Delia kigeziana ( Emden, 1941 )

Ackland, D. M., 2008, Revision of Afrotropical Delia Robineau-Desvoidy, 1830 (Diptera: Anthomyiidae), with descriptions of six new species, African Invertebrates 49 (1), pp. 1-75 : 46-50

Delia kigeziana ( Emden, 1941)

Figs 47 , 72–77

Hylemyia kigeziana Emden, 1941 b: 266 ; 1951: 360.

Delia kigeziana (Emden) : Pont & Ackland 1980: 716.

Diagnosis:

♂ Genal setae biserial; upper occipital setulae long and fine, with numerous setulae below row; abdomen long and narrow; sternite V processes ( Fig. 74 ) longer than base with very long lateral setae which have curling tips (longest nearly twice as long as processes).

Description:

Male.

Colour: Frontal stripe, parafrontals, parafacials, genae and face black in ground colour, with greyish dusting which varies from light grey to dark grey depending on point of view; parafacial at level of aristal base, when viewed from directly in front, dark grey, contrasting with light grey dusted interfrontalia, genae and face; occiput dark grey. Antennae black, arista black. Palpi brownish black; prementum of proboscis black, thinly dusted. Thorax black in ground colour, with fairly dense shifting brownish grey dusting, pleura slightly shining in places; with 3–5 darker brown vittae which when viewed from in front with wide median vitta (wider than acr rows), two narrow vittae along dc rows (setae arising from dark spots), and two wide diffused lateral vittae; viewed from behind these vittae are more distinct as grey dusting between vittae is more paler and distinct; scutellum with trace of median brown vitta. Wing membrane very faintly brownish, base more brownish; veins brown; squamae whitish, fringe pale. Legs brown, thinly grey dusted, slightly shining. Abdomen black in ground colour, grey dusted when viewed from behind, with distinct wide black vitta (more than half width of abdomen) extending across anterior margins of tergites; tergites are partly shining from certain viewpoints. Prehypopygial tergites grey dusted.

Head: Eyes narrowly separated posteriorly (by diameter of anterior ocellus), frontal stripe at narrowest part half diameter of anterior ocellus); parafacial at level of arista slightly less than width of postpedicel, but becoming half this width below; peristomal margin hardly projecting, gena below lowest point of eye margin 0.25× eye height; face almost flat, distance between vibrissal setae more than distance between them and nearest eye margin; 4–5 pairs of parafrontal setae; 1 pair of fine interfrontal setulae of upper half of frons; genal setae biserial (1–3 upturned setae anteriorly above proclinate lower row). Postpedicel twice as long as wide, not reaching peristomal margin (by 1/3 its width); arista pubescent, longest hairs slightly longer than basal aristal diameter. Proboscis short and slender, with short prementum (not as long as palpi and as wide as fore tibia). Upper occipital setulae long and fine, with numerous setulae below row.

Thorax: 6 pairs of presutural acr, longest pair about half length of 1st presutural dc; acr: dc ratio 10:3:10, no hairs between rows; 2 posthumeral setae; notopleural depression bare apart from two strong setae; prealar varying from half length of posterior npl, to absent in some specimens; scutellum bare on disc centrally and basally; anepisternite without developed upper anterior setula; katepisternals 1+2(3), lower posterior nearly as long as upper.

Wing: Vein C with anterior spinules as long as diameter of C, stronger spines before distal break at least twice this length, longer than small crossvein; lower surface of C bare. Large crossvein almost straight, last section of M 1+2 1.6–1.7× length of preceding section. Lower squama shorter than upper and smaller in area. Wing length 5.5–5.7 mm.

Legs: Mid femur with 4 long pv in proximal half; hind femur with 5–6 long av on whole length (slightly longer than depth of femur, without curling tips), about 2–3 pv towards apex; fore tibia without pv apical, 1 ad, 1 pv; mid tibia without av, 0–1 ad, 1 pd at same level, 2 pv; mid tarsomere 1 with some slightly lengthened setae on dorsal surface (all same length, not fringe of long curved setae as in metatarsata ); anterior and posterior setae on each mid tarsomere short and of equal length; hind tibia with 2–3 av, 4 ad, 3 pd, 3 pv in basal half. Pulvilli of fore legs slightly shorter than tarsomere 5.

Abdomen: Long and narrow, 3.5 times as long as greatest width, parallel-sided from tergites II to V, dorsoventrally compressed; sternite V somewhat projecting in lateral view; sternite III is 1.7 times as long as wide; sternite IV is 1.4 times as long as wide; both sternites III and IV ( Fig. 74 ) with short discal and lateral setae; sternite V processes ( Fig. 74 ) longer than base, with a few fine setulae on inner margins, lateral setae very long, with curling tips (longest nearly twice as long as processes, and very visible in dried specimens). Surstyli twice length of cercal plate ( Fig. 72 ), in caudal view ( Fig. 72 ) apical half narrower, inner margins sinuate, clothed with short setulae and hairs medially, in lateral view ( Fig. 73 ) more or less straight, slightly sinuate apically. Cercal plate 1.2 times longer than wide, heart-shaped, apex rounded, bearing a few short setae apically. Pregonite ( Fig. 75 ) becomes narrower apically, with 2 setae; postgonite without setae. Aedeagus with distal section ( Figs 76, 77 ) 1.4× length of aedeagal apodeme, divided into pair of short free paraphallic processes, dorsal prolongation slightly shorter. Acrophallus absent. Aedeagal apodeme in dorsal view 2.5 times as long as greatest width, excavated on dorsal surface. Ejaculatory apodeme 0.3× length of aedeagal apodeme, expanded at one end.

