Hemerodromia anisoserrata, 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 : 12

Hemerodromia anisoserrata sp. nov.

( Figs 14–15 , 75 )

Diagnosis. A species with yellow thorax and mediotergite darkened. Posterior margin of scutum with well defined black ‘scutoscutellar eye’. Sct absent. Cell bm+dm short. Male terminalia with epandrium truncate apically, and surstylus elongate with almost circular apex; a narrow process emerging beyond tip of epandrium below surstylus bent at ~90°, with two minute dentate setulae at tip.

Description. Male: Body length 2.4 mm; wing length 2.1 mm. Head. Black, dusted greyish; antenna and mouthparts pale whitish yellow, all setae pale; one pair erect ocl; 1–2 pair of minute vtl, distinguishable from sparse scattered minute hairs on vertex; postocular hairs minute. Antenna with postpedicel ~2.5–3.0X long as wide, a few minute outstanding setulae subapically; stylus shorter, ~0.5X long as postpedicel; scape with distinct fine dorsal seta. Thorax. Dusted greyish. Ground colour yellow; mediotergite brownish yellow, prothoracic ‘collar’ very narrowly darkened medially; anterior spiracle not distinctly emarginated above with small diagonal dark mark; ‘scutoscutellar eye’ strongly defined, black; sutures between prothoracic ‘collar’ and anterior margin of scutum, at anterior margin of laterotergite and posterior margin of meron black. All setae yellowish, minute, a pair of distinct npl, sct absent. Legs. Pale yellow. C1 ~1.1X longer than distance between C1 and C2, all setulae minute but with a few longer hairs dorsally. F1 ~ 1.1X long as C1, ~ 6X long as wide, evenly inflated, hardly constricted on proximal 0.3; femoral formula ~ 7/19–20/19 +1/8–9, denticles black, rows converging apically; spines yellow, pv and av rows very short, hair like, with most basal spine strong. T1 ~ 0.6–0.7X long as F1, evenly curved, ventral face shallowly concave; with ~ 15 similarly sized sharply pointed spinose setae ventrally; a short ciliation of distinct proclinate hairs dorsally throughout length. Ventroapical spur very small with erect black spinose ventroapical seta arising from near its base. Mid and hind legs slender with only small pale setulae. Wing. Membrane distinctly darkened by brownish yellow microtrichia, hyaline basally. Veins blackish, hyaline basally, darker about base of R2+3 and M1+2 and posterior border of cell bm+dm. Marginal setulae pale. R2+3 almost linear, joining C ~ 0.7X distance between end of R1 and R4; length of C between ends of R2+3 and R4 ~1.1X long as R4; R4 almost linear, only slightly S-shaped; R5 ~ 2.1X long as R4, almost linear; R4+5 fork distal to M1+2 fork by ~ 1.0–1.2X length of R4. M1 almost linear beyond base, convergent distally with R5; cell bm+dm short, ending at tip of R1. Halter yellowish white. Squama with margin greyish yellow. Abdomen. Yellow with tergites 2–6 brown or blackish becoming somewhat paler on distal segments; tergite 7 and sternite 7 with distinct yellow setae, a fan of brownish setae on posterior margin of tergite 8. Terminalia. Black. Cercus elongate, extending beyond tip of epandrium ( Figs. 14, 15 ); a small subapical thickening on inner face bearing strong spinose seta. Epandrium subquadrate with posterior margin almost linear for most of its length; three very strong bristly setae near pv margin ( Fig. 14 ). Surstylus present, extending distinctly beyond tip of epandrium; almost circular apically with series of dense minute dentate setulae on inner margin ventrally and posteriorly. A narrow process emerging beyond tip of epandrium, below surstylus, sharply bent downwards at ~90°, with two minute dentate setulae at tip (possibly lower lobe of surstylus). Hypandrium large, rather keel-shaped with few distinct bristles but distinctly pilose distally. Female: Similar to male. F1 with basal spines of av and pv rows stronger. Vein R5 only ~ 1.8X long as R4. Abdomen yellow with tergites 2–7 brown or blackish, tergite 2 narrowly yellow anterolaterally; sternites 7 brownish posteriorly, a few distinct erect pale setae on disc; terminalia black.

Type material. HOLOTYPE ♂, THAILAND: Loei Province, Phu Reua NP, Song Kon w/f (waterfall with wet slabs), 743 m, 17.3521°N, 101.3540°E, 27.xi.2013, netted, A.R. Plant ( QSBG). PARATYPE: 1♀, same data as holotype.

Etymology. The specific epithet is a concatenation of the Greek root aniso (not equal) and serrata in reference to this species not being identical with H. serrata Saigusa & Yang, 2002 .

Remarks. The two known examples of this species were taken during November from the vicinity of a waterfall at 743 m in Loei Province, northeast Thailand ( Fig. 75 ). Hemerodromia anisoserrata sp. nov. is clearly closely related to H. serrata Saigusa & Yang 2002 which was described from the Funui Mountains within the Qinling Range in central China. The terminalia of H. anisoserrata sp. nov. are similar to H. serrata (see Saigusa & Yang 2002, figs 53–54) excepting that the apical process of the surstylus is less rounded in H. serrata and the epandrium of H. anisoserrata sp. nov. is very different being apically truncate (distinctly pointed in H. serrata ). In addition the scutum of H. anisoserrata sp. nov. is generally entirely yellow (three blackish longitudinal stripes in H. serrata ) and H. anisoserrata sp. nov. has a yellowish mediotergite and lacks distinct scutellar setae. The present species is also closely similar to H. ocellata sp. nov. which has the narrow process emerging beyond the tip of the epandrium (lower lobe of surstylus?) linear rather than bent at 90° and bears two strong leaf-shaped specialised setae apically. Hemerodromia ocellata sp. nov. also has a much smaller and differently shaped epandrium and a much larger hypandrium compared with H. anisoserrata sp. nov.

Figures

FIGURES 14 – 15. Male terminalia of Hemerodromia anisoserrata sp. nov. 14, lateral view of terminalia; 15, dorsal view of cerci. Abbreviations: cer = cerci, epa = epandrium, hyp = hypandrium, sur = surstylus.

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.