Neoephydra, Mathis, Wayne N., 2008

Mathis, Wayne N., 2008, Two new neotropical genera of the shore-fly tribe Ephydrini Zetterstedt (Diptera: Ephydridae), Zootaxa 1874, pp. 1-15 : 9-10

Neoephydra , gen. nov.

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].

Type species: Neoephydra araucaria Mathis , sp. nov., by present designation.

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

Head: Mesofrons with vestiture variable; lacking cruciate, intrafrontal 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 stylelike, bare; postocular setae variable; large facial setae declinate; gena moderately high to high, gena-to-eye ratio 0.30 or larger.

Thorax: No well-developed acrostichal setae; dorsocentral setae 5 (1+4), development variable; supraalar seta variable; posthumeral seta lacking; intrapostalar seta present, although sometimes weak; hindtibia lacking apical seta.

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

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

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 , 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 sea shore ( Oliveira 1954a, 1958). Water evaporation from the shallow depressions is rapid, accounting for the concentration of salts.

Hennig (1943) and Oliveira (1954a, 1958) described and illustrated the larvae of four species belonging to this genus. Based on these illustrations, larvae of Neoephydra are typical of the tribe, with eight pairs of clawbearing 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.

Discussion. Neoephydra is a new generic name for most of the 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 members of Dimecoenia ( Wirth 1968) , are structurally dissimilar from the Nearctic species. After studying structures of the male terminalia, I concur with Steyskal and Wirth's findings and am proposing the new generic name, Neoephydra , for these taxa. Particular attention should be paid to structures of the male terminalia and female ventral receptacle.

The Neotropical and single Afrotropical species that are transferred to Neoephydra as new combinations are the following (list taken from Mathis and Zatwarnicki 1995 and Mathis 1995): N. abrupta (Cresson) , N. caesia (Wulp) , N. carrerai (Oliveira) , N. chilensis (Macquart) , N. ciligena (Rondani) , N. coltaensis (Cresson) , N. densepilosa (Hendel) , N. grumanni (Oliveira) , N. lenti (Oliveira) , N. lopesi (Oliveira) , N. prionoptera (Thomson) , N. travassosi (Mello and Oliveira) , N. tristanensis Frey (Afrotropical) , N. venteli (Oliveira) , N. zurcheri (Hendel) .