Entesia tessera, Winterton & Irwin, 2023

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), Zootaxa 5269 (1), pp. 1-82 : 53-57

Entesia tessera sp. n.

( Figs 34–36 ; 37C–E ; 51 )

Zoobank: urn:lsid:zoobank.org:act:5B692AB9-7CB8-4B5F-A6D3-6A54B9F38CF4

Diagnosis. Small, glaucous species with frontal calli; wing mottled; male with postocular and occipital macrosetae irregularly arranged; male frons as wide as ocellar tubercle; glossy frontal and parafacial calli in female, barely evident in male; cervical sclerite with macrosetae absent; posterior surface of mid coxa with setae absent; medial furrow of prosternum with setae present; scutellum with one pair of macrosetae; hind femoral subapical anteroventral seta present.

Description. Body length. 6.5–7.5 mm (male), 6.5–7.5 mm (female). Head. Relatively broad; frontal pubescence light brown dorsally, silver ventrally, frons flat, female with pair of domed calli above antennae and second pair on parafacial (female), male with frontal markings as a pair brown spots, glabrous concentrically, spots on parafacial barely evident, male frontal vestiture absent, female with a few minute setae lateral of ocellar tubercle, male frons width at narrowest point equal to ocellar tubercle; both sexes with postocular setae as single row of elongate black setae, strongly curved anteriorly, additional white macrosetae on occiput, occiput relatively convex, pubescent grey, occiput with scattered white setae; genal setae white, male admixed with dark setae extending onto lower part of parafacial; antennae much shorter than head, scape slightly thickened, cylindrical, dark yellow, overlain with grey pubescence admixed with large, dark setae; flagellum brown. Thorax. Scutum grey with broken, dark brown vittae, medial vitta narrow anteriorly, interrupted vittae laterally, scattered dark setae, denser anteriorly, macrosetae black, chaetotaxy: np, 3–4; sa, 1; pa, 1; dc, 6–7; sc, 1; scutellum concolourous with scutum; prosternum with setae in medial furrow; lateral lobe of cervical sclerite without macrosetae; pleuron with dense silver-grey pubescence, white setae on anepisternum, katepisternum and katatergite, anepisternum with brownish suffusion dorsally; coxae yellow, overlain with silver-grey pubescence, coxal setae white, macrosetae black (male) or yellow (female), mid- and hind coxae without setae on posterior surfaces; hind leg subequal in length to mid- and forelegs; femora uniform yellow (female) or dark grey-brown with apices yellow (male), covered with short, dark setae admixed with longer pale setae, hind femur with single subapical anteroventral macroseta; tibiae yellow, dark grey-brown apically; tarsi dark yellow or brown, wing starkly mottled infuscate, fenestrate in some cells in male, venation dark, costal margin setae arranged in two rows (irregularly); haltere brown. Abdomen. Sternite 1 lacking medial tuft of setae; abdomen glaucous grey pubescent, brown area laterally on all tergites, pale elongate setae, darker on posterior segments and terminalia, longer in male; abdominal tergite 2 with setae of uniform length, unmodified; male abdomen without silver velutum on tergites; terminalia brown. Male terminalia. Epandrium elongate, narrowed posteriorly; cerci round; macrosetae dark on epandrium and gonocoxites; outer gonocoxite process brown, small, narrow; phallus with dorsal apodeme of parameral sheath narrowly forked; distiphallus straight and narrow; ejaculatory apodeme narrow; gonocoxal apodemes relatively elongate. Female terminalia. As per genus description.

Etymology. The species epithet is derived from the Greek, tessares —four; referring to the four glabrous areas on the female head.

Comments. Entesia tessera sp. n. is a highly distinctive, yet diminutive species with mottled wings and glossy calli on the frons of the female; all other species have an entirely pubescent frons in both sexes. All legs are relatively short in this species. It is known from two localities in southern Argentina.

Type material— Holotype male, ARGENTINA: Chubut Province: Arroyo Rio Verde , 12 km S Alto Río Senguer [-45.0993, -70.7507], 710 m, 20.XI.1966, E.I. Schlinger, M.E. Irwin (MEI153964; MACN) . Paratypes. ARGENTINA: Santa Cruz Province: 3 males, 2 females, 5.6 km E Los Antiguos [-46.5698, -71.5703], 360 m, 23.XI.1966, E.I. Schlinger, M.E. Irwin (MEI153960–1, 153972, 153978–9; CSCA) .

Figures

FIGURE 34. Entesia tessera sp. n.: A. Male, oblique view; B. same, lateral view (Scale line: 1.0 mm).

FIGURE 35. Entesia tessera sp. n.: A. Female, oblique view; B. same, lateral view (Scale line: 1.0 mm).

FIGURE 36. Entesia tessera sp. n.: A. Male head, anterolateral view; B. female head, oblique view.

FIGURE 37. Entesia spp., male terminalia: E. rubidaster sp. n.: A. epandrium; B. gonocoxites with phallus in situ, ventral view; E. tessera sp. n.: C. epandrium; D. gonocoxites with phallus in situ, ventral view; E. sternite 8.

FIGURE 51. Distribution map of Entesia penai, E. notabilis, E. tessera and E. pallidiventroides.