Paraephydra Mathis

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 : 27

Genus Paraephydra Mathis

Paraephydra Mathis 2008: 4 [type species: Ephydrella freitasi Oliveira 1954 , original designation].

Diagnosis. Paraephydra is distinguished from other genera of Ephydrini by the following combination of characters: Moderately small to medium-sized shore flies, body length 2.40–3.80 mm; setation normally developed, not generally appearing pilose.

Head: Mesofrons shiny, with metallic luster, differentiated from microtomentose parafrons; cruciate interfrontal setae l; lateroclinate, fronto-orbital setae 2; antennal groove distinct but not deeply impressed; basal flagellomere lacking large seta inserted on lateral surface; arista as long or slightly longer than combined length of 1st 3 antennal segments, gradually tapered from base to apex, with subpectinate, dorsally branching rays on basal 2/3; postocular setae normally developed, not conspicuous; larger facial setae extended from interfoveal hump with 1–2, distinctly porrect to anaclinate.

Thorax: Females with 1 prescutellar, acrostichal setae; dorsocentral setae 4 (1+3), all well developed; supraalar seta present; presutural supra-alar seta lacking; intrapostalar seta either weakly developed or lacking; disc of scutellum concolorous with posterior portion of scutum; females lacking dense patch of setae between posterior 2 dorsocentral setae. Hindtibia with apical, anteroventral seta, length equal to or larger than width of tibia at widest point.

Abdomen: Female ventral receptacle with operculum flat, disc-like. Male terminalia: symmetrical; epandrium longer than wide, narrowed ventrally, fused almost imperceptibly with base of united surstyli; surstyli fused medially except at near apex; posterior surstylar process only slightly longer than lateral process; both processes apical; gonite, hypandrium, and apparently aedeagus fused to form 1 compact structure, curved anteriorly, wide basally, tapered to rounded apex.

Distribution. Neotropical; widespread but scarce, from Puerto Rico south through Brazil to Chile. None of the congeners is known to be sympatric.

Natural history. Like other ephydrines, Paraephydra occurs in wetlands. In southern Chile (Osorno Province), we collected specimens of P. stauros in a sedge meadow near the margins of small but apparently permanent ponds. Nothing is known about the immature stages or the microhabitat of the genus.

Discussion. Paraephydra is proposed to accommodate two closely related species, P. freitasi (Oliveira) and P. stauros Mathis. See “Remarks” section under P. f re i t as i for further comments on the classificatory history and placement of that species.

Sexual dimorphism is evident in the chaetotaxy of Paraephydra . Females, unlike males, have a prescutellar acrostichal seta that is larger than other acrostichal setulae. Based on this character, Oliveira (1954c) described P. freitasi in the genus Ephydrella , as that genus, unlike Dimecoenia, sensu Neotropical species, lacks these setae.