Ephydra Fallén

Mathis, Wayne N. & Marinoni, Luciane, 2016, Revision of Ephydrini Zetterstedt (Diptera: Ephydridae) from the Americas south of the United States, Zootaxa 4116 (1), pp. 1-110 : 87

Genus Ephydra Fallén

Ephydra Fallén 1810: 22 [type species: Ephydra riparia Fallén , by subsequent designation ( Curtis 1832: plate 413)].— Wirth 1968: 22 [catalog of South American species]; 1971: 357-377 [review of New World species, Figs. of male terminalia].— Mathis and Zatwarnicki 1995: 240 –247 [world catalog].

Diagnosis. Ephydra is distinguished from other genera of Ephydrini by the following characters:

Head: Lateroclinate, fronto-orbital setae 3, well developed, subequal; development of cruciate, interfrontal setae variable, either with 1 well-developed pair or weak to lacking; basal flagellomere simple, lacking secondary seta inserted below arista on lateral surface; arista variable, subpectinate to macropubescent, if subpectinate, basal thickening extended about 1/3 of aristal length, if macropubescent, basal thickening extended over 1/2 of aristal length; antennal groove distinct but not deeply impressed.

Thorax: Presutural supra-alar seta present, well developed; dorsocentral setae 5 (1+4); intrapostalar seta present; supra-alar seta present; disc of scutellum generally concolorous with posterior portion of scutum.

Abdomen: Structures of male terminalia considerably modified depending on subgenus and species group (see appropriate diagnosis of subtaxon for further details). Female ventral receptacle with operculum small, trapezoidal in shape; extended process relatively large, C-shaped, length 2– 3 X width of operculum.

Distribution. Occurring primarily in temperate regions of the world as follows. New World. Widespread mostly in the Nearctic Region but extended into the northern Neotropical Region (12°–65°N): Canada (just south of the Great Bear Lake), southward into Mexico (Oaxaca) and the West Indies (Dutch West Indies). Old World. Widespread, mostly in the Palearctic and Afrotropical (temperate) regions but extended into the northern Oriental Region: Norway to Japan, southward to the Canary Islands, South Africa, across southern Asia ( Afghanistan, Iran, and Tibet) to Japan and China.

Discussion. Wirth (1971, 1975) has provided an excellent revision of Ephydra on a worldwide basis, and his papers should be consulted for a more detailed discussion of the natural history and for identification of extralimital species. Our treatment is essentially a synopsis of Wirth's valuable study, although with some modification. Because Wirth borrowed and examined specimens from most major museums, we have not deemed it necessary to repeat that process. Consequently the “Specimens Examined” sections are omitted, and the reader is referred to Wirth's treatment for these data.