Africaterphis acroceroides ( Sabrosky, 1950 )

Midgley, John M. & Theron, Genevieve L., 2025, Revision of the Afrotropical spider fly genus Africaterphis Schlinger, 1968 (Diptera, Acroceridae) with the description of a new species, African Invertebrates 66 (1), pp. 193-206 : 193-206

Africaterphis acroceroides ( Sabrosky, 1950)

Figs 2 , 3 , 7 , 8 , 12 , 13

Terphis acroceroides Sabrosky, 1950: 50 – Schlinger (1960: 497).

Africaterphis acroceroides ( Sabrosky 1950: 50) – Schlinger 1968: 62; Schlinger 1980: 378; Barraclough 1984: 56.

Material examined.

Holotype (Photographs only). Democratic Republic of the Congo • ♂; Katanga Province, Tenke ; 30 Jul. – 9 Aug. 1931; Miss A. Mackie leg.; BMNH (E) # 241481 ; NHMUK 013444824 ; NHMUK

Paratype. Democratic Republic of the Congo • ♂; Katanga Province, Tenke ; 30 Jul. – 9 Aug. 1931; Miss A. Mackie leg.; BMNH (E) # 241481 ; USNMENT 01842970 ; USNM .

Other material.

Eswatini • 1 ♂; Mhlume ; 26°00'S, 31°65'E; 200 m asl; 18 Aug. 1983; Swept in dry grass; NMSA -Dip 0000006 ; NMSA .

Mozambique • 1 ♀; Ville Paiva d’Andrada ; Sept 1957; B. R. Stuckenberg leg.; Taken from Gallery forest; NMSA -Dip 000007 ; NMSA .

Zimbabwe • 1 ♂; Bomponi, Vumba ; 16 May 1965; D. M. Cookson leg.; NMSA -Dip 000010 ; NMSA • 1 ♂ same data as preceding; 24 May 1965; NMSA -Dip 000008 • 4 ♂♂; Eastern Vumba ; 6 May 1965; D. M. Cookson leg.; NMSA -Dip 000009 , 142294–6; NMSA • 1 ♀; Harare [as Salisbury ]; 23 Jul. 1965; I. L. Bissett leg.; AMGS -ENT 57645 ; AMGS .

Diagnosis.

Africaterphis acroceroides can be distinguished from the known species in the genus by the combination of yellow anterior half of the postpronotal lobes in males; brown anterior half of the postpronotal lobes in females (brown in female A. gertschi ; yellow and brown in male A. gertschi and yellow in female A. stefanfoordi sp. nov.) and predominantly yellow scutum with black dorsal fasciae in males; brown with darker brown dorsal fasciae in females (predominantly black in A. gertschi and predominantly brown in A. stefanfoordi sp. nov.).

Description.

Male. Length of entire specimen 5.5–6.7 mm, wing length 4–4.3 mm.

Head black, spherical, eyes contiguous above and below antennae. Antennae brown, minute; segment 1 hardly discernible under antennal tubercle; segment 2 short, round, pollinose; segment 3 shiny, not pollinose, round basally with large sensorial pits, with a straight, short, broad style arising dorso-apically at apex; style with one apical setae. Small, triangular area below antennae without eye facets. Antennal tubercle shiny, bluntly pointed, extending to the base of antennal segment 3; bare. Ocelli brown, on raised triangle; median ocellus absent; lateral ocelli large, oval, 2 times wider than long, not touching eye margin. Vertical depression rugose. Occiput smooth laterally and dorsally, slightly sculptured above on posterior margin, with bristle like pile dorsally. Mouthparts visible, reduced, without surrounding small raised lip.

Thorax rugose, more so on pale areas, with short white pile over entire surface. Scutum yellow, with three dorsal black markings. Central fascia arrow shaped, broad between postpronotal lobes, tapering strongly then approximately parallel sided, with small triangular constrictions just before the posterior margin. Postero-lateral maculae large, quadrilateral, black; narrowest at scutellar margin, medial margin parallel to central fascia, broadest in line with wing base. Dark fascia sometimes present below posterior calli. Strongly arched, slightly depressed on yellow parts. Scutellum yellow, except for a small basal black macula and margin. Postpronotal lobes yellowish-white, contiguous for about as long as length of ocellar triangle, with a small brown spot on postero-medial angle. Pleurites brown, yellow around prothoracic spiracle. Anepisternum and meron swollen; less rugose than scutum.

Legs pale yellow, except for pale brown coxa; with yellow pile.

Wings pale white, almost hyaline, except narrowly brown at base. Wing veins pale brown; well-developed anteriorly, reduced medially and absent posteriorly. Lower calypter yellowish-white with darker yellow border, broadly connected to thorax along half of antero-dorsal margin. Halter stem and knob dark yellow.

Abdomen densely punctured, longer than thorax, widest at segment 3, segments 1 narrower than segment 5; tergite 1 short, but prominently raised; tergites 4 to 6 fold over ventrally. With short appressed white pile over the entire surface, longer posteriorly. Tergite 1 dark brown, with thin yellow fascia on the posterior margin. Other tergites yellow with dark brown fasciae on anterior margin, broader centrally on tergites 2 and 3, occupying ⅛ to 1 / 3 of tergites 2 to 3 and 1 / 6 to ¼ of tergites 4 to 6. Sternites yellow. Genitalia small, brown.

Female as for male except:

Length of entire specimen 4.4–5.5 mm., wing length 3.1–4.0 mm.

Head: Mouthparts not visible, reduced, without surrounding small raised lip.

Thorax with short brown pile over entire surface. Scutum brown, with dorsal darker brown markings. Posterior calli yellow. Strongly arched, slightly depressed on light brown parts. Scutellum brown, paler brown centrally. Postpronotal lobes brown.

Wings: Lower calypter yellowish-white on surface and border. Halter stem and knob dark pale brown.

Abdomen: Tergite 1 brown, with thin pale brown fascia on the posterior margin. Other tergites yellow with brown fasciae on anterior margin, not broader centrally, ¼ of tergites 2 to 6. Sternites brown.

Comments.

The males of A. acroceroides are easily identified by their striking yellow and black colour patterns. This species has the widest known distribution in the genus (Fig. 1 ), ranging from the Democratic Republic of the Congo to Eswatini, though all collecting sites are in woodlands or forests.

Figures

Figure 1. Map of the distribution of Africaterphis species.

Figures 2–6. Frontal view of Africaterphis species 2 Africaterphis acroceroides female 3 Africaterphis acroceroides male 4 Africaterphis gertschi female 5 Africaterphis gertschi male 6 Africaterphis stefanfoordi sp. nov. female. Scale bars: 1 mm.

Figures 7–11. Lateral view of Africaterphis species 7 Africaterphis acroceroides female 8 Africaterphis acroceroides male 9 Africaterphis gertschi female 10 Africaterphis gertschi male 11 Africaterphis stefanfoordi sp. nov. female. Scale bars: 1 mm.

Figures 12–16. Abdomens of Africaterphis species 12 Africaterphis acroceroides female 13 Africaterphis acroceroides male 14 Africaterphis gertschi female 15 Africaterphis gertschi male 16 Africaterphis stefanfoordi sp. nov. female. Scale bars: 1 mm.