Parusia aurata ( Fabricius, 1794 ) 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 : 126-129

Parusia aurata ( Fabricius, 1794) gen. et comb. nov.

Figs 18 , 21–22 , 61

Voluccella aurata Fabricius, 1794: 413 .

Etymology

From Latin ‘ aurātus ’ = ‘gilded’, ‘golden’, presumably referring to the yellow apical margins of the tergites.

Type material

Lectotype (here designated)

“ Barbariae floribus” [= MOROCCO, ALGERIA or TUNISIA] • ♀; “Museum Paris, Barbarie, Coll Bosc 1828 [accession date]/ V. aurata . Fab. [in Bosc’s handwriting], florea [=?floribus, almost illegible] Barbariae/ aurata f.”; MNHN.

In his original description Fabricius states “Barbariae floribus Mus. Desfontaines” for this species. The Desfontaines collection was acquired by MNHN in 1826. The “Bosc” specimen with the Fabrician locality here designated as lectotype is dated 1828. That means it was not accessioned from the Desfontaines collection but was a specimen from the Bosc collection. It is presumed that a unique specimen would not have been exchanged thus this specimen is here not considered to be a holotype but a syntype that was exchanged with Bosc. The fate of the Desfontaines “type” is not known. (N. Evenhuis pers. com.).

A single female specimen with appropriate data was located in the general collection at MNHN.Although the labels are in Bosc’s handwriting and not Fabricius’, the pin through the insect is of the same type as seen with other Fabrician types. It was not uncommon for collectors of the time to replace labels with their own. Therefore it is concluded that this specimen is a syntype of aurata .

Other material examined

ALGERIA • 1 ♀; “ Mascara 29 April”; MNHN • 1 ♀; “21 April 1 ♀ ex. Coll. B. Aldgren ”; MNHN • 1 ♀; “ NE of Saida, Ain el Hannach 29 June 1983 1 ♀ (leg. J. Hutsebaut)”; MNHN • [♂ ♀ in cop. 3 ♂♂]; “Rouiba, J. Surcouf May-June 1911, Museum Paris”; MNHN • 2 ♂ ♀ in cop.; “same data 15 May 1913 ”; MNHN • 1 ♂; “Rocher Blanc, J. Surcouf, Museum Paris 1919”; MNHN • 5 ♂♂, 6 ♀♀; “March-April 1913”; MNHN • 1 ♀; “ Oran, J. Surcouf Museum Paris 1919” MNHN • 4 ♀♀; “Museum Paris, Env. D’Alger Bové 126-38, Usia aurata ”; MNHN .

MOROCCO • 2 ♂♂, 1 ♀; “ Guelmin , 11 km N. Guelmin, N29°08′30″ W10°05′48.4″ 430 m 23 March 2006 ”; PCJD • 1 ♂, 1 ♀; “ Azilal , Afourer N31°11′32.8″ W06°31′20.4″ 880 m 8 April 2006 ”; PCJD • 1 ♀; “ Marrakech , W of Demnate N31°43′58.2″ W07°16′58.9″ 700 m 6 April 2006 ” PCJD • 1 ♀; “ Agadir , Tioulit N29°53′28″ W09°00′00.2″ 1200 m 27 March 2006 (leg. J. Dils & J. Faes)”; PCJD .

TUNISIA • 2 ♀♀; “ Sfax Plage 30 April [18]99, Museum Paris , Tunisie , Museum Paris , Bleuse 1899”; MNHN .

Redescription

MEASUREMENTS. Body length: 2.3–5.2 mm. Wing length: 2.5–5.2 mm.

Male

HEAD. Gena and mouth margin black in ground colour, narrower than the apical breadth of a palp, grey dusted gena linear, mouth margin more shining. Frons black in ground colour, hind half narrowing distinctly from hind corners to just in front of anterior ocellus where eyes start to increasingly diverge gradually, then narrowing down gena. Eyes separated at their narrowest by 2.5–3 times the diameter of the front ocellus, hind ocelli separated from the eye margin by about half diameter of respective ocellus. Ocellar tubercle shining, barely dusted, narrow part of frons velvety black, appearing lightly grey or brown dusted from some angle, this colour narrowly continued down eye margins in some specimens. Anterior part of frons grey-white dusted, often more thinly so medially where dark ground colour shows from some angles. Yellow-brown hairs on ocellar tubercle almost twice as long as the width of the frons at rear, narrow part of frons bare, anterior part of frons with numerous white hairs some of which are longer than scape and pedicel combined, almost as long as postpedicel, inclined at 45°. Occiput dark in ground colour densely covered with grey dust largely obscuring ground colour, only slightly subshining, except on triangular area behind ocellar tubercle which is shining, thinly dusted. Yellow to white hairs dorsally not or only just overtopping ocellar tubercle, tips curved anteriorly, hairs much longer below, often wavy-tipped. Ommatidia uniform in size across the eyes. Antennae black, postpedicel variable about twice length of scape and pedicel together (tends to be relatively smaller in small individuals), sensilla in subapical sulcus can be pale and 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 or even longer. Proboscis short, only about twice head length, often less, basolaterally on dorsal surface with abundant, semi-erect brown hairs, diminishing in size towards tip. Basoventral membrane dark brown to brownish-white.

