Parusia loewi ( Becker, 1906 ) Gibbs, 2023

Gibbs, David, 2023, A world review of the bee fly tribe Usiini (Diptera, Bombyliidae) - Part 3: Parageron Paramonov s. lat., European Journal of Taxonomy 863 (1), pp. 1-162 : 138-141

Parusia loewi ( Becker, 1906) gen. et comb. nov.

Figs 17 , 31 , 65

Usia loewi Becker, 1906: 219 .

Etymology

Named after Friedrich Hermann Loew (1807–1879).

Type material

Lectotype (here designated)

SPAIN • ♂; “ Andalusia, Rosenhauer/ Coll. H. Loew /Zool. Mus. Berlin/95719 Typus ”; ZMHB.

Paralectotype

SPAIN • 1 ♀ [on same pin. A second label, not on the pin when examined but associated with these specimens]; “ grata Lw. ♀ det Becker”; ZMHB .

Other material examined

SPAIN • 2 ♂♂, 4 ♀♀; “ Malaga Province, Marbella 29, 30 April 1983 ”; NHMUK • 6 ♂♂, 10 ♀♀; “ 2–6 May 1983 (leg. J. Bowden)[dark form]”; NHMUK • 1 ♂, 1 ♀; “ Salamanca, Villar de Ciervo, Las Coronas 23–25 May 1999 yellow pan”; PCDG • 1 ♀; “ 6 km N. of Villar de Ciervo 26.v–2.vi.1999 1 ♀ (leg. H.- P. Tschorsnig)”; PCDG • 1 ♀; “ Andalusia, Veer de la Frontera 29 March 2000 1 ♀ (leg. D.J. Greathead)”; NHMUK • 1 ♂; “ Malaga ( Espagne ), Don José Maria, de la Fuentes”; MNHN • 2 ♀♀; “ Museum Paris , Espagne, coll. Dufouri / Usia aurata ”; MNHN • 1 ♂; “ Madrid, Maniola [?], G. Sharma / Usia / Usia aurata Em’s/Museum Paris, Coll. J. Surcouf 1919”; MNHN • 5 ♂♂, 2 ♀♀; “ Andalusia, near Padul , 783 m, N37°01′40″ W3°37′3″ 2 May 2008, Leg. D.J. Gibbs ”; PCDG • ♂ ♀ in cop.; “ 780 m N37°01′42″ W3°37′5″ 2 May 2008, Leg. D.J. Gibbs”; PCDG • 2 ♀♀; “ 840 m N37°02′47″ W3°38′43″ 1 May 2008, Leg. D.J. Gibbs”; PCDG .

Redescription

MEASUREMENTS. Body length: 2.4–5.0 mm. Wing length: 2.5–5.1 mm.

Male

HEAD. Gena and mouth margin brownish black to black in ground colour, narrower than the apical breadth of a palp, grey dusted gena narrow, linear, more shining mouth margin broader, sometimes yellowish. Eyes separated at their narrowest by twice the diameter of the front ocellus, hind ocellus separated from the eye margin by less than half the diameter of that ocellus. Frons brownish black to black in ground colour, ocellar tubercle shining, barely dusted, narrow part of frons matt blackish, noticeably converging from hind corners to well in front of anterior ocellus, then widening relatively abruptly onto anterior of frons. Front part of frons densely blue-grey dusted, rather more thinly so centrally. White hairs on ocellar tubercle conspicuously longer than the width of the frons at rear, narrow part of frons bare, anterior part of frons with numerous white hairs which are no more than half the length of those on the ocellar tubercle. Occiput dark in ground colour densely covered with grey or brownish dust, triangular area behind ocelli more thinly dusted, subshining. The whole covered with erect pale yellow to white hairs, short above just overtopping ocellar tubercle, much longer below, silky, slightly wavy but not very dense. Ommatidia uniform in size across the eyes. Antennae blackish, tip of pedicel somewhat paler in lectotype, postpedicel variable but usually approximately twice length of scape and pedicel together, sensilla in subapical sulcus sometimes whitish so conspicuous. All antennal segments with short pale brown hairs above, longest just before subapical sulcus. Palps short but easily visible, strongly clavate, brown to black, the pale yellow apical setae as long as the length of the palps. Proboscis not very long, approximately one and a half head lengths, dorso-laterally clothed with short, adpressed brown setae. Basoventral membrane brown.

