Chelipoda longicornis Collin

Published, First, 2007, The Hemerodromiinae (Diptera: Empididae) of New Zealand II. Chelipoda Macquart, Zootaxa 1537 (1), pp. 1-88 : 37-39

22. Chelipoda longicornis Collin

[ Figs. 38 , 82, 83 , 101, 102 ]

Chelipoda longicornis Collin, 1928: 34–35 .

Type material. Collin (1928) described Chelipoda longicornis from one male and one female from Ohakune, xi/1922, T. R. Harris [ BMNH]. Ohakune is in: New Zealand, North Island, RI. The male is here designated lectotype . The female (which is severely damaged, lacking its head) is here designated paralectotype.

Additional material: North Is. ; 2♀, TO, Ruapehu, Whakapapaiti Bush, Malaise trap in Nothofagus , 31/ xii/1986 – 3/i/1987, ARP ; 1♀, TO, Pureora Forest , 29/xii/1986. South Is.; 1♀, MB , Glen Hope Station , 42 o 30’S, 172 o 28’E, site code ‘ St. James’, FIT at ground level at forest edge, 31/i/– 13/ii/2001, RKD [all in NMWC] .

Description. Male: length = 3.5–4.5mm.

Head: black, grey-dusted with face paler; ocl black, rather stout, of similar strength as upo; lpo yellowish, biserial on lower occiput becoming black and uniserial above; upo uniserial, black, diverging slightly from eye margin on upper occiput; vt bristles not clearly differentiated from upo but a small dark bristle anterior to upo2 may represent vt1. Antennae ( Fig. 101 ) brownish-black with basal segments often paler; scape short cylindrical, 1.5X as long as wide bearing only short terminal bristles; pedicel globular, an apical circlet of fine setae longest below; postpedicel greatly elongated, at least 10X as long a broad, somewhat ventrally inflated basally (more apparent in wet material), distinctly pubescent with arista represented by a minute apical hair. Mouthparts yellow; palpi and labellum with pale hairs and setae; labium with posterior fringe of fine setae yellowish-brown.

Thorax: similar to female ( Figs. 82, 83 ); ground colour of mesonotum blackish, yellowish laterally between pprnlb and wing base, a median black stripe posteriorly on prescutellar depression and a pair of darker submedian stripes in front well marked and clearly visible from in front and above (even in wet-preserved material), a dark lateral marking extending from above pprnlb to postalar area and often joining submedian stripes anteriorly visible from above but fading in lateral view; pleura yellowish with 3 dark stripes of consignata pattern from pprnlb to base of wing, from below pcol to kat, and from side of pst over lower part of katepisternum and meron; front of pst and ventral region of katepisternum yellow. Dusting pattern of mesonotum with interstices between submedian and side stripes and median prescutellar stripe pale grey dusted strongly delimiting median, submedian and side stripes. Pleura with yellowish areas between dark stripes dusted greyish, intensity of dusting not so strong as to greatly obscure yellowish background. Dorsocentrals dc1, dc2 and dc3 strong, dc1 almost as long as dc2; dc5 small, fine; dc4 minute; sometimes a further minute dc between dc4 and dc5; acr developed, minute, irregularly biserial; np1, np2, pprn and sa bristles well developed, stronger than dc; ph small, fine with 2–3 smaller setae in front or behind; a pair of convergent scutellars and a postnotum with a few very fine setae. A few minute hairs on side of pst; anatergite with about 5 conspicuous black setae.

Legs: yellow, tibiae and tarsal segments darker. C 1 long, about 1.2X length of thorax, short-haired with some fine bristles apically; C 2 and C 3 with only short hairs on outer face and a few stronger bristles apically; C 3 with about 3 strong brownish-yellow bristles in front apically. Front trochanter with distinct dark dorsal hair.

