Chelipoda cycloseta, Published, 2007

Published, First, 2007, The Hemerodromiinae (Diptera: Empididae) of New Zealand II. Chelipoda Macquart, Zootaxa 1537 (1), pp. 1-88 : 53-54

35. Chelipoda cycloseta sp. n.

[ Figs. 68, 69 , 139 , 144 ]

Type material: Holotype ♂: New Zealand, Stewart Is., SI, Smoky Beach campsite, D48 21147 53768, 2m, pan traps, 14–15/i/2000, JBW & GMW [ CMNZ] . Paratypes: 2♂, same data as holotype [ NZAC, NMWC] .

Etymology: the specific epithet is a reference to the extraordinary costal bristle which encircles the front of the wing.

Description. Male: length 3.0mm.

Head: blackish with grey dust, face paler; distinctly dorsoventrally flattened ( Fig. 144 ), 1.5X as long as deep, eyes narrowly separated on face; ocelli mid way between antennae and vertex; upper occiput rounded (slightly concave centrally), merging gradually with vertex; ocl strong, divergent; verticals rather weaker, outer vertical (vt2) contiguous with upo; lpo very fine, hardly distinguishable from dense coating of pale pile on lower occiput. Antennae yellowish brown, arista darker; scape 1.5X as long as wide, a strong bristle dorsally and a slightly weaker one ventrally; ped globular; postpedicel pointed lanceolate, 2.2X as long as deep, arista almost 3X as long. Proboscis brown, narrow, rather anteriorly directed; palpi yellow, ovate, small with 1–2 minute apical setae.

Thorax: ground colour yellowish; scutum with brown stripes medially and laterally; pleura with faintly darker stripes from below pprnlb to root of haltere and across lower part of and meron. Evenly greyish dusted dorsally with lower pleura more thickly dusted and paler. All setae black; dc1 strong, erect; dc2 2X as long, reclinate, wavy; postsutural dorsocentrals present as distinct lines of multiserial pile which becomes longer and apically curved posteriorly ( Fig.144 ), unp very strong, outwardly directed; sa strong, erect; pprn, ph and lnp also present; a pair of minute acr at extreme front of scutum. A patch of short setae on katepisternum ventrally behind base of C 1.

Legs: yellowish, apical tarsal segments rather darker, C 1 posteriorly and F 1 posteriorly at base whitish. C 1 with strongly marked blackish anterior stripe, 0.85–0.9X as long as thorax, rather slender, 5.5X as long as deep, 2 strong black bristles in front near base. F 1 1.2X as long as C 1, slightly swollen, 4.5X as long as wide, widest 0.4 from base; virtually only a single row of bristles ventrally, very strong basally becoming denticlelike distally with closely adjacent series of fine pv bristly hairs behind; a series of fine bristles anteriorly and posteriorly, both becoming more ventrally positioned on distal 0.5. F 2 slender, 3–4 anteroapical curving bristles 3X as long as F 2 is deep. T 1 slender, almost linear, as long as F 1; a linear series of about 30 minute adpressed denticles ventrally and adjacent fine short pv hairs; av hairs longer than pv series particularly in basal 0.5; at2 0.3 as long as at3, both with short spinose bristles dorsally. Legs otherwise simple with unmodified chaetotaxy.

Wing: ( Fig. 139 ) veins and membrane tinged brown, somewhat narrowed basally below junction of C and R 1; cell cup absent; upper crossvein (dm-m) of cell dm absent (dm open); Veins M and R 4+5 unforked; R 2+3 sinuous, a faint ‘vena spuria’ immediately in front basally; C thickened about junction with R 1 and for a short distance beyond, bearing several fine hairs, one of which is as long as wing is wide at this point; slightly more distally is a series of 7–8 strong curving downwardly directed bristles, one of which is greatly elongated, irregularly twisted and locates into the strongly hooked apex of a small strongly sclerotized ‘turret’ arising perpendicularly from the ventral surface of the membrane near the base of subapical (R 5) cell. Basal costal bristle strong. Haltere white.

Abdomen: yellowish brown, tergite 6 with long hairs dorsally, otherwise short-haired. Terminalia ( Figs. 68, 69 ) very small, reflexed upwards, rather weakly sclerotized except for strong black curving subepandrial process. Epandrium and hypandrium separate, epandrium small, narrow, hardly overlapping hypandrium, bearing 2 very long and several smaller setae on posterior margin; cerci more or less fused with apex of epandrium and bearing 2 long and several smaller setae. Hypandrium with a pair of longish setae and a few smaller hairs posteriorly. Postgonite flattened distally with hooked apex. Phallus strongly reflexed posteriorly before tip.

Female: unknown.

Comments. C. cycloseta is a species of uncertain affinities. The absence of the upper crossvein in cell dm, pilose posterior dorsocentrals, presence of bristles on the katepisternum and the peculiar twisted costal bristle locating apically with a hooked prominence on the underside of the wing membrane are remarkable and unique characteristics of this species. In Collin (1928) it would key to Doliodromia Collin on account of absence of cell dm and vein cu forked apically but Doliodromia clearly belongs in the Hemerodromiini . Despite many differences from ‘typical’ members of the genus, C. cycloseta is tentatively included in Chelipoda as it would be premature to erect a new genus on account of current systematic uncertainties in Chelipodini and before the female has been described. The apex of the costal bristle appears to be held in place by its locating beneath a hook-shaped process emitting from a turreted prominence on the lower membrane. However, it is possible that its tip may actually be fused with the prominence in life and that it has become separated after death, although such a condition would pose considerable problems in understanding its ontogenesis. C. cycloseta is presently known only from Stewart Island in January.

Figures

FIGURES 63–70. Male genitalia of Chelipoda spp. 63–66. C. venatrix sp. n. 63. anterior view. 64. posterior view. 65. phallus. 66. apex of postgonite. 67. C. tangerina sp. n. posterior view (setae not shown on one side). 68–69. C cycloseta sp. n. 68. lateral view. 69. posterior view. 70. C. didhami sp. n. posterior 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. ♂.

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.