Tethina spinigera Munari, 2008

Munari, Lorenzo, 2016, The Canacidae of the Arabian Peninsula (Diptera: Brachycera: Carnoidea), Zootaxa 4092 (4), pp. 489-517 : 507

Tethina spinigera Munari, 2008

(figs. 36─37)

Tethina spinigera Munari, 2008a: 675 [ United Arab Emirates: al-Ajban; HT ♂, NMWC].

Distribution. Afrotropical: United Arab Emirates.

Diagnosis. Body length 1.9‒2.2 mm; dark grey species with head, wings, and legs yellow, the latter unusually long and robust; scutellum without dark spot on discal surface, concolorous with the rest of thorax; setal vestiture golden yellow. Head mostly yellow, except for the dark grey vertex and occiput; ventral face slightly protrudent, face vertically flattened; eye very slightly oblique, oval to rounded, its longest diameter 2.4 times as long as the height of the gena; gena yellow, uniformly microtomentose; mouth parts with very short and stumpy labella, distinctly shorter than the length of the buccal cavity; palpus short and tiny; thorax grey to brownish grey; acrostichal setulae arranged in 1-2 strongly irregular rows on the entire scutum; prescutellar acrostichals not longer than the other acrostichals; both proepisternal and proepimeral setae present; legs unusually long and robust; mid leg with tibia bearing 3 strong, pitch-black spurs apically, the mid one stronger and longer; tarsi with short, apical setae (spinulae) of the same colour, particularly strong and long on the mid leg tarsus; legs yellow, apical tarsomere of mid and hind legs noticeably pitch-black; all femora distinctly inflated in male individuals; wing with crossveins without any trace of white halo; abdomen predominantly grey, except for the broadly yellowish syntergite 1+2; male terminalia (figs. 36‒37) with epandrium without long setae, only bearing 5-6 pairs of very characteristic, stout spinulae on entire perianal margin; surstylus very characteristic in lateral view (fig. 36), moderately large and with ventral lobe in posterior view (fig. 37); female with simple, not swollen femora.

Remarks. As can be easily deduced from the diagnosis of this species, some derived, diagnostic characters, especially the peculiar spine-like setulation of the epandrium, place T. spinigera into a very distinctive taxonomic position. Indeed, it might be regarded as a possible sister species to all other Arabian species of the alboguttata - group.