F 1 same length as C 1, strongly inflated ventrally, widest 0.5 from base; femoral formula 5(3–5)/16(15–19)/ 13(12–15)/5(5–5), rows of denticles clearly separated from adjacent rows of spines but with a few denticles in posterior series apically tending to be more spine-like; basal ventral spine weak or absent but a few weak spines usually present continuing the line of and basal to the av series of spines; a few distinct apical hairs, otherwise short-haired. Mid and posterior femora and tibiae similar to C. consignata , pv bristle on F 2 0.7 from base distinct. T 1 shorter and stouter than in C. consignata , only 0.5 – 0.6X length of F 1, slightly curving and narrowed distally; ventral row of about 30 minute adpressed denticles with a similar number of rather erect fine hairs closely posteriorly; a few inconspicuous perpendicular cilia ventrally and dorsally. Front tarsi with rather erect hairs ventrally, particularly on at1, with more decumbent hairs elsewhere; at1 with a ventral series of about 15 minute brownish denticles; 1–8 perpendicular cilia dorsally and ventrally on all segments but ciliation labile and easily lost; at2 about 0.2X as long as at1. Mid and hind tarsi with segment 4 slightly shorter than segment 5; rather erect hairs and perpendicular ciliation distinguishable from otherwise decumbent chaetotaxy.

Wing: similar to C. consignata , membrane clear, veins brownish, Vein A 1 virtually absent and represented by little more than an impression in the membrane but stronger about the end of CuA 2. Squamae with blackish fringes. Halteres whitish-yellow.

Abdomen: brownish-black dorsally, paler ventrally; tergites with conspicuous dark marginal setae, strongest on posterior margins of tergites 1, 2 and 6, weaker on intermediate segments; tergite 7 almost bare; tergite 8 very narrow; sternites with only weak pale hairs.

Male genitalia very similar to C. cornigera (see figures for that species). Epandrium narrow, apically rounded bearing conspicuous long setae posteroapically and apically; hypandrium separated from epandrium, a pair of conspicuous dark setae posteriorly, almost as long as epandrial lobes and with a few smaller setae below cercus rather banana-shaped, separated from and subequal to epandrium, bearing fine setae apically and on inner face; Postgonite ( Fig. 38 ) with an apical lobe bearing two diverging setae and a rather palmate median lobe armed with 3–4 distinct fine setae.

Description. Female: similar to male but differing as follows; postpedicel ( Fig. 102 ) shorter than male, about 6–7X as long as wide, rather gradually narrowed apically with distinct arista 0.6 – 0.7X length of postpedicel. F 1 with strong black ventral bristle 0.2 from base but no weak spines continuing the line of and basal to the av series of spines; denticles of anterior row more numerous; femoral formula 5(5–5)/20(19–21)/15(13– 16)/5(5–6). Abdominal chaetotaxy weaker than male, tergites 7 and 8 not bare or narrowed; sternites 1–6 weakly sclerotized, sternites 7 and 8 slightly stronger sclerotized with numerous small hairs on disc as well as margins.

Comments. C. longicornis is a member of the C. consignata -group. It has black submedian stripes on the scutum which contrast strongly with the grey dusted surround; the postpedicel is very long with arista rather shorter in female and vestigial in male. The paler pleural ground colour, absence of distinct black and white striped dusting patterns on the side of the thorax and different relative lengths of the arista and postpedicel afford good characters to separate C. longicornis from C. cornigera . C. puhihiroa has similarly pale ground coloured pleura which are more strongly dusted, appearing rather black and white striped in dry specimens (but not as distinctly as C. cornigera ). The antenna of C. puhihiroa lacks an arista in both sexes and the postpedicel of the male is extremely long and thin. Differences in the male genitalia are small and inconspicuous. C. longicornis is known from forested mountainous regions of the central North Island and South Island of New Zealand on dates from November to February inclusive.

Figures

FIGURES 34–39. Male genitalia of Chelipoda spp. 34. C. lateralis sp. n. posterior view. 35–37. C. mirabilis Collin. 35. anterior view. 36. lateral view. 37. phallus. 38. C. longicornis Collin, apex of postgonite. 39. C. mediolinea sp. n. apex of epandrial lobe.

FIGURES 82–90. Thoracic ground colour and dusting pattern of Chelipoda spp. (schematic).

FIGURES 91–103. Antennae of Chelipoda spp. 91–92. C. abdita Collin. 91. ♀. 92. ♂. 93. C. abjecta Collin ♂. 94. C. modica Collin ♂. 95. C. consignata Collin ♂. 96. C. delecta Collin ♂. 97–98. C. cornigera sp. n. 97. ♀. 98. ♂. 99. C. delecta ♂ (basal segments omitted). 100. C. digressa Collin ♂. 101–102. C. longicornis Collin. 101. ♂. 102. ♀. 103. C. otiraensis (Miller) ♂.