Pegomya ringdahli Michelsen, 2015, sp. nov.

13. Pegomya ringdahli sp. nov.

(Figs 10, 36, 45, 54, 63)

“ Pegomya pilosa Stein ”. Hennig 1973c: 611 (in part), text fig. 532, plate fig. 987;? Suwa 1974: 215, figs 596‒600; Hackman 1976: 133 (in part); Hackman & Meinander 1979: 74 (in part).

“ Pegomya scapularis (Zetterstedt) ”. Ståhls et al. 1989: 105 (in part);? Suwa 1999: 237.

Etymology. Named after the Swedish dipterist Oscar Ringdahl (1885‒1966), who first collected this species in Sweden and Norway. His well- preserved specimens from Sweden now constitute the type material of the new species.

Description. Very similar to P. scapularis and previously not distinguished from that species. The following description outlines the differences. Male. Setation on postgena mainly black admixed with some yellowish setae and setulae. All femora extensively brownish black, at the most yellowish on less than basal third of mid and hind femora. Mid femur with 2‒4 pv setae on basal third shorter, none of them much longer than depth of femur. Long av setae on distal half of hind femur (Fig. 10) not exceeding 2x depth of femur where situated. Hind tibia (Fig. 10) with ground setulae on outer surface less conspicuously enlarged, lower pd seta shorter than hind tarsomere 1 and normally without a distal coil, and subapical d seta neither straight nor erect. Terminalia (Figs 36, 45, 54, 63): Sternite V with lateral setae relatively weak, no stronger than setae on inner lamella of posterior lobes. Postgonite with apical expansion circular, not ovoid. Distiphallus in lateral view more expanded distal to middle. Female. Practically indiscernible from P. scapularis in other respects than the mainly black setation on postgena admixed with some yellowish setae and setulae. Femora possibly more uniformly yellow, without distinctly darkened apices as in P. scapularis.

Material examined. [FMNH, MZLU, ZMUC]. Type material [in MZLU except 3♂, 1 ♀ paratypes in ZMUC]. SWEDEN: Jämtland: Åre, 5♂ [one the holotype] vii.1928, 1 ♂ 6.vii.1932, 3♂ 1♀ 21.vii.1932, 1♂ 11.viii.1946 (O. Ringdahl); Enafors, 1♀ 15.vii.1944, 1♂ 17.viii.1930 (O. Ringdahl); Undersåker, 1♂ 18.vii.1932 (O. Ringdahl). Torne Lappmark: Abisko, 1♂ 6.vii.1922 (O. Ringdahl). Other material. FINLAND: Nylandia: Tvärminne, 4♂, 4♀ reared 3‒14.iv.1975, ex larva in Leccinum scabrum (C. Oker-Blom). Savonia australis: Riistina, 1♂ 29.vii.1960 (L. Tiensuu); NORWAY: N Nordland (east): Narvik, 1♂ 4.vii.1926 (O. Ringdahl), 1♂ 16.vii.1964 (J. Møhl); Troms (outer): Tromsø, 2♂ 7 & 10.vii.1926 (O. Ringdahl). SWEDEN: Jämtland: Åre, 1♂ 17.vii.1929 (J.M. Aldrich). Lule Lappmark: 5km NE Kvikkjokk, Carex -swamp, 1♂ 2.vii.1959 (Brinck et al.); 7km NE Stora Sjöfallet, 550m, 1♂ 11.vii.1963 (Dahm et al.). Norrbotten: Pajala, 1♂ 27.vii.1955 (H. Andersson). Torne Lappmark: Abisko, Nuoljatunneln, 1♂ 4.vii.1958 (P.I. Persson); Abisko, Betula -forest at exit of Ridunjira brook, 1♂ 17.vii.1983 (H. Andersson).

Distribution. Europe: Finland, Norway, Sweden. A boreal and subarctic species in Fennoscandia. The species has not earlier been separated from the very similar P. scapularis and very likely has a wider, northern trans- Palearctic distribution. A record of P. scapularis from Japan (Suwa 1974, 1999) may also refer to the present species as judged from the illustrations of the male terminalia. However, the description of the chaetotaxy of the male hind leg is in better agreement with P. scapularis and makes this identification unsettled.

Biology. In Finland reared from Leccinum scabrum, see under “Material examined” for details. Hackman (1976) and Hackman & Meinander (1979), under the name of Pegomya pilosa, and Ståhls et al. (1989) confused the present species with P. scapularis.