Prosoeca ora, Theron & Ellis & Midgley, 2025

Theron, Genevieve L., Ellis, Allan G. & Midgley, John M., 2025, A revision of a spring-active clade of Prosoeca Schiner, 1867 (Diptera, Nemestrinidae), keystone pollinators from the Greater Cape Floristic Region in South Africa, with descriptions of three new species, ZooKeys 1257, pp. 249-284 : 249-284

publication ID	https://doi.org/10.3897/zookeys.1257.155954
publication LSID	lsid:zoobank.org:pub:7D8BD25C-6BBF-44AE-8E5F-0B055043E470
DOI	https://doi.org/10.5281/zenodo.17485617
persistent identifier	https://treatment.plazi.org/id/38EAD2FB-03B0-5E85-8C87-D9CED1CE7E39
treatment provided by	ZooKeys by Pensoft
scientific name	Prosoeca ora
status	sp. nov.

Treatment

Prosoeca ora sp. nov.

Figs 1 View Figure 1 , 2 B View Figure 2 , 2 C View Figure 2 , 3 E View Figure 3 , 4 E View Figure 4 , 5 E View Figure 5 , 6 E View Figure 6 , 8 C, D View Figure 8

Type material.

Holotype: South Africa: • 1 ♂, Northern Cape: Hantam Botanical Garden ; 27 Aug. 2017; T. van der Niet leg.; NMSA -DIP 219345 ; NMSA . Paratypes: South Africa: • 2 ♀♀ Northern Cape: Nieuwoudtville ; 26 Aug. 1999; P. Goldblatt & J. Manning leg.; visiting Babiana vanzyliae ( Iridaceae ); NMSA -DIP 79017 , NMSA -DIP 79018 ; NMSA . • 1 ♂ Northern Cape: Sutherland: Komsberg ; J. Manning leg.; NMSA -DIP 54396 ; NMSA . • 1 ♀ Northern Cape: Calvinia: Hantamsberg ; 3 Sep. 1994; 29; on Pteronia incana ; NMSA -DIP 54393 , [handwriting of Dr. J. Manning]; NMSA . • 1 ♂ Western Cape: Middelpos: Gannaka Pass ; 1 Jul. 1993; NMSA -DIP 76672 , [handwriting of Dr. J. Manning]; NMSA . • 1 ♂ 4 ♀♀ Northern Cape: Sutherland: Ouberg ; 24–25 Sep. 2022; visiting Dimorphotheca cuneata ; Allan Ellis leg.; NMSA -DIP 219360 – NMSA -DIP 219364 ; NMSA . • 1 ♀ Northern Cape: Smoushoogte Pass: De Plaat ; 32.81363°S, 20.70072°E; 17 Oct. 2008; Anton Pauw leg.; AP 414; NMSA -DIP 221842 ; NMSA GoogleMaps . • 1 ♀ Northern Cape: Nieuwoudtville: Greylon Renosterveld ; 03 Oct. 2012; Anton Pauw leg.; AP 674; visiting Hesperantha cucullata ; NMSA -DIP 221843 ; NMSA . • 1 ♀ Northern Cape: Nieuwoudtville: Glenlyon; Renosterveld ; 3 Sep. 2012; Anton Pauw leg.; AP 675; RMCA -ENT 000056701 ; RMCA . • 1 ♂ Northern Cape: Nieuwoudtville: Glenlyon; Renosterveld ; 3 Sep. 2012; Anton Pauw leg.; AP 676; RMCA -ENT 000056702 ; RMCA .

Other material examined.

