Cervicorniphora Hull

Reemer, Menno & Stahls, Gunilla, 2013, Generic revision and species classification of the Microdontinae (Diptera, Syrphidae), ZooKeys 288, pp. 1-213 : 25-26

Cervicorniphora Hull stat. n. Figs 61-62

Cervicorniphora Hull, 1945: 75. Type species: Microdon alcicornis Ferguson, 1926a: 171, by original designation.

Description.

Body length: 8 mm. Broadly built flies with oval abdomen. Head wider than thorax. Face convex in profile; wider than an eye. Lateral oral margins not produced. Antennal fossa about as wide as high. Vertex flat. Occiput rather wide, dorsally strongly widened. Eye bare. Eye margins in male not converging at level of frons; with mutual distance about five times the width of antennal fossa. Antenna longer than distance between antennal fossa and anterior oral margin; basoflagellomere longer than scape, bare, bifurcate, with dorsal branch narrower and shorter than ventral branch, ventral branch strongly curved; arista well-developed. Postpronotum pilose. Scutellum semicircular; without calcars. Anepisternum moderately sulcate; pilose anteriorly and posteriorly, bare medially. Anepimeron entirely pilose. Katepimeron convex; bare. 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 1/4 of cell dm. Abdomen oval, about 1.5 times as long as wide. Tergites 3 and 4 fused. Male genitalia: phallus unfurcate; epandrium without ventrolateral ridge; surstylus with long posterior process and wide anterior lamella. Female unknown.

Diagnosis.

Basoflagellomere bifurcate. Vein R4+5 with posterior appendix.

Discussion.

Although Ferguson (1926a) argued that the furcate antenna provides insufficient basis for erecting a new genus for Microdon alcicornis , Hull (1945) decided to erect Cervicorniphora for this species, as a subgenus of Microdon . Cheng and Thompson (2008) also considered this genus-group as a subgenus of Microdon . The phylogenetic analysis of morphological characters by Reemer and Ståhls (in press) did not provide many clues as to the taxonomic affinities of this taxon, although it seems clear that it is not related to other taxa in which the male has a furcate basoflagellomere. As the characters of Cervicorniphora (e.g. phallus not furcate) do not fit in the concept of Microdon s.s. (phallus furcate near base) as defined in the current paper, Cervicorniphora is here raised to genus rank, to avoid disrupting the monophyly of Microdon .

The female is unknown. In most other microdontine taxa in which the male has a furcate basoflagellomere (e.g. Carreramyia , Schizoceratomyia ), the female has an unfur cate basoflagellomere. So, the possibility that the female of Cervicorniphora has unfurcate antennae should be taken into account.

Diversity and distribution.

Described species: 1. Australia: New South Wales, Queensland and Tasmania ( Ferguson 1926a).