Usia dilsi Gibbs 2011, sp. nov.
Creators: name: Gibbs, David
Publisher: name: Zenodo
Year: 2011
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Diptera
Bombyliidae
Usia
Usia dilsi

description: Usia dilsi Gibbs sp. nov.   
(Plate VII)  
 Type material examined. HOLOTYPE: Morocco, 6 April 2008, Tetouan 140m, El-Biutz, N35º53'44.1" W5º28'4.2" leg. Dils J. Faes J. [♂ in NMWC]. PARATYPE: Morocco, 6 April 2008, Tetouan 140m, El-Biutz, N35º53'44.1" W5º28'4.2" leg. Dils J. Faes J. [♀ in NMWC, 11♂ 8♀ in PCJD]; 19 April 2006 Al Hoceima, Had Aouadi 285m, N35º08'23.7" W4º01'05.7", leg. Dils J. Faes J. [♀ in NMWC, 7♂ 11♀ in PCJD]; Museum Paris, Maroc, Rabat, R, Benoist 1928 / 5 May 1928 [♀ in MNHN]; Museum Paris, Env. De Tanger, G. Buchet 1901 [♀ in MNHN]; 5 March 2009, Taourirt 370m, Taourirt (Comanav), N34º24'35.4" W2º57'19.3", Leg. Dils J. Faes J. [3♂ 3♀ in PCJD].   
 Etymology. Named after Jos Dils who collected the holotype and all but two of the paratypes and contributed enormously to this revision by making his specimens freely available.   
 PLATE VII. Usia dilsi Gibbs sp.n.; 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.   
 Diagnosis. A small shining black species only known from Morocco, relatively long-haired and undusted, superficially similar to U. echinus. Long hairs ventrally on hind and mid femora, marginal scutellar hairs as long as median length of scutellum, anepisternum usually dusted, at least in part. Male with large genitalia, epandrium with tapering, triangular elongations apically that usually fold round cerci apically. Female not reliably identifiable without examination of genitalia (Plate VII).   
 Description. Measurements . Body length. 2.4–3.7mm Wing length. 2.3–4.0mm.   
 Male. Head. Frons relatively narrow, about a sixth head width, at narrowest point decidedly narrower than length of third antennal segment, parallel sided for hind three fifths, widening slightly in front. Rather matt, finely shagreened, shinier close to ocelli with very narrow, linear grey dust spots anterolaterally. Mouth margin very narrow, shining, linear almost absent. Ocellar tubercle shining, ocelli equilateral, lateral ocelli separated from the eye by half their diameter. Longest hairs on ocellar tubercle about as long as depth of hind femora, significantly longer than width across vertex at lateral ocelli. Occiput covered with grey dust obscuring ground colour, this dusting a noticeably thinner on triangular area behind vertex. Black hairs on occiput short above, much longer below, those on ventral side of head at least as long as those on ocellar tubercle. Antennae black, relatively elongate, third segment rather variable but usually elongate, straight dorsally before sulcus, undulating ventrally with convex base and slightly constricted subapically, about twice as long as scape and pedicel combined. A few very short dark setae on dorsum of third antennal segment immediately before apical sulcus, sensilla brown. Proboscis black, naked, about as long as mesonotum. Palps very small, black to brown, sub-clavate with a tuft of apical setae as long as the palp. Thorax. Entirely black, mesonotum shining and mostly smooth to inconspicuously wrinkled with hair insertions not obvious, a shagreened, more matt patch in front of scutellum. Very lightly grey dusted on pronotum, dorsal margin of postpronotal lobe, notopleuron close to suture and obscurely above wing base. Mesonotum with long, perpendicular black hairs as long as those on ocellar tubercle, acrostichals irregularly biserial, paramedian lines bare but not differing in surface texture, extending back to above wing bases, laterally hairs generally distributed, lateral hairs the longest. Scutellum sub-shining, surface somewhat matt, obscurely transversely wrinkled, disc with scattered long black hairs, hind margin with a very irregular row of longer, black hairs longer than scutellum is long, angled up at about 45º. Pleura black, relatively lightly grey dusted on lower central part of anepisternum which is broadly shining laterally and dorsally, anepimeron except shining central spot and katepisternum on dorsal third, meron mostly dusted. Dorsal half of anepisternum with dark hairs shorter than those on notopleuron. Wing. Clear to tinged brownish, the veins brownish yellow. Anal lobe convex, slightly but distinctly narrower than anal cell. Haltere. Yellowish knob, stem slightly infuscated basally. Legs. Black, shining but with rough texture to cuticle, with mid-length semi-erect hairs dorsally, fore and mid femora with conspicuously long antero- and posteroventral hairs, those on mid-femora longer than femora is deep, hind-femora with widely spaced, uniserial line of long, erect black anteroventral hairs, the longest clearly longer than the depth of the femora. The long hairs on the hind-femora seem to be fragile and in some specimens can be few or missing. Abdomen. Black, short with very broad tergites, surface sculpture of transverse wrinkles, hair insertions not easily seen. Disc of tergites covered with mid-length, dense black hairs, much longer hairs laterally and apically. Sternites grey dusted with long black hairs along apical margins. Genitalia. Large, globular, almost as large as the remainder of the abdomen, length of epandrium clearly exceeding length of sternites. Epandrium apically with triangular elongations that curl around the cerci their tips often overlapping, densely haired on disc, shining and almost bare laterally. Gonocoxite basally bilobed with long erect black hairs, a distinctly denser tuft of hairs where it curves inward (these hairs perpendicular differing from the proximally directed hairs at this location in U. echinus, view laterally). Gonostyli usually obscured by enclosing epandrium but relatively simple, elbowed and pointed. Tip of epiphallus bifurcated into two pointed lobes between which as a pad of spines.   
 Female. Very similar to the male. The frons of the female is noticeably broader than in males, between a fifth and a quarter head width, more evenly divergent anteriorly, lateral ocelli separated from eye margin by about the diameter of each ocellus and ocellar triangle more obtuse. The mouth margin is a little broader such that it is quite visible. Vestiture generally shorter, most conspicuously so on the discs of the tergites. Anal lobe averages wider. Apical sternite rather trapezoidal, base formed into a raised transverse ridge dulled with silvery dust, long black hairs laterally. In dry specimens the unsclerotised apical patch forms a grey-dusted longitudinal ridge. When macerated apical processes are distinctly separated from apical sternite by a translucent area, apical notch very shallow.   
 Discussion. Superficially very similar to the much more widespread but apparently allopatric U. echinus, and indeed likely to be closely related to this species. The epiphallus also shows some similarity to that of U. ignorata but the apical spines are positioned quite differently so I suspect this is convergence.   
 Distribution. Morocco. So far only known from the lowlands and hills of north Morocco south to Rabat. Within this very restricted range known from just five localities so seems to be scarce but when found can occur in good numbers.
description: Published as part of Gibbs, David, 2011, 2960, pp. 1-77 in Zootaxa 2960 on pages 35-38