Usia susanae Gibbs, 2011

Gibbs, David, 2011, 2960, Zootaxa 2960, pp. 1-77 : 63-65

Usia susanae Gibbs sp. nov.

( Fig. 22, Plate XVIII)

Usia pusilla: Engel, 1932: 77 , Textfig. 35, misidentification.

Type material examined. HOLOTYPE: Spain, Andalusia, Cortija del Alcazar , 990–1200m, N36º55'15" W4º5'18" 4.vi.2006, leg. D.J. Gibbs [♂ in NMWC] . PARATYPES: Spain, La Cuenca Alta, La Pedriz, NW of Manzanares el Real, 1520m 10 June 1995 / Espana, Prov. Madrid, J.P. Duffels [♂ head missing, ♀ in PCJD]; 31 May 2000, Torres de la Alameda (M), Malaise, A. Bari leg. [5♂ 3♀ in spirit PCMC-T]; Salamanca , Las Coronas , Viller de Ciervo , 23–25 May 1999 / yellow pan trap (SA) leg. P. Tschorsnig, [2♂ 1♀ in BMNH]; Andalusia, Cortija del Alcazar , 990–1200m, N36º55'15" W4º5'18" 4.vi.2006 [♀ in NMWC, ♀ in BMNH, ♀ in OUM, 10♂ 7♀ in PCDG]; 9 vi.2006 [♀ in NMWC, 2♂ 2♀ in PCDG]; Mirador de las Vibodes, 1527m N37º8'23" W3º27'23" 6 June 2006, leg. D.J. Gibbs [1♀ in PCDG]; Roman Br. Fondales, N 36˚55'20" W3˚19'10" 920m 8 June 2008 leg. D.J. Gibbs [♂ in NMWC, 2♂ 1♀ in PCDG]; W of Capilerilla N36˚56'21" W3˚20'26" 1480m 7 June 2008 leg. D.J. Gibbs [♀ in NMWC, 3♂ 2♀ in PCDG]; 11 June 2008 [♂ in PCDG]; 14 June 2008 [1♂ in PCDG]; above Portugos, N 36˚56'55" W3˚19'14" 1500m 9 June 2008 leg. D.J.Gibbs [2♂ in PCDG]; nr. Haza del Cerezo , N36˚57'34" W3˚19'44", 11 June 2008 1860m, leg. D.J. Gibbs [1♀ in PCDG]; Hispania / Moucavo, Veruela 600m, 27 June 1979, Osella [1♂ 1♀ in CNBFVR]; Prov. Granada, Sierra de Alfacar , 1500m, 19 June 1968 / Hispania mer., K. Sattler & D.J. Carter, B.M. 1968-363 [♀ in BMNH]; Sierra de las Nieves, Rhonda, 21 May [20]05/ Usia sp. , A. Sánchez Terrón det/ M.N.C.N, Madrid [♀ in MNCN]; Salamanca, 17 June [19]30, Dumest / Usia pusilla Now. / Usia pusilla ♂ Meig /. M.N.C.N, Madrid [♂ in MNCN] .

Other material examined. (probably this species but excluded from type series)

Spain, 1411, Museum Paris, Madrid, coll. Dufour, Usia pusilla [♀ in MNHN]; Museum Paris, Espagne , Penarroya, A. Seyrig 1923-24; 16 June [19]95, Albaracin , Teruel 1100m, Leg. T.W. Tolman / [♀ MNHN]; San Rafael, C. Bolivar/ M.N.C.N, Madrid [♀ in MNCN] .

Etymology. Named after Susan Miles, who accompanied me on many field trips and tolerated me frequently being distracted by bee flies.

Diagnosis. A small black short-haired Iberian endemic, very similar to U. pusilla . Hind femora with short, adpressed hairs, marginal hairs of scutellum about half mid-length of scutellum, hairs on ocellar triangle short, about as long as distance between lateral ocelli. From the very similar U. pusilla by narrower mouth-margin (in respective sexes) and usually smoother, more shiny mesonotum. Male readily identified by larger, elongate genitalia, especially epandrium, gonocoxite rather flat and gonostyli inserted sub-apically. Female genitalia and apical sternite very similar to U. pusilla , females sometimes not reliably identifiable, even with dissection (Plate XVIII).

