Pegomya glabroides Michelsen, sp. nov.

Pegomya glabroides Michelsen, sp. nov.

Figs. 24–31.

Etymology. The specific epithet ‘glabroides’ is derived from ‘glabra’, existing epithet for the first species of the P. terminalis species group described from the Nearctic Region, and ‘-oides’, a Greek adjectival suffix meaning ‘resembling’.

Description. Very small to small (WL 3.0–3.9mm; n=16).

Male. Externally closely resembling P. terminalis except for smaller size and brownish black colouring on all parts of head, body and appendages. Terminalia (Figs. 24–29) also similar, but lobes of sternite V (Figs. 24, 25) broadly obtuse and with only a few lateral setae, surstyli (Figs. 26, 27) with meso-basal laminate process more prominent in profile view and meso-distal process shorter, broad-based and with fewer setulae, and gonites overall (Fig. 28) shorter.

Female. Differing from P. terminalis by being extensively brownish black in ground-colour; only lower portion of frontal vitta and tibiae to varying extent orange-brown. Abdomen with black shine through thin layer of grey dusting, without any indication of a mid-dorsal stripe. Readily separated from P. granadensis by smaller size, absence of discal setae on tergite V and fewer hind marginal setae on sternite V. Oviscapt (Figs. 30, 31) with cerci distinctive: relatively large, discoid, with a cutting edge formed along inner apical margins.

Material examined. Type material. NORWAY [ZMUC, ZMUO]: Sør-Trøndelag, Kongsvoll, 900– 1100m, 1 male [holotype] 12–20.vi.1985 (O. Karsholt & V. Michelsen); Oppland, Dovre, Fokstua, 1 female [paratype] 19.vii.1953 (H. Krogerus). FINLAND [FMNH, ZMUC]: Kuusamo: Kuolajärvi, 4 females [paratypes] 10.vii.1935 (Krogerus). SWEDEN [MZLU, ZMUC]: Torne Lappmark: Abisko, 1 male [paratype] 7.vii.1948, 1 male [paratype] 6.viii.1948 (H.C. Huckett); Abisko valley, 2 females [paratypes] 25.vi.1957, 1 female [paratype] 7.vii.1957, 1 female [paratype] 11.vii.1957, 1 female [paratype] 16.vii.1957 (P.I. Persson); Abisko Nat. Park, wetland vegetation, 1 female [paratype] 25.vi.1973 (B.G. Svensson). Additional material. FRANCE [ZMUC]: Hautes-Alpes: Montgenèvre, 44.56N / 6.43E, 1800m, spruce wood, 1 female 12.vii.1990 (M. Barták).

Biology. The larval host plant is unknown, but a likely candidate is Equisetum variegatum Schleich., a species of horsetail that in Europe is primarily occurring in northern and elevated areas.

Distribution. A rarely collected species found in northern and elevated parts of Fennoscandia (Norway, Sweden, Finland). A wider distribution in Central Europe is documented by the find of a single female from Hautes-Alpes (France).

Relationships. A Nearctic taxon tentatively identified as Pegomya terminalis (Rondani) by Griffiths (1983: 190, figs. 266, 268–270; 1997: 695; also in Finnamore 1994: 212) on the basis of male specimens agrees with true P. terminalis in the colour of body and legs and structure of sternite V, but the gonites and surstyli are different and in better agreement with P. g l a b ro i d e s.