Sabeurina occidentalis, Deeming, 2018

Deeming, John C., 2018, A revision of the Afrotropical species of Pachylophus Loew (Diptera: Chloropidae) and some related Ovoviviparous genera, Zootaxa 4482 (1), pp. 1-51 : 29-31

Sabeurina occidentalis sp. n.

( Plate 7 , Fig. 29; plate 18 , Figs 92, 93)

Diagnosis. A black species, yellow on a lateral line extending from wing base over entire notopleuron and onto posterior half of postpronotal lobe, on all but base of scutellum, on parafacial, gena and lower face, on upper margin of katepisternum, knob of haltere, on fore and hind coxae, all trochanters, knees, apices of tibiae, and on all tarsi, but apical tarsomeres and fore tarsus somewhat brown, as also are base of postpedicel and palpus, dirty yellow on anterior margin of frons, squama and its fringe; setae and setulae black, but some on genal margin and legs pale; wing greyish hyaline with dark brown veins.

Description. Male. Head slightly wider than thorax; the frons almost twice as long as its width at narrowest point (ratio of 54:30), where it is half as wide as head, and projecting in front of eyes to a distance equal to two fifths of the eye length; gena one quarter of vertical height of eye; postorbital strip rather broad; frontal triangle roundedly convex-sided anteriorly, completely undusted; face dirty yellow dusted; gena shining; a broad pale pruinose strip beneath eye; occiput grey dusted; inner vertical seta very slightly longer than outer; vibrissa and postocellars minute; clypeus shining black, grey dusted on a medial line and in lateral half. Thorax with length, including scutellum, one and a half times its width; scutum faintly grey dusted, its surface intensively coarsely pitted and with dark short hairing, its lateral declivities yellowish dusted; disc of scutellum lacking such pitting, with a few scattered short dark setulae; 1 weak postpronotal, 1+2 notopleural, 1 dorsocentral, 1 postalar and 2 scutellar marginal setae, the apical of which is twice the length of the lateral; pleura shining, but propleuron dusted, as are upper posterior corner and lower margin of anepisternum, upper and posterior parts of anepimeron, anatergite, katatergite and mediotergite. Abdomen weakly grey dusted dorsally, the ventrally-facing incurved parts of the tergites shiny; terminalia (plate 7, Fig. 29).

Length about 4.3mm, of wing 3.1mm.

Female resembling male except in abdominal characters. Sternites (plate 7, Fig. 30) of distinctive shape, the second being long triangular, the third to fifth spindle-shaped and the sixth almost semicircular.

Material. Holotype, ♂, N. NIGERIA: Zaria, Shika, grasses beside stream, 6.iv.1974, J.C. Deeming ( NMWC) . Paratypes, 1♂ 1♀ Shika , on lush grasses in deep wet overgrown gulley, 7.iv.1973, J.C. Deeming & L.V. Knutson ; 2♀, Bauchi, on pond grasses, 1–7.iii.1997, J.C. Deeming (all in NMWC) ; 1♀, Mambilla Plateau [as "N.E. State "], Ngel Nyaki , 31.iii.1970, J.T. Medler ; 1♀, Gashaka , 26.iii.1970, J.T. Medler (both NHMUK) .

Figures

PLATE 7. Figs 28–31. 28, Sabeurina minuta (Loew) male, terminalia ventral; 29, Sabeurina occidentalis sp. n. male, terminalia ventral, (inset) female sternites; 30, Eurina lurida Meigen, male, terminalia ventral; 31, “Platycephala” scapularum (Becker) male, terminalia ventral.

PLATE 18. Figs 90–93. Sabeurina spp. 90, S. minuta (Loew), frons; 91, same, habitus; 92, S. occidentalis sp. n., frons; 93, same, habitus.