Chelipoda secreta Collin

Published, First, 2007, The Hemerodromiinae (Diptera: Empididae) of New Zealand II. Chelipoda Macquart, Zootaxa 1537 (1), pp. 1-88 : 40-41

24. Chelipoda secreta Collin

[ Figs. 57–59 , 85, 88 , 108, 110 , 123 ]

Chelipoda secreta Collin, 1928: 35 .

Type material. Collin (1928) described Chelipoda secreta from a female from White Rock, 26–28.xi.1922, J. W. Campbell and another female from Paradise, xii.1922, C. C. Fenwick [ BMNH]. Both localities are in New Zealand, South Island. The female from White Rock, 26–28.xi.1922 is here designated lectotype . The female from Paradise, xii.1922 is here designated paralectotype.

Additional material: 11♂, 31♀, mostly South Island locations from Westland to the Malborough Sounds with a single record from Stewart Is ; the few North Island records are scattered from the Tararua Ranges [ WN], the Volcanic Plateau [TO] and the Auckland [AK] region [ NZAC, NMWC, LUNZ] .

Description. Male: length = 3.5–4.5mm.

Head: brownish black, paler at front of frons, dusted greyish; face rather yellowish, covered with silver pile; lpo 3–4 serial, pale; upo uniserial, black; vt1 and vt2 strong and clearly differentiated from line of upo; ocl strong, black, about 2X length of verticals; ft minute and a pair of minute setae behind ocellar triangle.

Antenna: ( Fig. 110 ) with basal segments yellow; postpedicel blackish, elongate conical, about 9X as long as wide at base, arista 0.3X as long. Mouthparts yellow, palpi narrow bearing a few yellow hairs, labellum with distinct yellowish setae behind, becoming darker basally.

Thorax: mesonotum with yellowish brown broad median stripe of ground colour ( Fig. 85 ), partially fading in prescutellar depression and often darker at edges forming blackish submedian lines; a black marginal stripe from dc1 across unp to above base of wing; pprnlb anteriorly, interstices between submedian and lateral stripes and area from in front of wing across lnp to pprnlb clear yellow. Pleura ( Fig. 88 ) clear yellow with three dark stripes between anterior spiracle and root of wing, between anterior spiracle across lower anepisternum to posterior spiracle and from sides of prothoracic episternum across lower katepisternum and lower mr. Mesonotum dusted grey, edges of broad median stripe usually appearing as black submedian stripes when viewed from in front but disappearing in other views; pleural dusting not obscuring black and yellow ground colour stripes. Thoracic setae black, dc1 and dc2 strong, dc3, dc4 and dc5 small or absent; unp and sa of equal length (approx. 2X length of dc1), lnp smaller, acr minute, one pair of convergent apical sct.

Legs: slender, yellow, dusky on terminal tarsal segments; C 1 ( Fig. 123 ) almost 2X as long as thorax, slightly and evenly curved, a dense fringe of adpressed pale hairs beneath and a few black apical bristles; C 2 and C 3 much shorter, C 3 with a strong yellow anteroapical spine and a black posteroventral bristle. F 1 elongate, about as long as and only slightly wider than C 1; femoral formula 3(2–3)/17(15–19)/12(9–13)/7(5–8), the double row of denticles confined to distal 0.5 and anterior row of spines starting 0.3 from base, all equally strong; posterior row of spines becoming shorter and finer distally; a strong ventral bristle 0.2 from base. T 1 0.5X as long as F 1, slightly narrowed distally, about 30 minute adpressed denticles ventrally with an adjacent series of outstanding minute hairs and less numerous perpendicular cilia; about 3 perpendicular cilia dorsally situated amongst short adpressed hairs. Mid and hind legs simple, slender, T 2 with a distinct small pv about 0.7 from base and sometimes a few additional bristles between it and apex. MT 1 with a row of perpendicular cilia ventrally and a few dorsally; tarsal segments rather longer haired dorsally, at2 about 0.7X length of at3; at1 with a small erect bristle and a few perpendicular cilia amongst decumbent hairs dorsally and a series of more erect hairs and perpendicular cilia ventrally.