South Africa: • 1 ♀ Western Cape: Maitjiesfontein Koppie : E. Soetwater; 07 Sep. 2019; Allan Ellis leg.; NMSA -DIP 219351 ; NMSA . • 2 ♂♂ Northern Cape: Hantam Botanical Garden ; 27 Aug. 2017; T. van der Niet leg.; NMSA -DIP 219344 , NMSA -DIP 219346 ; NMSA . • 3 ♂♂ Northern Cape: Hantamsberg ; - 31.39563°S, 19.78919°E; 18 Sep. 18; Florent Grenier leg.; NMSA -DIP 219348 – NMSA -DIP 219350 ; NMSA GoogleMaps . • 1 ♂ Western Cape: 7 km N of Wuppertal: North slope ; 32°14'S, 19°10'E; 780 m; 31 Aug. 1995; J & A Londt leg.; Flowers; NMSA -DIP 50966 ; NMSA GoogleMaps . • 1 ♀ Western Cape: 7 km N of Wuppertal: North slope ; 32°14'S, 19°10'E; 780 m; 31 Aug. 1995; J & A Londt leg.; Flowers; NMSA -DIP 76690 ; NMSA GoogleMaps . • 1 ♂ 1 ♀ National Road 22 m from Touws River ; 3 Oct. 1964; B. & P. Stuckenberg leg.; NMSA -DIP 52836 , NMSA -DIP 78337 ; NMSA . • 1 ♂ Nothern Cape: Middelpos: Gannaka Pass ; 1 Jul. 1993; NMSA -DIP 51673 [handwriting of Dr. J. Manning] • NMSA . 2 ♂♂ Northern Cape: Smoushoogte Pass: De Plaat ; 32.81363°S, 20.70072°E; 17 Oct. 2008; Anton Pauw leg.; AP 414; visiting yellow annual Pseudoselago ; NMSA -DIP 221840 - NMSA -DIP 221841 ; NMSA GoogleMaps . • 1 ♀ Western Cape: Heuningvlei ; 32.20636°S, 19.07513°E; # SIM 1207 C; SI Morita leg.; Prosoeca peringueyi ; CDFA -ENT; CDFA GoogleMaps . • 1 ♀ Northern Cape: Nieuwoudtville: Trekpad ; 3 Sep. 2012; Anton Pauw leg.; AP 673 RMCA -ENT 000056703 ; RMCA . • 1 ♂ Northern Cape: Sutherland: Smoushoogte ; 32°48'49.1"S, 20°42'02.6"E; 7 Oct. 2008; Anton Pauw leg.; AP 415; RMCA -ENT 000056704 ; RMCA GoogleMaps .

Diagnosis.

Medium-sized (length 10–17 mm), thorax dark, scutellum and thorax with conspicuous grey border, abdomen black but tergites interrupted medially by a pale grey band, often flaring out posteriorly, and a dark brown median vitta, femora dorsally darker than tibia and tarsi, proboscis length 0.7 ± 0.02 × the length of the body (range of un-extended proboscis length 6–11 mm). Prosoeca ora sp. nov. can be distinguished from all other species in the clade by the distinct grey, brown and black patterning on the abdomen (Figs 2 B, C View Figure 2 , 3 E View Figure 3 ). Unlike P. parva sp. nov. which has hyaline wings, the wings of P. ora sp. nov. are infuscated on the anterior ¼ with a relatively straight costal margin in both sexes, whereas P. aquilo sp. nov. has a slight flexure in the costal margin of males (Fig. 5 D – F View Figure 5 ). Prosoeca ora sp. nov. has a proboscis that is shorter than the length of its own body, unlike P. marinusi , P. torquata , and P. peringueyi .

Description.

Male. Body length: mean 13.8 mm; range 10–17 mm ( n = 19). Intertegular width: mean 6.5 mm; range 4–8 mm ( n = 9). Proboscis length: 9.7 mm; range 6–11 mm ( n = 18). Wing length: mean 15.4 mm; range 11–18 mm ( n = 19).

