Delia urbana ( Malloch, 1924 )

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 : 27-31

Delia urbana ( Malloch, 1924)

Figs 17–22 , 27, 28

Hylemyia urbana Malloch, 1924 a: 139 ; Harrison 1953: 10.

Hylemyia capensis Malloch, 1924 b: 263 , 265; Emden 1941 b: 265. Syn. n.

Delia urbana (Malloch) : Hennig 1953: 669, figs 1–4; 1974 b: 792; Colless 1982: 90.

Delia capensis (Malloch) : Pont & Ackland 1980: 716.

Diagnosis:

♂ Mid tibia with a small av in distal quarter; hind femur ( Fig. 27 ) with long av, longest (about middle) being fully twice as long as depth of femur and have curled fine tips directed apically.

Description:

Male.

Colour: Frontal stripe, parafrontals, parafacials, genae and face pale reddish orange to blackish, with thin greyish dust; occiput darker above. Antennae brownish, basal segments paler orange-brown. Palpi brown; prementum brownish with thin dust.Thorax and scutellum light brownish olive to greyish dusted, pleura slightly translucent, scutum with very faint or more distinct median and lateral vittae. Wing membrane pale orange tinged, veins orange-brown; squamae whitish with pale fringe. Legs pale brownish orange, hardly shining.Abdomen dusted light brownish grey, only faintly shining when viewed from above, viewed from behind faint median vitta visible. Prehypopygial tergites dusted, sternites orange-brown.

Head: Eyes narrowly separated posteriorly (by width of anterior ocellus); parafrontalia linear at this point, separated by very narrow frontal stripe which is hardly half width of anterior ocellus, widening anteriorly to slightly more than width of postpedicel; parafacial medially equal to width of postpedicel; peristomal margin not projecting, face almost flat, distance between vibrissal setae slightly more than distance between them and nearest eye margin; gena below lowest point of eye margin 0.25–0.30× eye height; 4 pairs of parafrontal setae on anterior half of frons; 1 pair of fine interfrontal setulae, slightly closer to upper frontal setae than to anterior ocellus; genal setae uniserial; postpedicel 1.6 times as long as wide, not reaching peristomal margin; arista slightly thickened at base, with very short pubescence. Proboscis rather short and slender, with short prementum (slightly shorter than palpi), about as wide as fore tibia. Upper occipital setulae fine and short, without setulae below row.

Thorax: Presutural acr absent (or represented by very fine hairs which are not longer or stronger than scutal accessory hairs), rows close together, acr: dc ratio 10:2:10; dc generally arising from small dark spots; 2 posthumeral setae; notopleural depression bare apart from 2 strong setae; prealar seta absent; scutellum with dorsal surface largely bare, dorsal preapicals short and fine, lower surface with a few fine pale hairs; 2 proepisternals without associated hairs, only 1 rather weak proepimeral without associated hairs; anepisternite without developed upper anterior setula; katepisternals 1+2 (lower p only slightly shorter than upper).

Wing: Vein C with anterior spinules short (not longer than diameter of C), stronger seta before distal break as long as small crossvein; lower surface of C bare. Large crossvein straight, last section of M 1+2 2.0–2.3× length of preceding section. Lower squama narrow, smaller in area than upper. Wing length about 4 mm.

Legs: Mid femur with 3–4 long pv in proximal half; hind femur ( Fig. 27 ) with 9–10 long erect av in distal half to 3/4, longest of them (medial) at least 2.5× height of femur, with their tips curled (bent or curved towards apex of femur), and numerous fine long pv; a and ad on hind femur are also long and numerous; fore tibia with 1 short fine ad and 2 pv, and a short pointed apical pv; mid tibia with 1 very short av, and 1 equally short ad, and 1 slightly longer pd; hind tibia with 2–3 av, 3–4 ad, 3 pd, without pv. Pulvilli somewhat enlarged (those of fore legs almost as long as tarsomere 5).

