Ceriomicrodon Hull

Reemer, Menno & Stahls, Gunilla, 2013, Generic revision and species classification of the Microdontinae (Diptera, Syrphidae), ZooKeys 288, pp. 1-213 : 24-25

Ceriomicrodon Hull Figs 59-60

Ceriomicrodon Hull, 1937a: 25. Type species: Ceriomicrodon petiolatus Hull, 1937: 25, by original designation.

Description.

Body length: 11 mm. Very slender, wasp-like flies with long antennae and constricted abdomen. Face convex, somewhat produced on ventral half; narrower than an eye. Lateral oral margins clearly produced. Vertex flat. Occiput ventrally narrow, dorsally somewhat widened. Eye bare; frontally with narrow, horizontal area of enlarged ommatidia at level of antenna. Eyes in male strongly convergent at level of frons. Antennal fossa about 1.5 times as wide as high. Antenna longer than height of head; basoflagellomere more than twice as long as scape; bare. Postpronotum bare. Anepisternum with shallow sulcus; pilose along posterior margin and sparsely anterodorsally, widely bare in between. Anepimeron entirely pilose. Katepimeron flat; bare. Scutellum semicircular; without calcars. Wing: vein R4+5 with posterior appendix; vein M1 perpendicular to vein R4+5; postero-apical corner of cell r4+5 widely rounded; crossvein r-m located around basal 1/3 of cell dm. Abdomen very slender, constricted at tergite 2. Tergite 2 longer than thorax, about as long as tergites 3-5 together. Tergites 3 and 4 fused. Male genitalia: phallus furcate near apex, with dorsal process long and whip-like, ventral process very short; epandrium with ventrolateral ridge.

Diagnosis.

Postpronotum bare. Vein R4+5 with posterior appendix. Postero-apical corner of cell r4+5 widely rounded. Abdomen constricted. Tergite 2 longer than thorax.

Discussion.

Ceriomicrodon is treated as a subgenus of Microdon by Thompson et al. (1976) and Cheng and Thompson (2008). However, it does not agree with the diagnosis of Microdon as used in the present paper, because of several characters (e.g. postpronotum bare, abdomen petiolate, phallus with dorsal process long and whip-like). In addition, the phylogenetic results of Reemer and Ståhls (in press) indicate a relationship with e.g. Pseudomicrodon and Rhopalosyrphus .

Diversity and distribution.

Described species: 1. Known from Central (Mato Grosso) and Northern Brazil (Roraima).