Hercostomus sanipass, Grichanov, 2020

Grichanov, Igor Ya., 2020, New species of Hercostomus Loew, 1857 from Afrotropics (Diptera: Dolichopodidae) and key to Afrotropical fauna, European Journal of Taxonomy 722, pp. 16-36 : 23-25

Hercostomus sanipass sp. nov.

urn:lsid:zoobank.org:act:1832A474-762E-41A7-B328-2A89B2683C78

Fig. 3

Diagnosis

The new species is a sister species to H. koshelevae sp. nov., differing distinctly by its larger size, wider face, darker legs, strongly expanded fore tarsomere 3. The hypopygia are rather similar in the two species. Nevertheless, the proximal arm at the apex of ventral lobe of the postgonite in H. sanipass sp. nov. is thicker than that in H. koshelevae . The long basolateral cercal lobe in males of both species is very peculiar, being much shorter in males of close species with modified fore tarsus.

Etymology

The species is named for the well-known Sani Pass, a mountain pass located on the road between Underberg, KwaZulu-Natal and Mokhotlong, Lesotho, type locality for the new species. The species epithet “sanipass” is a noun in apposition.

Material examined

Holotype

SOUTH AFRICA • ♂; KwaZulu-Natal, Sani Pass ; 29°35′17.3″ S, 29°17′33.8″ E; 2050 m a.s.l.; 12 Dec. 1984; J. Manning leg.; NMSA.

Paratypes

SOUTH AFRICA – KwaZulu-Natal • 1 ♂; same collection data as for holotype; NMSA • 1 ♂; Sani Pass ; 2100 m a.s.l.; 13 Dec. 1984; J. Manning leg.; stream gulley; NMSA • 1 ♂; Sani Pass ; 2000 m a.s.l.; 14 Dec. 1984; J. Manning leg.; rocks in mountain stream; NMSA • 1 ♂, 1 ♀; Sani Pass ; [no date]; J. Manning leg; damp mossy rock along road; male terminalia dissected and stored in glycerin in a microvial pinned with the source specimen; NMSA .

Description

Male ( Fig. 3 )

MEASUREMENTS (in mm). Body length 4.9–5.5; antenna length 1.2; wing length 5; wing width 1.6 ( Fig. 3A ).

HEAD. Frons greenish-black, whitish pollinose; face black, densely white pollinose. One long, strong, vertical pair of ocellar setae, 1 short postvertical, pair of ocellar setae. Upper postocular setae black; lateral, lower ones white. Eye with short hairs; face glabrous. Face gradually narrowed towards palpus, 2.7 × as high as wide in middle, under antennae about 2 × as wide as width of postpedicel, at clypeus approximately as wide as width of postpedicel; clypeus not reaching lower margin of eyes. Antenna ( Fig. 3B ) slightly longer than height of head, entirely black; pedicel short and wide, internally convex anteriad,with short distal setulae; postpedicel asymmetrical,elongate, narrowed and angular apicodorsally, nearly 1.5 × longer than wide, covered with short pubescence; arista mid-dorsal, black, with short hairs. Length ratio of scape to pedicel to postpedicel to stylus (1 st – 2 nd segments), 27/14/28/18/63. Palpus and proboscis moderately small, yellow, with short black setae; palpus with 1 black bristle.

THORAX. Greenish-black, greyish pollinose. Five strong dorsocentral setae; 2 rows of acrostichals, nearly half as long as dorsocentrals; 2 strong notopleural, 1 strong humeral, 1 posthumeral setae present. Propleura with 1 strong black seta above fore coxa and 2 groups of short light hairs. Scutellum with 2 strong setae and 2 lateral hairs.

