Thinophilus cataractae, 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 : 38-41

Thinophilus cataractae sp. nov.

urn:lsid:zoobank.org:act:D888F387-9F93-4989-AD30-CC8506F40B0A

Fig. 13

Diagnosis

Thinophilus cataractae sp. nov. keys to T. fluvialis sp. nov., strongly differing from the latter in morphology of hypopygium, almost entirely black antenna, and black-brown palp on basal half. T. fluvialis male has antenna black dorsally, yellow ventrally; palp entirely yellow (see key above).

Etymology

The specific epithet ‘ cataractae ’(in Latin) refers to the Niagarakely waterfalls locality in the Niagarakely Forest, where the male type was collected.

Material examined

Holotype MADAGASCAR • ♂; “ Niagarakely Forest [19°09′ S, 48°13′ E]; Moramanga Distr.; Dec. 1955; B. Stuckenberg leg.; Thinophilus tinctus Parent ; P. Vanschuytbroeck det. 1957; I.R.Sc.N.B. I.G. 20938”; RBINS.

Paratype MADAGASCAR • 1 ♂; same collection data as for holotype; RBINS.

Description

Male ( Fig. 13A )

MEASUREMENTS. Body length 3.8 mm; antenna length 1 mm; wing length 3.5 mm; wing width 1.1 mm.

HEAD ( Fig. 13B ). Postcranium bluish black, grey pollinose; frons and face bluish black; clypeus black, grey pollinose; face under antennae about 2 × as wide as height of postpedicel; clypeus about ⅔ as long as epistoma, about as wide as long; palp black-brown on basal half, yellow distally, bearing black bristly hairs; proboscis dark brown; 2 diverging ocellars; 1 vertical, 1 postvertical, somewhat stronger and longer than, and not in row with upper postoculars; upper postoculars uniseriate, black; lower postoculars multiseriate, white, long; antenna black; scape with scale-like inner projection (spine-like from dorsal view; Fig. 13D ), as long as scape; pedicel simple, convex on inner side; postpedicel 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, 0.07/0.07/0.10/0.84.

THORAX. Metallic, grey dusted; mesonotum black, without matt spots; pleura bluish black; no acrostichals; 5 dorsocentrals of almost equal length; scutellum with 2 strong marginals and 2 minute laterals; 1 dark upper and 1–2 white lower propleural bristles of different length.

LEGS. Fore coxa brown; mid and hind coxae black; legs mostly dirty yellow, darker at knees; tarsi black from tip of basitarsus

FORE LEG. Coxa with long black setae and apical bristles; femur simple, with some short fine ventral setae at base and 3–4 posteroventral bristles at apex; tibia bearing 2 anterodorsal, 2 posterodorsal bristles and 3–4 short apical setae; tibia and tarsus ventrally with elongate simple setulae; segment 5 inconspicuously widened; length of femur, tibia and tarsal segments (in mm): 1.05/1.04/ 0.47/0.22/0.18/0.13/0.16.

MID LEG. Coxa with black setae and 1 bristle; femur ( Fig. 13C ) with anteroventral row of short dark hairs on basal half; 1 preapical anterior and 4–5 preapical posteroventrals; tibia bearing 2 anterodorsal; 2 posterodorsal, 4 apical bristles; segment 5 inconspicuously widened; length of femur, tibia and tarsal segments (in mm): 1.3/1.39/0.8/0.34/0.2/0.13/0.16.

HIND LEG. Coxa with 1 black exterior bristle; femur ventrally without remarkable setae; 3 anterodorsal bristles; tibia bearing 2 anterodorsal, 2 posterodorsal bristles, few very short ventrals, 4 apicals; segment 5 inconspicuously widened; length of femur, tibia and tarsal segments (in mm): 1.41/1.55/0.46/0.41/0. 28/0.17/0.18.

WING ( Fig. 13E ). Fumose, without dark spots; veins brown; distal part of M 1+2 straight; 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), 0.48/0.25; crossvein dm-m straight; ratio of dm-m to distal part of M 4, 0.32/0.30; anal vein distinct; halter yellow; lower calypter yellow, with white cilia.

ABDOMEN. Black, grey dusted; tergites 2–4 laterally whitish pollinose; setae and hind-marginal bristles black, short; sternites with short setae. Hypopygium ( Fig. 13F ) black with black appendages; epandrial lobe fingerlike, with strong apical bristle; hypandrium fused with epandrium, short, apically concave; phallosoma broad, acute apically, projected; phallus coiled, long and flat, band-like; surstylus relatively short and narrow (lateral view), not reaching apex of phallosoma ( Fig. 13G ), with 2 long wormlike ventral processes and 2–3 short spine-like apicoventral setae; cerci dorsally widely separated, elongate-ovate, with narrow finger-like apex, covered with long outer bristles.

Female

Unknown.

Figures

Fig. 13. Thinophilus cataractae sp. nov. A–E. Holotype, ♂ (RBINS). F–G. Paratype, ♂ (RBINS). A. Habitus. B. Head. C. Mid femur, anterior view. D. Antenna, dorsal view. E. Wing F. Hypopygium after maceration, lateral view. G. Distal appendages of hypopygium after maceration, lateral view.