Stomosis sp. 2
Differs from congeners in the combination of yellow anterior margin of frons, completely brown basoflagellomere, completely brown thorax, gena height 0.33x eye height, and shape of male terminalia.
Coloration and vestiture: Head brown posteriorly, yellow anteriorly. Frons usually competely yellow except for a brown ocellar triangle and orbital plates, but in some specimens the frons is brown on posterior 2/3 and yellow on anterior third of frons; lunule yellow, face light brown; gena yellow except for posterior margin; antenna brown; palpus usually yellow, sometimes with very narrow brown tip and proboscis light brown. Thorax completely brown, wing and calypter hyaline, veins brown, halter white, legs black except for lighter ventral side of fore coxa and yellow narrow bases of all tibiae as well as distal tip of fore tibia, and all basitarsi. Abdomen with all tergites and sternites brown.
Head: Frons with 3 orbital setae of which the posterior one is lateroreclinate, the medial one lateroclinate and the anterior one lateroproclinate, and 2 medioclinate frontal setae, postocellar setae medioclinate (cruciate). Arista about 2.1-2.6x as long as basoflagellomere width, pubescence on arista very short. Tip of ocellar triangle nearly reaching anterior third of frons. Gena height 0.33x eye height; labellum 1.1x eye height.
Thorax: 2 dc, 1 prsc, 1 pprn, 1 prs, 1 sa, 1 pa, 1 keps setae, posterior prsc about a third as long as posterior dc, seta between posterior prsc and posterior dc absent.
Wing with veins R4+5 and M parallel; M-ratio is 3.2-3.4. Length: 1.5-1.9 mm.
Male abdomen: Sternite 5 is divided into a narrow anterior and a narrow posterior part. The anterior part is bent behind sternite 4 and covered with setulae, which may be part of some kind of gland (Brake 2009, Pl. 12A)
1.7-2.1 mm
Australia (Western Australia)