Key to the Neotropical species of Odiniidae (modified from Shewell (1960), Sabrosky (1969), Prado (1973) and Gaimari (2007))

1. Posterior ocelli in front of line between medial vertical setae; ocelli usually arranged in isosceles triangle with posterior ocelli closely spaced; frons usually relatively arched and sometimes conspicuously tuberculate; scutellar disc sometimes setulose; in profile, face and frons more or less in line or sloping; TRAGINOPINAE ............................ 7

- Posterior ocelli in line with medial vertical setae; ocelli arranged in equilateral triangle or with distance between posterior pair greater than between either posterior ocelli more widely spaced; frons flat to slightly concave and never tuberculate; scutellar disc bare; in profile, face and frons meeting at a angle; ODINIINAE, Odinia Robineau- Desvoidy ....................................................................................................................................................................... 2

2. Wing with few black spots, usually restricted to cross-veins ....................................................................................... 3

- Wing with numerous black spots, most of them surrounded by a whitish corona ..................................................... 4

3. Cell R1 with two transverse black spots................... Odinia biguttata Sabrosky (Virgin Islands, Puerto Rico, USA)

- Cell R1 without spot ............................................................................................... Odinia brevitibia Shewell (Brazil)

4. Oral vibrissa and one or two subvibrissal setae distinctly flattened .... Odinia williamsi Johnson (Galápagos Islands)

- Oral vibrissa and subvibrissal setae slender, not unusually broadly flattened.............................................................. 5

5. Antennal segments almost entirely yellow ................ Odinia parvipunctata Sabrosky (Virgin Islands, Puerto Rico)

- Antennal segments with black or brown spots ............................................................................................................. 6

6. Anepisternum gray with brown stripe ventrally; cell cua1 with one small and one large brown spots, large one tran- versing cell, beginning in vein CuA1 and ending in wing ventral margin ............... Odinia surumuana Prado (Brazil)

- Anepisternum gray with brown stripe dorsally; cell cua1 with two very small brown spots, close to vein CuA1 ......... .............................................................................................. Odinia coronata Sabrosky (USA, El Salvador, Panama)

7. Ocelli on large tubercle well forward of vertex ........................................................................................................... 8

- Ocelli not on tubercle.................................................................................................................................................. 10

8. Arista long-plumose; vein M1 strongly curved forward at apex ..................................... Paratraginops Hendel ….. 9

- Arista pubescent; vein M1 straight ................ Neotraginops clathratus (Hendel) (Peru, Paraguay, Brazil, Colombia)

9. Base of scutellum thickly haired. Anterior four fronto-orbital setae not set in fuscous spots........................................ .......................................................................................................... Paratraginops pilicornis Cress (Guyana, Brazil)

- Base of scutellum bare. Anterior four fronto-orbital setae set in fuscous spots ............................................................. .................................................................................................................. Paratraginops plaumanni Shewell (Brazil)

10. Costal vein extended to vein M1 ................................................................................................................................. 11

- Costal vein extended to vein R4+5 or slightly beyond.................................................................................................. 22

11. Scutellum at most bearing 2–3 setulae along margin ......................................................... Lopesiodinia Prado ..... 12

- Scutellar disc and margins bearing numerous setulae ............................................................................................... 13

12. Arista pubescent; front little narrowed posteriorly .............................................. Lopesiodinia diversa Prado (Brazil)

- Arista with long rays; front very narrowed posteriorly ................................ Lopesiodinia alvarengai Prado (Brazil)

13. Only anterior fronto-orbital seta inclinate ........................................................................ Schildomyia Malloch …. 14

- Several anterior fronto-orbital setae inclinate.......................................... Neoschildomyia fusca Gaimari (Costa Rica)

14. Arista long-plumose.................................................................................................................................................... 15

- Arista pubescent.......................................................................................................................................................... 16

15. Clipeo with velvet brown spot ................................................................................... Schildomyia lanei Prado (Brazil)

- Clipeo without velvet brown spot........................................... Schildomyia vittithorax Malloch (Costa Rica, Panama)

16. With one postpronotal seta; acrosthical setae absent .................................................................................................. 17

- With two postpronotal setae; one pair of acrosthical seta........................................................................................... 18

17. Lunule with a large velvet black spot .................................................... Schildomyia trinidadensis Hennig (Trinidad)

- Lunule without a large velvet black spot .......................................................... Schildomyia peruviana Hennig (Peru)

18. Scutellum pale-golden pruinose, except a median brownish spot in anterior edge ....................................................... .............................................................................................................................. Schildomyia flavida Prado (Brazil)

- Scutellum grayish pruinose, with light-brown spots in many parts of scutellum, forming patterns ......................... 19

19. Fronto-orbital setae set on brown spots; antenna with dark spots ............................................................................. 20

- Fronto-orbital setae not set on brown spots; antenna almost entirely yellow................................................................. .................................................................................................................... Schildomyia brevihirta Malloch (Panama)

20. Thorax with spots scattered, not forming patterns. Abdomen light-brown. Male fifth tergite reticulate ...................... ........................................................................................................................... Schildomyia reticulata Prado (Brazil)

- Abdomen black. Thorax with spots arranged in line. Male fifth tergite normal ...................................................... 21

21. Lunule with a velvet black spot; basoflagellomere yellow, without black spots .. Schildomyia goyana Prado (Brazil)

- Lunule without a velvet black spot; basoflagellomere with black spot on inner and outer surface ............................... ............................................................................................................. Schildomyia punctifrons Malloch (Costa Rica)

22. Postocellar setae present; posterior part of head straight from dorsal view ................................................................... ............................................................................................................... Pradomyia hadromera Gaimari (Costa Rica)

- Postocellar setae absent; posterior part of head concave from dorsal view ............................................................... 23

23. Several anterior fronto-orbital setae inclinate; scutellar disc setulose................ Shewellia agromyzina Hennig (Peru)

- With single inclinate fronto-orbital seta; scutellar disc bare .............................................. Helgreelia Gaimari …. 24

24. Abdomen orange, with fine pale setulae......................................................... Helgreelia albeto Gaimari (Costa Rica)

- Abdomen predominately brown, with black setulae ................................................................................................. 25

25. Abdominal tergites wholly brown, without yellow margin; arista entirely pubescent ................................................... ...................................................................................................................... Helgreelia parkeri Gaimari (Costa Rica)

- Abdominal tergites mostly brown with posterior margin yellow; arista plumose on the basal half ............................. ............................................................................................................................ Helgreelia gaimarii sp. nov. (Brazil)