Paradelia helleni Ringdahl 1932

8. Paradelia helleni (Ringdahl, 1932)

Figs. 13, 50–53.

Pegomyia helleni Ringdahl, 1932: 20.

Pseudonupedia helleni (Ringdahl); Ringdahl 1959: 293, fig. 104; Hennig 1972: 436, plate figs. 702, 714.

Paradelia (Paradelia) helleni (Ringdahl); Griffiths 1987: 788, figs. 946–947, 950–952. For further references see Hennig (1972: 436).

Description. Closely resembling P. palliceps but differing as follows:

A smaller species: WL 3.8–5.5mm (n=7) vs. 5.5–6.6mm.

Male. More darkly coloured: cuticle of head, body and appendages black, covered in dark olive-grey to olive-brown dusting, more or less brownish black suffused on dorsal parts of head and body. Dark mid-dorsal stripe of abdomen broader, expanded anteriorly on tergites III-IV. Wing brownish black infuscated.

Upper frons broader than diameter of anterior ocellus; parafrontals subcontiguous, narrowly separated by frontal vitta. Prealar seta slightly shorter than p notopleural seta. Proepisternals 3–4; proepimerals 6–8. Vein C dorsally bare or with a few setulae near insertion of vein R1, ventrally finely setulose throughout or extensively bare. Mid and hind femora with rows of pv setae confined to basal two-thirds, those on mid femur long and coarse. Sternite V (Figs. 50, 51) very similar except angular lamella smoothly rounded on distal part beneath digitiform appendage. Hypopygium (Figs. 52, 53): not significantly different except for shape of surstyli in lateral aspect.

Female. Antenna, palpus and legs entirely brownish black to black.

Antennal postpedicel enlarged, fully extended to margin of face. Vein C dorsally bare or with a few irregular setulae near insertion of vein R1, ventrally with fine setulae becoming sparse or absent basal to insertion of vein Sc. Prosternum bare, exceptionally with a pair of setulae. Proepisternals 3–4; proepimerals 6–9. Oviscapt (Fig. 13) apparently different by having hind marginal setae on tergite VIII extensively duplicated laterally; diamond-shaped hypoproct a little shorter, wider than long.

Material examined. NORWAY [ZMUC]: Sør-Trøndelag (inner): Fokstua, Dovre, 1 male (W. Hellén); Kongsvoll, 900–1100m, 1 female 20–28.vii.1983 (V. Michelsen). RUSSIA [FMNH]: Lapponia rossica: Pummanki, 2 males [syntypes] (W. Hellén); Petsamo [= Pechenga], 1 female 8.vii.1929 (H. Lindberg). SWEDEN [MZLU, BMNH]: Torne Lappmark: Abiskodalen, 1 female 13.vii.1958 (P.I. Persson); Mt. Nuolja, 1 male 25.vii.1925 (O. Ringdahl), above the tree line, 1 male 1.viii.1970 (A.C. & B. Pont).

Other material (teste D.M. Ackland): SWEDEN [Coll. D.M. Ackland]: Torne Lappmark: Abisko: Mt. Nuolja, swept from sallow scrubs, 1 male 3.viii.1993 (A.C. Pont).

Distribution. A Holarctic species that appears widespread in the subarctic and cordilleran parts of North America according to Griffiths (1987); Eurasian records are few and confined to northern or elevated sites in Fennoscandia.