Spilogona tendipes Malloch 1920

Spilogona tendipes (Malloch, 1920)

(Fig. 10)

Limnophora tendipes Malloch, 1920b: 270. The male holotype in the C. A. Triplehorn Insect collection, Ohio State University, Columbus, Ohio. Type locality: Cordova, Alaska.

Limnophora (Spilogona) tendipes Malloch; Huckett, 1932: 60, 120.

Spilogona tendipes (Malloch); Huckett, 1965: 189, 201, 248.

Limnophora tendipes was described by Malloch (1920b) from 1 male from the south coast of Alaska. Huckett (1932) redescribed the holotype and included it in his key to male Spilogona. Huckett (1965) also included S. tendipes in his key to female Spilogona and recorded S. tendipes from the high arctic north coast of Baffin Land. It is not clear if this new record is based on females only. Sorokina & Khruleva (2012) further recorded S. tendipes from the high arctic Wrangel Island of Far East Russia based on 1 female. Presently, we record S. tendipes for the first time from NE Greenland based on 3 females from Zackenberg and add other 2 females from Wrangel Island. The key to female Spilogona by Huckett (1965) makes us quite confident that the females identified so far as Spilogona tendipes, all from high arctic localities in Canada, Far East Russia and Greenland, are conspecific. They are characterized by being large-sized (wing length exceeding 5 mm), covered in dense grey dusting with a bluish or greenish tinge and having paired dark marks visible on abdomen, a projecting lower face, small eyes, very broad parafacials, long and slender haustellum with a shiny prementum, 4 pairs of postsutural dorsocentral setae, subdorsal break in anepisternal row of setae with some setulae, mid tibia without setae ventrally, hind femur without distinct pv setae, hind tarsus with a v seta near base (see below), sternite I with some setulae laterally, and hypoproct with recurrent spines.

A few aspects make the association of the above females with the male holotype of Spilogona tendipes (Malloch) slightly uncertain: (1) the type locality lies in the warmer maritime climatic zone on the south coast of Alaska; (2) Huckett (1932, 1965) emphasized the presence of abundant setulae on the declivities of scutellum in the male holotype, but these declivities are practically bare in the females available to us. Arguments supporting the present identification are as follows: (1) Huckett (1965), who had examined the male holotype, was the first to associate it with female(s) from the high arctic Baffin Island; (2) a good overall agreement in characters considered of diagnostic value in Spilogona; (3) Malloch (1920b) and Huckett (1932) both mentioned one interesting character of the male holotype: the presence of a ventral ‘bristle’ or ‘spine’ near base of first tarsomere of the hind leg. This is a character that conveniently separates species of Anthomyiidae from nearly all Muscidae and from Fanniidae.

Among Muscidae, we have previously only noticed the presence of this seta in a few species of Stomoxyini and Drymeia Meigen. A short but distinct seta is also present on the hind tarsi of our females, which perhaps provides the most decisive evidence that they belong to Spilogona tendipes, as we are not aware of other species of Spilogona showing this character.

Material examined. RUSSIA: Wrangel Island: Somnitil’naya Bay, south of island, 2 females, 22, 26.vii.1966, leg. K. Gorodkov (1 female in SZMN and 1 female in ZMSP); middle part of the River Neozhidannaya, 71°01'N 179°08'W, 1 female, 10.vi–27.viii.2006, leg. O. Khruleva & A. Gruzdev (SZMN). GREENLAND: Zackenberg, on Chamerion latifolium, 3 females, 10, 12.viii.2011, leg. J. B. Mosbacher (ZMUC; Department of Bioscience, Aarhus University).

Distribution. Arctic: Greenland (NE), Russia (Wrangel Island), Alaska, Canada. New record for Greenland.