THORAX. Blackish ground colour largely obscured by blue-grey dust except along the conspicuous paramedian and antehumeral vittae where the shining black cuticle shows through, dulled by a variably very thin coating of brownish dust, subshining or even shining. Paramedian vittae variable a little narrower to a little broader then acrostichal dusted stripe, extending from very front of mesonotum to three quarters the way back. Antehumeral vittae divided at thoracic suture, sometimes a vague darker spot above wing base, area in front of scutellum usually darker, more thinly dusted. Mesonotum covered with moderately long, pale yellow hair, the longest hairs as long as those on the ocellar tubercle. Scutellum relatively sparsely haired on the disc, long hairs fringing the apical margin. Pleura dusted as notopleuron, with similar hairs on pronotum, posterior half of the anepisternum and a few scattered across katepisternum. Metepimeron partly yellow in lectotype, entirely dark in other specimens, glabrous.

WING. Membrane faintly brown tinged, especially in first basal cell, the veins brown. Crossvein r-m a little beyond basal third of discal cell, conspicuously beyond m-cu. Anal lobe moderately developed with evenly convex margin, about as broad as the anal cell.

HALTERE. Pale yellow to white, base of stem slightly brownish.

LEGS. Coxae dark with a coating of grey dust like that on the pleura. Remainder of legs black or very dark brown, only thinly dusted so not obscuring the shining cuticle. Coxae externally and femora ventrally covered with rather long, white hairs, on the femora longer than the greatest depth of the femora. Femora dorsally and tibia rather densely covered with short, white hairs.

ABDOMEN. All tergites black appearing undusted but rendered matt by thin dark brown dusting, dully shining on disc, tergite seven undusted, shining. Laterally on the reflexed margin densely grey dusted obscuring the ground colour, most extensive on tergite one where it extends to the scutellum. All tergites with narrow to quite broad, conspicuous and sharply demarcated yellow apical margins, narrowing laterally but even clear on tergite one here. Sternites black and densely grey dusted obscuring the ground colour, apical yellow margins less well defined. Tergites and sternites all covered with fairly long, erect white to very pale yellow hairs, longest on sternites.

GENITALIA. Conspicuously large and globular compared to most Protypusia gen. nov., but typical for Parusia gen. nov. Gonocoxites black to dark brown, shining, composed of two rounded hemispheres separated by a deep sulcus. Gonostylus sharply curved, tip at right angles to base and twisted, often visible in dried specimens. Epandrium shining black to dark brown, apico-lateral corners rounded. Both gonocoxite and epandrium covered in long whitish to pale yellow hairs, longest and densest on gonocoxite.

Female

Differs from the male in its more broadly separated eyes, three to three and a half times the diameter of the front ocellus, about one-fifth head width at narrowest point, hind ocelli separated from the eye margins by approximately twice the diameter of these ocelli. A few hairs on the middle part of the frons laterally. Hairs on legs and abdomen shorter, conspicuously so on the abdomen. Apical yellow margins to tergites rather broader, tergite eight not noticeably more shining than preceding tergites. Proximal part of genital fork strongly curved, sometimes at more than a right-angle when viewed laterally. Common spermathecal duct attached to distal end of main sclerotised part of genital fork at an acute angle so pointing towards base of abdomen or at right angles so pointing dorsally.

Dark form

A series from Malaga Province, southern Spain is significantly darker than the typical form and gives the appearance of being a different species. However, this darker appearance is due to no more than the dusting on the mesonotum being less extensive and thinner such that the ground colour shows through. In some individuals the dust also looks darker and browner but some in the series have dusting very like the typical form, just slightly less extensive. The paramedian vittae are much broader, divided by a narrow dusted acrostichal line which almost disappears posteriorly. Antehumeral vittae also more extensive, dusting on posterior part of mesonotum and scutellum inconspicuous such that these areas are subshining black. Dusting on occiput can be darker and browner. Tergites with narrower yellow apical margins. The male genitalia and female genital fork show some slight differences from the typical form but these are not sufficient to justify specific separation.

Remarks

This species seems to be the commonest and most widespread of the genus in Iberia, the other two Spanish species so far only known in Andalusia. The female genitalia suggest that it is closest to the other two Iberian species, with Pru. aurata showing the closest affinities in North Africa.

Distribution

Southern Spain north to Salamanca.

Figures

Fig. 17. Parusia loewi (Becker, 1906) gen. et comb. nov., ♂.

Fig. 31. Parusia loewi (Becker, 1906) gen. et comb. nov., ♀.

Fig. 65. Parusia loewi (Becker, 1906) gen. et sp. nov. a. Epiphallic complex ventral. b. Epiphallic complex lateral. c. Gonocoxite ventral. d. Gonocoxite lateral. e. Epandrium dorsal. f. Female genitalia ventral (Marbella). g. Female genitalia ventral (Salamanca).