Female.

Colour: More densely grey dusted than male. Head dark in ground colour, with dense brownish grey dust, less shifting than in male; frontal stripe varying from entirely dark brown to orange-brown in anterior half; parafacials at level of antennal base without shifting darker sheen-stripe or darker dusting; parafrontals darker on inner margins (along orbital setae); genae with brownish patch anteriorly close to vibrissa; occiput grey dusted; prementum thinly dusted, palpi dark brown. Thorax rather densely olivegrey dusted, with 3–5 vittae (as in male), those along dc more or less restricted to darker spots at bases of setae. Scutellum with brown median vitta (continuation of scutal median vitta as in male). Wing membrane tinged brownish grey, veins brown. Legs brownish black. Abdomen dark in ground colour, with wide median vitta (not as wide as in male).

Head: Eyes widely separated (by 1.6–1.7× their transverse width); frontal stripe at level of middle orbitals twice as wide as each parafrontal; parafrontals widening anteriorly to width of postpedicel. Parafrontal setae differentiated into 3 pairs of orbitals (all more or less exclinate), and 3 pairs of inclinate frontals, all in line; crossed interfrontal setae strong, placed at apex of frontal triangle; gena below lowest point of eye margin 0.5× eye height; genal setae uniserial. Proboscis relatively small and thin (as in male), prementum as long as palpi.

Thorax: acr shorter and finer than in male (hardly differentiated from accessory setulae and hairs); acr: dc ratio 10:2:10; 1+1 posthumerals; katepisternals 1+1 (sometimes short hair present below posterior seta). Prealar seta shorter than in male, sometimes completely absent.

Wing: Vein C with moderately long marginal spinules (twice as long as diameter of C), stronger pair before distal break equal to or longer than length of small crossvein; large crossvein straight, last section of M 1+2 nearly twice (1.85×) length of preceding section. Wing length 4.5 mm.

Legs: Hind femur with 6 av (4 in distal half), and 1–2 apical pv; fore tibia with 1 ad, 1 pv; mid tibia without av, 1 long ad and 1 slightly shorter pd at same level, 1–2 pv; hind tibia with 2 av, 4 ad, 3 pd (distal one longest), 2 erect pv in basal half.

Abdomen: Postabdomen when fully extended about as long as preabdomen.Very similar to D. bracata Rond. , differing only as follows: sclerites of sternite VIII ( Fig. 48 ) each with 3–4 setulae on posterior margin; sternite X more robust and posterior margin more rounded.

Lectotype (examined): ♂ ‘LECTOTYPE’ [white circular printed label with purple border]; ‘S. W. UGANDA / Kigezi Province / xi.1934 / B.M.E. Afr. Exp. / B. M. 1935-203’ [rectangular printed white label]; ‘Summit of / Mt Sabinio / 11–11500 ft / J. Ford’ [rectangular printed white label] ( BMNH) . Lectotype fixed by Emden (1951: 361). In reasonable condition, with left hind tarsus missing.

Paralectotypes (all BMNH): UGANDA: 14 ♂ 5♀Kigezi Prov., Mt Sabinio , alt. 11000–11500 ft, xi.1934, J. Ford; 15 ♂ 4♀Kigezi Dist., Mt Mgahinga , alt. 10000–11000 ft, xi.1934, F.W. Edwards; 1 ♂ 1♀same locality, alt. 8000 ft, 20.xi.1934, F.W. Edwards; 7 ♂ 5♀same locality, alt. 11000 ft, 22.xi.1934. F.W. Edwards; 1♀Mt Muhavura, 13500 ft, xi.1934, J. Ford; 1 ♂ 1♀Kigezi Dist., Mt Muhavura, alt. 10000–12000 ft, 20.xi.1934, F.W. Edwards; 1 ♂ Kigezi Dist., Kanaba , alt. 7800 ft, xi.1934, F.W. Edwards.

Discussion: Emden (1951: 36) listed 1 ♂ type, 43 ♂ and 22♀paratypes of D. kigeziana making a total of 66 specimens; I have only found 1 ♂ lectotype, 39 ♂ and 18♀paralectotypes, making a total of 58 specimens. The whereabouts of the other types is unknown. D. kigeziana are apparently known only from the original material.

Life history: Unknown.

Distribution: S.W. Uganda, at altitudes 2377–4115 m.

Figures

Figs 44–49. Delia spp., female abdomen, terminal segments, ventral view: (44) D. bracata (Zimbabwe); (45) D. arambourgi (Kenya); (46) D. ventralis (Uganda); (47) D. steiniella (Ethiopia); (48) D. kigeziana (Uganda); (49) D. tibila sp. n., female paratype (Ethiopia). Scale bar = 0.1 mm.

Figs 72–77. Delia kigeziana, male paratype (Uganda): (72) cercal plate and surstyli; (73) ditto, lateral view; (74) sternites III–V; (75) gonites; (76) distiphallus, lateral view; (77) ditto, ventral view. Scale bar = 0.1 mm.