Paraephydra freitasi (Oliveira)

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 : 28-30

6. Paraephydra freitasi (Oliveira)

Fig. 35–40 , Map 6

Ephydrella freitasi Oliveira 1954c: 292 .— Wirth 1968: 23 [Neotropical catalog].— Mathis and Zatwarnicki 1995: 247 [world catalog].

Paraephydra freitasi .— Mathis 2008: 5 –7 [generic combination, revision].

Diagnosis. Specimens of P. f rei t a s i may be distinguished from other congeners of Paraephydra by the following combination of characters: Mesofrons brown; face white to silvery white; gena short, gena-to-eye ratio 0.38; femora completely yellow; tarsi with basal tarsomeres mostly yellowish, becoming darker brown apically; and conformation of male terminalia. Moderately small shore flies, body length 2.73–2.76 mm (holotype); dorsum generally dark or bluish green to gray, subshiny to shiny, paler in color, gray to yellowish.

Head ( Fig. 35 ): Head ratio 0.62–0.69; frontal ratio 0.56–0.57; mesofrons mostly shiny, with metallic luster, brown, becoming greenish blue laterally; ocelli in isosceles triangle, distance between medial ocellus and either posterior ocellus longer than distance between posterior ocelli; microtomentose, with small strip near vertex of parafrons along tract of vertical and fronto-orbital setae shinier, more or less concolorous with lateral margins of mesofrons. Antenna brown to black; basal flagellomere slightly grayer, appearing more microtomentose. Facial ratio 1.01–1.07; face mostly microtomentose, white to silvery white. Eye ratio 0.92–0.95; gena-to-eye ratio 0.31– 0.38; gena moderately high, more or less unicolorous with face.

Thorax ( Fig. 36 ): Scutum dull gray to shiny, dark, bluish green, shinier posteriorly, dull coloration restricted to anterior portion anterior of 1st dorsocentral seta; scutellum shiny, unicolorous, concolorous with posterior portion of scutum; pleural areas brownish or bluish gray to whitish gray, dull, microtomentose; coloration change between scutum and pleural areas rather marked. Wing length 2.61–2.85 mm; costal vein ratio 0.23–0.31; M vein ratio 0.72–0.74; wing mostly hyaline. Legs more or less concolorous; femora unicolorous, pale, yellow to yellowish orange; tibiae nearly concolorous with femora but slightly darker apically and ventrally; tarsi with basal tarsomeres mostly brown to dark brown apically, basitarsomere sometimes yellowish basally and ventrally.

Abdomen: Tergites generally unicolorous although metallic luster of anterior segments tends to be more concolorous with scutum, bluish green; posterior tergites becoming progressively more brownish in color; lateral margins duller, more microtomentose, grayer. Male terminalia ( Figs. 37–40 ): epandrium in posterior view ( Figs. 37 ) elliptical to obovate but more or less truncate ventrally, lateral margins shallowly curved to sinuous, especially toward venter; base of fused surstyli with partial suture to indicate fusion with venter of epandrium; posterior surstylar processes very slightly divergent; length of fused surstylar plate ( Figs. 37–38, 39 ) more than twice width; internal terminalia much reduced and compact; phallapodeme apparently lacking or fused with base of aedeagus and hypandrium; aedeagus ( Fig. 40 ) moderately wide throughout its length, elongate, shallowly curved; female ventral receptacle with a short, flattened cap and a robust, C-shaped extension.

Type material. The holotype female is labeled “[ Brazil] Bodoquena[,] Mato Grosso XI-1941 [Nov 1941] Com. I O C/ COL. INST.O. CRUZ NO. 719/ HOLOTYPE Ephydrella freitasi Oliveira [red].” Three female paratypes are labeled with the same label data as the holotype except for collection numbers, which are 718, 720, and 721. The type series is in the IOC. The holotype is glued to a paper point and is in good condition. Two of the paratypes lack abdomens but otherwise the specimens are in good condition. The third paratype is missing its head, and the left wing has been removed and is glued apart from the remainder of the specimen.

Type locality. Brazil. Mato Grosso do Sul: Bodoquena (20°31.1'S, 56°43.3'W).

Other specimens examined. ARGENTINA. Entre Ríos: Rio Paraná, Ibicuy, Puerto Ibicuy (33°44'S, 59°11'W), 10 Dec 1979, C. M. and O. S. Flint (1♂; USNM).

PARAGUAY. Nueva: Asunción (20°48'S, 61°55'W), 21–25 Mar 1986, M. Pogue, A. Solis (1♂; USNM).

PERU. Lima: Lima, Lagunas de Villa (12°03.3'S, 77°03'W), 14 Feb 1984, W. N. Mathis (20♂, 20♀; USNM).

WEST INDIES. Puerto Rico. Laguna Cartagena (S Mayaguez; 18°0.1'N, 67°06.1'W), 8 Apr 1972, L. V. Knutson (2♂, 1♀; USNM).

Distribution (Map 6). Neotropical: Argentina (Entre Ríos), Brazil (Mato Grosso do Sul), Chile (Osorno, Valdivia), Paraguay (Nueva), Peru (Lima), West Indies ( Puerto Rico).

Remarks. Oliveira (1954c) tentatively placed this species in the genus Ephydrella Tonnoir and Malloch , awaiting males to further clarify its generic status. Using the brief descriptions of Ephydrella species for comparison, Oliveira noted that P. f re i t as i, like species of Ephydrella , has a well-developed, prescutellar, acrostichal seta. But Oliveira lacked males for critical study of postabdominal structures and was unable to satisfactorily resolve the generic affinity of this species. As an added complication, it has now been discovered that not all members of Ephydrella have prescutellar, acrostichal setae and that their occurrence in species related to P. freitasi is limited to females.

Identification of this species remains somewhat suspect, as males from the type locality or from a site nearby are still lacking and structures of the male terminalia provide important characters for species recognition in this tribe, including Paraephydra . In part, we are basing the identification of this species on the distributional information, with this species apparently being the more widespread Neotropical species, especially east of the Andes.

Discovery of P. freitasi in Puerto Rico was unexpected, as its congeners are mostly from southern South America. This finding leads us to suspect that the distribution of Paraephydra will be discovered to be more widespread than is presently known and that it would not be surprising to discover representatives of the genus in northern South America and Central America, perhaps even Mexico.

MAP 6. Distribution map for Paraephydra freitasi (Oliveira) .

Figures

FIGURES 35 – 40. Paraephydra freitasi (Oliveira). (35) head, lateroblique view; (36) mesonotum, dorsal view; (37) epandrium, cerci, surstyli, posterior view; (38) same, lateral view; (39) surstylus, lateral view; (40) internal male terminalia (fused hypandrium gonite, aedeagus), lateral view (from Mathis 2008).