Head. (Figs 4 E View Figure 4 , 6 E View Figure 6 ) Ground colour generally grey to black. Ocellar tubercle somewhat bulbous and developed, just evident above upper eye margin in profile, with dense silvery pruinescence; width between eyes at the anterior ocellus 2.5–3.5 × the length of the anterior ocellus; anterior ocellus separated from posterior ocelli by shallow transverse groove; pile generally long, black. Frons trapezoid; width anterior to ocellar tubercle 0.5–0.6 × the width above antennal insertions; slightly to moderately swollen between antennal insertions and anterior ocellus; swelling recedes strongly towards eye margin; pruinescence relatively dense, silver to brown; pile mostly white (sometimes with black pile dorsally), usually dense on entire frons (sometimes sparse). Antenna with scape 1–1.5 × length of pedicel; first flagellomere shorter than the length of scape + pedicel; style shorter than scape + pedicel + flagellomere 1; ground colour dark brown to black, style darker than remainder of antenna; scape, pedicel and flagellomere 1 with irregular silver to brown pruinescence; pedicel with mostly elongate pile, black pile, flagellomere 1 with short black pile basally on the dorsal side. Facial area bulbous in profile, with horizontal groove present; with silver to brown pruinescence, evenly distributed across face; pile mostly white, elongate, usually dense (sometimes sparse), similar to that of frons. Gena with pile mostly off-white to golden (sometimes with some black pile), elongate and dense, forming the beard. Proboscis 0.6–0.8 × the length of the body, dorsal and ventral side black. Palpus with first segment significantly longer than that of second segment, second segment much narrower than first segment; colour generally dark brown to black; pile long on both segments.

Thorax (Fig. 3 E View Figure 3 ). Scutum dark grey to black; pruinescence mostly brown, with pale grey to silvery pruinescence complete along the lateral sides of the scutum, joining on scutellum; median and paired sublateral vittae absent; pile mixture of black and pale to golden, sparse, shorter than the pile on the posterior of the scutellum; postalar callus with black pile dorsally, ventral side with a tuft of golden pile. Scutellum anterior margin covered by brown pruinescence; posterior margin with a dark, black border; pile on disc of scutellum golden or black, relatively long, sparse compared to scutum; pile along posterior margin elongate, a mixture of black and pale, white or yellow, same density as on disc of scutellum; with some pale yellow to golden pile laterally. Pleuron mostly blackish; with silver pruinescence, sparser than on scutum; pile generally a mixture of black and white to yellow, relatively long, of intermediate density; most dense and elongate in two tufts, ventral and anterior to the base of the wing and between postalar callus and posterior spiracle; tuft of pile anterior to wing base directed posteriorly, mostly white to golden with some black pile; tuft of pile on katatergite directed posteriorly, black and golden (sometimes mostly pale yellow to golden); katepimeron with sparse elongate white pile. Legs. Coxae dark brown to black; with pile mostly off-white to golden, elongate, dense. Trochanters mostly blackish, with some yellow-brown colouring; pile short, very sparse. Femora red-brown to dark brown (sometimes more yellow-brown), with dark marking on dorsal side of the distal end present; pile short golden with long black and white interspersed, mostly short, dense, but with elongate pile dorsally on proximal 1 / 3–1 / 2; ventral pile typically longer, sparse; hind femur with short pile more evenly distributed than on fore and mid femora. Tibiae red-brown to black (sometimes closer to yellow-brown); with dense, short, pale pile and sparse, darker, elongate pile, most dense on hind tibia. Tarsi red-brown to dark brown, hind tarsi tend to be darker. Wings (Fig. 5 E View Figure 5 ). Shape relatively slender; broadest just basal to termination of CuP on posterior margin; alula broad; costal margin close to straight, without distinct anteriorly curved flexure; Sc termination on C aligned with termination of M 4 on posterior margin of wing; R 1 terminated closer to R 2 + 3 than to Sc; termination of Sc and R 1 well separated; short appendix just beyond fork on R 4 + 5 always absent; cross vein between M 1 and M 2 absent; cross vein just beyond fork between R 4 and R 2 + 3 absent; R 1 relatively straight; R 4 deep bowing upward; R 5 deeply bowing upward; M 1 and M 2 gently bowing upward; cell cua open at margin; CuA and CuP well separated. Dark marking on R 1 positioned just basal to humeral cross vein; membrane with smoky brown infuscation; appearing darker on anterior 1 / 2–1 / 3 of wing; posterior region of wing somewhat paler but never hyaline; isolated darker patches distinct in pale region; the distinction between brown infuscation and pale membrane gradual, never striking. Tuft of pile on base of wing white. Haltere with pale brown to yellow stalk; bulb dark brown.