Abdomen: About 1.75 times as long as greatest width (at basal margin of tergite III), dorsoventrally compressed; sternite III ( Fig. 19 ) nearly as wide as sternite IV ( South Africa) to narrower than this ( Australia), with long marginal and discal setae ( Fig. 20 ). Sternite V processes ( Fig. 19 ) without setae on inner margins, lateral setae not quite as long as processes. Surstyli in caudal view ( Fig. 17 ) expanded medially, about twice as long as cercal plate; dorsal surface covered in fine erect hairs; in lateral view ( Fig. 18 ) more or less straight (slightly sinuate). Cercal plate 1.6 times as long as wide, with narrowly rounded apex. Pregonite with 2 distal setae; postgonite with minute setula. Distal section of aedeagus ( Fig. 21 ) rather short, 1.5× length of aedeagal apodeme, divided in distal half into pair of free paraphallic processes, and small weakly sclerotized plate-like acrophallus ( Fig. 22 ), level with base of paraphalli. Aedeagal apodeme 2.25 times as long as wide in dorsal view, excavated on dorsal surface. Ejaculatory apodeme 0.42× length of aedeagal apodeme.

Female.

Colour: Dark in ground colour with shifting brown and grey dusting; frontal stripe dark brown posteriorly, orange-brown on anterior half. Viewed from front at a low angle frontal triangle is light brownish grey dusted with dark brown velvety round patch between anterior ocellus and cruciate interfrontals, and similar patch surrounding ocellar tubercle; parafrontals brassy brown dusted when viewed from above, which becomes darker brown from in front; parafacials brassy dusted; genae with darker shifting brown patch behind vibrissal area; occiput grey to brownish dusted; prementum dark brown, thinly dusted, semi-shining in parts; palpi dark brown. Thorax dark in ground colour, with shifting brownish olive to grey dusting; scutum with traces of shifting vittae and semi-shining areas, viewed from behind darker medially, two wide lateral vittae which are very indistinct, lateral declivities lighter grey dusted; pleura with weakly shining brown patches, especially on anepisternite and katepisternum. Wing membrane weakly brownish tinged, hardly darker basally; squamae white with whitish fringe. Legs dark brown, weakly dusted and semi-shining.Abdomen dark in ground colour, viewed from above tergites with many shining patches, especially medially and laterally. Viewed from behind distinct shining black median vitta becomes visible, anterior margin of tergite III and posterior half of tergite IV darker, otherwise greenish grey dusted.

Head: Eyes separated by 1.45–1.50× their transverse width; frontal stripe at level of middle orbitals twice as wide as each parafrontal which widen anteriorly to slightly more than width of postpedicel; parafacial at narrowest part slightly less than width of postpedicel. Frontal setae differentiated into 3 pairs of lateroclinate orbitals, and 2 pairs of inclinate frontals (all in line); crossed interfrontals strong, placed just above middle of interfrontalia; gena below lowest point of eye margin 0.33× eye height; 4–5 anterior genal setae immediately posterior to subvibrissal setae biserial and upwardly directed; upper occipital setae with scattered row of setulae below. Prementum and proboscis as in male.

Thorax: 2–3 presutural acr, one pair longer than rest (half length of 1st presutural dc); notopleural depression bare, apart from two strong setae. Prealar seta short and fine, but distinct (0.3–0.5× length of posterior npl); scutellum with only 2–4 short hairs on disc; anepisternite without developed upper anterior setula; 2 proepisternal setae, one long, one short; one strong proepimeral seta with 2–3 associated hairs; katepisternals 1+1 (posterior seta with short hair below it).

Wing: Vein C with anterior spinules strong and rather long, those on section between costal breaks about 2.5× costal diameter, pair of stronger spines before distal break nearly 1.5× length of small crossvein; large crossvein straight, last section of M 1.7–1.8× preceding section; lower squama smaller in area then upper. Wing length 4.75 mm.

