Entesia penai sp. n. (Figs 25; 26F–H; 51) Zoobank: urn:lsid:zoobank.org:act: 1F3DFF58-70A2-458C-992F-6C708238BD89 Diagnosis. Slender, tan and dark brown species; male with single row of postocular macrosetae, macrosetae absent medially on occiput; male frons wider than anterior ocellus at narrowest point; cervical sclerite with macrosetae absent; wing smoky infuscate; posterior surface of mid coxa and medial furrow of prosternum with setae absent; scutellum with one pair macrosetae; hind femoral subapical anteroventral seta present; distiphallus short and broad. Description. Body length. 7.0–8.0 mm (male), 7.5 mm (female). Head. Frons flat, pubescence brown, setae absent, male frons width at narrowest point slightly wider than anterior ocellus; male postocular macrosetae black, in a single row; occiput relatively convex in both sexes, pubescence tan-brown, macrosetae absent medially; genal setae black; antennal scape shorter than flagellum, cylindrical, dark yellow, sparsely covered with short, dark setae; flagellum brownish orange, darker distally. Thorax. Scutum pubescent brown, lighter laterally, scattered short dark setae, macrosetae black, chaetotaxy:np, 4; sa, 1; pa, 1; dc, 3–4; sc, 1; scutellum concolourous with scutum; prosternum without setae in medial furrow; cervical sclerite lacking macrosetae; pleuron tan, overlain with sparse greyish pubescence, few black setae on anepisternum and katepisternum, katatergite setae black; coxae yellow, overlain with brownish pubescence, setae mostly dark, macrosetae few in number, black, mid- and hind coxae without setae on posterior surfaces; hind leg length noticeably longer and thicker than mid- and forelegs; femora dark yellow, suffused with dark brown, lighter apically, uniform short, dark setae; hind femur with single subapical anteroventral macroseta (sometimes lacking); tibiae yellow, dark grey-brown apically; tarsi dark yellow with apices brown; wing uniform faint infuscate, darker anteriorly, venation yellow basally along major veins, darker distally, costal margin setae arranged in two rows; haltere stem pale with knob mostly brown. Abdomen. Dark brown, yellow posteriorly on tergites; female abdomen dark yellow; sternite 1 lacking medial tuft of setae; male abdomen without silver velutum on tergites, vestiture mostly dark setae, elongate laterally; abdominal tergite 2 with patch of short modified setae posteromedially; terminalia brown. Male terminalia. Epandrium sub-quadrangular, posterolateral corners angular; cerci relatively narrow and elongate; macrosetae dark on epandrium and gonocoxites; outer gonocoxite process well developed, narrow with numerous medially directed macrosetae, dense apically; inner gonocoxal process and gonostylus relatively small; phallus with dorsal apodeme of parameral sheath subtriangular; ventral apodeme broad, extending beyond dorsal apodeme; distiphallus broad, straight and short; ejaculatory apodeme narrow. Female terminalia. As per genus description. Etymology. The species epithet is named after the prolific Chilean collector and famed field entomologist, Luis Enrique Peña (1921–1995). Comments. Entesia penai sp. n. is closely related to E. lurida sp. n. and E. delicata sp. n. but can be distinguished by the dark brown body colour and pubescence and the male eyes wider than the anterior ocellus at narrowest point. Entesia penai sp. n. is known only from three localities in western Argentina. Type material— Holotype male, ARGENTINA: Neuquén Province: Estancia Mamuil Malal Lolen, 25 km N Junin de los Andes [-39.7836, -71.0345], 3.I.2006, M.E. Irwin, Malaise nr. Rio Malleo, 990 m (MACN). Paratypes. ARGENTINA: La Rioja Province: 1 female, 28 km N Chepes, Sierra de Arganaraz Higuerita [-31.1891, -66.6898], 11–16.IX.1999, M.E. Irwin, F.D. Parker, Malaise in side wash (CSCA). Neuquén Province: 3 males, same data as holotype (CASC, CSCA). Salta Province: 1 male, 8 km S Cafayate [-26.1476, -65.9549], 27.IX–1.X.2009, M.E. Irwin, Malaise in semi-stable dunes, 1650 m (CSCA).

Published as part of Winterton, Shaun L. & Irwin, Michael E., 2023, Revision of the South American stiletto fly genera Entesia Oldroyd and Melanothereva Malloch, with the description of a new genus (Therevidae: Agapophytinae), pp. 1-82 in Zootaxa 5269 (1) on pages 40-44, DOI: 10.11646/zootaxa.5269.1.1, http://zenodo.org/record/7841047