Two New Nearctic Species of Spilomyia (Diptera: Syrphidae), with a Note on the Taxonomic Value of Wing Microtrichia in the Syrphidae

Abstract

Three species of Spilomyia from western North America have been in the Canadian National Collection under the name Spilomyia interrupta Williston, 1882. Two of these are described below as new. Through the co-operation of Mr. Paul Arnaud, then of the U.S. National Museum, I examined the two female syntypes of interrupta and four other specimens of the group. One syntype, labelled “W.J.; Acc. 19702, Williston; Type No. 875, U.S.N.M.; Spilomyia interrupta Will.” on four labels is hereby designated as lectotype; it has been so labelled. The other syntype is a specimen of the species described below as Spilomyia citima n.sp. The other four specimens in the U.S.N.M. are all of interrupta: 1 ♂, Hopland, Calif., Sept.; 1 ♂, Mountains near Claremont, Calif.; 1 ♀, Tuolumne, Calif.; 1 ♀, Medford, Oreg. The C.N.C. contains two specimens of interrupta: 1 ♂, Hopland, Calif., Sept.; 1 ♀, Rowena, Oreg., Sept. 1, 1923 (on flowers of Eriogonum umbellatum). Mr. R. H. Foxlee of Robson, B.C., kindly sent me several specimens for study and donated most of them to the C.N.C.; it gives me pleasure to dedicate one of the new species to him.