Syrphocheilosia claviventris (Strobl, 1910):104

The genus Syrphocheilosia is separated from other genera in the subfamily Syrphinae by the combination of the following characters: black face and scutellum; antenna shorter than head; arista plumose (pile less than twice as long as aristal width); metasternum entire (not reduced); abdomen parallel side or oval, with 2nd tergum as wide or wider than 3rd; male metatibia simple; male holoptic; eye bare; face not produced forward; scutum distinctly and finely rugose; black legs and abdomen; and arista pilose.

The genus Syrphocheilosia was described by Stackelberg (1964), who designated his aterrima as genotype. Thompson (1980) synonymized aterrima under Cheilosia claviventris Strobl, which became Syrphocheilosia claviventris. Peck (1988) followed Thompson. Syrphocheilosia has only one species.

Synonyms:

Chilosia claviventris Strobl, 1910: 104.

Chilosia tyrolica Szilady, 1938: 140.

Syrphocheilosia aterrima Stackelberg, 1964: 469.

New description:

MALE.

Head: Face not produed forward, with distinct round facial tubercle, not distinctly wider ventrally, with sides approximately parallel, black with small microtrichia but without the aspect of pollinosity, yellow-withish pilose; gena black, yellow-withish pilose; frontal triangle black, black pilose; vertical triangle black, black pilose; dichoptic, eye bare; antenna dark brown to black; arista pilose, with short, appressed pile (pile less than twice as long as aristal width); occiput black, black pilose with pale pile ventrally and posterior to vertical triangle.

Thorax: Scutum and scutellum black, distinctly and finely punctuate, golden brown pilose; postpronotum bare; subscutellar fringe complete with brown pile. Pleuron black, golden brown pilose; metasternum entire (not reduced), bare; calypter brownish yellow; plumula whitsh; halter brownish yellow; spiracular fringes brownish. Wing: Wing membrane light brown, microtrichose. Alula broad, microtrichose. Legs: simple, black, with dark brown short pile.

Abdomen: unmargined, parallel-sided, with 2nd tergum as wide as 3rd; dorsum black, distinctly rugose, yellow pilose; sterna black.

Syrphocheilosia claviventris (Strobl, 1910).

Strobl, P.G. (1910) Die Dipteren von Steiermark. II. Mitteilungen des Naturwissenschaftlichen Vereines für Steiermark 46, 45-292. [1910.10.17]

GenBank accession number for this species are: protein-coding COI gene (EF127334) and rRNA 28S gene (EF127415).

Thompson (1980) and Peck (1980) considered Syrphocheilosia as a valid genus, but Thompson and Rotheray (1998) considered it as a subgenus of Platycheirus. Recently, Mengual et al. (2008) studied the phylogeny of the subfamily Syrphinae using two genes, mitochondrial COI and nuclear 28S rRNA. Their results supported the idea of a different genus and Syrphocheilosia was recovered as sister group of Spazigaster, being Rohdendorfia sister group of both.

Adults have been seen visiting flowers of Anemone ranunculoides, Caltha, Cardamine, Potentilla verna, and Ranunculus (Speight 2010).

S. clavicentris flights from the end of May to mid August (Speight 2010).

Palaearctic species found in Alps (France, Germany, Switzerland, Liechtenstein, Austria, northern Italy); northern Turkey; Armenia and the Caucasus.

Preferred environment of adults: freshwater/open ground; close to flushes and streamlets in unimproved, calcareous and non-calcareous montane and alpine grassland, from the top of the Picea zone to above 2,000 m. (Speight 2010).

Adults fly low among grasses etc., in a manner reminiscent of Cheilosia species (Speight 2010).