Paraephydra stauros 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 : 30-32

7. Paraephydra stauros Mathis

Figs. 41–44 , Map 7

Paraephydra stauros Mathis 2008: 8 .

Diagnosis. This species is similar to P. f re i t as i but is distinguished from it by the following combination of characters: Mesofrons metallic green; face mostly unicolorous, grayish white to silvery white; gena comparatively high, gena-to-eye ratio 0.57–0.58; forefemur two toned, bluish gray basally, dull, microtomentose, becoming paler, less microtomentose and yellowish orange apically; tarsi brown to brownish black; shape of structures of male terminalia distinctive. Moderately small to medium-sized shore flies, body length 2.40–3.60 mm (averaging 3.02 mm); generally dark dorsally, dull, olivaceous brown to shiny, metallic green becoming paler in color ventrally, mostly gray.

Head: Head ratio 0.65–0.66; frontal ratio 0.49–0.50; subquadrate mesofrons narrowed slightly anteriorly, shiny with metallic green luster, anterior portion with some smaller, generally inconspicuous setae in addition to larger, cruciate, interfrontal setae; ocelli in isosceles triangle, distance between medial ocellus and either posterior ocellus longer than distance between posterior ocelli; fronto-orbits slightly shinier with faintly evident metallic green luster. Antenna mostly unicolorous, basal flagellomere slightly browner and less gray; arista long, longer than combined length of segments 1–3, with dorsal, subpectinate branching on basal 2/3. Facial ratio 1.05–1.70; area immediately between antennal bases brown, otherwise face mostly unicolorous, grayish white to silvery white. Eye ratio 0.91–0.93; gena-to-eye ratio 0.57–0.58; gena high, concolorous with face.

Thorax: Scutum gray to olivaceous brown anteriorly, microtomentose, dull, becoming shinier, less microtomentose and more greenish to dark greenish blue in coloration; scutellum shiny with metallic dark greenish blue luster. Pleural areas grayish brown to brown dorsally, becoming paler, bluish gray to gray ventrally. Wing hyaline or slightly infumate; costal vein ratio 0.41–0.43; M vein ratio 0.76–0.79. Legs mostly concolorous; forefemora and usually hindfemora two-toned, bluish gray basally, dull, microtomentose, becoming paler, less microtomentose and yellowish orange apically; tibiae concolorous with apices of femora basally, becoming browner apically; tarsi mostly brown to brownish black.

Abdomen: Dorsum of tergites microtomentose to subshiny; basal tergites subshiny medially, mostly greenish blue, lateral margins becoming duller, grayer; apical tergites subshiny medially although less so than basal ones, with more brownish coloration, lateral margins also becoming grayer and more microtomentose. Male terminalia ( Figs. 41–44 ): epandrium in posterior view ( Figs. 41 ) obovate but more or less truncate ventrally, lateral margins slightly sinuate, especially toward venter; base of fused surstyli with partial suture to indicate fusion with venter of epandrium; length of surstylar plate ( Figs. 41–43 ) only slightly greater than width; apical surstylar prongs mostly parallel, deeply emarginate; phallapodeme, aedeagus and hypandrium greatly reduced and compacted; aedeagus ( Fig. 44 ) mostly wide throughout its length; aedeagus conspicuously curved.

Type material. The holotype male is labeled “ CHILE: Osorno Pr. Anticura (1 km. W) 432 m. elev.[,] 1–3 Feb. 1978 [,] WNMathis/ HOLOTYPE ♂ Paraephydra stauros Mathis USNM [red].” The holotype is double mounted (minuten in a block of plastic elastomer), is in excellent condition (abdomen has been removed, dissected; parts are in an attached microvial), and is deposited in the USNM. The allotype female bears the same locality label data as the holotype. Other paratypes are as follows: CHILE. Valdivia: Valdivia (7 Km S; 39°49'S, 73°14'W), 4 Jun 1969, P. and P. Spangler (2♂, 4♀; USNM).

Type locality. Chile. Osorno: Anticura (1 km W; 40°39'S, 72°10'W; 432 m).

Distribution (Map 7). Neotropical: Chile (Osorno, Valdivia).

Etymology. The specific epithet, stauros , is a masculine Greek noun meaning cross and refers to the prominent pair of cruciate interfrontal setae of this species. The name is a noun in apposition to the generic name.

Remarks. Although some intraspecific variation in color is evident, the color of the legs, as noted in the key and description, seems to hold. The sampling of this species, however, is based on the few specimens listed previously.

MAP 7. Distribution map for Paraephydra stauros Mathis.

Figures

FIGURES 41 – 44. Structures of male terminalia of Paraephydra stauros Mathis. (41) epandrium, cerci, surstyli, posterior view; (42) same, lateral view; (43) surstylus, lateral view; (44) internal male terminalia (fused hypandrium gonite, aedeagus), lateral view (from Mathis 2008).