Usia hyalipennis Macquart, 1840

Gibbs, David, 2011, 2960, Zootaxa 2960, pp. 1-77 : 50-53

Usia hyalipennis Macquart, 1840

(Plate XIII)

Usia hyalipennis Macquart, 1840: 106 . Stat. rev.

Type material examined. LECTOTYPE (Evenhuis & Greathead 1999: 671): Algeria, Museum Paris, Env. D’Alger, Bové 126-38/ 126, 38 [on reverse of round blue label]/ U. hyalipennis Macquart det. [in Macquart’s own hand ( Fig. 24)][♀ pinned through base of abdomen, in good condition, in Macquart coll. MNHN]. PARALECTO- TYPE: Algeria, Museum Paris, Env. D’Alger, Bové 126-38/ 126, 38 [on reverse of round blue label]/ Usia hyalipennis ( Fig. 25). [♀ pinned through dorsum of thorax, in good condition but left hind tarsus, right mid-leg, right hind-tibia and part of proboscis missing, in Macquart coll. MNHN]

Other material examined. Algeria, near Algiers 28 April 1893 leg. A.E. Eaton / “near Algiers, on the slopes of Bowyarea , to the left of the quarries” (note by donor)[♂ in BMNH]; Museum Paris, Algérie, Eolough, Museum Paris, Bleuse1899 [♀ in MNHN]; Teniet-el-Haad, Juin 1893, Dr. Chobaut [♀ in MNHN]; Fila-fila, Algérie, A. Thery [♀ in MNHN] ; Tunisia, Tabarka, Cap Negro , 15 May 1995, leg. J.C. Deeming [♂ in NMWC] .

Etymology. The name derives from the Latin “ hyalus = glass and penna = wing”, alluding to transparent wings, although this species is no more clear-winged than many others.

Diagnosis. A medium sized to relatively large, all black Micrusia with mid-length hair and strikingly matt mesonotum. Mid and hind-femora with some hairs as long as depth of femur, scutellum with marginal hairs about half mid-length of scutellum, hairs on ocellar triangle about as long as narrowest width of frons and mesonotum strongly shagreened and matt, much more so than any other species sharing the other features. Male with elongate epandrium protruding at 45º below tip of abdomen, female most readily identified by mesonotal surface sculpture. PLATE XIII. Usia hyalipennis Macquart, 1840 ; a epiphallic complex ventral, b epiphallic complex lateral, c gonocoxite ventral, d gonocoxite lateral, e epandrium dorsal, f epandrium lateral, g female genitalia ventral, h female sternite 8 ventral.

Redescription. Measurements. Body length. 3.3–5.0mm Wing length. 2.7–4.1mm.

Male. A medium size to relatively large, all black Micrusia with mid-length hair and strikingly matt mesonotum. Head. Frons relatively broad, about a fifth head width, at narrowest point no wider than the length of the third antennal segment, rather matt laterally, more shining centrally. Front of frons laterally with discrete pale grey, linear dust spots, each occupying about one sixth of the width of frons at this point. Mouth margin very narrow, shining almost disappearing below, above near antennae widening, grey-dusted. Ocellar triangle obtuse, lateral ocelli separated from the eye by their diameter or a little less. Hairs on ocellar tubercle relatively long, almost as long as width of frons at narrowest point. Occiput covered with grey dust obscuring ground colour except on shining triangular area behind vertex and a narrow band behind upper third of eyes. Black hairs on occiput relatively long above a little longer than half length of longest hairs of vertex, longer below, even longer than those on vertex. Antennae black, relatively long, third segment quite elongate and parallel sided, about twice as long as scape and pedicel combined. Very short dark setae on dorsum of all segments, a few longer ones immediately before apical sulcus. Proboscis black, naked, about as long as mesonotum and scutellum combined. Palps very small, black, clavate with long, dark apical setae, longer than the palps. Thorax. Entirely black, mesonotum with a rough, shagreened surface texture completely effacing points of hair insertions, surface sculpture oblique-striated along paramedian lines making them distinct from certain angles. Light grey-dusted on pronotum, inner part of postpronotal lobe and a small triangular patch between thoracic suture and wing base. Mesonotum with mid-length, fairly abundant black hairs, acrostichals irregularly bi- to triserial, paramedian lines bare, laterally hairs generally distributed, the longest hairs, on notopleuron and front of mesonotum, about as long as depth of front femora, those on disc half this length, posteriorly proclinate. Scutellum matt like mesonotum, surface strongly roughened, disc with scattered short hairs, hind margin with irregular fringe of black hairs, longest about half the length of the scutellum. Pleura black, predominantly grey-dusted but with anepimeron shining centrally and katepisternum undusted in lower half. Upper and hind part of anepisternum with longish black hairs. Wing. Clear, very slightly yellow tinged basally, the veins pale brown, costa and stem vein blackish basally. Anal lobe convex, about as wide as or a little narrower than anal cell. Haltere. Yellow knob, stem slightly infuscated basally. Legs. Black, front and mid-coxae grey-dusted anteriorly, hind-coxae uniformly dusted, all with fairly long black hairs, particularly on fore-coxae. Rest of legs shining but with rough texture to cuticle, femora with short but erect hairs, those beneath the femora include some which just exceed the median width of the tibia. Hairs on tibia and tarsi very short and adpressed. Abdomen. Black with very broad tergites, surface sculpture stellate with radiating ridges from each hair insertion. Disc of tergites covered with short black hairs, laterally, the hairs as long as the depth of the hind femora apically. Tergite 1 grey-dusted on reflexed margin, tergites two to three much more thinly dusted. Sternites densely grey-dusted with long black marginal hairs, hairs more extensive on sternite 1. Genitalia. Elongate and prominent protruding at 45º below tip of abdomen. Epandrium strongly tapering with rounded apicolateral extensions, gently convex, smooth but some wrinkling basally, shining and shallowly grooved basolaterally. Covered with very short inconspicuous scattered dark setae. Gonocoxite flattened cuticle wrinkled but with two shining concavities just above middle, basally with erect mid-length hairs, medially with much shorter reclinate setae.

Female. Very similar to male, frons very slightly broader, about one-fourth the head width. Mesonotal and abdominal hairs in general shorter. Apical sternite oblong, moderately embossed basally, tufts of black hairs laterally, slightly more translucent apicomedially and with conspicuous apical notch.

Discussion. A distinctive species, probably with affinities with U. novakii and the shorter haired U. pusilla and U. susanae . The male genitalia are particularly reminiscent of those of U. susanae and many specimens of U. hyalipennis have been misidentified as U. pusilla .

Both of the Macquart specimens are females, however it is difficult to see why this species was synonymised under U. versicolor if the type specimens had been examined. The smooth and dusted mesonotum of female U. versicolor is quite different to the roughened, matt mesonotal disc of U. hyalipennis Macquart. Although males collected in association with females have not come to my notice, this is such a distinctive species that the males described above are quite evidently conspecific with the type females.

Distribution. Algeria, Tunisia. Only known from seven widely scattered localities along the north coast of Algeria and Tunisia. All but the two types have been collected as singletons so this would appear to be rather a scarce species.