Chelipoda gracilis, Published, 2007

Published, First, 2007, The Hemerodromiinae (Diptera: Empididae) of New Zealand II. Chelipoda Macquart, Zootaxa 1537 (1), pp. 1-88 : 55-57

37. Chelipoda gracilis sp. n.

[ Figs. 31 , 81, 134, 145]

Type material. Holotype ♂: New Zealand, South Is. , KA, Kaikoura, clear window trap in podocarp / Nothofagus forest canopy, 1990–1991, RKD [ NZAC] . Paratypes: 62♂, 64♀, same data as holotype [ NZAC,

NMWC, LUNZ].

Etymology: from the Latin gracilis meaning slender or slight.

Description. Male: length = 2.5–3.0mm.

Head: (Fig. 81) orange-brown, strongly dorsoventrally flattened, almost 2X as long as deep; upper occiput distinctly flattened, produced posteriorly with lateral carinate ridges on each side forming distinct posterior lobes bearing short stout black spines; vertical bristles minute. Frons pale, 1.5X as long as distance between posterior ocelli; ocl small, pale. Face very narrow, eyes almost touching below antennae widening slightly above mouth. Pile on lower occiput very short, pale. Antenna: (Fig. 81) pale yellow, scape 2X as long as wide, a short seta dorsally; postpedicel narrowly pointed ovate, about 4X as long as wide, minutely pubescent, arista 1.5X as long. Mouthparts yellow, proboscis as long as head is deep, palpi very small.

Thorax: pale yellow with faint indication of darker dorsomedian line and another on pleura between cervical area and base of wing. Scutum rather flattened, anterior margin trapezoid, strongly produced anteriorly hiding prothoracic ‘collar’ in dorsal view; anterior margin acute-angled, overhanging cervical area in lateral view. Anterior 2 pairs of dorsocentrals strong; dc1 articulated at extreme anterior margin of scutum, modified as transparent flat triangular plates projecting forwards over upper occiput (Fig. 81); dc2 and pprn strong, directed anteriorly, curving inwards distally; anterior ph, unp, sa and sct strong; dc3 absent, posterior ph, dc4 and dc5 minute; anatergite with 3–4 rather long yellowish setae.

Legs: pale whitish yellow with only ‘knees’ of mid and hind pair darkened. C 1 0.7X as long as thorax. F 1 ( Fig. 145 ) 1.2–1.3X as long as C 1, sinuous, slightly constricted medially with dorsoapical process bearing a recurved spur when viewed from above; a line of close set ad yellow hairs distally which are longer than F 1 is deep; a very strong black pv bristle arising from a tubercle 0.25 from base with some smaller bristles basally and fine hairs distally following a bare medial section; av series consisting of 4 strong yellowish basal spines becoming fine and small beyond base, changing abruptly 0.6 from base to small black denticles. T 1 linear, about 30 minute adpressed denticles ventrally and 2–3 short bristles behind 0.7 from base; at2 as long as at3; mid and hind legs slender, F 2 distally and T 2 throughout with av hairs longer than limb is wide; pt1 longer than pt2 + pt3 + pt4 + pt5.

Wing: ( Fig. 134 ) with veins yellowish brown; cell cup absent, no trace of veins A 1 or CuA 2, lower margin of cell dm quite close to posterior margin of wing; costa slightly distorted, more closely apposed to R 1 in subcostal cell, bearing strong yellow setae between junction with h and R 1. Haltere white.

Abdomen: yellowish dorsally, paler below; tergites weakly sclerotized with sparse longish hairs on disc and posterior margins; sternites very weakly sclerotized bearing only minute hairs. Terminalia ( Fig. 31 ) very small, reflexed forwards; hypandrium separated from and partly overlapped by epandrium; epandrial lobes rounded-quadrate with 2 very long bristles posteroapically and several smaller setae on posterior margin; hypandrium complete, not divided but less strongly sclerotized medially, several distinct setae on posterior margin; subepandrial process and postgonite narrow, reaching almost to apex of rather broad phallus; cerci free, quite broad in lateral view, narrower in posterior view, extending beyond epandrial lobes and bearing conspicuous setae.

Description. Female: differing from the male as follows.

Head: less dorsoventrally compressed than male, only 1.5X as long as wide, upper occiput more rounded, without bristly lateral carinae; vt1 distinct but small and fine, vt2 contiguous with and indistinguishable from upo series of fine hairs; lower occiput with fine pile and longer yellow hairs behind and laterally. Scape rather shorter than in male.

Thorax: with dark stripes more conspicuous and an additional brown stripe on scutum laterally. Scutum more rounded, not strongly produced anteriorly, hardly concealing cervical area in dorsal view. Chaetotaxy similar to male but all setae normal (dc1 not plate like and placed close to but not on extreme anterior margin of scutum); dc2 and pprn straight, not curved distally.

Legs: yellow, C 1 0.8X as long as thorax. F 1 1.2X as long as C 1, maximally inflated 0.2 from base, narrowing evenly distally, not medially constricted and without dorsoapical process; 2 pv, 2–3 av and 1 basal bristle beneath on basal 0.2, all strong; pv series more or less absent medially but present as fine hairs distally; a linear av series of about 15 minute black denticles approximately in line with av bristles. T 1 lacking posterior bristles 0.7 from base, at2 slightly shorter than at2. F 2 and T 2 lacking distinct av ciliation.

Wing: simple, veins without unusually strong setae, cell cup absent but CuA 2 present, recurved and rounded, strong basally but very weak distally; lower margin of discal cell not close to posterior margin of wing.

Abdomen: with terminal papillae yellowish brown with fine white hairs.

Comments. C. gracilis is a slender pale yellow almost transparent species with a dorsoventrally compressed head. Males have large spines on the occiput and the anterior margin of the scutum is strongly produced, bearing two forwardly directed flat plate-like structures. It is known only from one South Is. locality where it was associated with podocarp and Nothofagus forest canopy. There is a related species from NC: Arthur’s Pass, 29/xi.1977 (NZAC) represented by three males. This species has its head dorsoventrally compressed and the scutum is similarly flattened and produced anteriorly but dc1 is not modified into a flat plate. The wing has strong bristles on the costa basally and F 1 is normally bristled and not constricted medially. The specimens are damaged and will not be formally described here.

Figures

FIGURES 29–33. Male genitalia of Chelipoda spp. 29–30. C. fuscoptera sp. n., 29. lateral view. 30. posterior view. 31. C. gracilis sp. n. posterior view. 32–33. C. inconspicua Collin. 32. anterior view. 33. posterior view.

FIGURES 140–146. Morphology of Chelipoda spp. 140. C. cornigera sp. n. ♂ habitus. 141. C. abdita Collin ♂ F, ven1 tral view. 142. C. mirabilis Collin ♂ C & front trochanter. 143. C. modica Collin ♂ habitus. 144. C. cycloseta sp. n. ♂ 1 head & thorax. 145. C. gracilis sp. n. ♂ front leg. 146. C. oblata Collin ♀, anterior view.

FIGURES 131–139. Wings of Chelipoda spp. 131–133. Base of wing showing cell cup. 131. C. inconspicua Collin. 132. C. abdita Collin. 133. C. modica Collin. 134–139. Whole wings 134. C. gracilis sp. n. ♂. 135. C. modica Collin ♂. 136. C. abdita Collin ♀. 137. C. digressa Collin ♂. 138. C. mirabilis Collin ♂. 139. C. cycloseta sp. n. ♂.