Xanthocanace hamifer, Munari, Lorenzo, 2008

Munari, Lorenzo, 2008, Beach and Surge Flies (Diptera: Canacidae) from the Arabian Peninsula, with descriptions of three new species, Zootaxa 1848, pp. 37-46 : 40-41

Xanthocanace hamifer sp. nov.

( Figs. 8–10 )

Type material. Holotype ɗ: [printed white label] “ UAE: Qurrayah / 19.iii.2007 / F. Menzel & A. Stark” // [printed red label] “ HOLOTYPUS / Xanthocanace / hamifer sp. nov. ɗ / L. Munari des.”. The specimen is in excellent condition except for the right wing which is wrinkled. The holotype is deposited in NMWC, and is double mounted (micropinned laterally in a block of plastic material); abdomen dissected, stored in glycerol in a small plastic tube, and pinned below the specimen. Paratypes 6 ɗɗ 1 Ψ, same data as holotype. The paratypes are deposited in NMWC, UAEIC, and in the author’s collection (property of MCNV).

Description. Size. Body length 2.10–2.38 mm, wing length 1.68–2.10 mm. Habitus. Small fly with body dark grey dorsally, pale grey laterally; legs bicolour, showing grey femora and pale yellow tibiae. Setal vestiture poorly developed, formed by sparse, minute, pale yellowish setae and setulae. Wings with brown veins and hyaline membrane. Head. Frontal plate (frons), from posterior ocelli to anterior margin, markedly broad, evenly flat, shiny black, apparently strongly sclerotized, with yellowish lateral and anterior edges; rest of head dark grey to yellowish; postocellar setae absent or present as minute, thin setulae just behind middle of posterior pair of ocelli; paravertical seta moderately long, inclinate, simulating an arrear medial vertical seta; lateral vertical about as long as paravertical; true medial vertical seta absent; postocular setae more or less developed; postgenal setae inconspicuous; ocellar setae absent; 5–6 pale, strongly lateroclinate, orbital setae; frons entirely covered with several, evenly spaced, moderately long, yellow setae; antenna dark grey, with proximal segments of arista noticeably elongated and thickened, sausage-shaped, reddish brown, remaining segments very thin and pale; eye glabrous, horizontally subrectangular, parallel to longitudinal axis of head, its vertical diameter about 1.4 times as long as genal height; face subquadrate, covered with whitish yellow to yellowish microtomentum, strongly contrasting with rest of head; peristomal setae quite inconspicuous, hardly discernible; clypeus and sclerotized parts of mouth dark grey. Thorax. Entire mesonotum thinly microtomentose, subshiny, except for postpronotal lobes that are covered with dense, whitish grey microtomentum; pleura dull, pale grey, concolourous with postpronotum; scutum sparsely setose, with setae and setulae pale yellowish; 1 short, posterior dorsocentral seta present, remaining surface with several, minute setulae, among these 4 rows of acrostichal setulae are discernible; 1 short postpronotal; 1–2 notopleurals, anterior one, if present, sometimes slightly shifted upward; 1 external postalar; scutellum with pair of inclinate, apical setae and pair of moderately long, latero-median setae arising from discal surface, the latter bearing numerous, fairly long setulae; anepisternum and katepisternum with scattered, thin, pale setulae; anepimeron, katatergite, and meron without setae and setulae. Legs. Evenly setulose, bearing short, pale yellow setulae; forefemur without ctenidium, only with row of anteroventral, thin setulae on distal half; legs bicouloured, with coxae, trochanters, and femora grey, tibiae and tarsi yellow, latter sometimes with distal tarsomeres slightly infuscated. Wing. Veins dark brown, membrane hyaline; alula small, with fringe formed by moderately long, pale yellowish setae; costal vein reaching end of M1; R2+3 slightly bent; R2+3, R4+5 and M1 subparallel; crossvein r-m ending just before middle of cell dm; crossvein dm-cu as long as or slightly shorter than last section of CuA1; halter pale yellow. Abdomen. Grey, with setal vestiture formed by sparse, minute, golden yellow setae on lateral sides of tergites, mid surface of them being almost entirely hairless. Male terminalia (figs. 8–9). Epandrium rather elongated, with sparse, fairly long, dorsal setae; surstylus characteristically hook-shaped, bearing long, narrow, bent process apically.

Female. Similar to male except for usual, slight dimorphism. Female terminalia (fig. 10). Postabdomen with cerci abruptly oriented forwardly, their ventral sides being just below hypoproct; outline of cercus distinctly sharp, with strong, blunt, apical, spinelike seta; sternite 8 with two median, elongated sclerites, each bearing 2 stout setae; hypoproct microscopically setulose, strongly curved towards sternite 8 (fig. 10).

Distribution. United Arab Emirates.

Remarks. This new species is externally strongly similar to X. zeylanica Delfinado, 1975 , in particular the thinly microtomentose, subshiny mesonotum. It consistently differs, though, from Delfinado’s species mainly by the bright yellowish face, the proximal segments of arista noticeably elongated and thickened, sausage-shaped, reddish brown (remaining segments very thin and pale, hairlike), and for having a quite peculiar surstylus, which is typified by a hooked process, in both lateral and caudal views (figs. 8–9).

Etymology. The species epithet, hamifer , is a compound Latin word meaning hook-bearer, and refers to the peculiar shape of the surstylus.

Figures

FIGURES 8 – 10. Xanthocanace hamifer sp. nov. 8. Male terminalia caudal view; 9. Ditto, lateral view; 10. Female postabdomen ventral view. Legend: ce = cercus, hyprct = hypoproct, st = sternite. Scale bar = 0.1 mm.