1+2

Legs: Mid femur with a short av in proximal half, 2–3 short pv in proximal half; hind femur ( Fig. 28 ) with 4–5 av in proximal half, which are slightly longer than greatest height of femur, only 2–3 short preapical pv; fore tibia with a strong ad (just below middle), a strong pv, more or less at same level; mid tibia with a small av, 1 long and strong ad, 1 pd, 2 pv; hind tibia with 2–3 av, 4 ad, 3 pd, without pv.

Abdomen: About 1.6 times as long as wide (at anterior margin of tergite III); tergites with rather short hindmarginal setae, most of them only half as long as tergites, including those on tergite V.

Types of urbana: Malloch described urbana from Sydney, Australia: 1 ♂ holotype, 8 ♂ paratypes, 2 ♀paratypes. His statement that the ‘types would be returned to Dr E.W. Ferguson.’ Dr A.C. Pont (pers. comm.) advises that these types were originally in the Sydney School of Public Health and Tropical Medicine, but were transferred recently to the ANIC.

Holotype of capensis : ♂: SOUTH AFRICA: ‘Holotype’ [white printed circular label with red perimeter]; ‘Capetown / Aug 1905 / G. A. K. Marshall / 1908–212’ [rectangular printed white label]; ‘ Hylemyia / capensis / Det. / J. R. Malloch Type’ [white rectangular printed and handwritten label with black border]. In good condition, examined during present study (BMNH).

Paratype of capensis : 1 ♂ same data as holotype. In fair condition, right fore and mid leg missing ( BMNH) . Other material examined: SOUTH AFRICA: Western Cape: 6 ♂ 8♀Cape Peninsula, Witsands Dunes , 25– 26.ix.1959 ( NMSA); 2 ♂ Brak R. mouth, Mossel Bay Dist. , 23.x.1964 ( NMSA); 1 ♂ Groot R. Pass, nr Plettenburg Bay , indigenous forest, 11.ix.1959 ( NMSA) .

Discussion: Hennig (1953: 669–670) was the first author to provide drawings of the genitalia of urbana , based on two males from Australia in the DEI. Harrison (1953: 10) reported that a female of urbana was identified in Auckland, New Zealand, in an aeroplane coming from Sydney in April, 1952.

Colless (1982: 90) suggested that urbana (along with four other species of Australian Anthomyiidae ) might be an introduced species, and compared urbana with dispar Bezzi (= arambourgi Séguy ). D. urbana is in fact easily distinguished from dispar (the latter having longer aristal hairing and the male hind femur with shorter av on hind tibia which do not have fine and curling tips). I have examined many specimens of urbana from Australia and can find no difference (including the genitalia) from specimens (including the types) of capensis from Africa. I therefore synonymize the two names. Malloch’s paper describing urbana was published on 2 July 1924, and his paper describing capensis in September of the same year. The distribution of urbana is similar to that of Anthomyia punctipennis Wiedemann which is found both in Africa and the Australian region, and both species are probably introductions to the latter area.

Life history: Colless (1982: 90) mentions a single record of urbana from cocoon masses of a pergid sawfly; otherwise there are a few known rearings from grass including Cynodon dactylon (L.). There are no breeding records from Africa.

Distribution: Australia (New South Wales, Queensland), New Zealand, and South Africa.

Figures

Figs 17–22. Delia urbana, male (S. Africa): (17) cercal plate and surstyli; (18) ditto, lateral view; (19) sternites III–V, ventral view: (20) ditto, lateral view; (21) distiphallus, lateral view; (22) ditto, ventral view. Scale bar = 0.1 mm.

Figs 23–30. Hind femur and arista: (23–28) Hind femora: (23) Delia flavibasis, male; (24) D. arambourgi, male; (25) D. bracata, male; (26) ditto, female; (27) D. urbana, male; (28) ditto, female; (29, 30): Arista, male: (29) D. arambourgi, (30) D. bracata.