Ephydrini

Mathis, Wayne N. & Sepúlveda, Luciane Marinoni and Tatiana A., 2025, Phylogeny and taxonomy of the shore-fly tribe Ephydrini with comments on related tribes in Ephydrinae (Diptera: Ephydridae), Zoologia (e 24044) 42, pp. 1-42 : 9-11

Key to genera and subgenera of Ephydrini

1. Head with clypeus prominent, greatly exposed below oral margin ...................................... Halmopota Haliday

1’. Head with clypeus largely retracted into oral cavity, at most barely exposed ...................................................... 2

2. Thorax with prosternum setulose on at least posterior portion. Pulvilli much reduced or absent; tarsal claws long and nearly straight ................................................ 3

2’. Thorax with prosternum bare. Pulvilli well developed; tarsal claws short and distinctly curved .................... 12

3. Antenna with basal flagellomere bearing a large lateral seta just below insertion of arista............................. ............................................................... Setacera Cresson

3’. Antenna with basal flagellomere without a lateral seta ................................................................................... 4

4. Head with 3 or more well-developed fronto-orbital setae. Anterior presutural supra-alar seta usually well developed, subequal to notopleural setae................... 5

4’. Head with 2 well-developed fronto-orbital setae present. Anterior presutural supra-alar seta absent or much reduced, much smaller than posterior notopleural seta... 8

5. Head with 5–6 well-developed fronto-orbital setae..... ............................................ Neoephydra Mathis (in part)

5’. Head with 3–4 well-developed fronto-orbital setae (Genus Ephydra Fallén ) ................................................. 6

6. Thorax with 2 presutural dorsocentral setae, anterior seta sometimes rather short. Face very thickly setulose; arista short, weakly haired, thicker on its basal half; usually 2 posteriorly directed rows of well-developed cruciate interfrontal setae present, with these rows closer to orbital setae than to each other. Male with basitarsomere of foreleg bearing ventral tuft of long setulae near tip ................ Ephydra (Hydropyrus) Cresson

6’. Thorax with 1 presutural dorsocentral seta. Face with 1 well-developed row of facial setae and 1 of oral setae, otherwise thinly short-haired; arista without markedly swollen basal region; usually not more than 1 pair of interfrontal setae situated as close to each other as to orbital setae. Male with basitarsomere of foreleg without ventral tuft of setulae ........................ 7

7. Head with 1 well-developed interfrontal seta present; palpus well developed. Crossvein dm-m making nearly a right angle with vein M l ........................................... ................................................. Ephydra (Ephydra) Fallén

7’. Head with interfrontal seta weak or absent; palpus small. Crossvein dm-m forming an acute angle with vein M l. .............................. Ephydra (Halephydra) Wirth

8. Head with cruciate interfrontal setae present............ 9

8’. Head with cruciate interfrontal setae absent ........... 11

9. Thorax with dorsocentral setae 4 (1+3). Arista bearing subpectinate dorsally branching rays on basal 1/2 ...... .......................................................... Paraephydra Mathis

9’. Thorax with dorsocentral setae 5 (1+4). Arista at most minutely haired on basal 1/2 ...................................... 10

10. Aristal rays long, length subequal to width of pedicel. Hindfemur of male not differing markedly from fore- or midfemur, lacking stout setae as above; hindtibia of male lacking tuft of setulae; hindtarsi of male cylindrical, normal.................................. Dimecoenia Cresson

10’. Aristal rays short, length approximately 1/2 width of pedicel. Hindfemur of male conspicuously swollen, bearing short row of 4–5 stout setae along anteroventral surface toward base; hindtibia of male with ventroapical tuft of setulae; hindtarsi of male variously modified .................................................. Cirrula Cresson

11. Thorax with a well-developed prescutellar acrostichal seta; 2 postpronotal setae, dorsal seta about 1/2 length of ventral seta; prosternal setulae sparse (Australasian) ............................ Ephydrella Tonnoir and Malloch

11’. Thorax lacking a well-developed prescutellar acrostichal seta; 1 postpronotal seta; prosternal setulae numerous (Neotropical)....... Neoephydra Mathis (in part)

12. Thorax with dorsocentral setae 4 (1+3); postpronotal seta(e) either weak, at most 1/4 length of posterior notopleural seta, or lacking. Hindcoxa bare posteriorly.. ........................................................................................ 13

12’. Thorax with dorsocentral setae 5 (1+4) (anterior setae reduced in Austrocoenia ); postpronotal seta distinct, at least 1/2 as long as posterior notopleural seta. Hindcoxa bare or with a row of setae posteriorly............. 14

13. Antenna with arista bearing long hair-like rays dorsally, length of longest rays subequal to height of basal flagellomere; frons only moderately to sparsely microtomentose, especially subshiny mesofrons (Holarctic) ........................................ Coenia Robineau-Desvoidy

13’. Antenna with arista either almost bare or bearing short hair-like rays dorsally, length of longest rays about 1/2 height of basal flagellomere; frons uniformly and densely microtomentose, dull, mesofrons little differentiated from parafrons (Neotropical)................. ............................................ Notiocoenia Mathis (in part)

14. Head with paravertical seta large, at least 1/3 length of medial vertical seta ...................................................... 15

14’. Head with paravertical seta small, generally subequal to setae of postocular row........................................... 18

15. Wing with R stem vein bearing 1–2 setulae dorsally, inserted beyond transverse septum. Scutellar disc convex. Hindcoxa with row of setae along posteroventral margin (Genus Paracoenia Cresson ) .......................... 16

15‘. Wing with R stem vein bare dorsally. Scutellar disc almost flat. Hindcoxa bare posteriorly along ventral margin (Genus Calocoenia Mathis ) ............................ 17

16. Thorax with both supra-alar and katepisternal setae either lacking or much reduced; midfemur of male lacking row of closely set setae along posteroventral surface; apical 4 tarsomeres explanate and short; pulvilli lacking; basal flagellomere short, less than length of pedicel; general coloration black............................... ........................................... Paracoenia (Thiomyia) Wirth 16’. Thorax with both supra-alar and katepisternal setae well developed; middle femur of male with row of closely set setae along posteroventral surface; apical tarsomeres normally developed, cylindrical; pulvilli evident; third antennal segment longer than second; general coloration olivaceous gray to dark green or bluish green .............. Paracoenia (Paracoenia) Cresson

17. Larger species, body length over 3.25 mm. Gena-to-eye ratio 0.25 or larger. Costal setulae well developed, projected obliquely anteriad from ventral and dorsal surfaces......................... Calocoenia (Calocoenia) Mathis

17’. Smaller species, body length under 2.75 mm. Gena-to-eye ratio 0.20 or smaller. Costal setulae weakly developed, only on dorsal surface ............................................. ..................................... Calocoenia (Leptocoenia) Mathis

18. Head with frons mostly lacking setulae and with coloration and vestiture generally uniform, microtomentose, dull; arista long, nearly double length of basal flagellomere. 1 interalar seta inserted just posterior of transverse suture .............. Notiocoenia Mathis (in part)

18’. Head with mesofrons conspicuously setulose, especially laterally, tan to brown, generally distinct from grayer parafrons, microtomentum denser; arista short, subequal to length of basal flagellomere. Interalar seta lacking................................ Austrocoenia Wirth