Amalopteryx Eaton, 1875

Costa, Daniel N. R., Mathis, Wayne N., Marinoni, Luciane & Sepúlveda, Tatiana A., 2024, Phylogeny and taxonomy of the shore-fly tribe Scatellini (Diptera: Ephydridae: Ephydrinae), Zoologia (e 23100) 41, pp. 1-35 : 10-13

Amalopteryx Eaton, 1875

Amalopteryx Eaton 1875: 58 (feminine). Type species: Amalopteryx maritima Eaton 1875 , monotypy. – Papp 1979: 360–361 [revision]. – Mathis and Zatwarnicki 1995: 254–255 [world catalog].

Diagnosis. Specimens of Amalopteryx are distinguished from other genera of Scatellini by the following combination of characters: Moderately large shore flies, body length: 3.25 mm; dark brown to dark gray species. Stenopterous wing; frontal vitta invested with microtomentum; eye conspicuously wider than high, usually obliquely oriented; length of sclerite 2 of labellum longer than width of labellum, overlapping prementum; posterior notopleural seta insert- ed distinctly elevated above level of anterior seta; arms of gonal arch fused; and gonal arch and phallapodeme fused.

Description. Medium-sized shore flies, body length 3.24 mm; dark brown species.

Head: Frontal vitta generally dull, densely microtomentose. Lateroclinate fronto-orbital setae 2. Antenna short, concolorous with head; basal flagellomere slightly inflated, brown; arista macropubescent. Face conspicuously protruding; interfoveal dorsal hump of face at half the height of head; facial setae conspicuous, 1–2 lateral facial setae curved laterodorsally; long ventroclinate setae along oral margin; eye nearly round, slightly wider than high. Genal height medium to high (gena to eye ratio 0.43), a row of setulae at the ventral margin of gena, without a distinct genal seta.

Thorax: Mesonotum dull, densely microtomentose; small setulae towards anterior margin of mesonotum; dorsocentral setae 3 (1+2); a row of small acrostichal setae extending to scutellum, without a longer prescutellar acrostichal setae; intrapostalar setae relatively long, half-length of postalar seta; basal scutellar setae conspicuously smaller than apical setae; posterior notopleural setae distinctly elevated above level of anterior seta; postsutural supra-alar setae small, shorter than postalar seta. Wing length 2.56 mm, width 0.30 mm, stenopterous in only known species, generally infuscate. Legs typical, usually without distinct setae, concolorous with thorax; tarsi most brown; tarsal claws conspicuously curved and puvilli present below each claw.

Abdomen: Tergites gray to brown, microtomentose; small and scattered dorsal setae. Male Terminalia: sternite 5 present, sternite 6 absent. Epandrium as a plate roughly ellipsoid, with a narrow opening below the cerci in posterior view; surstyli absent or fused indistinguishably with ventral margin of epandrium; gonites distinctly Y-shaped, dorsal arms sharply terminated, without setae; phallapodeme dorsoventrally flattened, with 2 lateral projections, rod-like, lacking a keel; ejaculatory apodeme lacking. Aedeagus shoe-shaped in lateral view, short and without a distiphallus. Female Terminalia: sternite 8 divided into 2 lateral, lunate sclerites; female cerci with a long, slender setae inserted posteroventrally. Female ventral receptacle apparently absent.

Distribution. Afrotropical (Sub-Antarctic Islands: Crozet Islands, Heard Island, Kerguelen Island, McDonald Island).

Remarks. Amalopteryx is a monotypic genus, and the only included species, A. maritima , has stenopterous wings. Like Lamproscatella and Haloscatella , this genus has a row of genal setulae but lacks a distinctive genal seta. Structures of the male terminalia are similar to those of Scatophila .

Amalopteryx maritima is a saprophagous and microphagous species. Womerseley (1937) described the immature stages of this species.