Suragina bilobata Muller, 2024

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

publication ID	https://doi.org/ 10.3897/afrinvertebr.65.140524
publication LSID	lsid:zoobank.org:pub:BCB49D2E-F772-49EB-A17A-47EB21194212
DOI	https://doi.org/10.5281/zenodo.14548347
persistent identifier	https://treatment.plazi.org/id/2A09AA55-0318-5007-9423-6F0E3255F9FB
treatment provided by	African Invertebrates by Pensoft
scientific name	Suragina bilobata Muller
status	sp. nov.

Treatment

Suragina bilobata Muller sp. nov.

Figs 3 View Figures 1–8 , 13 View Figures 9–13 , 39 View Figures 37–42 , 77 View Figures 75–87

On the material.

The type series of specimens available for this new species are in poor condition as these come from long-term Malaise samples, with the most complete specimen missing its 1 st flagellomere (present in other more damaged specimens), and all specimens exhibiting some loss of setation on the head, body and legs. In the description missing setulae are recorded as unknown (referring to the unknown characteristics such as length or colour), but the alveoli are present. While it is not ideal to designate a holotype and paratypes from material in this state, it should be taken into account that procurement of additional material from Madagascar is not viable due to the highly seasonal nature of Athericidae adults and the prohibitively expensive nature of performing fieldwork in Madagascar. The forests of Madagascar are threatened by deforestation (e. g. Harper et al. 2007), with Ranomafana National Park being one of the largest remaining primary rainforests in Madagascar ( Torppa et al. 2020). Describing and identifying endemic species could contribute to its conservation. This species is thus far the only species of Suragina that does not have a reniform 1 st flagellomere, instead it is bilobate and c-shaped (Fig. 13 a View Figures 9–13 ). It was also briefly mentioned by Woodley (2017: 888). Woodley regarded the specimens as Suragina , and viewed the 1 st flagellomere shape as “ a highly autapomorphic antennal flagellum ”. In all other regards, S. bilobata Muller , sp. nov. possesses characters unique to Suragina : the frons velvety-black on upper half and silver-grey on lower half in combination with hind coxa having a well-developed anterior apical point, and generally slender and elongated legs. Given the unique antennal characters and contrasting black and orange colouration of this species, there is little doubt that any future specimens collected will be easily attributable to S. bilobata Muller , sp. nov.

Type material examined.

Holotype: Madagascar • 1 ♀; Fianarantsoa Province; Ranomafana National Park, radio tower ; 21°15.05'S, 47°24.43'E; 1127 masl; 23–30 Apr. 2002; M. E. Irwin, R. Harin’Hala leg.; Malaise in open area nr forest edge; CSCA. GoogleMaps

Paratypes: 2 ♀; same data as Holotype; CSCA GoogleMaps .

Holotype and paratypes deposited in CSCA.

Diagnosis.

Suragina bilobata Muller , sp. nov. has its 1 st antennal flagellomere uniquely bilobed, or c-shaped (Fig. 13 a View Figures 9–13 ), contrasting to the typical reniform shape found in other Afrotropical Athericidae . The overall appearance of the species is reminiscent of other dark Afrotropical species (e. g. Suragina bezzii ), but the combination of the antennal shape, and wing with a dark stigma, substigmal marking, and hyaline band before apical brown suffusion makes it easy to distinguish from all other known species.

Description.

Measurements (♀ n = 1): Wing span: 8.1 mm; body length: 8.9 mm; wing span to body length ratio: 1.03.

Male. Unknown.

Female (Fig. 13 View Figures 9–13 ).

Head: Black ground colour, with bluish-grey pruinosity on majority of head; eye bare; dichoptic; ommatidia of similar size; lateral edge of eye without any indentation; ocellar tubercle elevated, visible in profile, same velvety-black as upper half of frons, surface setulae unknown; vertex bluish-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 with paired dark markings; occiput with same bluish-grey pruinosity as rest of head; paired black markings with unknown setulae on upper occiput running down to near occipital foramen, abutting posterior margin of eyes, flanking vertex; upper occiput otherwise with pale setulae; lower occiput lateral marginal setulae unknown, with long pale setulae medially, these continue ventrally on head to mouthparts that have mix of pale and dark ventral setulae; frons bluish-grey pruinose, velvety-black from ocellar tubercle to lower half of eye; frons running almost parallel, widening towards antennal base; frons setulae unknown; face with silver-white pruinosity and gena bluish-grey, face with a mix of pale and dark setulae, genal setulae unknown; clypeus with bluish-grey pruinosity, bare; face separated anteriorly from clypeus by shallow transverse suture, with deeper sutures laterally; face not appearing to bulge laterally when viewed in profile; clypeus visible in profile, face not; antennal bases separated ca 0.5–0.75 × width of scape, with slight longitudinal groove running between; scape, pedicel, and 1 st flagellomere dark brown with some whitish pruinosity, 2 nd flagellomere dark brown; scape and pedicel of similar size; 1 st flagellomere bilobate, c-shaped (Fig. 13 a View Figures 9–13 ), upper lobe ca 2 × length of scape and pedicel combined, lower lobe ca 3 × length of scape and pedicel combined; 1 st flagellomere lobes covered on all surfaces with pale setulae that are as long as lobes are wide; 2 nd flagellomere arista-like; pedicel with dark dorsal and ventral setulae, similar in size, scape with only dark dorsal setulae; palpus brown with bluish-grey pruinosity, with dark setulae throughout, ca 0.5 × length of proboscis; proboscis ca same length as head height; proboscis dark brown with some whitish pruinosity on prementum, dorsal setulae unknown, ventrally with short dark setulae and some scattered longer pale setulae.

