Delia metatarsata
Creators: name: Ackland, D. M.
Publisher: name: Zenodo
Year: 2008
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Diptera
Anthomyiidae
Delia
Delia metatarsata

description: Delia metatarsata (Stein, 1914)
Figs 101, 119–124
Chortophila metatarsata Stein, 1914: 136; 1919: 154.
Hylemyia metatarsata (Stein): Emden 1941 b: 267; 1951: 367.
Delia metatarsata (Stein): Pont & Ackland 1980: 716.
Diagnosis:
♂ 3–4 pairs of long presutural acr, one pair longer than the others; 3 posthumeral setae; base of wing brownish and large crossvein sinuate; hind femur without pv; fore tibia with a long straight blunt preapical pv; mid tarsomere 1 with long dorsal fringe; tergites IV and V (Fig. 122) with hindmarginal setae not longer than tergites; surstyli (Fig. 119) in lateral view straight.
Description:
Male.
Colour: Frontal stripe, parafrontals, parafacials, genae and face black in ground colour, with shifting thin brownish grey dust; parafacials from above whitish grey dusted (tinged with pink), at level of aristal base with pale bluish grey dust depending on point of view. Antennae dark brownish black, with brown dust, arista dark brown. Palpi black; prementum of proboscis black dusted. Thorax and pleura dark in ground colour, with brownish grey dusting, traces of 5 dark vittae when viewed from behind: wide median vitta, 2 narrow vittae which in line with presutural dc, stopping short of suture, and postsuturally pale dusted; and 2 wide lateral setae; scutum semi-shining from some angles; scutellum concolorous with scutum. Wing membrane brownish tinged in basal half, but not on posterior half of wing; veins brown; squamae whitish, upper squama with brown border, lower squama pale bordered. Legs black, slightly shining.Abdomen black in ground colour, densely dusted dark grey, when viewed from behind, dust becomes paler; wide black median vitta present, covering central third of each tergite and widening on basal and posterior margins of each tergite so that latter (and lateral margins) are black. Sternites, prehypopygial tergites and genitalia brownish black.
Head: Eyes narrowly separated posteriorly (by 1.2–1.0× diameter of anterior ocellus), frontal stripe distinct throughout (at narrowest part by slightly less than diameter of anterior ocellus); parafacial medially equal to width of postpedicel; peristomal margin slightly projecting, face concave, distance between vibrissal setae more than distance between them and nearest eye margin. Gena below lowest point of eye margin 0.30– 0.37× eye height; genal setae biserial posteriorly, with 5–6 strong upcurved uniserial setae level with anterior eye margin. 6–7 pairs of strong parafrontal setae, which mainly inclinate and cross each other (interspersed with a few finer setulae); 1 pair of interfrontal setulae on upper half of frons (closer to anterior ocellus than to lunule). Postpedicel not quite twice as long as wide, not reaching peristomal margin (by half its width); arista with very short pubescence, longest hairs not as long as aristal diameter. Proboscis short and slender, with short prementum (about as long as palpi and as wide as fore tibia). Upper occipital setulae long and fine, with numerous setulae below row, lower part of occiput with rather long dense coarse setulae.
Thorax: 3–4 pairs of long presutural acr, one pair longer than rest (0.6× length of posterior presutural dc); acr: dc ratio 10:10:10, with a few fine hairs between rows; 3 posthumeral setae, outer seta about half length of others, with some long hairs around base; notopleural depression bare apart from two strong setae; prealar short and fine, but distinct (0.5–0.6 length of posterior npl); scutellum bare on disc centrally and basally; anepisternite without developed upper anterior setula; katepisternals 1+2, lower posterior nearly as long as upper, with numerous rather long hairs on disc.
Wing: Vein C with anterior spinules short and weak, hardly as long as diameter of C, spines before distal break hardly differentiated from anterior spinules; lower surface of C bare. Large crossvein strongly sinuate, last section of M 1+2 equal to length of preceding section. Lower squama smaller in area than upper. Wing length 5.5–6.0 mm.
Legs: With rather lengthened and semi-erect hairs on tibiae. Mid femur with full row of short av which longer basally, and full row of longer pv; hind femur with about 6–7 long av in distal half, merging into shorter and more numerous av in basal half, no pv; fore tibia with long straight blunt preapical pv and 1 long median pv; mid tibia without av, 0–1 ad, 1 pd, 2 pv; mid tarsomere 1 with long dorsal fringe of curved setae and with posterior apical setulae on each tarsomere longer than anterior setulae; hind tibia with 2 av, 7–8 ad, 2 pd, 12–15 erect pv on almost whole length.
