Myolepta vara (Panzer, 1798)

Steenis, Jeroen Van, 2020, A new species of the genus Myolepta Newman (Diptera: Syrphidae), with short description and key to all species of the M. vara subgroup, Zootaxa 4750 (3), pp. 370-390 : 371-372

Key to the species of the Myolepta vara subgroup

1 Metasternum pilose*; pleura either predominantly non-pollinose, shiny ( Figs 11A, 11D ) or almost entirely grey-pollinose, dull ( Fig. 11C ); pile on scutum and tergum IV at least partly sub-appressed (e.g. Figs 1B, 1D , 2D, 2F ); pile on metafemur short, clearly shorter than width of metafemur ( Figs 13A, 13 C−D)................................................... 2

- Metasternum non-pilose, bare; pleura predominantly grey-pollinose ( Fig. 11B ); pile on scutum and tergum IV erect ( Figs 2B , 5B ); pile on metafemur long, clearly longer than width of metafemur ( Fig. 13B )........................................................................ Myolepta obscura ( Becher, 1882) (central and southern Europe to Middle Asia)

2 Sterna II−IV almost entirely grey-brown pollinose, in most species with a narrow vitta along lateral margin of sterna III and IV non-pollinose and shiny ( Figs 17 A−B, 17D−E); tergum I densely grey-pollinose, non-shiny, strongly contrasting with tergum II (e.g. Fig. 1A ); tibiae at least basally partly yellow (e.g. Figs 1B , 2F ); pile on scutum and abdomen rather long, dense and light-yellow to orange................................................................................. 3

- Sterna II-IV almost entirely non-pollinose, shiny ( Fig. 17C ); tergum I only slightly grey-pollinose, sub-shiny, hardly contrasting with tergum II ( Fig. 1C ); tibiae entirely black ( Figs 1D , 4D ); pile on scutum and abdomen rather short, less dense and predominantly white...................................... Myolepta nigra ( Loew, 1872) (eastern North America).

3 Face in male grey-pollinose with medial non-pollinose and shiny fascia from mouth-edge to tubercle ( Fig. 8A ) or only tubercle non-pollinose ( Fig. 16C ); scutum with light-yellow to yellow pile ( Figs 11A, 11C ); pleura extensively pollinose, at least posterior anepisternum, anepimeron and dorsal part of katepisternum densely grey pollinose ( Figs 11A, 11C ); sterna entirely greybrown pollinose, sometimes lateral margins very narrowly weakly pollinose and sub-shiny.......................... 4

- Face in male with non-pollinose and shiny fascia from mouth-edge and strongly widening dorso-laterally to tubercle ( Fig. 16D ); scutum with orange-yellow pile ( Fig. 11D ); pleura almost entirely non-pollinose, shiny, slightly pollinose on posterior anepisternum and dorsal part of katepisternum, densely grey pollinose on proepimeron and anepisternum ( Fig. 11D ); sterna grey-brown pollinose, dull, except lateral margins of sterna III and IV non-pollinose and shiny........................................................... Myolepta vara ( Panzer, 1798) (central and south-eastern Europe to Middle Asia).

4 Scutum anteriorly broadly grey-pollinose with anteromedially a wide rectangular vitta reaching halfway to suture ( Fig. 2C ); pleura almost entirely grey-pollinose, dull ( Fig. 11C ); male face grey-pollinose with only tubercle non-pollinose and shiny ( Fig. 16C ); face wider, mouth-edge 2.5 times wider than frons.................. Myolepta shikokuana Shiraki, 1968 ( Japan)

- Scutum anteriorly rather narrowly grey-pollinose without anteromedial extension ( Figs 1A , 4A ); pleura non-pollinose and shiny, except posterior part of anepisternum, dorsal part of katepimeron and anepimeron grey-pollinose, sub-shiny ( Fig. 11A ); face in male with narrow non-pollinose and shiny fascia from mouth-edge to tubercle ( Fig. 8A ); face narrower, mouth-edge 2 times wider than frons.............................................. Myolepta angustifacia sp. n. (eastern Siberia)

Figures

FIGURE 1. Adult habitus of Myolepta hoverflies, male; A, C dorsal view; B, D. lateral view. A, B. Myolpeta angustifacia sp. n., holotype, fig no JvSMo1-001. C, D. Myolepta nigra, Douglas Co, Canada, fig no JvSMo1-002. Scale 1.0 mm.

