Suragina dimidiatipennis ( Brunetti, 1929 )

Muller, Burgert S., Swart, Vaughn R. & Snyman, Louwrens P., 2024, Revision of Afrotropical Suragina Walker, 1859 (Diptera, Athericidae), African Invertebrates 65 (2), pp. 247-327 : 247-327

Suragina dimidiatipennis ( Brunetti, 1929)

Figs 18 , 43

Atrichops dimidiatipennis Brunetti, 1929: 3.

Suragina dimidiatipennis : Stuckenberg 1980: 313.

Type material examined.

[ from digital photographs] Holotype: Nigeria • 1 ♀; Ibadan ; [07°23.78'N, 03°55'E]; 27 Mar. 1923; Presented by Imperial Bureau of Entomology British Museum; 1484, 1929–48; ( NHMUK 014064158 ).

Paratype: Nigeria • 1 ♀; So [Southern] Nigeria; Ibadan ; [07°23.78'N, 03°55'E]; 10 Aug. 1920; Presented by Imperial Bureau of Entomology British Museum; 1484, 1929–48; ( NHMUK 014064159 ) .

Diagnosis.

Head and thorax with dark brown ground colour and silver-grey pruinosity. Abdomen is orange-yellow to dark orange, brown on terminal segments. Tergites 2 and 3 with large brown markings. Wing brown suffused on apical half with dark brown stigma and substigmal marking (Fig. 43 ), in this regard, it is most similar to S. zombaensis Muller , sp. nov., but differs from it by having wide subrectangular markings on the upper occiput compared to narrow markings in S. zombaensis Muller , sp. nov., and a marked difference in abdominal colour and patterning, with the latter having medial longitudinal blackish markings with bluish-grey pruinosity that are completely absent in S. dimidiatipennis .

Redescription.

(Based on digital photographs of ♀ Holotype and ♀ paratype)

Measurements (♀ n = 2): Wing span: 7.9–8.8 mm (avg. 8.4 mm); body length: 10.3 (avg. 10.3 mm); wing span to body length ratio (avg.): 0.81.

Female (Fig. 18 ).

Head: Dark brown ground colour, with silvery-grey pruinosity on majority of head; eye bare; dichoptic; ommatidia of similar size; lateral edge of eye without any visible indentation; ocellar tubercle slightly elevated, visible in profile, dark setulose, silvery-grey pruinose; vertex silvery-grey pruinose, with dark setulae; anterior ocellus similar in size to posterior pair; ocellar tubercle in front of dorsal margin of eye; dorsal inner edge of eye without discernible paired dark markings, same silvery-grey pruinose as rest of head; occiput with same silvery-grey pruinosity; paired widely-shaped blackish-brown subrectangular markings with dark setulae on upper occiput running down to occipital foramen, abutting posterior margin of eyes, flanking vertex; upper occiput otherwise with pale setulae; lower occiput with lateral margins and medial area with long pale setulae, these continue ventrally on head to mouthparts that have pale ventral setulae; frons silvery-grey pruinose with short dark setulae on lower half, velvety-black from ocellar tubercle to lower half of eye; frons running almost parallel, widening only very slightly towards antennal base; frons with long dark setulae; face and gena silvery-grey pruinose, with pale setulae; clypeus with silvery-grey pruinosity, bare; face separated anteriorly from clypeus by shallow transverse suture, deeper sutures laterally; face not appearing to bulge laterally when viewed in profile; clypeus visible in profile, face not; antennal bases separated ca 1 × width of scape, with obvious longitudinal groove running up into lower frons; scape, pedicel mostly orange, dorsally orange-brown, otherwise with some silvery-grey pruinosity; 1 st flagellomere entirely orange; 2 nd flagellomere brown; scape appearing larger than pedicel when viewed dorsally; 1 st flagellomere reniform, 2 × size of pedicel; 2 nd flagellomere arista-like; pedicel with dark dorsal and ventral setulae, similar in size, scape with only dark dorsal setulae; palpus orange with mostly darker setulae, and some interspersed pale setulae; palpus ca 0.5 × length of proboscis; proboscis ca same length as head height; proboscis orange-yellow with dark setulae and some paler shorter setulae.

