Pegomya zonata Zetterstedt 1838

5. Pegomya zonata (Zetterstedt, 1838)

(Figs 6, 28, 37, 46, 55, 68)

Anthomyza zonata Zetterstedt, 1838: 697.

“ Pegomya tenera (Zetterstedt) ”. Hennig 1973c: 646 [male], text figs 562, 563, table figs 761, 902, 982; Suwa 1974: 215, figs 591‒595; Hackman 1976: 133; Hackman 1979: 63; Hackman & Meinander 1979: 74.

Pegomya zonata (Zetterstedt). Hennig 1973c: 646 [female only], figs 595, 596; Michelsen 1985: 61; Suwa 1999: 238; Suwa 2005: 105; Michelsen 2006b: 111.

Pegomya (Phoraea) zonata (Zetterstedt). Griffiths 1983: 232, figs 311, 325, 327‒330. For further synonymy and references, see Hennig (1973c) and Griffiths (1983).

Description. Size. Medium sized, wing length 5.2‒6.0 mm. Male. Antenna fuscous yellow to fuscous brown on scape and pedicel, black on postpedicel. Palp ochre yellow, more or less darkened on distal third. Setation on postgena mainly black admixed with some yellowish setae and setulae. Thorax wholly dark or slightly translucent yellow on postpronotal callus and prosternum, covered in grey dusting that on mesonotum has a golden brown tinge. Legs ochre yellow with darkened tarsi; fore femur darkened postero-dorsally or more extensively, mid and hind femora to varying extent diffusely darkened on distal part. Abdomen fuscous ochre yellow to ochre brown with narrow dark hind marginal bands on tergites II‒IV, covered in ash-grey dusting that in posterior view delimits a narrow median dark stripe on at least tergites III‒V. Parafrontalia narrow and contiguous, usually separating eyes by less than transverse diameter of anterior ocellus. Prealar seta shorter than posterior notopleural seta. Vein C without d setulae. Fore tarsus not compressed or otherwise modified. Mid tibia with 1 ad. Hind femur (Fig. 6) with 7‒8 av setae of moderate length on distal two-thirds and 1‒2 pv setae at mid-length. Terminalia (Figs 28, 37, 46, 55) with distinctive profile outline of surstylus and shape of postgonite and epiphallus. Female. Scape and pedicel ochre yellow, except somewhat brownish infuscated in late-season individuals; postpedicel black. Palp yellow with less than distal third darkened, sometimes wholly yellow. Frontal vitta normally orange-yellow on lower half and black on remaining upper part; ocellar triangle matt by dusting. Setation on postgena black admixed with some fine yellow setulae. Thorax and abdomen matt, covered in moderately dense light grey dusting. Thorax ochre yellow except darkened on discal part of scutum, dorsal part of postnotum, and sometimes diffusely on a minor part of the pleura, covered in light grey dusting with a golden brownish tinge on mesonotum. Legs wholly yellow, at the most diffusely brownish darkened at dorsal tips of femora. Abdomen ochre yellow with narrow dark hind marginal bands on tergites II‒IV, somewhat shining through thin cover of light grey dusting. Tergites of oviscapt shiny black. Legs usually wholly yellow with brownish yellow tarsi. Frons parallel-sided, frontal vitta about 4x as wide as parafrontalia; pair of crossed interfrontal setae modest sized to completely absent; parafrontalia on upper part with 2 reclinate, and 1 proclinate orbital setae, on lower part with 2‒3 inclinate frontal setae. Chaetotaxy of thorax and legs in most respects as in male, but mid tibia with ad seta stronger, mid femur with only 2 weaker pv setae near base and hind femur with 0‒1 short pv seta on middle third. Wing vein C bare on d surface. Hind femur normally with a nearly complete row of 5‒8 av setae. Fully extended oviscapt much longer than preabdomen. Oviscapt (Fig. 68): Sternite VIII pieces narrow, bare except for 1‒2 hind marginal sensilla. Hypoproct small, only well retained on apical part bearing a pair of setae. Cerci short, with convex lateral margin and obtuse apex.

Material examined. [FMNH, MZLU, NHMO, SZNM, ZMUB, ZMUC]. CZECH REPUBLIC: South Bohemia. DENMARK: S Jutland, E Jutland, NW Jutland, NE Jutland, NE Zealand. FINLAND: Regio aboensis, Nylandia, Karelia australis, Tavastia australis, Savonia australis, Tavastia borealis, Savonia borealis, Karelia borealis, Ostrobottnia media, Ostrobottnia kajanensis, Lapponia kemensis, Lapponia inarensis, Lapponia enontekiensis. GERMANY: Schleswig - Holstein: Ostholstein. NORWAY: Oppland, Buskerud, Rog aland, Hordaland, Sør-Trøndelag, Nord-Trøndelag, Finnmark. RUSSIA: Leningrad, Karelia, Murmansk, Altai: Ust’- Koksa area, Nizhne-Mul’tinskoe lake, 1633m, 1♂ 13.vii.2013 (T. Novgorodova), Sakha: Yakutsk, 1♂ 1.vii.1901 (R. B. Poppius). SWEDEN: Skåne, Halland, Småland, Öland, Östergötland, Västergötland, Uppland, Dalarna, Härjedalen, Jämtland, Norrbotten, Åsele Lappmark, Lycksele Lappmark, Pite Lappmark, Lule Lappmark, Torne Lappmark. BRITAIN: Scotland: Highlands.

Distribution. PALEARCTIC. Common and widespread in the boreal to low arctic parts of Europe; less common in the lowlands of western and central Europe south to the Alps. Outside Europe recorded from Japan (Suwa 1974, 1999, 2005) and Russia: Altai, Sakha (new records). NEARCTIC. Common and widespread across boreal to low arctic North America (Griffiths 1983) and Greenland (Griffiths 1983; Michelsen 2006b).

Biology. In southern Finland (Hackman 1976, Hackman & Meinander 1979, Ståhls et al. 1989) reared from larvae in sporocarps of the Boletus edulis, Leccinum versipelle and L. scabrum species groups (Boletaceae). Also reared from Leccinum spp. in Finnish Lapland (Ståhls et al. 1989), Yukon Territory and British Columbia (Griffiths 1983). The female lays her eggs in the pore layer of the host fungus.