Platycheirus (Platycheirus) jaerensis Nielsen, 1971

Prokhorov, A. V., 2019, New records of the hoverflies (Diptera: Syrphidae) from Russia, Ukrainska Entomofaunistyka (Oxford, England) 10 (2), pp. 17-22 : 18

Platycheirus (Platycheirus) jaerensis Nielsen, 1971

( Figs 2–4)

Material examined. Russia: Moscow Region, Tabolovo env., 55.9153N 36,0485E, in the garden, 30.07.2018, on flowers of Angelica sylvestris , 1 ♀ (A. Prokhorov) .

Distribution: Estonia, Finland, France (Jura), Germany, Hungary, Latvia, Norway, Sweden, Switzerland; Alaska and Canada in N America ( Peck, 1988; Tóth, 2011; Haarto & Kerppola, 2014; Young et al., 2016; Speight, 2018; Syrphidae checklists, 2019); Russia (first record).

Diagnosis. Platycheirus jaerensis belongs to the P. peltatus group ( Van Steenis & Goeldlin de Tiefenau, 1998; Bartsh et al., 2009; Young et al., 2016). In Europe, female of this species is most similar to P. amplus Curran, 1927 , P. holarcticus Vockeroth, 1990 , P. peltatus (Meigen, 1822) and P. nielseni Vockeroth, 1990 in having fore and mid femora entirely yellow (in similar P. islandicus Ringdahl, 1930 and P. parmatus Romani, 1857 , fore and mid femora with a broad black ring). Platycheirus jaerensis can be separated from P. amplus and P. holarcticus by tergite 2 with large rhomboid maculae ( Fig. 2) that reach or almost reach the anterior corners of the tergite (in P. amplus and P. holarcticus , tergite 2 with small lunular to reniform maculae that not reach the anterior corners of the tergite). From similar P. peltatus ( Figs 5–7) and P. nielseni it can be clearly distinguished by the yellow scape and pedicel ( Figs 3, 4) (in P. peltatus and P. nielseni , scape and often pedicel black, as on Figs 6, 7); paired yellow abdominal maculae at most with faint silvery pruinescence (in P. peltatus and P. nielseni , paired yellow abdominal maculae with heavy silvery pruinescence). These characters were based on Bartsh et al. (2009) and Van Veen (2010).