Revision of the South American stiletto fly genera Entesia Oldroyd and Melanothereva Malloch, with the description of a new genus (Therevidae: Agapophytinae) Author Winterton, Shaun L. 0000-0001-8995-0907 Author Irwin, Michael E. 0000-0001-8995-0907 wintertonshaun@gmail.com text Zootaxa 2023 2023-04-18 5269 1 1 82 http://dx.doi.org/10.11646/zootaxa.5269.1.1 journal article 250756 10.11646/zootaxa.5269.1.1 534416d1-dc29-4214-af33-41db3aa3d0e6 1175-5326 7841047 FE9E6180-3AC3-4CC3-9F09-F279EBC37692 Entesia guttata sp. n. ( Figs 10–12G, H ; 50 ) Zoobank: urn:lsid:zoobank.org:act: 627C01EE-8AE0-48EE-BD77-132B07A80A15 Diagnosis . Slender species with yellow and grey pubescence with opaque white wings with brown speckling; scutum with a pronounced dome shape; male with macrosetae irregularly arranged on postocular ridge and occiput; male frons wider than anterior ocellus but narrower than ocellar tubercle; tibial and tarsal macrosetae and claws relatively elongate and narrow; posterior surface of mid coxa and medial furrow of prosternum lacking setae; scutellum with one pair macrosetae; hind femoral subapical seta present. Description . Body length . 7.0– 8.6 mm (male), 7.4–8.5 mm (female). Head . Relatively small; frons rounded, pubescence grey ventrally, brown dorsally with dark band midway, male frontal vestiture absent, female with very few sparse short setae, male frons at narrowest point slightly wider than anterior ocellus; male occiput relatively convex, single row of postocular macrosetae, additional macrosetae irregularly arranged medially on occiput, macrosetae black along ridge, pale on occiput, occiput pubescence greyish silver, brownish dorsally; genal setae dark; antennal scape shorter than flagellum, cylindrical, black with grey pubescence admixed with a few small pale macrosetae; flagellum orange-yellow, style dark. Thorax . Scutum with a pronounced dome shape; male scutum yellow orange with grey pubescence, faint silver-grey dorsocentral vittae and dark brown medial vitta (narrowed posteriorly); female scutum dark brown, grey dorsocentral vittae and laterally, both sexes with sparse, short, dark setae; scutal macrosetae black, chaetotaxy: np, 4; sa, 1; pa, 1; dc, 4–6; sc 1; scutellum brownish orange, dark brown anteromedially, grey pubescent marginally; prosternum without setae in medial furrow; pleuron with grey pubescence suffused with orange, white setae on anepisternum and katepisternum, katatergite, anepisternum with brownish suffusion dorsally; lateral lobe of cervical sclerite lacking macrosetae; coxae yellow, overlain with silvergrey pubescence, coxal setae mostly pale, macrosetae few in number, mid- and hind coxae without setae on posterior surfaces; femora dark yellow, suffused with dark brown (darker in male), lighter apically, extensive short pale setae, hind femur with single subapical anteroventral macroseta; tibiae and tarsi dark yellow with macrosetae and claws elongate, pulvilli relatively small; wing opaque white with irregular brown speckled infuscation, venation yellow, darker distally and on cross-veins, costal margin setae arranged in two rows; haltere stem yellow, knob white. Abdomen . Sternite 1 lacking medial tuft of setae, male abdomen without silver velutum on tergites, abdomen of both sexes dark yellow, suffused with grey laterally, vestiture mostly elongate pale setae, denser laterally (uniformly short in female); tergite 2 with setae of uniform length, unmodified; terminalia concolourous with rest of abdomen. Male terminalia . Epandrium sub-quadrangular, angular anteriorly; macrosetae pale on epandrium and gonocoxites; outer gonocoxite process relatively elongate, subtriangular; phallus with dorsal apodeme of parameral sheath subtriangular; ejaculatory apodeme narrow. Female terminalia . As per genus description. Etymology . The species epithet is an adjective derived from the Latin, guttatus —dappled, speckled, spotted; referring to the distinctive speckling on the wing. FIGURE 10 . Entesia guttata sp. n. : A. Male, oblique view; B. same, lateral view (Scale line: 1.0 mm). FIGURE 11 . Entesia guttata sp. n. : A. Female, oblique view; B. same, lateral view (Scale line: 1.0 mm). Comments . This species is similar to E. dolichochele sp. n. and shares characteristics such as opaque white wings with brown speckling and elongate tibial and tarsal macrosetae and claws. It is likely also associated with sandy habitats. Type material— Holotype male, ARGENTINA : Chubut Province : 24 km W Sarmiento , 310 m [ -45.5361 , -69.2936 ], 21–31.XII.2005 , M.E. Irwin , Malaise in small dry wash ( MACN ) . Paratypes . ARGENTINA : Chubut Province : 8 males , 1 female , same data as holotype ( MACN , CSCA ) .