PLATE XVIII. Usia susanae Gibbs , sp. nov.; a epiphallic complex ventral, b epiphallic complex lateral, c gonocoxite ventral, d gonocoxite lateral, e epandrium dorsal, f female genitalia ventral, g female sternite 8 ventral.

Description. Measurements. Body length. 2–6mm Wing length. 2.4–4.7mm.

Male. Head. Frons relatively narrow, about a fifth head width, at narrowest point about as wide as length of third antennal segment, rather matt with poorly defined narrow stripes of whitish dust on anterolateral corners. Frons widens towards front relatively evenly, discontinuity of the eye margin medially a little more distinct than in U. pusilla . Mouth margin very narrow hardly visible, decidedly narrower than in U. pusilla . Ocellar triangle equilateral, lateral ocelli separated from the eye by their diameter or a little less. Longest hairs on ocellar tubercle very short, shorter than distance between lateral ocelli and appreciably shorter than in U. pusilla . Occiput covered with grey dust, including area behind vertex which is slightly more shining, and relatively short black hairs, shorter above, longer below. Antennae black, relatively long, third segment elongate, about twice as long as scape and pedicel combined, straight dorsally, convex ventrally at base, blunt ended, a few short setae dorsally, especially just before sulcus. Proboscis black, naked, about as long as mesonotum and scutellum. Palps small, clavate, black with distinct apical setae. Thorax. Entirely black, mesonotum subshining, surface sculpture roughened and wrinkled but not as matt as in U. pusilla , hair insertions more distinct than in U. pusilla . Lightly pale dusted on pronotum, notopleuron and above wing. Hairs short, on disc of mesonotum similar to those on vertex, acrostichal line wide bi- (in small specimens) to irregularly quadriserial or more (in large specimens), paramedian lines bare back to level of wing base, usually more transversely striate than mid-line, laterally hairs evenly distributed becoming longer on notopleuron. Scutellum subshining, rough-textured like mesonotum, disc sparsely haired, marginal hairs very short, hardly a third the length of the scutellum. Pleurae black, predominantly covered in grey dust, anepisternum often with a shining strip around dorsal half of margin, anepimeron with small central shining patch and katepisternum ventrally dust-free. Anepisternum with dark hairs similar to those on mesonotum in upper half and posterior margin. Wing. Clear to vaguely tinged brownish yellow, veins pale brown, decidedly more yellow basally. Anal lobe convex, as wide as anal cell. Haltere. Yellow knob, stem infuscated. Legs. Black, coxae dusted on anterior face, otherwise shining but with rough texture to cuticle, with very short, adpressed dark hairs, front and mid-femora ventrally practically bare. Hairs shorter and denser on tibia. Abdomen. Black, compact with broad tergites, surface sculpture of transverse welts at hair insertions, covered with relatively short black hairs. Only tergite 1 with any grey dust, this restricted to reflexed margin. Sternites grey-dusted with black hairs along posterior margins. Genitalia. Fairly large and noticeably more elongated than in U. pusilla , positioned under the tip of the abdomen. Epandrium flask-shaped, broadly rounded apicolateral projections that, in dry specimen, wrap around the cerci and tip of gonocoxite. Epandrium rather evenly covered with short, dark hairs, shining, undusted. Gonocoxite with longer hairs, lobed basally, in lateral view much flatter than in U. pusilla . Gonostyli placed subapically, relatively simple, sharp tipped.

Female. Very similar to male, frons marginally wider diverging more evenly. Mouth margin very narrow, linear, hardly differing from male and clearly narrower than in U. pusilla . Hairs generally slightly shorter, especially on tergites. Abdominal dusting often also extending on to tergite 2 laterally. Sternite eight broadest basally, oblong, quite clearly embossed in basal half. In dry specimen apical half with short fold where sclerite membranous, this often with covering of grey dust. When macerated no significant translucent patches, a distinct apical notch. Furca pointed.

Discussion. Forms a sibling pair with the sympatric U. pusilla , the two often occurring together, even in the same flowers. Also probably has affinities with U. novakii and U. hyalipennis that have similar epiphallus.

Distribution. Spain. A rather frequent species in Andalusia, less frequent north to the Pyrenees, nearly always found together with U. pusilla and on current evidence usually the more abundant of the two. Records of U. pusilla from Portugal are as likely to be this species.