Ephydrella spathulata Cresson

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 : 245-247

6. Ephydrella spathulata Cresson

Figs. 39–43

Ephydrella spathulata Cresson 1935: 355 .— Miller 1950: 111 [catalog of New Zealand Diptera ].— Harrison 1959: 248–249 [fauna of New Zealand].— Mathis 1989: 647 [Australasian/Oceanian catalog].— Mathis and Zatwarnicki 1995: 248 [world catalog].

Diagnosis.—This species is distinguished from congeners by the following combination of characters: Moderately large shore flies, body length 4.30–4.60 mm. At least abdomen and mesonotum green or brown, more sparsely microtomentose, subshiny to shiny.

Head: Frons and face generally dark colored, brown; mesofrons shiny brown with dark brown; parafrons grayish brown to black, densely microtomentose. Gena-to-eye ratio 0.40–0.43.

Thorax: Mesonotum dark brown with even darker brown, shinier longitudinal stripes through acrostichal and dorsocentral tracks; anepisternum brown, similar to facial color, other pleurites gray, some specimens with faintly greenish gray to bluish gray. Acrostichal setulae irregularly arranged in 4–5 rows, inconspicuous. Costal vein ratio 0.23–0.24; M 1 vein ratio 0.66–0.74. Legs blackish brown with basitarsomere of middle leg yellowish brown.

Abdomen ( Figs. 40–43 ): Tergites microtomentose, grayish green. Male terminalia ( Figs. 40–43 ): Epandrium in posterior view ( Fig. 40 ) almost as wide as high, widest on basal half, dorsal half tapered to evenly arched dorsal margin, epandrium in lateral view ( Fig. 41 ) robustly developed, irregularly hexagonal; cercal cavity in posterior view ( Fig. 40 ) about half overall epandrial height, cerci in posterior view ( Fig. 40 ) drop-like, tapered dorsally, medial margin shallowly concave, in lateral view ( Fig. 41 ) semicircular; surstyli in posterior view ( Fig. 40 ) elongate, robustly developed, digitiform, slightly wider on apical portion, apex obtusely pointed, bearing setulae along medial margin toward base, in lateral view ( Fig. 41 ) irregularly clavate, setulae more evident on basal half; medioventral projection in posterior view ( Fig. 40 ) triangular, short, each process tapered to acute apex; phallus in lateral view ( Fig. 43 ) longer than high, irregularly rectangular, dorsal margin arched, in ventral view ( Fig. 42 ) basal ¾ rectangular, less sclerotized, gradually becoming broader to apical ¼, apical portion abruptly narrowed to bifurcate as 2 narrow apical projections; phallapodeme in lateral view ( Fig. 43 ) elongate, narrow, with keel 3X longer than wide, keel broadly rounded, narrow, ventral extension (to postgonite) and dorsal extension (to base of phallus) about equal in length, in ventral view ( Fig. 42 ) with basal margin broadly V-shaped; postgonite+hypandrium in lateral view ( Fig. 43 ) as a irregularly rectangular lateral shield of phallus, basal margin sloped from shorter dorsal margin to longer ventral margin, dorsal margin irregularly curved, apical margin with 2 concave scallops ventrad from pointed dorsoapical, pointed corner, in ventral view ( Fig. 42 ) with lateral margins extended laterally, somewhat triangular with vertex broadly rounded, basal margin somewhat truncate, apical slope tapered to acute apical point, extended thereafter basally nearly straight.

Primary Type Material.— The holotype male of Ephydrella spathulata Cresson is labeled “Queenstown N[EW]. Z[EALAND]. 12-12-22 [12 Dec 1922] Leon Cuetis [handwritten]/ CPAlexander donor/ ♂ [♂ symbol in red]/9172/ Type No. 51099 U.S. N.M. [red; number handwritten]/ TYPE No. Ephydrella SPATHULATA E T Cresson, Jr. [red; species name handwritten].” The holotype is directly pinned, is in fair condition (generally appearing tattered; basal flagellomeres and several cephalic setae missing; wings torn; structures of male terminalia exposed well) and is deposited in the USNM (51099).

Type Locality.— Australasian : New Zealand. South Island. Queenstown (45°01.6'S, 168°39.6'E) .

Specimens Examined from New Zealand. — SOUTH ISLAND. CO : Berwen Station (upland bog; 44°32'S, 169°52.2'E; 1589 m), 2 Feb 2002, R . P. Macfarlane (3♂, 2♀; USNM). OL : Queenstown (45°01.6'S, 168°39.6'E), 12 Dec 1922, L. Cuetis (1♂; holotype, 5♀; paratypes; USNM). Glenorchy (44°51'S, 168°23.3'E), R . S. Oliver , 1 Mar 1923 (1♀; paratype; USNM) .

Distribution ( Fig. 39 ).—Australasian/Oceanian: New Zealand. South Island (CO, OL).

Natural History.—The habitat of this species extends to subalpine tussocks around sluggish springs on the south end of the Ewe Range. The range of this species would seem to be central Otago or inland on South Island.

Remarks.—This species is distinguished from congeners, especially E. novaezealandiae , by the following combination of characters: facial protrusion mostly unicolorous; at least abdomen and mesonotum green or brown, more sparsely microtomentose, subshiny to shiny; acrostichal setulae irregularly arranged in 4–5 rows, inconspicuous; legs blackish brown with basitarsomere of middle leg yellowish brown; surstylus narrow basally, somewhat angularly spatulate apically.

Figures

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.