Usia manca Loew, 1846

Gibbs, David, 2014, A world revision of the bee fly tribe Usiini (Diptera, Bombyliidae) Part 2: Usia sensu stricto, Zootaxa 3799 (1), pp. 1-85 : 39-42

Usia manca Loew, 1846

( Figure 11 ; Plate VIII)

Usia manca Loew, 1846: 412 .

Usia sicula Egger, 1859: 400 , syn. nov.

Type material of Usia manca examined. LECTOTYPE here designated; Italy (Sicily), 306/ Mt. Etna/ Usia manca m/ 9684/ Coll. H. Loew/ Type / Zool. Mus. Berlin [♀ in ZMHB].

Originally described from an unspecified number of females. One syntype was found in ZHMB and is here designated as lectotype.

Type material of Usia sicula examined. LECTOTYPE here designated; Italy, [small gold circle/ small red strip]/ Sicily 1858/ Schiner 1869/ Type / sicula det. Becker [♀ in NMW] ; PARALECTOTYPE; Italy, [small gold circle/ small red strip]/ Sicily 1858/ Schiner 1869/ Type / sicula det. Becker [♀ in NMW] ; Schiner 1869/ sicula [undecipherable]/ Type / sicula det. Becker [♀ in NMW = Usia versicolor Fabricius ].

Originally described from an unspecified number of specimens. Three females found in NMW, one of which proved to be a female Usia versicolor Fabricius. Of the remaining specimens the one in best condition was chosed as the lectotype.

Other material examined. Italy, Sicily, Etna , 3km NW Milo , 1000m, 5 June 1999, ♂ ♀ ; Nébrodi, Mt. Soro , 1700m, 7 June 1999, ♀ ; Catania, Randazzo , Monte Spagnolo , 1200m, 6 June 1999, ♂ ♀ (leg. B.Merz) ( MHNG); 4♂ 1♀; Mt Etna, Monte Spagnolo, 6 June 1999, 2♀ leg. J.C.Deeming ( NMWC) ; Puglia, Forest a Umbra, 400m, 24 May 1995, 1♂ 6♀ (leg. J. Dils) ; Vieste, 450m, N41°48′8" E16°7′3″, 2 June 1999, ♂ ; Vico del Gargano, 450m, N41°52′15" E15°58′36″, 1 June 1999, 19♂ 7♀ ; Mattinata SS 89, 500m, N41°45′20" E16°4′47″, 2 June 1999, 4♂ (leg. J. Dils & J. Faes) ; Toscana, Colognole, 275m, N43°30′43" E10°25′4″, 26 May 2000, 1♂ ; Tirrenia, 0m, N43°37′18" E10°17′30″, 30 May 2000, ♀ (leg. G. van de Weyer) ; Museum Paris, Roy de Naples, O. Costa, 1-55, 1- 55, 607, sicula Egger det. Becker [2♂] ; Sicilia, Messina, 15 May 1947, Barajon [2♀] ( MNHN) ; Sicilia (PA), Bosco della Ficuzza, 865m, Pulpito del Re, N37.53174 E13.23768, ( Ferula communis ), 15 & 16 May 2004 (retino), D. Birtele, P. Cerretti, G. Nardi, D. Whitmore leg. [♂2♀] ; Sicilia (PA), Ficuzza, Valle Cerasa, UTM33 S362011 4190550, 986m, 23 June 2005, net, Legit D. Birtele, P. Cerretti, M. Lopresti, D. Whitmore [♀] ; Sicilia (PA), Bosco della Ficuzza, Cima Cucco (hill top) 995m, UTM33 S360328 4192550 ; 25 June 2005, hand net, Legit D. Birtele, P. Cerretti, M. Lopresti, D. Whitmore [♀] ; 25 June–1 July 2005, Malaise trap [8♀] ; Sicilia (PA), Parco della Madonie, Battaglietta, 1630m, UTM33 S414589 4192881, 29 June 2005, hand net, Legit D. Birtele, P. Cerretti, M. Lopresti, D. Whitmore [♀] ; Sicilia (PA), Bosco della Ficuzza, Nr. Alpe Cucco, 776m, UTM33 S360943 4193339, 23 June 2005, hand net, Legit D. Birtele, P. Cerretti, M. Lopresti, D. Whitmore [♂] ; Sicilia (PA), Bosco della Ficuzza, Torretta Torre, 950m, UTM33 S359993 4196856, 24 June 2005, hand net, Legit D. Birtele, P. Cerretti, M. Lopresti, D. Whitmore [♀] ; Sicilia (Palermo), Bosco della Ficuzza Torretta Torre, 940m, Plot Conrcofor SIC1, “Luglio–Agosto” 2005, trappola a bicchiere, A. Gatto legit, Conecofor programme – CNBF [♂] (CNBFVR).

