Ephydrella Tonnoir & Malloch, 1926

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 : 20-21

Ephydrella Tonnoir & Malloch, 1926

Figs 31–33

Ephydrella Tonnoir and Malloch 1926: 6 (feminine; as a subgenus of Ephydra ; type species: Ephydra novaezealandiae Tonnoir and Malloch 1926 , original designation). – Cresson 1935: 354 [generic status]. – Harrison 1959: 244–249 [fauna of New Zealand]. – Marshall and Wright 1974: 301–318 [ultrastructure of hindgut]. – Bock 1987: 155–166 [revision of Australian species]. – Mathis

1989: 647–648 [Australasian/Oceanian catalog]. – Mathis and

Zatwarnicki 1995: 247–248 [world catalog].

Mydaezealandia Salmon 1937: 359 (type species: Mydaezealandia glauca Salmon 1937 (= Ephydrella spathulata Cresson 1935 ),

original designation). – Salmon 1950: 2 [synonymy].

Diagnosis. Ephydrella is distinguished from other genera of the tribe Ephydrini by the following combination of characters: moderately large shore flies, body length 3.0–6.0 mm.

Head: Frons with shiny, metallic mesofrons, parafrons relatively dull, appearing somewhat “membranous”; two well-developed, lateroclinate fronto-orbital setae; cruciate interfrontal setae lacking; paravertical setae not evident; medial and lateral vertical setae well developed. Basal flagellomere lacking a lateral seta; arista long, almost double length of basal flagellomere, basal half somewhat swollen; dorsal aristal branches not evident, at most arista appearing macropubescent. Face with larger setae at lateral and oral margins; 1 large genal seta.

Thorax: Mesonotum dark colored, brown to metallic dark green or blue, similar to frons, with longitudinal light gray stripes in area of acrostichal tracks, scutellum triangular, posterior angle rounded, relatively acutely angulate, or narrowly truncate. Chaetotaxy: 1 well-developed pair of prescutellar acrostichal setae, otherwise as setulae; 4 (1+3) or 5 (1+4) well-developed dorsocentral setae, sometimes these appreciably reduced, posterior seta displaced laterally; 1 postpronotal seta; 1 presutural supra-alar seta; 1 supra-alar seta; 1 postalar seta; 2 lateral scutellar setae; prosternal setulae sparse on at least posterior portion; anepisternum with 1 long seta; katepisternum with 1 long, dorsoclinate seta. Wing generally hyaline; R stem vein bare above; costal vein ratio 0.23–0.25; M 1 vein ratio 0.68–0.76. Male hindfemur not differing markedly from fore- or midfemur, lacking stout setae; male hindtibia lacking tuft of setulae; male hindtarsi cylindrical, normal; pulvilli much reduced or absent; tarsal claws long and nearly straight.

Abdomen: Male with five visible tergites, female with 6–7; coloration similar to that of notopleuron, often submetallic but with varying levels of microtomentum. Male terminalia symmetrical, epandrium longer than wide, bearing prominent surstyli, these often elongate, with medial, often small triangular structure between surstyli, with medial fissure; aedeagus in lateral view cylindrical, moderately slender, base with more sclerotized, distinctly curved process; phallapodeme in lateral view elongate, keel distinct, either apices rod-like, slender; gonite sheathing aedeagus, usually longer than wide, variously shaped, but usually acutely pointed apically; subepandrium narrow band than arches over base of aedeagus; hypandrium shallowly v-shaped, angle very obtuse. Female terminalia: Female ventral receptacle with small papilla-like operculum; egg guide sternites bearing two pairs of strong setae.

Natural history: Bock (1987) observed that larvae of some Australian species are associated with marine algae of the genus Cladophora .

Distribution. Ephydrella is thus far only found on Australia and New Zealand.

Remarks. Ten species have been described thus far, all from Australia and New Zealand, and at least one species from New Zealand has not been described.

The shape of the surstylus and its relative length compared to the length of the medioventral process are used extensively to identify species of Ephydrella .

Figures

Figures 31–36. Ephydrella and Halmopota. Ephydrella novaezealandiae, (31) head anterior; (32) head lateral; (33) thorax dorsal.Halmopota salinarius, (34) head anterior; (35) head lateral; (36) thorax dorsal.