Melanochthiphila arabica, 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 : 475-477

Melanochthiphila arabica sp. n.

( Figs 30–36 )

Diagnosis. A completely black almost totally lustrous species with elongate first flagellomere and very long setae on head and thorax; 1+3 dorsocentral setae; legs black but apical one third of tibiae and all tarsomeres yellow.

Description. Male. Head: ( Figs 31, 32 ) lustrous black including all setae and setulae; without any pollinosity except over two small narrow greyish arcs on lunule just above each antennal base and on a small area just behind ocellar triangle; head in profile very slightly higher than long and protruding only slightly beyond anterior eye margin; frons more or less square with a few minute black setulae scattered asymmetrically around middle; length of lunule at middle at least equal to length of pedicel; ocelli forming equilateral triangle; gena in frontal view very oblique and in strict profile deepest part is below posterior eye margin and at least 3 times as wide as height of first flagellomere; viewed from below, gena at level of lower facial margin as wide as distance between vibrissae, and laterally with 5 short setae in line near posteroventral corner; 2 long reclinate orbital setae, very long proclinate ocellar setae arising in line with anterior ocellus and almost reaching lunule; post-oculars distinct and posteriorly reach almost to lower eye margin; post-verticals strong and crossed; face smooth and lustrous black centrally but parafacial and gena finely rugose; antenna completely black but for very narrow yellowish brown encircling base of arista; arista pale creamy yellow over almost entire length of third segment, second segment black and first light brown; arista micropubescent, setulae less than half thickness of base of arista; pedicel black with silvery grey pollinosity on dorsal and medial surface; first flagellomere about 2.8 times long as wide, anterior third slightly curved dorsally and apico-dorsal corner pointed; palp black.

Thorax: ( Fig. 30 ) black with completely lustrous scutum and scutellum except for posterior half of postpronotum; prescutellum present but very narrow; pleura with thinly spread grey pollinosity best seen on anterior part of anepisternum, anepimeron and meron; chaetotaxy: 1 long and 1 short postpronotal, 2 notopleurals, 1+3 long dorsocentrals, 1 presutural, 1 supra-alar, 1 post-alar, acrostichals very short, few in number and in 3 irregular rows extending only between the two middle dorsocentrals, prescutellars absent, 2 pairs of scutellars, 1 strong anepisternal at middle of posterior margin; 1 strong katepisternal at middle of superior margin; legs with femora including knees black, lustrous anteriorly, thinly greyish pollinose posteriorly; tibia black over basal two thirds and thinly greyish pollinose; tarsi and apical one third of tibiae yellow; front femur with row of setae postero-dorsally and postero-ventrally; hind femur distinctly thickened—about 2.5 times thickness of tibia; wing hyaline and veins pale yellow except for apical one third of veins R2+3, R4+5 and M and costa joining them, brown; squama and halter pale yellow, almost white.

Abdomen: lustrous black, but sternites 1–4 lightly grey pollinose; each segment from 1–5 getting progressively longer; tergite 2 devoid of black setulae over most of surface, setulae being present only along hind margin and over postero-lateral corners; rest of tergites with distinct black setulae scattered over whole surface.

Postabdomen ( Figs 33–36 ): syntergite 7+8 very narrow but symmetrical; sternites 6 and 7 symmetrical and almost equal in length; genitalia very small compared to those in related genera; epandrium in profile more or less pentagonal in shape with the ventral angle rounded and only slightly produced; cerci about 2/3 as high as epandrium; hypandrium very narrow and forming a broad semi-circular arc; phallapodeme small and narrow, only in its dorsal 2/5 expanded; aedeagus, in profile, broad at base, narrowing more or less symmetrically towards apex and with shallow obtuse bend from basal 1/3; aedeagus from ventral view more or less elongated elliptical; postgonites short, narrow and directed anteriorly; pregonite markedly reduced forming only a small rounded lobe at the posterior and medial end of the hypandrium and bears about 3 distinct setulae.

Length body 3.4 mm, wing 2.8 mm.

Female: unknown

Etymology. The name arabica refers to the country where this species was discovered.

Material examined. Holotype, ♂, Saudi Arabia, Abha , Al-Souda, Bani Mazen, 18°12ʹN 42°27ʹE, 16.ix.2014, HAD . Holotype deposited in NMWC. Paratype: 1♂, same data and depository as holotype .

Distribution. Saudi Arabia.

Similar species: Melanochthiphila aenea Frey, 1958 was described from the Cape Verde Islands where nine specimens were collected by H. Lindberg on a sandy costal area ( Frey 1958). I found another undescribed species, represented by only one female specimen, in a sandy area at altitude inland in Morocco ( Ebejer 2016). The new species differs from both of these in having a longer first flagellomere and much longer setae on the head and thorax, the whole body more lustrous and the femora entirely black. It also differs significantly from M. nigroaenea in details of the male postabdomen.

Figures

FIGURES 30 – 32. Melanochthiphila arabica sp. n. holotype, male, 30) habitus, left lateral view, 31) frons oblique left dorsal view, 32) face anterior view.

FIGURES 33 – 36. Melanochthiphila arabica sp. n. paratype, male, 33) abdomen, ventral, 34) aedeagus, a, lateral, b, ventral, scale bar = 0.1 mm, 35) postabdomen, lateral, 36) postabdomen, ventral, scale bar = 0.2 mm. Abbreviations: se sclsubepandrial sclerite, and as in figs 5, 6.