FIGURE 2. Adult habitus of Myolepta hoverflies, male; A, C, E. dorsal view; B, D, F. lateral view. A, B. Myolepta obscura, Paris, France, fig no JvSMo1-003. C, D. Myolepta shikokuana, Fukui pref., Japan, fig no JvSMo1-004. E, F. Myolepta vara, Mechelen, the Netherlands, fig no JvSMo1-005. Scale 1.0 mm.

FIGURE 4. Adult habitus of Myolepta hoverflies, female; A, C dorsal view; B, D lateral view. A, B. Myolpeta angustifacia sp. n., paratype, Shadriha river, Russia, fig no JvSMo1-006. C, D. Myolepta nigra, Jordan, Canada, fig no JvSMo1-007. Scale 1.0 mm.

FIGURE 5. Adult habitus of Myolepta hoverflies, female; A, C, E dorsal view; B, D, F lateral view. A, B. Myolepta obscura, Pichoy, France, fig no JvSMo1-008. C, D. Myolepta vara, Mechelen, the Netherlands, fig no JvSMo1-009. Scale 1.0 mm.

FIGURE 8. Adult head of Myolepta hoverflies, frontal view. A. Myolpeta angustifacia sp. n., holotype, fig no JvSMo1-001. B. Myolpeta angustifacia sp. n., female paratype, Shadriha river, Russia, fig no JvSMo1-006. C. Myolepta nigra, Douglas Co, Canada, fig no JvSMo1-002. D. Myolepta nigra, female, Jordan, Canada, fig no JvSMo1-007. Scale 1.0 mm.

FIGURE 11. Adult pleura of Myolepta hoverflies, lateral view. A. Myolpeta angustifacia sp. n., paratype female, Shadriha river, Russia, fig no JvSMo1-006. B. Myolepta obscura, female, Pichoy, France, fig no JvSMo1-008. C. Myolepta shikokuana, male, Fukui pref., Japan, fig no JvSMo1-004. D. Myolepta vara, female Mechelen, the Netherlands, fig no JvSMo1-009. Scale 1.0 mm.

FIGURE 13. Adult metafemur and tibia of Myolepta hoverflies, lateral view. A. Myolpeta angustifacia sp. n., paratype female, Shadriha river, Russia, fig no JvSMo1-006. B. Myolepta obscura, female, Pichoy, France, fig no JvSMo1-008. C. Myolepta shikokuana, male, Fukui pref., Japan, fig no JvSMo1-004. D. Myolepta vara, female, Mechelen, the Netherlands, fig no JvS- Mo1-009. Scale 1.0 mm.

FIGURE 16. Adult head of Myolepta hoverflies; frontal view. A. Myolepta obscura, male, Paris, France, fig no JvSMo1-003. B. Myolepta obscura, female, Pichoy, France, fig no JvSMo1-008. C. Myolepta shikokuana, male, Fukui pref., Japan, fig no JvSMo1-004. D. Myolepta vara, male, Mechelen, the Netherlands, fig no JvSMo1-005. E. Myolepta vara, female, Mechelen, the Netherlands, fig no JvSMo1-009. Scale 1.0 mm.

FIGURE 17. Adult sterna of Myolepta hoverflies, ventral view. A. Myolpeta angustifacia sp. n., holotype, fig no JvSMo1-001. B. Myolpeta angustifacia sp. n., female paratype, Shadriha river, Russia, fig no JvSMo1-006. C. Myolepta nigra, male, Douglas Co, Canada, fig no JvSMo1-002. D. Myolepta obscura, female, Pichoy, France, fig no JvSMo1-008. E. Myolepta vara, female, Mechelen, the Netherlands, fig no JvSMo1-009. Scale 1.0 mm.