Paracoenia Cresson

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 : 23-24

Genus Paracoenia Cresson

Paracoenia Cresson 1935: 356 . Type species: Coenia bisetosa Coquillett 1902 , original designation.— Wirth 1965: 755 –756 [Nearctic catalog].— Mathis 1975: 65 –85 [revision of Nearctic species].— Mathis and Zatwarnicki 1995: 250 –252 [world catalog].

Diagnosis. Paracoenia is distinguished from other genera of the tribe Ephydrini by the following combination of characters: Small to large shore flies, body length 2.10–4.40 mm; dark colored and often with subshiny, metallic reflections.

Head: Face projected, transversely arched; paravertical setae large, subequal to vertical setae.

Thorax: Postpronotal seta distinct, at least 1/2 as long as posterior notopleural seta; dorsocentral setae 5 (1+4); scutellum with dorsum convex; prosternite bare. R stem vein bearing 1–2 setulae above, inserted beyond transverse septum. Pulvilli well developed; hindcoxa with row of setae posteriorly along ventral margin; tarsal claws short and distinctly curved.

Abdomen: Male terminalia: Surstyli distinct as elongate, narrow, arm-like projections, projections oriented ventrally; a medial, triangular process between surstylar arms; gonite (sometimes called hypandrial process) well developed, sheathing aedeagus.

Discussion. The lineage comprising Paracoenia and related genera is probably the sister group to the remaining taxa of Ephydrini . This lineage plus the remaining taxa of Ephydrini , as here delimited, is characterized by the following character states (some have become modified secondarily): 1. Number of dorsocentral setae: Although other genera of the subfamily Ephydrinae sometimes have five pairs of dorsocentral setae (e.g. Notiocoenia Mathis and Austrocoenia Wirth ), the anterior pair (or pairs) is weakly developed. There are five welldeveloped pairs only in members of Ephydrini (the anterior pair is presutural; specimens of Cirrula gigantea have the anterior four pairs of dorsocentral setae weakly developed, a condition we interpret to be secondary). 2. Development of intrapostalar seta: In most species of the family, the intrapostalar seta is either lacking or is very much reduced, less than one-half the length of the postalar seta. In members of this lineage, the intrapostalar seta is frequently as long. 3. Setal vestiture of proepisternum: Throughout most of the family the proepisternum is bare of setae (although frequently it is thinly to densely microtomentose). In members of this lineage, there are numerous setulae that are generally conspicuously evident.