Paradelia lunatifrons Zetterstedt 1845

1. Paradelia lunatifrons (Zetterstedt, 1845)

Figs. 6, 8, 9, 11, 16–22.

Anthomyza lunatifrons Zetterstedt, 1845: 1708.

Pegomyia minima Stein, 1906: 100. Synonymized by Ringdahl (1938: 212). Pegomyia (Pegomyiella) lunatifrons (Zetterstedt); Ringdahl 1938: 212. Pegomyiella lunatifrons (Zetterstedt); Ringdahl 1959: 257.

Paradelia lunatifrons (Zetterstedt); Hennig 1972: 442.

Paradelia (Pegomyiella) lunatifrons (Zetterstedt); Griffiths 1987: 747. For further references see Hennig (1972: 442) and Griffiths (1987: 747).

Description. Small to medium-sized (WL 3.8–5.7mm; n=73). General facies strikingly delicate. Head small and abdomen very slender compared to gibbous thorax, wing comparatively long and legs slender.

Male. Antenna and palpus brownish black. Head and thorax brownish black, abdomen darkly reddish brown. Body dusting olive grey, becoming olive brown on dorsum of thorax. Mesonotum with shifting dark reflections obscuring any pattern of dark stripes; abdomen with dark mid-dorsal stripe extremely narrow, maintained only on tergites III–V; dusting largely maintained on pregenital and genital segments. Legs, apart from dark tarsi, dirty ochre yellow. Wing lightly tinged with brown, at base becoming ochre yellow and concolorous with calyptrae and haltere.

Upper frons much narrower than diameter of anterior ocellus; parafrontals widely contiguous. Frontal setae 2(–3) pairs on lower half of frons. Pair of interfrontal setulae present. Genal setae few, arranged in single row. Parafacial in middle about as wide as basal width of fore tibia. Prealar seta decidedly shorter than posterior notopleural seta. Proepisternals 2; proepimerals 4–7. Prosternum bare. Vein C devoid of setulae on dorsal and ventral surfaces. Setation of legs unusually short and weak: Fore tibia without submedian setae. Mid femur without preapical a seta and ventrally only with a basal mid-ventral seta. Mid tibia with 0 ad, 1 pd and 1–2 p submedian setae. Hind femur without pv setae, only with a mid-ventral seta basally. Hind tibia with 1 av, 2 ad and 2 pd submedian setae. Tergite VI free. Sternite V (Figs. 17, 18) with relatively short and simple posterior lobes, subdistally on modestly upraised inner margins with an inconspicuous bare angular lamella. Hypopygium (Figs. 19, 20): surstyli slender, not constricted latero-distally. Gonites (Fig. 22): pregonite with 1 submedian and 1 apical setula; postgonite with submedian setula inserted slightly distal to mid-length.

Female. Antenna and palpus brownish black, basally sometimes dirty ochre. Head mainly brownish black, more or less translucent yellowish on anterior parts, covered in greyish dusting; frontal vitta yellow ochre on lower part, black to reddish brown on upper part. Thorax entirely dark, densely olive grey dusted without clear signs of darker striping on anterior mesonotum. Legs, apart from brown ochre to blackish tarsi, largely yellow ochre, more or less darkened on posterior side of fore femur. Abdomen ochre yellow, with a matt shine through thin light grey dusting.

Setation of legs as in male except for presence of short ad submedian seta on fore tibia and preapical a seta on mid femur. Oviscapt (Fig. 11) with ovoid hypoproct and long, slender cerci.

Material examined. Many specimens have been seen from the following European countries: CZECH REPUBLIC, FINLAND, NORWAY, SLOVAKIA, SWEDEN, UNITED KINGDOM.

Biology. In Czech Republic collected in peat-bogs (1 female taken November 1 on excrement of Red Deer), in meadows, in forest clearing, in mixed forest and at edge of spruce forest; 2 females taken by car net September 26; 1 male on composite flower August 10. I have collected both sexes in numbers in south Sweden by sweeping stands of young spruce.

Distribution. A somewhat local and rarely collected but widely distributed species in boreal and elevated parts of the Holarctic Region. European and North American distributions were summarized by Michelsen (2004) and Griffiths (1987) respectively. It is further recorded from Kamtchatka, Far East Russia by Ringdahl (1930) and from Japan by Suwa (1974).