Dasysyrphus pauxillus (Williston, 1887)

Prokhorov, A. V., Popov, G. V., Shparyk, V. Yu. & Vasilyeva, Yu. S., 2020, New Records Of Hoverflies (Diptera, Syrphidae) From Ukraine. V, Zoodiversity 54 (3), pp. 237-258 : 249-250

Dasysyrphus pauxillus (Williston, 1887) ( figs 42–46 )

M a t e r i a l e x a m i n e d. Ukraine. Kyiv Region: Dibrova env., 50.194443 N 30.203628 E, 25.04.2010 , 1 {

(M. Zaika); Irpin env., 50.50 N 30.28 E, Lyubka River floodplain forest, 20.04.2019, 1 {(A. Prokhorov) .

D i s t r i b u t i o n: Austria, Belgium, the Czech Republic, Denmark, Finland, France, Germany, Great Britain, Greece, Italy, North Macedonia, the Netherlands, Norway, Poland, Romania, Serbia, the Slovak Republic, Spain, Sweden, Switzerland; Russia (European part, Siberia); Nearctic Region (from Alaska to California and across to New York) ( Doczkal, 1996; Holinka & Mazánek, 1997; Nielsen, 1999; Stănescu & Pârvu, 2005; Bartsch et al., 2009 a; Krpač et al., 2009; Mielczarek, 2009 –2020; Reemer et al., 2009; Ball et al., 2011; Williams et al., 2011; Locke & Skevington, 2013; Haarto & Kerppola, 2014; Ricarte & Marcos-García, 2017; Barkalov & Mutin, 2018; Speight et al., 2018; Speight, 2020; Wakkie, 2020); Ukraine (first record).

Diagnosis. Dasysyrphus pauxillus is very similar in appearance to D. lenensis Bagatshanova, 1980 , D. nigricornis (Verrall, 1873) and D. pinastri (De Geer, 1776) in having yellow paired maculae on tergites 3+4 not reaching the lateral margin of tergites ( fig. 43 ). The male of D. pauxillus differs from the males of D. lenensis and D. pinastri by: mesonotum predominantly covered in pale pile ( fig. 43 ) (in others, mesonotum predominantly covered in black pile); the lower part of the face is covered in black pile ( figs 45, 46 ), or with pale and black pile mixed (in others, the lower part of the face is covered in pale pile); last antennal segment yellowish ventrally, antenna completely dark in D. lenensis and D. pinastri , tergite 2 with black macrotrichia on the side margin (in others, tergite 2 with pale macrotrichia on the side margin, only with black ones at the hind corners of the tergite) ( Bartsch et al., 2009 a; Van Veen, 2010). The genitalia of D. pauxillus , D. lenensis and D. pinastri are clearly different in the structure of the gonostylus and aedeagus ( Doczkal, 1996: figs 15–22 ).

Dasysyrphus pauxillus differs from D. nigricornis by: frons with an angle of approximation of eyes blunt ( fig. 42 ) (in D. nigricornis , frons with an angle of approximation of eyes acute); eyes meeting over a distance distinctly shorter than the frons length ( fig. 46 ) (in D. nigricornis , eyes meeting over a distance not shorter than the frons length) ( Bartsch et al., 2009 a).

Genitalia of our specimen with a triangular projection of distiphallus, projecting ventrally even more than shown in the figures in Doczkal (1996: fig. 16 ), Bartsch et al. (2009 a: page 190) and Locke & Skevington (2013: fig. 14D ).

Note. There are many Holarctic species that have a habitus similar to pauxillus and their concepts are even more confusing ( Locke & Skevington, 2013).

Figures

Figs 42–46. Dasysyrphus pauxillus male: 42 — habitus, dorsal view; 43 — habitus, lateral view; 44 — abdomen, ventral view; 45 — head, anterolateral view; 46 — head, frontal view.

Figs 9–16. Cheilosia fraterna male: 9 — habitus, dorsal view; 10 — habitus, lateral view; 11 — hind femur and tibia, lateral view; 12 — fore tarsus, dorsal view; 13 — mid tarsus, dorsal view; 14 — head, anterolateral view; 15 — head, frontal view; 16 — head, lateral view.

Figs 17–21. Cheilosia fraterna female: 17 — habitus, dorsal view; 18 — habitus, lateral view; 19 — mesonotum, lateral view; 20 — head, anterolateral view; 21 — head, frontal view.

Figs 22–25. Cheilosia nebulosa female:22 — habitus, dorsal view; 23 — habitus, lateral view; 24 — head, frontal view; 25 —head, anterolateral view.