Bengalia chekiangensis Fan, 1965

(Figs 1–20)

Bengalia (Ochromyia) chekiangensis Fan, 1965: 194 (in key; also p. 192, fig. 756 [apex of ST5 wiTh flap only]). HoloType ♂ (SIBSCAS; not examined), by monotypy (“a single specimen”). Type locality: China, Zhejiang Province, Tianmushan. [NB: the species is not listed in Shanghai Institute of Entomology Academia Sinica (1992), but I was informed by Dr. Weibing Zhu (Shanghai) that the type is present in SIBSCAS.]

Bengalia chekiangensis: Fan (1992: 534; 1997: 454); Feng et al. (1998: 1378) (China [Anhui, Jiangxi, Zhejiang]).

Bengalia chekiangensis: Thinh (2004: 7) (Vietnam) .

Bengalia chekiangensis: Verves (2005: 238; catalogue entry).

Bengalia chekiangensis: Yang et al. (2014: 88) (Taiwan; examined).

Diagnosis. Male. Length: 10.0–11.0mm (n=4). Frons at vertex / head width ratio 0.29–0.31 (mean 0.31, n=6). Mesonotum bluish-grey. Anepimeron with pale setulae only (Fig. 12). Legs yellow. Fore tibia with strong spinous setae intermingled with shorter ones (Fig. 7). Fore femur with 2–3 strikingly short strong spinous setae (Fig. 7). Tegula black with pale edges (Fig. 9). ST5 flap transversely oval, with projections on each side (Fig. 10). Cercus with long distal prong. Surstylus with almost parallel upper and lower edges, obliquely truncated distally (Fig. 2). Uniquely shaped bacilliform sclerite process (Fig. 20). Dorsal surface of phallus curved in lateral view (Fig. 16). Internal hypophallic lobes close together (Fig. 17). Semidomes almost circular in apical view. Distal lip projection almost flat, flush with inner surface of dorsal half of semidomes, with a distal, rather deep bay, a central sclerotisation, and an undulating lateral edge (Figs 16–18).

Female. Length: 10.0– 11.5mm (n=5). Frons at vertex/head width ratio: 0.32–0.33 (mean 0.32, n=3). Main external features as in male.

Remarks. Only the ST5 flap had previously been illustrated for this species (Fan 1965). Nothing was known about its terminalia.

Biology. B. chekiangensis has been captured at an altitude above 1200m in Vietnam (Thinh 2004).

Distribution. China, Taiwan *, Vietnam.

Material examined (non-type). CMNH. Taiwan: 5 ♂, 5 ♀, labelled (1) TAIWAN: Nantou / Mushe. 24 May 1988 / C. Young, J. Rawlins / R. Davidson; (2) Bengalia ♂ (or ♀) / chekiangensis / Fan, 1965 / Det.H.Kurahashi [both labels printed]. [T1+2 yellow with narrow black marginal band; T3 yellow with black marginal band in hind 1/4 and middorsal black stripe of about same width; T4 and T5 black and greasy. 1 male dissected: dried abdominal tergites glued to a piece of card on pin above labels; terminalia in glycerol in glass microvial on pin below labels.]. CNC. Taiwan: 1 ♂, labelled (1) 1387 [printed, pale blue label]; (2) Sun Moon Lake / TAIWAN 13.VII.68 / J.W.Boyes [printed]; (3) Boyes Cytolog. / Coll. #1387 / To remain / in C.N.C. [yellow label with black print, except handwritten number in black ink]; (4) Bengalia sp. / Det. Shewell 1971 [printed, except first line and “71” in last line, which are handwritten]; (5) T5 without discal.s.; hind tibia / without fringe; post. margin of eye / straight; fore tibia w> 3vs / Not torosa [pencil writing by T. Tantawi]; (6) Bengalia (m) / chekiangensis Fan, 1965 / K.Rognes det. 2016 [printed] [T5 partly torn from T4 and terminalia partly extruded; I had an accident with the forceps and tore parts of the right wing (see Fig. 14); the genital capsule had already been extruded prior to my examination and, together with T5 and ST5, partly separated from T4 by a tear; I managed to remove the genital capsule together with T5 and ST5 from the rest of the abdomen by continuing the tear between T4 and T5; dissected; abdominal tergites glued to a piece of card on pin above labels; terminalia in glycerol in glass microvial on pin below labels].