Nothybidae Frey, 1927

Zhou, Jiale, Marshall, Stephen A. & Yang, Ding, 2021, Synopsis of Nothybidae (Diptera: Brachycera) from China, with redescription of Nothybus absens Lonsdale & Marshall, Zootaxa 4926 (2), pp. 201-223 : 202

Family Nothybidae Frey, 1927

Nothybidae Frey, 1927: 66 .

Type genus: Nothybus Rondani, 1875 .

Diagnosis. Slender, long-legged flies 5.5–15.0 mm in length, usually yellowish orange to brown with abdomen partially dark brown to blackish brown. Head suborbicular with three velvety black patches (rarely fused); two fronto-orbital setae, one inner vertical seta and one outer vertical seta; vibrissa, ocellar and postocellar setae absent; pedicel with dorsal seam; first flagellomere angled, twice as long as wide. Thorax strongly produced anteriorly, anterior margin widely separated from fore coxa; subscutellum inflated and subconical, reaching or surpassing the apex of scutellum; thorax usually with brownish mottling and stripes; one anepisternal seta, one notopleural seta, one supra-alar seta, one postalar seta, one dorsocentral seta, one lateral scutellar seta and one apical scutellar seta; postpronotal, anterior notopleural and katepisternal setae absent. Precoxal bridge present and fused to prosternum; postmetacoxal bridge absent. Wing with alula and anal lobe nearly absent; C unbroken; Sc complete; cells cua and bm very short, but the latter open; cell br open; radial and medial veins divergent. Abdominal sternite 5 in male simple with ventral outline straight; tergite and sternite 7 separate in female, not forming oviscape.

Remarks. For detailed redescription of the family, see Lonsdale & Marshall (2016). Nothybid flies resemble Micropezidae at the first glance, but can be distinguished from the latter by the following features: katepisternal setae absent (vs. present in Micropezidae ); fore coxa widely separated from anterior margin of thorax (vs. close to anterior thoracic margin in Micropezidae ); subscutellum inflated, at least reaching apex of scutellum (vs. not enlarged in most Micropezidae although a similar state occurs in a few Eurybatinae); precoxal bridge present (vs. absent in Micropezidae ); R 4+5 and M 1 divergent (vs. convergent in Micropezidae ).