Chamaemyia aurilinea, Ebejer, M. J., 2017

Ebejer, M. J., 2017, A conspectus of the silver-flies (Diptera: Chamaemyiidae) of the Middle East with descriptions of new species of Chamaemyia Meigen and Melanochthiphila Frey, from the Arabian Peninsula, Zootaxa 4319 (3), pp. 461-482 : 463-465

Chamaemyia aurilinea sp. n.

( Figs 1–7 )

Diagnosis. The species is recognized by its elongate eye, black antenna and femora, completely yellow tibiae and tarsi, and by the golden brown pollinosity on the scutum along a broad vitta between the dorsocentral lines; beneath the dorsocentral setae runs a narrow brown vitta thus bordering the golden pollinose area.

Description. Male. Head: ( Figs 2, 3 ) as long as high, silver-grey pollinose except on mesofrons where it is dark brownish-grey and ocellar triangle and midline stripe to lunule more of a pale golden brown; central facial sclerite higher than broad; lunule silver-grey pollinose as orbits; eye elongate, length to height 1.3:1; gena at narrowest part as high as height of first flagellomere; occiput dark grey pollinose except for narrow postocular margin, which is paler grey; 2 long orbitals, each about 3/4 length of frons, long proclinate ocellars arising in line with anterior ocellus and reaching anterior margin of frons, medial vertical a little longer than posterior orbital, lateral vertical as long as anterior orbital; postverticals half as long as medial vertical, wide apart and parallel; a few very short setulae in front of and medial to anterior orbital; all setae and setulae black; antenna black apart from yellow ring around insertion of arista and basal 1/4 on medial aspect of first flagellomere; arista entirely black with micropubescence that is barely distinguishable; pedicel with one long black seta dorsally and several black setae along medial, lateral and ventral margins, ventrally reaching middle of first flagellomere; gena with row of 4 black setae along middle, posterior two longer; proboscis and palp pale yellow.

Thorax: ( Fig. 3 ) scutum silver-grey pollinose with a distinct golden vitta running from anterior dorsocentral to scutellum, bordered dark golden brown on each side along dorsocentral line; postpronotum, notopleuron, supraalar depression, posterior half of anepisternum and epimeron distinctly golden-grey pollinose contrasting with scutum; prescutellum present but very narrow; scutellum pale golden-grey pollinose; chaetotaxy: 1 postpronotal, 2 notopleurals, 1+2 dorsocentrals, 1 presutural, 1 supra-alar, 2 post-alar, acrostichals in 2–4 rows anteriorly, becoming 2 rows posterior to middle dorsocentral, prescutellars short but distinct about 3 times as long as other acrostichals, 2 pairs of scutellars, 1 strong and 1 weak katepisternal just behind middle of superior margin; all setae apart from acrostichals long; legs: coxae and femora black with dense grey pollinosity and with apical 1/5 of femora pale yellow, tibiae and basal tarsomeres yellow, apical 4 tarsomeres dark brown; fore femur with posterior and posteroventral rows of long setae; all setae and setulae of legs black; hind femur distinctly thickened—about 2 times thickness of tibia; wing ( Fig. 4 ) hyaline veins dark brown apart from pale yellow R1 and costa from base almost to apex of R2+3 and stem veins including veins bordering basal and anal cells; squama and halter entirely pale yellow.

Abdomen: pale greyish brown pollinose with one pair of small black spots on each tergite 3–5, fairly densely scattered black setulae on all tergites those along posterior margin longer, about 2/5 as long as tergite.

Postabdomen: ( Figs 5–7 ) epandrium small, black and densely grey pollinose as rest of abdomen, postgonite ( Fig. 6, 7a ) in ventral view, broad at apex; aedeagus ( Fig. 7c ) in ventral view broadening at apex; in lateral view ( Fig. 7d ) long and narrow.

Average length male and female: body 3 mm, wing 2.9 mm.

Female: similar to male in all respects of pollinosity and colouration but first flagellomere and distal tarsomeres more often darker than in males; abdomen with two pairs of black spots on tergites 3–5 and a small lateral spot on tergite 6; dorsal spots round, lateral spots elongate.

Variation: The third segment of the arista may be pale brownish-yellow; the intensity of the golden and the brown vittae on the scutum varies such that in pale specimens they are discernible only posteriorly or from certain angles; the distal tarsomeres particularly of the middle and hind leg may be less distinctly dark brown;

Etymology. The name is from the Latin words aurum —gold and linea —line, and refers to the golden brown vitta on the scutum.

Material examined. Holotype, ♂, Saudi Arabia: Asir, Abha, Al-Souda , Bani Mazen , 1–25.v.2013, Malaise Trap, HAD ( NMWC) . Paratypes: 6♂ 2♀, Asir, Abha, Al-Souda, Al-Muktatha dam, 1.ii.2012, JCD ( NMWC) ; 2♂ 6♀, Asir, Abha, Al-Souda, Al-Muktatha dam, 14.iii.2013, HAD ( NMWC) ; 4♀, same data ( CERS-JU) ; 2♂ 3♀, same data ( CSCA) ; 1♀, Asir, Abha, Hay Al-Nusub , 18°13ʹN 42°30ʹE, 9–30.v.2014, Malaise trap, HAD (CERS- JU) ; 5♂5♀, Abha, Al-Souda, Al-Muktatha dam, 31.xii.2014, HAD (CERS-JU); 3♂ 3♀ same data ( BMNH) ; 2♂ 2♀, same data (MJE) ; 4♂ 1♀, same data ( NMWC) ; Yemen: 1♂ 1♀, Ta’Izz, 3–24.i.1999, light trap, A. van Harten ( NMWC) ; 1♂, Ar-Rujum , 16.x.2000 – 15.i.2001, Malaise trap, A. van Harten & A.M. Hager (NMWC); 2♂, Ar- Rujum , 15.i.–9.iv.2001, Malaise trap, A. van Harten ( NMWC) .

Distribution. Saudi Arabia.

Figures

FIGURES 1 – 4. Chamaemyia aurilinea sp. n. paratype, 1) female habitus left lateral view, 2) same, dorsal view, 3) head, lateral, 4) right wing.

FIGURES 5 – 7. Chamaemyia aurilinea sp. n. paratype, 5) male postabdomen right lateral view, 6) same, ventral view, 7) gonites and aedeagus: a, right gonites ventral view, b, same right lateral view, c, aedeagus ventral, d, same right lateral view. Abbreviations: hyp—hypandrium, aed—aedeagus, ph apd—phallapodeme, ep—epandrium, cer—cercus, prg—pregonite, psg—postgonite. Scale bar = 0.3 mm.