Hydrellia similis, Júnior, Francisco De Assis Rodrigues, Mathis, Wayne Nielsen & Couri, Márcia Souto, 2014

Júnior, Francisco De Assis Rodrigues, Mathis, Wayne Nielsen & Couri, Márcia Souto, 2014, Hydrellia Robineau-Desvoidy (Diptera: Ephydridae) from Brazil with an emphasis on the faunas from the states of Parana and Rio de Janeiro, Zootaxa 3753 (6), pp. 501-541 : 537-539

Hydrellia similis sp. nov.

(Figs.: 20.5–20.6, 30.1–30.8 and 31)

Diagnosis. Body length of male 2.45 mm; ocellar setae present; 7–8 aristal rays; maxillary palpus yellow; welldeveloped dorsocentral setae 0+1; fore femur with a well-developed ctenidium along anteroventral margin (fig. 20.6); tarsi yellowish brown, becoming darker from the tarsomere 3; sternite 5 roundly triangular at anterior margin, with a broad and ornamented medial acuminate process on posterior margin, lateral arms with no cleft (figs. 30.1 and 30.2); surstylus with a deep, narrow, medial sulcus on apical half and a smaller, lateral cleft forming a lateral, narrow process (figs. 30.1 and 30.7), in lateral view with a prominent, elongate ax-like carina at merger of surstyli on basal half, superior margin of surstylar carina shallowly concave and sinuous (fig. 30.8).

Description. Head: frons twice or more times broader than high, densely microtomentose, fronto-orbital plate brownish black, appearing velvety, except for the greenish or golden brown fronto-orbits, ocellar triangle almost all greenish or golden brown, but sometimes black microtomentose on anterior margin; both proclinate and reclinate fronto-orbital setae present, with a third smaller setula between them; ocellar setae present, twice or more times smaller than pseudopostocellar seta; scape dark brown to black; pedicel black with some gray microtomentum mainly on anterodorsal and anteroventral corners; pedicel with 2 ventral hair like setulae but with no outstanding seta on dorsal corner; first flagellomere densely gray microtomentose; 7–8 aristal rays; lunule silver; face densely golden brown or silver microtomentose, in lateral view with an upper medial carina and distinct antennal grooves; facial setae 5, usually with 1 smaller shallowly declinate dorsal secondary facial setulae; parafacial concolorous with face; genal groove dusted with some black microtomentum anteriorly; 1 genal seta; gena, postgena and occiput gray microtomentose; maxillary palpus yellow, spatulate; epistomal ratio: 1.85; mesofacial ratio: 2.65; vertex ratio: 5.43; eye-to-gena ratio: 3.81; head ratio: 1.31.

Thorax: mesonotum golden brown, densely microtomentose; postpronotal lobe silvery gray; well-developed dorsocentral setae 0+1, presutural seta sometimes developed but not as postsutural one; 3 scutellar setae, mid pair weakly developed; pleurae silvery gray, notopleuron dusted with greenish or golden brown microtomentum on mid anterior margin or wholly brown; supra-alar area densely black microtomentose; 1 anepisternal seta well developed; 1 mesokatepisternal seta; 1 postpronotal seta with a second much smaller setulae over it. Wings: length 2,0 9 mm; hyaline with pale brown venation; knob of halter fluorescent yellow to pale yellow, stem brown; costal sections indices: II/I: 2.42; III/IV: 2.90; V/IV: 3.76; vein M ratio: 3.29. Legs: coxae, trochanters, femora and tibiae almost all concolorous with pleural areas, except for posterior margin of coxae and femora sometimes glossy or opaque brown; fore femur with a well-developed ctenidium along anteroventral margin (fig. 20.6); tarsi yellowish brown, becoming darker from the tarsomere 3.

Abdomen: densely grayish brown dorsally, silvery gray laterally and ventrally; anterodorsal corners of tergites 3–5, when in lateral view grayish brown (fig. 20.5). Male terminalia: sternite 5 attached with anterior margin of hypandrium, roundly triangular at anterior margin, with a broad and ornamented medial acuminate process on posterior margin, lateral arms with no cleft (figs. 30.1 and 30.2); epandrium broad, forming an inverted U (fig. 30.1); surstylus with a deep, narrow, medial sulcus on apical half and a smaller, lateral cleft forming a lateral, narrow process (figs 30.1 and 30.7), in lateral view with a prominent, elongate ax-like carina at merger of surstyli on basal half, superior margin of surstylar carina shallowly concave and sinuous (fig. 30.8); postsurstylus in ventral view broad (figs. 30.1 and 30.2); pregonite simple, rod-like except for apical bifurcation, each lobe bearing an apical setula (figs. 30.1 and 30.2); aedeagus in ventral view fusiform (fig. 30.3), in lateral view with a pointed shallowly recurved process (fig. 30.4); phallapodeme in lateral view shallowly bifurcate at attachment to hypandrium (fig. 30.6), in ventral view greatly expanded laterally, flange-like at aedeagal terminus, bifurcate at hypandrial terminus (fig. 30.5).

Material examined. Holotype male ( MNRJ): “ Brazil, Paraná, Bocaiúva do Sul (25°14.9'S, 49°8.9'W, 890 m), 2–4.Nov.2010. D. and W. N. Mathis”. Paratypes: Labelled the same as holotype (1 male; MNRJ). Paraná, Castro (8 km N; 24°45.3'S, 49°58.9'W; 1010 m), 25–26.XII.2009. D. and W. N. Mathis (1 male; USNM).

Distribution. Neotropical: Brazil (Paraná).

Etymology. The specific epithet, similis , refers to the fact that this species is morphologically very similar to H. vilelai sp. nov.

Notes. Hydrellia similis sp. nov. belongs to the griseola species group. Externally, we cannot consistently distinguish this species of the others in the group and rely primarily on structures of the male terminalia to differentiate them. Females presently are unknown.