THORAX. Black cuticle dulled by dense olive-brown to grey dust except along well defined paramedian and antehumeral vittae where the underlying cuticle shows through and is dulled by black dusting, often subshining in smaller individuals. Paramedian vittae clear to just behind wings, widening rearwards, dusted acrostichal stripe approximately equal width throughout. Antehumeral vittae interrupted at the thoracic suture. Mesonotum covered with moderately long, pale yellow hair, the longest hairs longer than those on the ocellar tubercle. Scutellum more thinly dusted centrally, long-haired on the disc, hairs fringing the apical margin longer than those on mesonotum. Pleura similar to mesonotum laterally, white hairs on pronotum, posterior half of the anepisternum and much of katepisternum (can be sparse in smaller individuals).

WING. Membrane faintly brown tinged, the veins brown. Crossvein r-m beyond basal third but before mid-point 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 infuscated.

LEGS. Coxae black with a coating of grey dust like that on the pleura, obscuring ground colour. Remainder of legs black, essentially undusted so the shining cuticle is not dulled. Coxae externally and femora ventrally and posteriorly on front femora, covered with rather long, pale yellow or white hairs, on the femora longer than the greatest depth of the femora. Femora dorsally and tibia rather densely covered with both short adpressed white hairs, and on tibia a few longer, semi-erect hairs, especially at base.

ABDOMEN. All tergites velvety black, dusting on disc black, laterally on the reflexed margin dark greybrown dusted mostly obscuring the ground colour, most extensive on tergite one. Middle tergites with narrow but conspicuous and sharply demarcated yellow apical margins, these variable and can be absent on small individuals; on tergite one this margin disappears laterally, on remaining tergites it tapers away on reflexed margin. Sternites black, grey dusted like sides of tergites, largely obscuring the ground colour, apical yellow margins narrow and obscure. Tergites and sternites all covered with relatively long pale yellow hairs, mostly longer than length of respective tergite.

GENITALIA. Very large and globular, as deep as abdomen and up to a third its length (including genitalia), relatively even larger in small individuals. Gonocoxites shining black, composed of two rounded

hemispheres separated by a deep sulcus. Epandrium also shining black. Both gonocoxite and epandrium covered in long yellow hairs, longer than on tergites, especially so on gonocoxite.

Female

Very similar to male except for broader frons, narrowest at rear, being one-fifth to one-fourth head width, hind ocellus separated from eye by about one to one and a half times the diameter of that ocellus. Frons widening more evenly towards the front, hairs more extensive, irregularly uniserial along eye margins to rear of front ocellus. Thorax very similar, hairing tending to be rather shorter. Yellow apical margins to the tergites relatively broader, especially on tergites seven and eight, latter shining and undusted, tergite nine also shining but lacking yellow margin. Abdominal hairing distinctly shorter. Proximal part of genital fork only moderately at an angle with the arms, attached to arms by thin, linear sclerotised strip, broadest closest to tip, blunt ended. Arms of genital fork very broad. Basal spermathecal ducts expanded relative to apical ducts, fusing at proximal tip of the vaginal plate that is not differentiated from the genital fork.

Remarks

Based on female genitalia seems to show affinities with both the other African/Tyrrhenian species and the three Iberian species. The development of the basal spermathecal duct is intermediate between these two groupings. The male genitalia and external characters do not offer any clues as to its affinities.

Distribution

Algeria, Morocco, Tunisia.

Figures

Fig. 18. Parusia aurata (Fabricius, 1794) gen. et comb. nov., ♂.

Fig. 21. Parusia aurata (Fabricius, 1794) gen. et comb. nov., ♂.

Fig. 22. Parusia aurata (Fabricius, 1794) gen. et comb. nov., ♂.

Fig. 61. Parusia aurata (Fabricius, 1794) gen. et comb. nov. a. Epiphallic complex ventral. b. Epiphallic complex lateral. c. Gonocoxite ventral. d. Epandrium dorsal. e. Female genitalia ventral. f. Female genitalia lateral.