LEGS. including coxae dirty yellow; mid and hind coxae blackish laterally; hind femur brown at extreme apex; hind tibia reddish yellow; tarsi black from tip of basitarsus, fore tarsomere 5 yellow, hind basitarsus brown. Fore coxa with black hairs anteriorly and several setae in apical half; mid coxa with 1 strong lateral seta in addition to anterior hairs; hind coxa with 1 strong lateral seta. Femora without long hairs. Fore tibia with 2 short posterodorsal setae. Fore tarsomere 3 flattened and strongly widened, 2 × longer than wide, with dorsal comb of short black setulae; tarsomeres 4–5 with semi-accumbent dorsal hairs, tarsomere 4 with black and white or with only black hairs and tarsomere 5 with white hairs, as long as width of tarsomeres ( Fig. 3C ). Length of fore femur, tibia and tarsomeres 1–5 = 1.5 mm, 1.59 mm, 0.76 mm, 0.71 mm, 0.49 mm, 0.13 mm, 0.16 mm. Mid femur with 1 anterior and 1 posteroventral subapical seta. Mid tibia with 3 anterodorsal, 2 posterodorsal and 5 apical setae. Length of mid femur, tibia and tarsomeres 1–5 = 1.83 mm, 2.32 mm, 1.16 mm, 0.58 mm, 0.47 mm, 0.26 mm, 0.14 mm. Hind femur with one subapical anterior seta. Hind tibia with 3 anterodorsal, 3 posterodorsal, 4–5 fine ventral, 5 apical setae. Hind tarsomeres 1–2 with 1–2 short apical setae. Length of hind femur, tibia and tarsomeres 1–5 = 2.03 mm, 2.74 mm, 0.75 mm, 0.92 mm, 0.47 mm, 0.25 mm, 0.15 mm.

WINGS. Simple, greyish, veins brown. Costa simple. R 1 reaching to first third of wing length. R 2+3 and R 4+5 weakly divergent. Ratio of part of costa between R 2+3 and R 4+5 to between R 4+5 and M 1+2, 7/3. R 4+5 and M 1+2 slightly convergent in distal part; M 1+2 joining costa before wing apex. Crossvein dm-m straight, almost perpendicular to longitudinal wing axis, forming right angle with M 1+2 and acute angle with M 4 longitudinal veins. Ratio of dm-m to distal part of M 4, 45/82. Posterior wing margin almost evenly convex. Anal vein distinct, almost reaching wing margin; anal lobe pronounced; anal angle obtuse. Lower calypter yellow, brown anteriorly, with black setae. Halter yellow.

ABDOMEN. Greenish-black, weakly pollinose, with black hairs and long marginal setae. Segment 7 about as long as epandrium. Segment 8 large, covering more than half lateral side of epandrium, with numerous fine short dark cilia. Genitalia ( Fig. 3D ) with epandrium brownish black in proximal part and dirty yellow in distal part, rounded-oval, twice longer than high. Foramen positioned before middle of left lateral side. Hypandrium mid-ventral, with short base, 4 long thin lobes of different lengths and widths. Phallus thin, projected. Distoventral epandrial lobe as short rounded prominence, fused to epandrium, with 2 short and 1 long setae. Surstylus yellow, bilobate; ventral lobe broad, simple, ¾ length of dorsal lobe, with 1 subapical seta; dorsal lobe of surstylus expanded in distal half, with short narrow process at apex, several subapical setulae and 1 strong mid-dorsal seta. Distal lobe of postgonite as long as ventral lobe of surstylus, narrow, broad and pointed at apex. Ventral lobe of postgonite ( Fig. 3E ) strongly sclerotized, with 2 long arms (anterior and posterior) at apex forming letter V, 2 short symmetrical processes between them, covered with denticles on ventral side. Cercus ( Fig. 3F ) broad, yellow, densely covered with short light hairs, longer at apex; cercus with basolateral lobe, longer than cercus, densely covered with long setae, and with distolateral narrow process bearing 3 thick hook-tipped setae at apex; 1 strong seta proximal to process, 3 strong setae at apex of cercus.

Female

Similar to male except lacking male secondary sexual characters.

Ecology

According to type specimen labels, imagos inhabit rocks in mountain streams and damp mossy rocks along roads.

Distribution

South Africa.

Figures

Fig. 3. Hercostomus sanipass sp. nov., ♂, paratype, no date (NMSA). A. Habitus. B. Antenna. C. Fore tibia and tarsus. D. Hypopygium, right lateral view. E. Distoventral appendages of epandrium. F. Cercus.