Ephydrella Occurring

Mathis, Wayne N. & Zatwarnicki, Tadeusz, 2025, A review of Ephydrella Tonnoir and Malloch from the New Zealand subregion (Diptera: Ephydridae) with description of a new species, Zootaxa 5673 (2), pp. 227-251 : 231

Key to Species of Ephydrella Occurring on New Zealand

(some couplets for males only)

1. Legs, including basitarsomere, blackish brown.............................................................. 2

- Legs blackish brown with basitarsomere of middle leg yellowish brown.......................................... 6

2. Facial protrusion or hump distinctly two-toned, dorsal half blackish brown, ventral half bluish gray. Lateral surstylar processes very long and robust ( Figs. 20–21 ), length equal to height of epandrium............................ E. bicolor sp. nov.

- Facial protrusion or hump unicolorous. Surstylus thinner and shorter ( Figs. 13–14 ), length less than height of epandrium... 3

3. Mesonotum mostly dull, tannish brown to brown with distinctive gray area laterally from postpronotum through notopleuron................................................................... E. assimilis (Tonnoir and Malloch) , in part

- Mesonotum mostly shiny, metallic bluish green to bronze, lacking distinctive gray area laterally....................... 4

4. Lateral surstylar processes comparatively short, about 3–4X length of ventromedial process ( Figs. 4 , 27 , 34 , 40 ); basal half of lateral surstylar process bearing long setulae, apical half bearing short, stout setulae; associated with freshwater to slightly brackish water habitats................................................................................. 5

- Lateral surstylar process relatively long, about 6X length of ventromedial process ( Fig. 47 ); basal 4/5 of lateral surstylar process bearing long setulae; apical 1/5 bearing short, stout setulae; associated with hot springs.......... E. thermarum Dumbleton

5. Surstyli in posterior view ( Fig. 4 ) with lateral margin shallowly and evenly curved at the base, apical extensions straight, parallel-sided......................................................................... E. aquaria (Hutton)

- Surstyli in posterior view ( Fig. 27 ) with lateral margin shallowly but distinctly sinuous, apical extensions oriented laterally............................................................................. E. macquariensis (Womersley)

6. Body generally bluish gray, densely microtomentose, mostly dull, at most subshiny; acrostichal setulae generally arranged in 2 conspicuous rows.................................................... E. assimilis (Tonnoir and Malloch) , in part

- At least abdomen and mesonotum green or brown, more sparsely microtomentose, subshiny to shiny; acrostichal setulae irregularly arranged in 4–5 rows, inconspicuous............................................................. 7

7. Surstylus narrow basally, somewhat angularly spatulate apically ( Fig. 40 )........................ E. spathulata Cresson

- Surstylus digitiform, more or less parallel sided ( Fig. 34 )..................... E. novaezealandiae (Tonnoir and Malloch)

Figures

FIGURES 17–23. Ephydrella bicolor sp. nov. 17–19. Head and thorax. 17. Head, anterior view. 18. Head, lateral view. 19. Thorax, dorsal view. Scale bar = 0.5 mm. 20–23. Male terminalia (specimen from New Zealand. Tuku, 20 Feb 1967). 20. External structures, posterior view. 21. Same, lateral view. 22. Internal structures, ventral view. 23. Same, lateral view. Scale bar = 0.1 mm.

FIGURES 13–16. Male terminalia of Ephydrella assimilis (Tonnoir & Malloch; specimens from New Zealand. Waima River, 8 Jan 1994, W. N. Mathis). 13. External structures, posterior view. 14. Same, lateral view. 15. Internal structures, ventral view. 16. Same, lateral view. Scale bar = 0.1 mm.

FIGURES 4–9. Male terminalia and distribution maps of Ephydrella. 4–7. Male terminalia of E. aquaria (Hutton) (specimens from New Zealand Danseys Pass, 12 Jan 2004, W. N. Mathis). 4. External structures, posterior view. 5. Same, lateral view. 6. Internal structures, ventral view. 7. Same, lateral view. Scale bar = 0.1 mm. 8–9. Distribution maps. 8. E. aquaria (Hutton). 9. E. assimilis (Tonnoir and Malloch).

FIGURES 27–30. Male terminalia of Ephydrella macquariensis (Womersley; specimens from Macquarie Island. Aerial Cove, 3 Mar 1961, K. C. Watson). 27. External structures, posterior view. 28. Same, lateral view. 29. Internal structures, ventral view. 30. Same, lateral view. Scale bar = 0.1 mm.

FIGURES 34–37. Male terminalia of Ephydrella novaezealandiae (Tonnoir & Malloch; specimens from New Zealand. Otago Peninsula, Hoopers Inlet, 13 Jan 2004, W. N. Mathis). 34. External structures, posterior view. 35. Same, lateral view. 36. Internal structures, ventral view. 37. Same, lateral view. Scale bar = 0.1 mm.

FIGURES 38–43. Distribution maps and male terminalia of Ephydrella. 38–39. Distribution maps. 38. E. bicolor sp. nov. (stars) and E. novaezealandiae (Tonnoir & Malloch) (circles). 39. E. spathulata Cresson (stars) and E. thermarum Dumbleton (circles). 40–43. Male terminalia of E. spathulata Cresson (specimen from New Zealand. Berwen Station, 2 Feb 2002, R. P. Macfarlane). 40. External structures, posterior view. 41. Same, lateral view. 42. Internal structures, ventral view. 43. Same, lateral view. Scale bar = 0.1 mm.

FIGURES 47–50. Male terminalia of Ephydrella thermarum Dumbleton (specimens from New Zealand. Old Waiotapu Road, 8 Feb 1998, W. N. Mathis). 47. External structures, posterior view. 48. Same, lateral view. 49. Internal structures, ventral view. 50. Same, lateral view. Scale bar = 0.1 mm.