Platycheirus europaeus Goeldlin de Tiefenau, Maibach

Platycheirus europaeus Goeldlin de Tiefenau, Maibach

& Speight, 1990 ( figs 1–9)

Material examined. Russia: Moscow Region, Tabolovo, 55.915N 36.049E, in the garden GoogleMaps , 18.08.2015, 1 ♂, 7.06.2019, 1 ♀; Tabolovo env.: 55.9133N 36.0757E, clearing in mixed forest, 20.08.2015, 1 ♂, 4.06.2017, 2 ♂, 10.06.2019, 1 ♀; 55.906097N 36.069301E, glade in mixed forest, 13.06.2016, 1 ♀, 29.05.2017, 4 ♂, 1 ♀; 55.900201N 36.04062E, edge of mixed forest, 14.06.2016, 2 ♀ (A. Prokhorov).

Distribution. Austria, Belarus, Belgium, Bulgaria, Czech Republic, Denmark, Finland, France, Germany, Great Britain, Greece, Hungary, Italy, Latvia, Lithuania, the Netherlands, Norway, Poland, Romania, Serbia, Slovak Republic, Slovenia, Spain, Sweden, Switzerland; Russia (north of European Territory, Siberia, Far East); Japan ( Maibach et al., 1992; Dirickx, 1994; Holinka & Mazánek, 1997; Wolff, 1998; Nielsen, 1999; Reemer, 2000; Stubbs & Falk, 2002; Van de Weyer, 2002; Vujić et al., 2002; Stănescu & Pârvu, 2005; Pakalniškis et al., 2006; De Groot & Govedič, 2008; Karpa, 2008; Bartsh et al., 2009; Reemer et al., 2009; Tóth, 2011, 2014; Williams et al., 2011; Polev, 2013; Haarto & Kerppola, 2014; Ôhara et al., 2014; Ricarte & Marcos-García, 2017; Barkalov & Mutin, 2018; Speight et al., 2018; Speight, 2020; Mielczarek & Żóralski, 2021); central part of European Russia (first record).

Diagnosis. Platycheirus europaeus belongs to P. clypeatus group of species ( Speight & Goeldlin de Tiefenau, 1990; Bartsh et al., 2009). This group can be recognized from the entirely black antenna, orange-brown markings on the abdominal tergites, facial tubercle and upper mouth-edge projecting anteriorly no further than the frontal prominence, male fore tibia widening progressively from base to apex ( Speight & Goeldlin de Tiefenau, 1990). Based on the external morphological features, Platycheirus europaeus can be often confused with some members of this group: P. angustatus (Zetterstedt, 1843) , P. angustipes Goeldlin de Tiefenau, 1974 , P. clypeatus (Meigen, 1822) , P. occultus Goeldlin, Maibach and Speight, 1990 and P. ramsarensis Goeldlin, Maibach & Speight, 1990 .

Platycheirus europaeus male differs from males of P. angustipes , P. clypeatus and P. occultus by the underside of the first fore tarsomere with a V-shaped pale furrow (in the other species, the underside of the first fore tarsomere with a straight, pale central furrow, sometimes ending in a small round pit containing a black mark). Platycheirus europaeus is similar to P. angustatus and P. ramsarensis in having underside of the first fore tarsomere with a V-shaped pale furrow. It can be separated from P. angustatus by the posterior anepisternum covered with microtrichia (in P. angustatus , posterior anepisternum shining, without microtrichia), posterior side of fore femur (except for the bent white seta) with only straight macrotrichia (in P. angustatus , posterior side of the fore femur with several bent macrotrichia in addition to the bent white seta). Platycheirus europaeus differs from P. ramsarensis by: V-shaped furrow on underside of the first fore tarsomere situated in apical half, but near the middle (in P. ramsarensis , the V-shaped furrow on underside of the first fore tarsomere is at the tarsomere apex); entire posterior side of the fore femur with macrotrichia (in P. ramsarensis , posterior side of the fore femur bare in apical half); the first hind tarsomere not distinctly swollen (in P. ramsarensis , the first hind tarsomere distinctly swollen).

Platycheirus europaeus female is most similar to females of P. magadanensis Mutin, 1999 , P. podagratus (Zetterstedt, 1838) and P. ramsarensis in having the hind femur mainly black, at most narrowly yellow at base. From P. angustatus it can be separated by the abdomen broader, tergites square or transverse (in P. angustatus , abdomen slender, tergites longer than wide); posterior anepisternum covered with microtrichia (in P. angustatus , posterior anepisternum shining, without microtrichia). From P. ramsarensis it can be distinguished by: tergite 2 square, or only slightly transverse (in P. ramsarensis , tergite 2 distinctly transverse): tarsi of the fore and mid legs entirely yellow (in P. ramsarensis , at least couple of tarsomeres of tarsi of the fore and mid legs black); entire posterior side of the fore femur with macrotrichia (in P. ramsarensis , only basal half of posterior side of the fore femur with macrotrichia). Platycheirus europaeus female can be separated from P. podagratus by the tergite 3 with square spots (in P. podagratus , all paired spots on tergites 2–4 round, or spots on tergites 3 and 4 roughly shaped as quarters of a circle); dust spots on frons larger, leaving only the central third shining (in P. podagratus , dust spots on frons smaller, leaving the central half shining); tarsomeres 2 and/or 3 of the tarsus of hind leg yellow (in P. podagratus , the tarsus of hind leg entirely black). From very similar P. magadanensis it differs by the paired spots on tergites 3 and 4 reaching anterior margins (in P. magadanensis , paired spots on tergites 3 and 4 not quite reaching their anterior margins); vertex in front of the posterior ocelli distinctly transverse (almost twice as wide as long) (in P. magadanensis , vertex in front of the posterior ocelli almost square, less than 1.5 times as wide as long).