Etymology. from Latin manca possibly means “crippled?” but it is difficult to see why such an epithet would be chosen; sicula from Sicels (Latin Siculi; Greek Σικελοί Sikeloi), a tribe who inhabited eastern Sicily during the Iron Age and gave their name to the type locality, Sicily.

Diagnosis. A small to very small shining black species but somewhat variable in size, known only from Italy. Entirely black, sometimes with gold and violet reflections, especially in females, vestiture fine and brownish, darker than similar species, the hairs erect or slightly inclined. Occiput shining, male eyes separated by the distance across lateral ocelli, rear half of frons parallel, silvery dusting coalescing in front of anterior ocellus or, in females, almost reaching level of anterior ocellus. Acrostichal setulae mostly proclinate but in some males a few of the most anterior ones reclinate. Pleurae dusted apart from shining anterodorsal third of anepisternum. Wings decidedly brown-tinged, the anal lobe very narrow, rear margin almost straight, half width of anal cell. Genitalia typical of the group differing only subtly from close congeners, most importantly in the membranous apical margin of epandrium which extends for less than half of length of sclerite.

Redescription. Measurements. Body length. 2.3–5.5mm. Wing length. 2.4–5.1mm.

Male. Head. Oral margin very narrow, almost linear, disappearing below viewed laterally, shining blackish to vaguely brown. Frons black, subshining, with conspicuous silvery dust spots laterally that extend back almost to anterior ocellus where they coalesce to occupy whole width of frons. Eyes separated at their narrowest by less than one seventh head width, equal to width across lateral ocelli inclusive. Lateral ocellus separated from the eye margin by about the diameter of that ocellus. Ocellar tubercle shining, undusted, eye margins in front of anterior ocellus parallel, then widening relatively evenly to rear of oral opening. Pale yellowish hairs on ocellar tubercle longer than the width of the frons, rear of frons in front of anterior ocellus lacking hairs laterally, anterior part of frons a scattering of setulae on the undusted area. Occiput shining black with any brownish dusting confined to occipital callosities, but even here not obscuring black ground colour, and erect pale hairs, shorter and more even above those closest to upper eye margin with procurved tips. Ommatidia uniform in size across the eyes. Antennae black, third segment about one and half times longer than scape and pedicel together, narrow and swollen basoventrally, sensilla inconspicuous, translucent pale brownish. All antennal segments with very short brown hairs above, longest just before apical sulcus. Palps very small, brown to black, apically broader than very narrow oral margin, the brown apical setae small about one-third as long as the length of the palps. Proboscis shorter than head-thorax length, black, dorsally hairless. Thorax. Mesonotum shining black, grey dusting on dorsum of post-pronotal lobe and adjacent anterior slope of mesonotum, notopleuron and above wing root. Disc relatively sparsely and distinctly punctured, many areas with smooth polished cuticle significantly wider than a puncture diameter, anterior slope of thorax and anterior part of paramedian vittae entirely impunctate. Paramedian vittae extending from anterior slope of thorax to about half way to wing insertions. Mesonotum relatively sparsely clothed with pale yellow to brownish vestiture, most hairs nearly perpendicular, those on the disc and posteriorly slightly leaning forward. Laterally the hairs are longer and are inclined towards the middle of the mesonotum. Acrostichal hairs between the bare paramedian vittae in 4–5 irregular lines, in most specimens all proclinate, occasionally a few of the anterior ones reclinate, dorsocentrals not distinguishable from the general vestiture. Scutellum shining as adjacent parts of mesonotum, erect-hairs on the disc a little lass dense than on rear of mesonotum. Pleurae entirely grey dusted except for a variable shining patch in anterodorsal corner of anepisternum which is polished black. Fairly long white hairs on pronotum and posterior and dorsal margin of the anepisternum. Wing. Membrane distinctly and uniformly brown tinged, yellower proximal to the basal cells, squama very pale yellow, the veins brown, yellower basally. Crossvein r-m at or a distinctly before the middle of discal cell, conspicuously beyond dm-cu. Anal lobe very narrow, linear, trailing edge almost straight, about half width of anal cell. Haltere. Yellow, base of stem slightly brownish. Legs. Coxae black with a coating of grey dust like that on the pleurae. Remainder of legs black, undusted, shining below the setulae. Coxae externally and femora ventrally covered with moderately long, white hairs, on the femora a little more than the greatest width of the tibia. Femora dorsally and tibia rather densely covered with short, recumbent, white hairs. Abdomen. All tergites shining black undusted, each densely punctorugose, the punctures connected by transverse groves, a very narrow shining apical margin. Disc uniformly and densely covered with relatively dark brownish, recumbent hairs, longer paler and more erect laterally. Sternites grey dusted basally, more shining apically, faintly punctate, with fairly long, erect white hairs. Genitalia. Relatively large for this species group, simple, globular. Epandrium tapering, with apicolateral extensions short and rounded, apical margin with a median ‘V’-notch extending less than half length of epandrium, shining black, the cuticle punctate evenly coated with pale brown erect hairs. Gonocoxite about twice as broad as long, shining, uniform black, haired as epandrium, gonostyli simple, curved with basal ‘thumb’.

