Chamaemyia grisea, 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 : 466-468

Chamaemyia grisea sp. n.

( Figs 8 –14)

Diagnosis. A uniformly grey species with black antenna and yellow tibiae and tarsi; the wing exhibits no darkening at all on crossveins or on veins towards base.

Description. Male. Head: ( Figs 9, 10 ) slightly longer than high, ratio 1.1:1, uniformly silver grey pollinose; face slightly broader than high; lunule pollinose as frons, narrow at sides and at middle about as long as pedicel; eye elongate, length to height 1.4:1; gena at narrowest part about 0.8 as high as height of first flagellomere; occiput uniformly grey pollinose; 2 long orbitals, posterior seta about 2/3 length of frons, anterior seta about half length of frons; long proclinate ocellars arising marginally posterior to anterior ocellus and almost reaching anterior margin of frons, medial and lateral verticals a little longer than posterior orbital, postverticals convergent and half as long as medial vertical; a few very short setulae in an irregular row forming arc on anterior half of frons between anterior orbital and lunule; all setae and setulae black; antenna black, yellow only around insertion of arista and basal 1/4 of medial surface of first flagellomere; arista pale brownish yellow with black second segment and extreme base of third segment, micro pubescent; pedicel with one long black seta dorsally and 4–5 long black setae ventrally, these reaching middle of first flagellomere; gena with an irregular row of long black setae along middle; proboscis and palp pale yellow.

Thorax: ( Fig. 9 ) completely pale greyish brown pollinose with a faint golden sheen from certain angles of light, on posterior half of scutum, notopleuron and upper posterior area of anepisternum; prescutellum present but very narrow; pleura with dense silver grey pollinosity as on scutum; chaetotaxy: 1 postpronotal, 2 notopleurals, 1+2 dorsocentrals, 1 presutural, 1 supra-alar, 2 post-alar, acrostichals in four rows anteriorly, becoming 2 rows at level of transverse suture, prescutellars short barely longer than other acrostichals, 2 pairs of scutellars, 1 strong katepisternal at postero-superior corner; all setae apart from acrostichals very long; legs: coxae and femora black, trochanters partly yellow, knees tibiae and basitarsomeres clear yellow, anterior tarsomeres 3-5 a little brownish at sides; fore femur with posteroventral and posterior rows of long setae; all setae and setulae of legs black; hind femur distinctly thickened—about 1.9 times thickness of tibia; wing ( Fig. 11 ) hyaline with a faint yellowish tinge; veins yellow becoming paler yellow on posterior half and basal half of wing; squama and halter creamy white.

Abdomen: ( Fig. 8 ) pale silver grey pollinose with one pair of small black spots dorsally on each tergite 3–5, fairly densely scattered short black setulae on all tergites those along posterior margin longer, about half as long as tergite; tergite 7 lustrous except for posterior margin.

Postabdomen: (Figs 12–14) epandrium small, black and only thinly pollinose; postgonite (Fig. 14a) in ventral view broader before apex and distinctly hook-shaped apically in lateral view (Fig. 14b); aedeagus (Fig. 14c, d) pointed apically in both ventral and lateral view.

Average length, male and female: body 2.6 mm, wing 2.8 mm.

Female: similar to male in all respects of pollinosity and colouration but lateral oblique elongate spots present on tergites 3–5.

Etymology. The name is derived from the Greek word grizos —grey, and refers to the almost uniform grey colouration of the species.

Material examined. Holotype, ♂, Saudi Arabia: Abha, Al-Souda, Al-Muktatha dam, 14.iii.2013, HAD ( NMWC) . Paratypes: 1♂ 2♀, same data ( NMWC) ; 2♀, same data ( CERS-JU) ; 1♂ 1♀, same data (MJE) ; 1♀, same data ( CSCA) ; 1♂1♀, Abha, Al-Souda, Al-Muktatha dam, 1.ii.2012, JCD (NMWC); 1♀, Abha, Al-Souda, Bani Mazen, 18°12ʹN 42°27ʹE, 19.vi–9.vii.2013, Malaise trap, HAD (CERS-JU); 1♂, Abha, Al-Souda, Al-Muktatha dam, 31.xii.2014, HAD (CSCA).

Distribution. Saudi Arabia.

Figures

FIGURES 8 – 11. Chamaemyia grisea sp. n. paratype, 8) female habitus left lateral view, 9) head and thorax, dorsal view, 10) head, left lateral view, 11) right wing.