Cyrtosia marginata Perris

Evenhuis, Neal L. & David, Charles, 2004, Status of Cyrtosia marginata Perris (Diptera: Mythicomyiidae) with remarks on the type and new distribution records, Zootaxa 731, pp. 1-10 : 2-5

Cyrtosia marginata Perris

Cyrtosia marginata Perris, 1839: 56 . Loew, 1846: 422; Rondani, 1856: 165; Schiner, 1860: 70; Bezzi, 1903: 190; Becker, 1908: 21; Kertész, 1909: 907; Verrall, 1909: 14; Bezzi, 1924: 3; Bezzi, 1926: 257 (key); Santos Abreu, 1926: 86; Séguy, 1926: 224; Séguy, 1930a: 98; Séguy, 1930b: 79 (key); Engel, 1933: 110 (key); Efflatoun, 1945: 45; Séguy, 1949: 85 (key); Zaitzev, 1966: 135; Steyskal & El Bialy, 1967: 33; Hull, 1973: 256; Hall, 1976: 3; Bowden, 1980: 383; Evenhuis, 1983: 479; Zaitzev, 1989: 47; Evenhuis, 1991: 33; Zaitzev in Contini et al., 1995: 6; Evenhuis, 2002: 23.

Diagnosis. Easily distinguished from the congeners by the following characters: Front black with yellow just above bases of antennae, face yellow; occiput black; thorax brown with yellow notopleural stripe (from humeral callus to postalar callus) interrupted at transverse suture; scutellum black with yellow along posterior margin; pleura patterned with black (or brown) and yellow as in Figs. 2 , 6 ; legs with coxae and femora brown, yellow apically; abdomen with at least some sternites brown to pale brown, rarely all yellow to white.

Biology. Nothing is known of the immature stages. Adults have been taken at flowers of Hypochaeris radicata and Pilosella sp. ( Asteraceae ) on the dunes of the Channel Island of Jersey. The junior author made the following observations while collecting: “I spent about 2 hours on the dunes there yesterday [8 June 2003] and caught several, all in yellow composites ( Pilosella sp.) They are so small that it was only by getting within about 2 foot of the flowers that I could see them, or distinguish them from a meligethid beetle which was present in every flower or other minute flies. I did see one, I think, on yellow Sedum flowers. They did not seem to be in the much commoner pink or white Burnet Rose flowers. It was a cold blustery day yet the Cyrtosia were very strong fliers. They would leave the flowers as I approached and fly off, but if I sat quietly they returned with very controlled flight. It was possible to watch about the last 6 inches of their approach, all in about force 5 winds.”

Types. The original description was based on four specimens from Mont­de­Marsan, Landes, in southern France. There are two sets of two specimens in MNHN glued to the same card. One of the sets has a label “COTYPE” in red and a determination label by Engel below it indicating one specimen is of Cyrtosia marginata while the other is labeled as “ Apolysis eremophilus Loew ” [in fact, this specimen is the syntype of Apolysis cinereus Séguy, 1926 .] The specimen on the left (viewed with the pin at the bottom of the card) is selected here as lectotype male of Cyrtosia marginata Perris. It is glued on its left side to the card and in fair condition with minor damage to the right wing ( Fig. 3 ). The other set of specimens are also glued to a single card with one specimen being Cyrtosia marginata (paralectotype) and the other a syntype of Apolysis cinereus .

Distribution. France, Germany [new record], Channel Islands [new record], Spain. [ Algeria, Canary Islands, Italy, Morocco, and Yugoslavia are here deleted from the range of distribution (see below for details).]

Material Examined. CHANNEL ISLANDS: Jersey: 4ɗ 4Ψ, Les Blanches Banques in St. Ouen, 8 June 2003, 49°12'3"N, 2°12'39"W, C. David. FRANCE: 1ɗ, Landes: [type specimen listed above]; 1ɗ, Pyrenees­Oriental: St. Cyprien, 12.vi.1954, M. Bequaert ( IRSNB). GERMANY: 1Ψ, Lebus, nature reserve “Oderberge”, west of River Oder, north of Frankfurt/Oder, M. von Tschirnhaus (NLE). SPAIN: 4ɗ, 7Ψ, Zaragosa Prov: Monegros: Pina de Ebro, Retuerta de Pina, 360 m, 7.vi.1991, pan traps between Juniperus thurifera and Rosmarinus sp., J. Blasco­Zumeta (NLE).

Remarks. The specimen from Germany has much more black on the mesonotum than typical specimens of marginata (which are primarily brown) and the postalar callus and tip of the scutellum is less extensively yellow than in typical marginata ; otherwise it agrees in morphological characters (the genitalia were not dissected because of the unique specimen).

Figures

FIGURE 2. Cyrtosia marginata Perris, male habitus, lateral view. From Jersey, Channel Islands.

FIGURE 3. Lectotype of Cyrtosia marginata Perris (left) and syntype of Apolysis cinereus Séguy (right).

FIGURES 4 – 7. Cyrtosia thoraces, lateral view, head at right, to show pattern of notopleural stripe and pleural sclerites. 4. Cyrtosia canariensis Engel; 5. Cyrtosia jeanneli Séguy, holotype; 6. Cyrtosia marginata Perris; 7. Cyrtosia obscuripes Loew.