Setacera aurata (Stenhammar 1844)

Setacera aurata (Stenhammar)

Ephydra aurata Stenhammar, 1844:167.—Zetterstedt, 1846: 1810 [review].—Nartschuk, 1970:387 [key].

Ephydra micans [in part] of authors [not Haliday, 1833:175].—Loew, 1860:36 [review].—Schiner, 1863:261 [review].—Becker, 1896:218 [review]; 1905:209 [palaearctic catalog]; 1926:75 [review].—Dahl, 1959:111 [review].

Setacera aurata.—Collin, 1963:148 [review].—Dahl, 1974:186 [distribution, figure of male terminalia].—Papp, 1975:109 [distribution, figures of head, male and female terminalia].—Karnecká, 1980:421 [list, Czechoslovakia].

Setacera micans [in part] of authors [not Haliday, 1833:175].—Canzoneri, 1978:28, 29 [figure of male terminalia].

DESCRIPTION.—Medium-sized to moderately large shore flies, length 3.52 to 4.76 mm; generally olivaceous brown with some faint greenish to bluish coloration dorsally, becoming grayer and duller ventrally.

Head (Figure 43): Head width-to-height ratio averaging 1 : 0.63; frons width-to-length ratio averaging 1 : 0.48; mesofrons, fronto-orbits, and dorsum of interfoveal carina with metallic luster, blue to bluish green, dorsum of interfoveal carina also with sparse tomentose vestiture, slightly duller; dorsal surface of face shorter than anterior surface, angle formed by these surfaces obtuse, about 110°, anterior surface mostly silvery white, often with some yellowish to yellowish brown coloration dorsally; eye height-to-width ratio averaging 1 : 1; eye-to-cheek ratio averaging 1 : 0.43.

Thorax: Legs, except for tibial-femoral articulation mostly dark colored, gray to blackish, articulation pale. Costal vein ratio averaging 1 : 0.26; M1+2 vein ratio averaging 1 : 0.90.

Abdomen: Male and female terminalia (Figures 44–49) as in species group description.

TYPE MATERIAL.—The male lectotype, designated by Dahl (1959) as a “holotype,” is labeled “[a green diamond, white on underside]/Holotypus aurata Stenh R Dahl [species epithet and “R Dahl” handwritten, red].” The lectotype is double mounted (clipped pin in plastic tube), is in poor condition (lower portion of head and numerous setae are missing, wings are torn, terminal segments of abdomen have been removed, dissected, and are in an attached microvial), and is in the Zetterstedt collection, Zoological Institute, Lund, Sweden (the specimen is temporarily in the custody of Dr. Richard Dahl, Helsingborg, Sweden

OTHER SPECIMENS EXAMINED.—ENGLAND. Essex: Pitsea, 24 Sep 1926, Richards (3; USNM Norfolk: Ring Mere, north of Thetford, 5 Aug 1953 (1; UMO); Roudham Heath, 1 Sep 1937 (1; UMO FRANCE. La Panne, 8 Aug 1923, M. Goetghebuer (1, 1; USNM NETHERLANDS. Amsterdam, Mar-Oct, Meijere (2, 2; ITZA Diemen, 9 Jul 1905, Meijere (1; ITZA Hilversum, 5 Mar-16 Oct, 1907–1911, Meijere (2, 4; ITZA Zerbrug, Feb 1908, Gillary (1; ITZA NORWAY. Bergen, 2 Mar 1952, H. Wiering (1; ITZA SWEDEN. Ostergötland: (1 ; NRS Scania: Fyleoset, Ystad, 17 Jun–8 Jul, 1951–1954, R. Dahl (4, 5; ZIL); Lilla Viken, Höör, 3 Jul 1954, R. Dahl (2?; ZIL N. Tvarminne strand, 19 Jul 1960, R. Dahl (1; USNM GERMANY (DDR Berlin (Jungfhd) (1; NRS W. GERMANY. Borkum, Jul 1895 (1; NRS FINLAND. Jakobstad (Pietarsaari), 1952, Sotra (1; USNM Locality unspecified (6, 3; HU, ITZA, NMW, ZIL

Collin (1963) also recorded this species from the following counties in England and Wales: Cambridgeshire, Essex, Glamorganshire, and Norfolk. Dahl (1974) examined specimens of S. aurata from the following localities in Sweden (unverified and all collected by him Skane: Forslovsholm, 20 Jul 1971; Höör, 1 Aug 1966; Ystad, Fylean, 8 Jul 1954, Lomma, 24 Aug 1954. Blekinge: Karlshanm, 3 Aug 1968. Karnecká (1980) listed this species from Bohemia and Moravia in Czechoslovakia.

DISTRIBUTION (Figure 50—Palaearctic. Northern Europe from Norway and European Russia south to France and Hungary.

DISTRIBUTION.—The composite distribution of the trina group occupies an area from Great Britain through Germany, Italy, and Israel to Iran. Nearly all specimens I have examined are from type-localities only.