Parusia cyrenaica, 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 : 132-135

Parusia cyrenaica gen. et sp. nov.

urn:lsid:zoobank.org:act:86B4C22C-807D-4B74-A9B1-302D5B582605

Fig. 63

Etymology

Treated as a noun in apposition, named after the former Libyan, and before that Roman, province Cyrenaica in eastern Libya where the type series was collected.

Type material

Holotype

LIBYA • ♂; “Cyrenaica, Nr. Barce [Al Mari], 14 March 1958, leg. K.M. Guichard ”; NHMUK.

Paratypes

LIBYA • 2 ♂♂, 1 ♀; “Cyrenaica, Nr. Barce [Al Mari], 14 March 1958, leg. K.M. Guichard ”; NHMUK .

Description

MEASUREMENTS. Body length: 4.5–5.1 mm. Wing length: 4.3–5.0 mm.

Male

HEAD. Gena and mouth margin black in ground colour, narrower than the apical breadth of a palp, gena very narrow, linear, more shining mouth margin a little wider. Frons black in ground colour hind half narrowing slightly from hind corners to just in front of the front ocellus, then widening fairly abruptly, the eye margin a little concave. Eyes separated at their narrowest by approximately twice the diameter of the front ocellus, hind ocelli narrowly separated from eye margin, less than half diameter of ocellus. Ocellar tubercle shining, thinly dusted, narrow part of frons densely blackish dusted, grey dusted on front half from point where it starts to widen, slightly paler laterally and down past antennal bases. Pale yellow to white hairs on ocellar tubercle about twice as long as the width of the frons, narrow part of frons bare, anterior part of frons with numerous pale yellow hairs, some of which are almost as long as those on the ocellar tubercle (variable and hairs easily lost). Occiput dark in ground colour densely covered with grey dust including area behind ocellar tubercle, and outstanding pale yellow hairs, short dorsally, not overtopping ocellar tubercle, much longer ventrally where hairs are as long as those on front of mesonotum and wavytipped. Ommatidia uniform in size across the eyes. Antennae black, postpedicel variable but usually about twice length of scape and pedicel together, sensilla in subapical sulcus brown so not conspicuous. All antennal segments with short yellow hairs above, longest and rather dense just before subapical sulcus. Palps short but easily visible, strongly clavate, black, the yellow apical setae as long as the length of the palps and rather tufted. Proboscis not very long, approximately twice head length, dorso-laterally clothed with short, adpressed brown setae. Basoventral membrane dark brown to blackish.

THORAX. Black ground colour largely obscured by dark grey dust, paramedian and antehumeral vittae conspicuously matt black dusted, cuticle obscured. Paramedian vittae a little narrower then dusted acrostichal line anteriorly, widening rearward stopping rather abruptly above the wing base.Antehumeral vittae narrowed, but not entirely interrupted at the thoracic suture. Mesonotum rather uniformly covered with long, pale yellow hairs, the longest longer than those on the ocellar tubercle. Scutellum dark grey dusted as on mesonotum, slightly more thinly dusted medially, relatively densely haired, hairs longer than those on mesonotum especially marginally. Pleura with similar dark grey dusting, hairs on pronotum, all but lower anterior corner of anepisternum and all but rear third of katepisternum.

WING. Membrane faintly brown tinged, rather more infuscated in costal cell, cell r 1 and first basal cell, the veins dark brown. Crossvein r-m a little before middle of discal cell, conspicuously beyond m-cu. Anal lobe moderately developed with evenly convex margin, a little broader than the anal cell.

HALTERE. Pale yellow, base of stem slightly brownish.

LEGS. Coxae black with a coating of dark grey dust like that on the pleura. Remainder of legs black or very dark brown, essentially undusted so the shining cuticle is not dulled. Coxae externally with rather long, pale yellow hairs, anterior four femora ventrally and posteriorly similarly haired, hind femora with similar long pale yellow hairs on anterior and ventral faces, longer than the greatest depth of the femora. Femora elsewhere and tibia rather densely covered with short steeply inclined pale yellow hairs, and on tibia with some longer hairs dorsally.

ABDOMEN. All tergites black dusted, matt, becoming thinly dusted and more or less shining on tergites six and seven, laterally on the reflexed margin densely grey dusted obscuring the ground colour, most extensive on tergite one. Hairs on disc arising from small, shining circles, contrasting with the matt black remainder of disc. All tergites with very narrow but conspicuous and sharply demarcated dark yellow apical margins, on tergite one this margin barely visible laterally, on remaining tergites it broadens laterally then tapers away on reflexed margin and occasionally obscure medially. Sternites black and densely grey dusted obscuring the ground colour, apically any yellow margins very obscure, hardly visible. Tergites and sternites all covered with long, erect golden-yellow hairs.

GENITALIA. Conspicuously large and globular, even larger than closely related species (except Pru. faesae gen. et sp. nov.). Gonocoxites black, shining, composed of two rounded hemispheres separated by a deep sulcus. Epandrium shining black, corners rounded. Gonostyli long and relatively straight, very slightly curving in basal two thirds, curving inward more sharply in apical third, twisted, apical flange small. Both gonocoxite and epandrium covered in long yellow hairs, those on gonocoxite even longer than those on tergites.

Female

Only one specimen available, with missing head. Very similar to male except hairing generally a little shorter and paler. Proximal part of genital fork a simple sclerotised rod, basal spermathecal ducts greatly

expanded and joining just before the fused vagial plate/genital fork, conspicuously long, exceeding the tip of the genital fork.

Remarks

This distinctive Parusia sp. represents the most westerly known extension of the genus, and is isolated from its nearest congener by more than 1000 km of Libyan and Tunisian desert. The thick basal spermathecal ducts shows an affinity with the other four species of Parusia gen. nov. occurring in Africa, but not obviously closest to any one of these species.

Distribution

Northeastern Libya

Figures

Fig. 63. Parusia cyrenaica 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.