Thorax (Fig. 3 View Figures 1–8 ): Scutum shining black with two feint dorsocentral bluish-grey pruinose vittae running from pronotum to before scutellum, ending in a large bluish-grey pruinose posterior patch; pronotum bluish-grey pruinose with long pale setulae; postpronotal lobe dark brown, slightly bluish-grey pruinose with long pale setulae; notopleuron bluish-grey pruinose with long pale setulae just behind postpronotal lobe and rest of surface with dark setulae; postalar wall and postalar callus brown with bluish-grey pruinosity; scutellum uniform black with slight bluish-grey pruinosity; scutum setulae unknown; majority of pleura bluish-grey pruinose, except for anatergite and anepimeron yellowish-brown; all pleura that are bluish-grey pruinose have long pale setulae; anepimeron with long pale setulae, anatergite and meron bare; proepisternum and proepimeron with long pale setulae; anterior and posterior spiracles and surroundings brownish-yellow, bare; postspiracular scale dark brown; postscutellum black with slight bluish-grey pruinosity.

Legs: All coxae dark brown bluish-grey pruinosity on surface; fore and hind coxae with pale setulae, fore coxa with short dark setulae at apex, mid coxa with dark setulae on anterior apical surface, and inner and outer lateral surfaces, interspersed with some pale setulae; hind coxa with pale setulae on anterior edge surrounding well-developed anterior apical point, lateral apical edges with longer pale setulae; all trochanters glossy black with short pale setulae; fore femur yellow with extreme basal and apical margins appearing shiny dark brown to black; mid femur similar to fore femur, except basal area dark brown, this basal area similar in length to trochanter; hind femur dark brown on basal half to two-thirds; all tibiae and tarsi dark brown to black; fore tarsal claws, empodium and pulvilli unknown; fore tarsi with long, somewhat curved sensory setulae along antero- and posteroventral surfaces, sensory setulae ca 2 × as long as tarsal segment is wide; leg setation mostly unknown; all femora apparently with a mix of short pale and dark setulae; all tibiae with short dark setulae; hind leg overall stouter than remaining legs; combined length of hind tarsal segments subequal to hind tibia; tibial spur formula 0: 2: 2.

Wing (Fig. 39 View Figures 37–42 ): Dark brown stigma over apex of veins R 1 and R 2 + 3 and cells sc, r 1, base of cell r 2 + 3, crossvein r – m, bases of discal cell, cell m 3 and apex of cell br; cell bm with similar dark substigmal marking medially and apically, otherwise hyaline; vein CuA with a dark marking along length; entirety of cells m 1 and m 2, apex of cell m 3, apical half of cell r 5, apical two-thirds of cell r 4 and apical half of cell r 2 + 3 brown suffused; rest of wing 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 light brown, knob darker brown, with some short and dark setulae.

Abdomen: Tergite 1 with bluish-grey pruinosity on anterolateral margins, medially with a dark marking and a longitudinal suture; tergites 2–4 with a triangular dark marking, narrowing towards posterior with posterior and lateral margins of each segment with bluish-grey pruinosity; tergite 5 and onwards a deep orange colour, with posterior margin appearing darker; sternites 1–4 dark brown with bluish-grey pruinosity, sternites 5 and onwards orange-yellow; setation unknown.

Terminalia (Fig. 77 View Figures 75–87 ): Cercus dark orange-brown with pale setulae; genital fork has distal apodeme apically expanded with truncated appearance, without a clear fork, median lobe with shallow apical emargination, paired apical lobes with expanded appearance, inner edge with clustered microtrichia at apex; arms gradually rounded; three oval-shaped, apically rounded spermathecae, sclerotised, short and stout.

Etymology.

From the Latin “ bi ”, two and “ lobatus ”, having lobes; named for the unique bilobed or c-shaped 1 st flagellomere. Feminine noun in the nominative singular case.

Distribution.

Madagascar.