Neoephydra Mathis, 2008

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 : 22-24

Neoephydra Mathis, 2008

Figs 37–51

Dimecoenia in part of authors [misidentification], not Cresson 1916: 152. – Wirth 1968: 23 [catalog of South American species, distribution]. – Lizarralde de Grosso 1989: 57–58 [fauna of Argentina]. – Mathis and Zatwarnicki 1995: 238–240 [world catalog].

Neoephydra Mathis 2008: 9 (feminine; type species: Neoephydra araucaria Mathis 2008 , original designation). – Mathis and Marinoni 2016: 31–74 [revision, Neotropical species].

Diagnosis. Neoephydra is distinguished from other genera of Ephydrini by the following characters: medium-sized to large shore flies, body length 3.00– 5.30 mm.

Head: Mesofrons with vestiture variable; lacking cruciate, interfrontal setae; lateroclinate, fronto-orbital setae either 2 or 5–6, not 3; basal flagellomere lacking large seta inserted on lateral surface; arista moderately short, thickened basally, with macropubescent vestiture dorsally, apical half style-like, bare; postocular setae variable; large facial setae declinate; gena moderately high to high, gena-to-eye ratio 0.30 or larger.

Thorax: Chaetotaxy: Acrostichal setae, including a prescutellar pair, not well-developed; dorsocentral setae 5 (1+4), development variable; supra-alar seta variable; presutural supra-alar seta lacking; intrapostalar seta present, although sometimes weak. Wing generally hyaline; costal vein ratio 0.19–0.36; M 1 vein ratio 0.64–0.86. Hindtibia lacking apical seta; tarsal claws nearly straight; pulvilli essentially absent.

Abdomen: Male terminalia symmetrical, epandrium longer than wide; surstyli fused medially except near apices and with 1–2 lateral projected processes or prongs in addition to apical prominences; aedeagus in lateral view shallowly crescent-shaped and generally quite slender, at least apically. Female terminalia: Female ventral receptacle with small papilla-like operculum.

Natural History: Like many taxa of the subfamily Ephydrinae , specimens of Neoephydra inhabit diverse and what would appear to be environments inimical to life. Oliveira (1954a) noted that Dr. Herman Lent found larvae, pupae, and adults of a Chilean species in the hot effluent of a high altitude, hot water geyser located at El Tatio (5200 m), near San Pedro de Atacama. Although the temperature of the water was not taken, Dr. Lent stated that it was sufficiently hot to cook an egg. Dr. Lent also observed a small, predatory toad, Telmatobius peruvianus Wiegmann ( Anura : Leptodactylidae ), whose diet consisted solely of freshly emerged, adult flies.

Numerous larvae and pupae of a second species, collected in southern Brazil, were found to inhabit warm, algae-covered, and often saline water that had accumulated in depressions of large rocks near the seashore ( Oliveira 1954b, 1958). Water evaporation from these shallow depressions is rapid, accounting for the concentration of salts.

Hennig (1943) and Oliveira (1954b, 1958) described and illustrated the larvae of four species belonging to this genus. Based on these figures, larvae of Neoephydra are typical of the tribe, with eight pairs of claw-bearing prolegs on the ventral surface, the terminal pair being larger and with crochets opposable to those of the other prolegs. The posterior spiracles are borne on a long respiratory tube which bifurcates posteriorly.

Distribution. Members of Neoephydra are only known from the Neotropics and some island in the south Atlantic Ocean, where they are widespread and occur in habitats similar to those of the Holarctic genera Ephydra Fallén and Setacera Cresson.

Remarks. Neoephydra is the generic name for most South American species that had been placed in the genus “ Dimecoenia . ” As noted by Steyskal (1970) and Wirth (1971), the Neotropical species, which were treated as congeners of Dimecoenia ( Wirth 1968) , are structurally dissimilar from the Nearctic species. We came to the same conclusion as Steyskal and Wirth after studying structures of the male terminalia. To identify species, particular attention should be given to structures of the male terminalia and female ventral receptacle.

Three species groups are also recognized (the araucaria , dasycephala , and neotropica groups). These groups were proposed for specimens that are dissimilar superficially from the typical Neoephydra ( araucaria Group) but which have structures of the male and/or female terminalia that closely resemble those of other similar aggregates. Mathis and Marinoni (2016) chose the informal category of “species group” for these groups because of its flexibility, without encumbering additional, relatively fixed nomenclature, such as would be required for the subgeneric category.

The monophyly of Neoephydra is established by the following characters: (1) Conformation of the male terminalia: The surstyli are fused medially except near their apices and each surstylus bears one or two additional, anterolateral prongs. This conformation is unique within the subfamily Ephydrinae . (2) Conformation of female ventral receptacle: All species groups have a small, papilla-like operculum, which is also apparently unique to females of Neoephydra .

It is likely that the species groups of Neoephydra are monophyletic, although the araucaria Group lacks characterization by derived character states. The monophyly of the remaining groups is well established, as evidenced by the ap - propriate characterization heading each group’s treatment.

Figures

Figures 37–51.Neoephydra.Neoephydra_araucaria, (37) habitus.Neoephydra mallonota, (38) head anterolateral; (39) thorax dorsal; (40) epandrium and cerci posterior; (41) internal structures of male terminalia lateral; (42) male terminalia lateral. Neoephydra neotropica, (43) head anterolateral; (44) thorax dorsal; (45) epandrium and cerci posterior; (46) male terminalia lateral; (47) internal structures of male terminalia lateral. Neoephydra trichina, (48) head lateral; (49) thorax dorsal; (50) epandrium and cerci posterior; (51) male terminalia lateral.