Thinophilus fluvialis, Grichanov, 2023

Grichanov, Igor Ya., 2023, A review of the Afrotropical Thinophilus Wahlberg, 1844 (Diptera: Dolichopodidae), with the descriptions of ten new species, European Journal of Taxonomy 878, pp. 1-52 : 36-38

Thinophilus fluvialis sp. nov.

urn:lsid:zoobank.org:act:07D13005-A8FF-41E2-B35A-EDACC244BAE7

Fig. 12

Diagnosis

Thinophilus fluvialis sp. nov. is close in habitus to T. manambato sp. nov., differing in fore coxa with mainly black bristles and setae; mid coxa with black bristle and setae. The last species have fore coxa with mainly white setae, with at most 2–3 black apical bristles; mid coxa with white setae and one black bristle. The hypopygium of T. manambato is similar to that in T. fluvialis , but the surstylus of the latter is thin (lateral view), bearing about seven short spine-like apicoventral setae; the surstylus of T. manambato is broad (lateral view), with simple ventral and apical setae. Thinophilus fluvialis keys to T. cataractae sp. nov. (see key above), differing in colour of the antenna, palp, and in morphology of hypopygium.

Etymology

The specific epithet refers to the ‘riverine’ inhabitation of the male type collected.

Material examined

Holotype TANZANIA • ♂; “ Muhuwesi River ; 10.85° S, 37.18° E; alt. 540 m; 18 Dec. 2015; N. Vikhrev leg.”; ZMUM.

Description

Male ( Fig. 12A )

MEASUREMENTS. Body length 3.1 mm; antenna length 0.7 mm; wing length 2.8 mm; wing width 0.8 mm.

HEAD ( Fig. 12B ). Postcranium bluish black, whitish pollinose; frons blackish violet, grey pollinose, with shining spot under ocellar tubercle; face shining violet on upper half; clypeus and adjacent part of face black, grey pollinose; face under antennae about as wide as height of postpedicel; clypeus 0.4 × as long as epistoma, 1.6 × as wide as long; palp yellow, bearing black bristly hairs; proboscis dark brown; 2 diverging ocellars; 1 vertical, 1 postvertical, much stronger and longer than, and not in row with upper postoculars; upper postoculars uniseriate, black; middle and lower postoculars multiseriate, white, long; antennal scape, pedicel and postpedicel blackish dorsally, yellow ventrally ( Fig. 12C ); scape with scale-like inner projection; pedicel simple, convex on inner side; postpedicel apically browned, rounded, with short pubescence, as high as long; arista-like stylus dorsal, black and thick basally, thin distally, shortly pubescent; length ratio of scape to pedicel to postpedicel to stylus, 0.07/0.07/0.12/0.54.

THORAX. Metallic, grey dusted; mesonotum blue-green; pleura bluish black; no acrostichals; 6 dorsocentrals decreasing in length anteriorly; scutellum with 2 strong marginals and 2 minute laterals; 3 upper and 4 lower, white propleural bristles of different length.

LEGS. Fore coxa yellow; mid and hind coxae black, yellow at apex; legs mostly yellow; tarsi black from middle of segment 3.

FORE LEG. Coxa with mainly black setae and bristles, with white hairs at base; femur simple, with few short fine black ventral setae, with 4 preapical posteroventral setae; tibia bearing 2 anterodorsal, 2 posterodorsal and 2 apical short bristles; tarsal segments with short simple setulae; segment 5 weakly widened; length of femur, tibia and tarsal segments (in mm): 0.86/0.8/0.33/0.18/ 0.13/0.1/0.11.

MID LEG. Coxa with black setae and 1 black bristle; femur with ventral row of several very short black setae; 1 preapical anterior and 1 preapical posteroventral; tibia bearing 2 anterodorsal; 2 posterodorsal, 4 apical bristles; tarsal segment 5 weakly widened; length of femur, tibia and tarsal segments (in mm): 0.98/1.08/0.6/0.2/0.18/0.11/0.12.

HIND LEG. Coxa with 1 black exterior bristle; femur with ventral row of several very short black setae; about 5 anterodorsal bristles; tibia bearing 3 anterodorsal, 3 posterodorsal bristles, 2 ventrals, 4 apicals; segment 5 weakly widened; length of femur, tibia and tarsal segments (in mm): 1.16/1.38/0.37/0.26/0. 21/0.14/0.13.

WING ( Fig. 12D ). Hyaline, without darker shades; veins yellow-brown, more yellowish at base; distal part of M 1+2 convex; tip of R 4+5 parallel with M 1+2; ratio of part of costa between R 2+3 and R 4+5 to that between R 4+5 and M 1+2 (in mm), 0.32/0.17; crossvein dm-m straight; ratio of dm-m to distal part of M 4, 0.25/0.27; anal vein distinct; halter yellow; lower calypter yellow, with white cilia.

ABDOMEN. Copper green dorsally, weakly dusted; shining violet laterally; setae and hind-marginal bristles on tergites black, short; sternites with short setae. Hypopygium ( Fig. 12E ) black with black appendages (cut); epandrial lobe reduced; hypandrium fused with epandrium, short and broad, apically concave; phallosoma broad, rounded at apex; phallus long, coiled, simple, gradually broadened towards apex; surstylus straight and thin (lateral view), with 3 long dorsal bristles, several short ventral setae and about seven short spine-like apicoventral setae; cerci dorsally adjoined, leaflike, with short marginal bristles ( Fig. 12F ).

Female

Unknown.

Figures

Fig. 12. Thinophilus fluvialis sp. nov., holotype, ♂ (ZMUM). A. Habitus. B. Head.C. Antenna.D. Wing. E. Hypopygium after maceration, lateral view. F. Hypopygium after maceration, ventral view.