Thorax: Scutum dark brown with central vitta, delineated by silver-grey pruinosity on presutural surface; central vitta ending before scutellum; scutum with large paired presutural dark brown markings behind postprontal lobe; pronotum yellowish-brown with pale setulae; postpronotal lobe brown, base same dark brown as proceeding presutural scutal area; scutellum with short dark setulae; notopleuron appearing silver-grey pruinose when viewed dorsally, setulae dark; postalar wall and postalar callus orange-brown; scutellum orange-yellow with short dark setulae; scutum generally with short dark setulae with postsutural setulae somewhat longer; majority of pleura dark brown, except for anepisternum, katepisternum and meron with silver white pruinosity; pruinose pleura have long pale setulae; anepimeron setulae unknown; anatergite and meron bare; proepisternum and proepimeron with long pale setulae; anterior and posterior spiracles and surroundings yellow, bare; postspiracular scale brownish; postnotum dark brown, silver-grey pruinose on lateral margins.

Legs: Fore coxa orange-yellow, mid and hind coxae dark brown; fore coxa with long pale setulae on anterior and posterior surfaces, anterior apex with short dark setulae; mid coxa with dark setulae on anterior surface; hind coxa with dark setulae on anterior surface as well as dark setulae surrounding well-developed anterior apical point, lateral apical edges also with long dark setulae; fore trochanter orange-yellow with short pale setulae, mid trochanter dark brown, hind trochanter missing; fore and mid femora orange-yellow; hind femur missing (original description has hind femur with basal and apical third “ brownish-yellow ” interpreted here as orange-yellow, and middle third “ black ” interpreted here as blackish-brown); fore tibia blackish-brown; mid tibia darker orange-yellow than that of mid femur; hind tibia and tarsi missing (original description has hind tibia and tarsi “ black ”, interpreted here dark brown based of photos); fore tarsi dark brown, mid tarsi yellowish-brown; fore tarsal claws and pulvilli missing, not described; fore tarsi with long, somewhat curved sensory setulae along antero- and posteroventral surfaces, sensory setulae ca 2 × as long as tarsal segment is wide; fore and hind femora with pale setulae, some darker setulae on apical dorsal surface of fore femur; fore and hind femora with long pale setulae on apical ventral and posteroventral surfaces; mid femur with long pale setulae on ventral surface; fore and mid tibiae with short dark setulae; hind leg overall stouter than remaining legs; hind tarsi missing not measured; tibial spur formula unknown.

Wing (Fig. 43 ): Brown suffused on apical half; darker brown stigma over apex of veins R 1 and R 2 + 3 and cells sc, r 1; darker suffused substigmal marking over crossvein r – m, bases of discal cell, cell m 3 and apex of cell br; cell bm hyaline; veins dark brown; costa without distinct downward flexure over stigma; cell cua closed a short distance from wing margin; cell m 3 open, veins M 1, M 2, M 3 present; haltere stalk yellow, knob light brown, with some short and dark setulae. Holotype ( NHMUK 014064158) with an elongated hyaline marking in cell r 2 + 3, paratype ( NHMUK 014064159) without such a hyaline marking.

Abdomen: Overall orange-yellow to dark orange colour; tergite 1 orange-yellow; tergites 2 and 3 with large brown markings taking up majority of surface, somewhat darker on lateral margins as well; tergites 4 and 5 orange-yellow; remaining tergites orange-brown, with posterior margins of especially tergites 7 and 8 darker; sternites orange-yellow, with sternites 3 and 4 covered in darker marking; rest of sternites orange-yellow; tergites with short dark setulae dorsally, and long pale setulae laterally; sternites with short pale setulae; tergite 1 medially with a longitudinal suture.

Terminalia: Cercus dark brown with pale setulae; internal structures unknown, type material not dissected.

Distribution.

Nigeria.

Figures

Figures 18, 19. Suragina Walker spp. dorsal habitus: S. dimidiatipennis (Brunetti): 18 ♀ holotype (NHMUK 014064158); S. falsa Oldroyd: 19 ♀ holotype (NHMUK 014064160). 18, 19 Copyright NHMUK under CC BY 4.0. Scale bars: 1 mm.

Figures 43–48. Suragina Walker spp. wing dorsal view: 43 S. dimidiatipennis (Brunetti) ♀ holotype (NHMUK 014064158) 44 S. falsa Oldroyd ♀ (NHMUK 014064160) 45 S. freidbergi Muller, sp. nov. ♀ paratype (BMSA (D) 92158) 46 S. liberiaensis Muller, sp. nov. ♀ paratype (NMSA - DIP 158445) 47 S. malavaensis Muller, sp. nov. ♂ (ICIPE) 48 S. milloti (Séguy) ♀ (CSCA). 43, 44 Copyright NHMUK under CC BY 4.0. Scale bars: 1 mm.