Abdomen: About 1.8–2.0 times as long as greatest width (at basal margin of tergite III), dorsoventrally compressed; stronger hindmarginal setae on tergites IV and V (Fig. 122) not longer than length of tergites. Sternite V (Fig. 121) short (1.3 times as wide as long); sternite IV (Fig. 121) is 1.4 times as wide as long (wider posteriorly) with numerous long lateral setae; sternite V (Fig. 121) with processes longer than base, with about 5 long fine setulose hairs on inner margins, lateral setae long and numerous; apex of processes with 1 short and rather blunt setae amongst 2–3 finer pointed seta. Surstyli (Fig. 119) about as long as cercal plate, narrow in caudal view, with some long setulae on inner margins in basal half, in lateral view (Fig. 120) more or less straight. Cercal plate twice as long as wide, with 8–10 very long bent setae apically, and pair of longer median lateral setae. Aedeagus with distal section (Figs 123, 124) 1.35× length of aedeagal apodeme, divided on slightly less than distal third (0.30) into pair of free paraphallic processes and dorsal prolongation of about same length.Acrophallus absent. Aedeagal apodeme in dorsal view weakly expanded anteriorly, 4.2 times as long as greatest width. Ejaculatory apodeme 0.24 times as long as aedeagal apodeme, expanded at one end.
Female. As in male except for the following:
Colour: Frontal triangle dusted light brownish; parafrontals dark brownish dusted, darker than parafacials; gena with shifting brownish patch anteriorly adjacent to vibrissa; wing membrane as in male, but wing base not so infuscated.
Head: Eyes widely separated (by 1.20× their transverse width); frontal stripe at level of middle orbitals 1.6× width of parafrontal; parafrontalia widening anteriorly to slightly more than width of postpedicel. Parafrontal setae differentiated into 5 pairs of orbital setae (more or less exclinate) and 5 pairs of frontal setae (more or less inclinate), all strong; uppermost 4 pairs of frontal setae overlap anterior 3(4) pairs of orbital setae, so that setae biserial in middle of parafrontal; crossed interfrontal setae strong, placed at apex of frontal triangle; gena below lowest point of eye margin 0.4× eye height.
Thorax: 3 posthumerals; katepisternals 1+2, lower posterior setae short and fine. Prealar seta as in male. Wing length 6.1 mm.
Legs: Fore tibia with 1 ad, 1 pv; mid tibia without av, 3 strong ad, 3 strong pd, and 2 long pv; hind tibia with 3 av, 6 ad, 4 pd.
Abdomen: Postabdomen when fully extended about as long as preabdomen. Tergites VI and VII weakened centrally but with continuous row of setulae along posterior margin. Spiracles 6 and 7 both situated on tergite VI, spiracle 6 medially on lateral margin, spiracle 7 laterally on posterior margin (in row of setulae); sternites VI and VII oblong, 4 times as long as wide with a few posterior setulae. Tergite VIII divided into 2 elongate plates which become wider anteriorly, but continuous along posterior margin which bears about 12 longer setae; sternite VIII (Fig. 101) represented by pair of elongate sclerites which pointed on inner posterior corner and each bear 7–8 laterally directed setulae medially; sternite X setulose and pilose; cerci not projecting significantly beyond tip of sternite X, bearing pair of long setulae. Three spermathecae of equal size, almost spherical, 0.040× 0.035 mm.
Holotype: Stein described this species from a single male collected on Mt Kenya, alpine prairies with Senecio arborescens, 4000–4100 m, ii.1912. The location of this holotype is unknown, and is presumed lost.
Material examined: KENYA: 8 ♂ 2♀Aberdare Range, Mt Kinangop, alt. 12000 ft, 30.x.1934, F.W. Edwards (BMNH).
Discussion: There is little doubt about the identity of D. metatarsata. Stein’s figures (1914: 137) of the dorsal fringe on mid tarsomere 1 and the darker base to wing can only refer to this species.
Life history: Unknown.
Distribution: Only recorded from Kenya (Mt Kenya and the Aberdare Range).
description: Published as part of Ackland, D. M., 2008, Revision of Afrotropical Delia Robineau-Desvoidy, 1830 (Diptera: Anthomyiidae), with descriptions of six new species, pp. 1-75 in African Invertebrates 49 (1) on pages 64-67, DOI: 10.5733/afin.049.0101, http://zenodo.org/record/7665342