Hercostomus storozhenkoi Grichanov, 2025

Hercostomus storozhenkoi Grichanov , sp. nov.

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( Figs 8 View FIGURE 8 , 9 View FIGURE 9 )

Type material. HOLOTYPE: ♂ ( Figs 8A, 8B View FIGURE 8 , 9 View FIGURE 9 ), labelled: “ Burundi, Rutana province, Karera Waterfalls , 3.83038°S, 30.07687°E, 9.XI.2024, D. Dubrovskiy ” ( ZIN) GoogleMaps . Holotype in good condition, but missing left mid tarsus and segments 3–5 of left fore tarsus (male with terminalia dissected and stored in glycerin in microvial pinned with the specimen). PARATYPES: 2 ♀, same data as holotype (dried and mounted on pins; ZIN) GoogleMaps .

Description. Male ( Fig. 8A View FIGURE 8 ). Head ( Fig. 8B View FIGURE 8 ). Frons bluish black, whitish pollinose; face silvery white pollinose, narrow, more than 2 times higher than wide below antennae; face below antennae slightly wider than height of postpedicel, 3 times as wide as face at clypeus; clypeus narrow, white pollinose; one long strong vertical seta; 1 shorter postvertical and pair of long ocellar setae; postocular setae black; eye with short hairs; clypeus not reaching lower margin of eyes; antenna ( Fig. 9A View FIGURE 9 ) about as long as height of head, black; pedicel short and high, convex anteriorly on both lateral sides, with short distal setulae; postpedicel subtriangular, angular distally, 1.3 times as long as high, covered with short pubescence; arista-like stylus black, arising at middle of dorsal edge, with short hairs. Length (mm) of scape, pedicel, postpedicel, arista-like stylus (stylomeres 1 and 2), 0.25/0.23/0.41/0.26/1.03. Palpus and proboscis small, brown, with short setae; palpus with 1 short black seta.

Thorax. Greenish black, weakly grey pollinose; metepimeron yellow; 6 strong dorsocentral setae; acrostichals biserial, long; 2 strong notopleural, 1 strong humeral, 1 posthumeral setae present; propleura with 1 strong black seta above fore coxa, with few short white hairs; scutellum with 2 strong and 2 short lateral setae.

Legs. Mostly yellow, with black setae; fore and hind coxae yellow; mid coxa with brown spot (invisible on wet specimens); fore tarsus with blackish segments 1 and 2, dirty white segment 3, black segments 4 and 5; mid and hind tarsi black from tip of basitarsus; hind tibia at apex and hind basitarsus brownish; fore coxa with several short light hairs anteriorly and black setae distally; mid coxa with 1 strong lateral seta in addition to dark anterior hairs; hind coxa with 1 strong black lateral seta at middle; fore femur without distinct setae; fore tibia with 2 short posterodorsal setae; fore tarsomeres 1 and 2 simple, with few short semi-erect hairs ventrally at base of basitarsus; tarsomere 3 thickened, with black setulae; tarsomeres 4–5 flattened laterally and slightly widened, with dorsal row of short flat setae ( Fig. 9B View FIGURE 9 ); mid femur with 1 anterior and 1 posteroventral subapical setae; mid tibia with 2 anterodorsal, 1 posterodorsal and 3 apical setae; mid tarsus simple; hind femur thin, with one subapical anterodorsal seta; hind tibia simple, with 2 anterodorsal, 3 posterodorsal and 2 apical setae. Femur, tibia and tarsomere (from first to fifth) length (mm): fore leg: 0.69/0.68/0.47/0.34/0.14/0.12/0.11, mid leg: 0.55/0.64/0.37/0.19/0.13/0.10/0.06, hind leg: 0.65/0.94/0.28/0.35/0.21/0.13/0.09.

Wing ( Fig. 9C View FIGURE 9 ). Simple, greyish, veins brown; costa simple; R 1 reaching to first third of wing length; R 2 + 3 and R 4 + 5 divergent; length (mm) of costal section between R 2+3 and R 4+5 and this between R 4+5 and M 1, 0.39/0.11; M 1 distinctly convergent with R 4+ 5 in distal part; M 1 weakly convex anteriorly, with indistinct bend in middle of distal part, joining costa at wing apex; crossvein dm-m almost straight, oblique to longitudinal wing axis, forming almost right angles with M 1 and M 4; length (mm) of dm-m to distal part of M 4, 0.21/0.47; posterior wing margin almost evenly convex; anal vein distinct, almost reaching wing margin; anal lobe weakly developed; anal angle obtuse; lower calypter yellow, with long black setae; halter yellow.

Abdomen. Greenish black, weakly pollinose, with black hairs and marginal setae; sternites brown; segment 7 narrow, 2/3 as long as epandrium; segment 8 large, black, covering half lateral side of epandrium, with black setae; hypopygium ( Figs 9D–9F View FIGURE 9 ) blackish brown with yellow and brown appendages and yellow cercus; epandrium elongate-ovate, 2.2 times longer than high, with asymmetrical ventral margins; foramen positioned at middle of left lateral side; distoventral epandrial lobe short, with short apical spine, one long ventral seta at base; hypandrium basoventral, with short base and pair of long thin asymmetrically curved lobes; phallus thin, concealed; surstylus bilobate, with long and thin lobes; each lobe with one thick and few long simple setae; distal lobe of postgonite long and thin, nearly straight; ventral lobe of postgonite broad, subtriangular, strongly sclerotized, with serrate ventral margin; cercus covered with light hairs; small basolateral lobe bearing 3–4 strong short setae, long narrow apex bearing 5 long pedunculate setae.

Measurements (mm). Body length 2.8, wing length 2.7, wing width 0.9, antenna length 0.6.

Female ( Fig. 8C, 8D View FIGURE 8 ). Similar to male except lacking male secondary sexual characters. Measurements (mm). Body length 2.5, wing length 2.6, wing width 0.9, antenna length 0.6. Femur, tibia and tarsomere (from first to fifth) length (mm): fore leg: 0.76/0.74/0.42/0.19/0.14/0.11/ 0.11, mid leg: 0.69/0.84/0.46/0.22/0.17/0.12/0.11, hind leg: 0.74/0.95/0.24/0.33/0.20/0.13/0.10. Face and clypeus slightly wider than male face; antenna with postpedicel about as long as high; terga 9+10 divided medially into two short hemitergites, each bearing 4 thick spines.

Differential diagnosis. Hercostomus storozhenkoi sp. nov. belongs to the H. nectarophagus species subgroup ( Grichanov 2020b) of the Hercostomus longiventris lineage (Brooks 2005) and keys to H. enghoffi Grichanov, 1999 and H. selikhovkini Grichanov, 1999 in Grichanov (2020b), differing from the last two species in small size, fore tarsomeres length ratio and setation, shape of male cercus, etc. The male fore tarsomere 5 is black and as long as tarsomere 3 in H. storozhenkoi sp. nov., but white and 2–3 times longer than tarsomere 3 in H. enghoffi and H. selikhovkini .

Remark. Figures 8A, 8C View FIGURE 8 and 9A–C View FIGURE 9 of holotype were taken before the specimen was dried and dissected.

Distribution. The new species is only known from the type locality in Burundi ( Rutana Province).

Etymology. The specific epithet is dedicated to the Russian entomologist, Dr. Sergey Yu. Storozhenko (Vladivostok).