Syrphidae

Thompson, Christian, 2008, A conspectus of New Zealand flower flies (Diptera: Syrphidae) with the description of a new genus and species, Zootaxa 1716, pp. 1-20 : 2

Key to the genera of New Zealand Syrphidae

1. Postpronotum bare; head posteriorly strongly concave and closely appressed to thorax so that postprono- tum is partly or entirely hidden ( Fig. 18 ); male abdomen with tergum 5 visible dorsally ( SYRPHINAE ) 9

- Postpronotum pilose; head posteriorly less strongly concave so that postpronotum is clearly exposed ( Fig. 19 ); male abdomen with tergum 5 not visible dorsally ( ERISTALINAE ).................................................. 2

2. Anterior anepisternum pilose....................................................................................................................... 6

- Anterior anepisternum bare......................................................................................................................... 3

3. Cell R 2 + 3 closed ( Fig. 10 )............................................................................................................................. 8

- Cell R 2 + 3 open ( Figs. 11–16 )........................................................................................................................ 4

4. Face with a tubercle; vein R 4 + 5 strongly to moderately sinuate; metafemur with basolateral patch of black setulae, without a ventroapical tubercle or carina ..................................................... Helophilus 12 (7) spp.

- Face without a tubercle ( Fig. 24 ); vein R 4 + 5 straight or only slightly sinuate ( Fig. 11 ); metafemur without patch of setulae, with ventroapical carina or tubercle................................................................................. 5

5. Wing completely microtrichose; metafemur with a ventroapical tubercle; metepisternum bare .................. ......................................................................................................... Paratropidia 1 sp.; bilineata (Walker)

Figures

FIGURES 17 – 19. 17. Generalized syrphid thorax, lateral view; 18 – 19. Head and thorax, lateral view. 18. Simosyrphus grandicornis (Macquart); 19. Psilota decessum (Hutton).

FIGURES 10 – 16. Wings, dorsal view. 10. Eristalis tenax (Linnaeus); 11. Paratropidia bilineata (Walker); 12. Merodon equestris (Fabricius); 13. Helophilus hochstetteri Schiner; 14. Helophilus seelandica (Gmelin); 15. Eumerus funeralis (Meigen); 16. Psilota decessum (Hutton).

FIGURES 20 – 26. Adult structures. 20. Eristalinus aeneus (Scopoli), posterior lateral thorax and wing base, dorsal view; 21 – 22. Metasternum and metalegs, ventral view. 21. Melanostoma mellinum (Linnaeus); 22. Platycheirus sp. 23 – 26. Heads, lateral view. 23. Eristalis tenax (Linnaeus); 24. Paratropidida bilineata (Walker); 25. Eristalinus aeneus (Scopoli); 26. Helophilus cingulatus (Fabricius)