Wing: clear with brownish yellow veins; A 1 absent represented at most by a slight darkening of the membrane about the end of CuA 2. Halteres whitish.

Abdomen: tergites brown with distinct hind marginal setae, strongest on segments 1 and 2 and at sides of segment 6; sternites paler, short haired.Male genitalia ( Fig. 57–59 ) very similar to C. cornigera sp. n.; epandrium narrow, apically rounded bearing conspicuous long setae at sides, apically and posteroapically; hypandrium separated from epandrium, two pairs of long conspicuous setae posteriorly, cercus rather bananashaped, separated from and almost reaching to apex of epandrium, bearing fine setae apically and on inner face; postgonite ( Fig. 59 ) rather prominent, an apical lobe bearing two diverging setae, a median lobe with 4– 5 short setae and a smaller basal lobe (see figure).

Description. Female: Differing from the male as follows:-

Antenna: ( Fig. 108 ) shorter with proportionately longer arista, postpedicel 4X as long as wide, arista equally long.

Thorax: mesonotum with black submedian stripes imparted by dusting pattern usually stronger (recalling C. longicornis ) and more generally visible from differing perspectives.

Legs: shorter and less slender than male; C 1 about 1.3X as long as thorax, linear, without fringe of adpressed hairs beneath; F 1 slightly shorter than C 1, distinctly inflated ventrally, widest 0.5 from base; femoral formula 3(3–5)/16(13–19)/12(11–13)/5(4–6); tarsi shorter haired dorsally.

Abdomen: brown dorsally, paler ventrally, short haired; cerci dark brown with fine longish hairs.

Comments. C. secreta is in the C. consignata -group with black submedian stripes on the scutum strongly contrasting with grey dusted surround. It is allied with C. longicornis but the female has postpedicel shorter and C 1 very long with a strong fringe of adpressed hairs in the male. The pattern of mesonotal dusting in which the submedian stripes are black and strongly differentiated for the surround is less well developed in C. secreta (particularly males) than in C. longicornis , C. cornigera and C. puhihiroa . However the colour and shape of the antennae, poor development of dc3, and in males the exceptionally elongate legs provide ready recognition features.

C. secreta is widespread, occurring on North, South and Stewart islands although most records are from South Island in a variety of mountain and coastal forests, scrub and roadside situations. The species has most frequently been found by sweeping undergrowth but also in FIT, Malaise, yellow pan and light traps. Adults are active from late November and early February.

Figures

FIGURES 56–62. Male genitalia of Chelipoda spp. 56. C. rakiuraensis sp. n. posterior view. 57–59. C. secreta Collin. 57. anterior view. 58. posterior view. 59. apex of postgonite. 60–61. C. tainuia sp. n. 60. lateral view. 61. apex of phallic structure. 62. C. trepida Collin, posterior view.

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

FIGURES 104–116. Antennae of Chelipoda spp. 104–105. C. monorhabdos sp. n. 104. ♀. 105. ♂. 106–107. C. puhihiroa sp. n. 106. ♀. 107. ♂. 108. C. secreta Collin ♀. 109. C. rakiuraensis sp. n. ♂. 110. C. secreta Collin, ♂. 111. C. tainuia sp. n. ♂. 112. C. trepida Collin ♂. 113. C. venatrix sp. n. ♂. 114. C. tangerina sp. n. ♂. 115–116. C. didhami sp. n. 115. ♀. 116. ♂.

FIGURES 117–123. Legs of Chelipoda spp. 117–119. C. abdita Collin. 117. ♀ right mid leg, posterior view. 118. ♀ right posterior leg, posterior view. 119. ♂ front leg, posterior view. 120. C. inconspicua Collin ♀ front leg, posterior view. 121. C. otiraensis (Miller) ♂ front leg, anterior view. 122. C. tangerina sp. n. ♂ front leg, posterior view. 123. C. secreta Collin ♂ front leg, posterior view.