Female. As male except as follows: frons wider, about one-sixth head width, wider than width across lateral ocelli and diverging more evenly, not parallel in hind half. Dusting of frons extending back almost to anterior ocellus but not coalescing, a few short setulae close to eye margins forward of anterior ocellus. Oral margin a little wider, especially medially. Acrostichals almost always entirely proclinate, even the foremost. Wings slightly less intensely infuscated, especially marginally, anal lobe broader, trailing edge relatively evenly rounded, just a little narrower than anal cell. Genitalia. Tip of abdomen coming to a rounded point; apical sternite almost rectangular, a little wider than long, with a small apical notch, in undissected specimens it can be seen to be apically silvery dusted. Furca typical of the group, with narrowly rounded tip and fairly long arms, conspicuous dark-pigmented rectangular vaginal plate.

Discussion. This small Italian endemic is a sibling species of Usia putilla Becker of France and Spain but with a slightly wider frons and a much narrower anal lobe. It is also very close to Usia annetteae Gibbs of the Middle East which has an even broader frons and anal lobe than both.

The type specimen of Usia manca Loew in ZMHB and the two types of U. sicula Egger in NMW are all female; a third female syntype in NMW labelled as a type of U. sicula proved to be an example of U. versicolor Fabricius. The most important characters of the male frons, wings and genitalia were not available to Becker (1906b) who retained these two as separate species. He seemed to have had non-type material of both available to him when he described the male of U. sicula and listed a female U. manca from “Transkaspien” in Loew’s collection. Unfortunately, these specimens were not discovered during this study, but if the locality was accurate, they were very likely examples of U. annetteae . If so then Becker’s conclusion that there are two species involved was correct. There are now numerous specimens available from Sicily and mainland Italy and it is quite clear that there is only one species of Usia belonging to the lata species group present in this geographical region. The single U. manca type and two U. sicula types are essentially identical, the differences mentioned in Becker (1906b) such as the position of crossvein r-m and colour of wing membrane are variable and of no use in species diagnoses.

Distribution. Southern Italy (including Sicily) north at least to Tirrenia.

Figures

FIGURE 11. ♂ U. manca wing.