ~ 6–7/16/15 +1/5–7, denticles black, rows converging apically; spines yellow, pv and av rows similarly long, becoming somewhat longer proximally, shorter than limb is deep throughout. T1 ~ 0.6–0.7X long as F1, evenly curved, ventral face shallowly concave; with one row of ~ 20 sharply pointed spinose setae ventrally; a distinct ventroapical erect black or yellowish black spinose seta present; ventroapical spur very small, yellow; a short ciliation of distinct proclinate hairs dorsally on distal 0.2. Mid and hind legs slender with only small pale setulae, somewhat longer dorsally on distal 0.3 of T3. Wing. Membrane slightly darkened by rather even covering of greyish brown microtrichia but hyaline basally. Veins brownish, somewhat darker about base of R2+3, R4+5 and posterior margin of cell bm+dm but pale yellowish near base. Marginal setulae pale. R2+3 gently curved, joining C ~ 0.5X distance between end of R1 and R4; length of C between ends of R2+3 and R4 ~ 2X long as R4; R4 slightly S-shaped; R5 ~ 2.2–2.5X long as R4, slightly downcurved; R4+5 fork distal to M1+2 fork by ~ 1X length of R4. M1 almost linear beyond base, distinctly convergent distally with R5; cell bm+dm moderately long, ending distinctly beyond tip of R1. A very faint vestigial ‘stump’ of vein CuA2 present. Halter yellowish white. Abdomen. Yellow with tergites 2–6 and 8 black. All setae yellow, short but longer on sternites 6 and especially posterior margins of sternites 7 and tergite 8. Terminalia. Black. Cercus of complex structure ( Figs 20, 21 ); about as long as epandrium; more weakly sclerotized proximally, strongly sclerotized distally with tip slightly anteroventrally spatulate, inturned, bearing strong setae; a group of 3 inwardly directed strong setae on inner face at ~0.5 from base. Epandrium ( Fig. 20 ) somewhat subovate proximally in lateral view, becoming narrower distally, with small quadrate process apically bearing a close ciliation of fine hairs. Surstylus present, emerging slightly beyond epandrium and immediately ventral to tip; three groups of feather-like highly coalescent setae apically. Hypandrium rather triangular in ventral view ( Fig. 22 ), with ~5 pairs strong setae on distal 0.5; divided ventrobasally, fused ventroapically. Female: similar to male but denticles and spines on F1 more numerous, femoral formula ~ 6/20/17 +1/7; basal spines of pv and av rows stronger, as long as limb is deep. Abdomen with much shorter setae; terminalia black.

Type material. HOLOTYPE ♂, THAILAND: Chiang Mai Province, Doi Inthanon NP, Check point 2 trap 1, 1,639 m, 18°31'39.5"N, 98°29'59.7"E, 2–29.v.2014, MT, W. Srisuka et al. [QSBG-2014-130]( QSBG). PARATYPES: 1♂, same data as holotype; 1♀, Check point 2 trap 2, 1,639 m, 18°31'39.5"N, 98°29'59.7"E, 2– 29.v.2014, MT, W. Srisuka et al. ( QSBG).

Additional material. 2♀, Chiang Mai Province, Doi Suthep NP, 1,356 m, 18°49'04.4"N, 98°53'05.7"E, 30.vii.–30.viii.2011, MT, W. Srisuka et al.; 3♀, Kamphaeng Phet Province, Mae Wong NP, Chong Yen, 1,306 m, 16°5.212'N, 99°6.576'E, 24.ix.–1.x.2007, 24–31.xii.2007. MT, Piluek C. & Inpuang A. ( QSBG & NMWC).

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

Remarks. Hemerodromia betalutea sp. nov. is best recognised amongst other predominantly yellow species by having the epandrium with a small quadrate process apically bearing a close ciliation of fine hairs and with surstylus emerging slightly beyond with three groups of feather-like coalescent setae apically. It is only known from hill evergreen forests at 1,306–1,639 m in Khampaeang Phet and Chiang Mai provinces in northern Thailand ( Fig. 78 ). Adults have been taken from December to July during the cool dry season and first part of the Southwest Monsoon.

Figures

FIGURES 20 – 22. Male terminalia of Hemerodromia betalutea sp. nov. 20, lateral view of terminalia; 21, dorsal view of cerci; 22, ventral view of hypandrium. Abbreviations: cer = cerci, epa = epandrium, hyp = hypandrium.

FIGURES 73 – 81. Distribution of Hemerodromia spp. in Thailand at a resolution of 0.25 ° and symbols sized to 0.5 ° of latitude and longitude. 73, H. acutata Grootaert, Yang & Saigusa; 74, H. alphalutea sp. nov.; 75, H. anisoserrata sp. nov.; 76, H. anomala sp. nov.; 77, H. attenuata sp. nov.; 78, H. betalutea sp. nov.; 79, H. conspecta sp. nov.; 80, H. deltalutea sp. nov.; 81, H. deminuta sp. nov.