Lonchaeidae

Macgowan, Iain, 2021, The Lonchaeidae of Vanuatu (Diptera: Schizophora), Zootaxa 4926 (3), pp. 342-362 : 360-361

Key to the Lonchaeidae of Vanuatu

1. Lunule without setulae......... Tribe Earomyiini .. .. Lamprolonchaea .........................................2.

- Lunule with setulae........................... Tribe Lonchaeini ..........................................6.

2. Basal tarsomeres mainly pale, darkened only at apex.........................................................3.

- All tarsomeres brownish-black...........................................................................4.

3. Male terminalia: Phallus a slender curved J-shape, apical section sinuous half twisted to the left, apex bulbous ( Fig. 10 ). Surstylar plate with two pointed posterior processes ( Fig. 11 )........................ Lamprolonchaea photinia McAlpine

- Male terminalia; phallus with a distinct basal bulge, apical section straight and simple, apex slightly flared ( Fig 2 ). Surstylar plate without pointed posterior processes ( Fig. 3 )........................... Lamprolonchaea conchapinna McAlpine.

4. Male terminalia: Phallus with two basal bulges ( Fig. 14 ). Surstylus rather triangular, not rectangular or rounded ( Fig. 16 ).......................................................................... Lamprolonchaea ustulata McAlpine.

- Male terminalia: Phallus without basal bulges ( Figs. 6 & 18 ). Surstylus rectangular or rounded ( Figs. 8 & 19 )............5.

5. Male terminalia: Phallus relatively short and wide, without spicules on apical half ( Fig. 6 ). Surstylus relatively large and rectangular ( Fig. 8 )......................................................... Lamprolonchaea lustrata McAlpine.

- Phallus a slender, open J-shape, with an obvious group of small spicules apically. ( Fig. 18 ) Surstylus small and rounded ( Fig. 19 )......................................................................... Lamprolonchaea vila sp. nov.

6. Male terminalia: inner surface of surstyli without an obvious row of prensisetae (teeth) ( Fig. 27 ). Katepisternum usually with one seta near dorsal margin and arista bare........................................................ 7. Lonchaea .

- Male terminalia: inner surface of surstyli with an obvious row of prensisetae ( Figs. 35 & 37 ). Katepisternum usually with two setae near dorsal margin and plumose arista......................................................... 11. Silba .

7. Legs entirely black. Arista plumose. Male; mid leg, tibia and basal tarsomere with an anteroventral fringe of setulae longer than width of tibia ( Fig. 28 ). Large species, wing length more than 4mm. Male terminalia; epandrium 2x higher than wide ( Figs 26 & 27 ).......................................................................... Lonchaea malekula sp. nov.

- At least some tarsomeres yellow. Arista bare. Male mid leg and basal tarsomere not setulose. Small species wing length approximately 2.5mm. Male terminalia; epandrium not 2x higher than wide.………..( L. impressifrons species-group).......8.

8. Male terminalia: cerci without basal stalk ( Figs. 10 , 37, 38 ). Disc of scutellum setulose. Surstyli relatively broad, mitten-shaped with a V-shaped notch on posterior margin..................................................................9.

- Male terminalia: cerci with narrow basal stalk (Figs. 21 &31). Disc of scutellum bare. Surstyli simple, pregonites relatively small and asymmetrical...............................................................................10.

9. Male terminalia: Pregonites, apex broad, blunt and medially directed, without a medial projection ( Figs. 23–25 )........................................................................................ Lonchaea iridala McAlpine.

- Male terminalia: Pregonites, apex slender and slightly curved, medially with a large, triangular inwardly directed process ( Fig. 29 ).......................................................................... Lonchaea pentecosti sp. nov.

10. Male terminalia: Phallus an open J-shape, apex simple (Fig. 22). Pregonites both long and blade-like, without medial projections (Fig. 20)...................................................................... Lonchaea efate sp. nov.

- Main stem of phallus bent back towards base, apex flared (Fig. 32). Pregonites, shorter and broader with medial processes (Fig. 31)............................................................................... Lonchaea tanna sp. nov.

11. Calypteres greyish with a darker margin, fringe short and dark. Male terminalia; hypandrium with numerous finger-like ventral projections, phallus simple ( Figs. 33–35 )................................................ Silba erromango sp. nov.

- Calypteres white with a white fringe. Hypandrium without numerous ventral projections............................12.

12. Male terminalia; epandrium wider than high ( Figs.36–37 ), phallus complex ( Figs. 38–39 )......... Silba hebridensis sp. nov.

- Male terminalia; epandrium higher than wide. Phallus a simple J-shape, with a very characteristic angled apex ( Fig 40 )..................................................................................... Silba perplexa (Walker) .

Figures

FIGURE 40. Silba perplexa (Walker, 1861). Epandrium and associated structures lateral view.

FIGURES 9-12. Lamprolonchaea photinia McAlpine, 1964. 9. Epandrium and associated structures, lateral view. 10. Phallus, lateral view. 11. Surstylar plate, ventral view. 12. Surstylus, medial surface.

FIGURES 1-4. Lamprolonchaea conchapinna McAlpine, 1964. 1. Epandrium and associated structures, lateral view. 2. Phallus, lateral view. 3. Surstylar plate, ventral view. 4. Surstylus, medial surface.

FIGURES 13-16. Lamprolonchaea ustulata McAlpine, 1964. 13. Epandrium and associated structures, lateral view. 14. Phallus, lateral view. 15. Surstylar plate, ventral view. 16 Surstylus, medial surface.

FIGURES 5-8. Lamprolonchaea lustrata McAlpine, 1964. 5. Epandrium and associated structures, lateral view. 6. Phallus, lateral view. 7. Surstylar plate, ventral view. 8. Surstylus, medial surface.

FIGURES 17-19. Lamprolonchaea vila sp. nov. 17. Epandrium and associated structures, lateral view. 18. Phallus, lateral view. 19. Surstylus, medial surface.

FIGS. 26-28. Lonchaea malekula sp. nov. 26. Epandrium and associated structures, lateral view. 27. Surstylus, internal view. 28. Tibia and basal tarsomeres of mid leg.

FIGURES 33-35. Silba erromango sp. nov. 33. Epandrium and associated structures, ventral view. 34 same, lateral view. 35. Surstylus, internal view.

FIGURES 36-39. Silba hebridensis sp. nov. 36. Epandrium and associated structures, ventral view. 37. Surstylus, internal view. 38. Phallus and parameres lateral view. 39. Phallus, parameres and postgonites, ventral view.

FIGURES 23-25. Lonchaea iridala McAlpine, 1975. 23. Epandrium and associated structures, lateral view. 24. Same, ventral view. 25. Phallus, lateral view. (after McAlpine, 1975).

FIGURES 29 & 30. Lonchaea pentecosti sp. nov. 29. Epandrium and associated structures, lateral view. 30. Phallus, lateral view.