Abdomen (Fig. 3 E View Figure 3 ). Colour of abdomen generally black; T 2 with posterior margin stout and relatively broad; abdomen tapering abruptly after T 3. Tergites with silvery pruinescence; membrane between T 1 and T 2 with silvery to brown pruinescence; medial brown pruinescent vitta distinct, extending from the posterior margin of T 1 to terminalia, usually not covering the full length of each tergite; grey pruinescence surrounding medial vitta, on T 2 – T 5; posterior margin of T 2 – T 4 with contrasting pruinescent border. Pile on tergites mostly black, both long and short, of intermediate density; along anterior margins of T 2 white to pale yellow (sometimes more golden), elongate, dense; posterolateral pile on T 2 – T 4 black and white, elongate, dense; T 5 with pile along lateral margins more evenly distributed than that of T 2 – T 4. Sternites typically paler than tergites; grey to black; pruinescence silvery, relatively sparse (sometimes with relatively dense golden pruinescence). Sternites with pile off-white to golden, mostly long, dense; pile on membrane adjacent to lateral margins of S 2 – S 4 typically with profuse, decumbent, elongate, pale yellow to golden.

Genitalia (Fig. 8 C, D View Figure 8 ). Hypandrium triangular in shape; broad, tapering gradually towards the apex; laterally convex; 1.9 × longer than basal width; with apical 1 / 3 projecting past the top of the gonocoxites. Hypandrium vestiture short, sparse, on the apical 1 / 2. Gonocoxite apical 1 / 2 not parallel sided; gonocoxites widest in apical 1 / 3, narrowing apically; rounded apically. Gonocoxite vestiture on the lateral 1 / 2, of apical 2 / 3, long, laterally projecting. Gonostylus with parallel sides and globular apical section. Phallus near parallel sided; narrowing apically.

Female. Same as male, except for genitalia dimorphism and the following characters: Head. Ocellar tubercle width between eyes at the anterior ocellus 3.4–4.5 × the length of the anterior ocellus. Frons width anterior to ocellar tubercle 0.6–0.7 × the width above antennal insertions. Facial area with horizontal groove present (less pronounced than in males). Legs. Femora dark brown to black (sometimes closer to red-brown).

Geographical distribution.

Prosoeca ora sp. nov. has been recorded from Nieuwoudtville in the Northern Cape to Matjiesfontein and Touws River in the Western Cape (Fig. 1 View Figure 1 ).

Biology.

Prosoeca ora sp. nov. is on the wing from early August to mid-October in the winter-rainfall region of the Western and Northern Cape provinces of South Africa. This species has been recorded visiting Pteronia incana , Dimorphotheca cuneata , Babiana vanzyliae , Hesperantha cucullata and yellow Pseudoselago ( Scrophulariaceae ). Additionally, based on the representative specimen accessioned into NMSA from Goldblatt and Manning (2007), we note that Prosoeca ora sp. nov. is likely the pollinator of Romulea syringodeoflora .

Etymology.

From the Latin ora = edge or rim; referring to the characteristic grey pruinescence on the dark thorax forming a distinct border. To be treated as a noun in apposition.

Comment.

The single female specimen from Soetwater ( NMSA -DIP 219351 , NMSA) shows significant genetic differentiation from other P. ora sp. nov. specimens but resembles this species morphologically. This specimen is placed in P. ora sp. nov. until further sampling can resolve its relationship within this clade.