Parusia taeniolata (Costa, 1883), 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 : 144-148

Parusia taeniolata (Costa, 1883) stat. rev., gen. et comb. nov.

Fig. 67

Usia taeniolata Costa, 1883: 103 .

Etymology

From Latin ‘ taenia = ‘ribbon’, ‘stripe’ and ‘ lātē ’ = ‘broad’, ‘wide’; possibly referring to yellow stripes on abdomen.

Type material

None seen, but as only one species of the “ aurata ”-group is recorded on Sardinia (type locality of Pru. taeniolata ), it is assumed that the material cited below is conspecific with the holotype (type locality: Italy, Sardinia).

Other material examined

ALGERIA • 1 ♂; “ Oran, Mékalis 1 ♂ ex. Coll. B. Aldgren (leg. L. Bleuse)”; MNHN • 1 ♂, 2 ♀♀; “Tarfaia, Algérie, A. Thery, Museum Paris, Algérie, Tarfaia, A. Théry 1902”; MNHN .

FRANCE • 2 ♂♂, 3 ♀♀; “ Corsica, Ajaccio , 27 May 1951 coll. A. Bayard, Usia aurata Fabric, Sadt. , Museum Paris ex coll. Hesse ”; MNHN • 1 ♂; “Bonifacio 17/596, Museum Paris, Coll. Abeille de Perrin 1919, Usia aurata ”; MNHN .

ITALY • 1 ♀; “ Sardegna, Cagliari, Domus de Maria N38°56′02″ E08°52′14″ 50 m 14 May 1998”; PCJD • 5 ♂♂, 1 ♀; “ Camisa N39°18′06″ E09°31′24″ 50 m 16 May 1998”; PCJD • 1 ♂, 3 ♀♀; “ Oristano, Sèneghe N40°06′44″ E08°36′48″ 600 m 19 May 1998”; PCJD • 1 ♂; “ Nuoro, Burruiles N40°43′46″ E09°39′24″ 50 m 12 May 1998”; PCJD • 4 ♂♂, 6 ♀♀; “ Escalaplano N39°38′31″ E09°21′11″ 350 m 16 May 1998”; PCJD • 1 ♂, 3 ♀♀; “ Seũlo N39°53′32″ E09°11′29″ 400 m 17 May 1998”; PCJD • 1 ♂, 1 ♀; “ Ortueri N40°00′21″ E09°02′41″ 450 m 18 May 1998”; PCJD • 1 ♂; “ Desulo N40°01′55″ E09°14′56″ 1350 m 20 May 1998”; PCJD • 1 ♀; “ Tertenia N39°34′56″ E09°35′39″ 100 m 21 May 1998”; PCJD • 2 ♂♂, 2 ♀♀; “ Talana N39°59′34″ E09°36′22″ 50 m 22 May 1998”; PCJD • 1 ♂; “ Ulassai N39°46′05″ E09°30′37″ 750 m 22 May 1998”; PCJD • 1 ♂; “ Cardedu N39°46′47″ E09°40′06″ 0 m 22 May 1998 (leg. J. Dils & J. Faes)”; PCJD • 1 ♂, 3 ♀♀; “ Sardegna (Cagliari) Isola, San Pietro Aprile 2000, M. Zillich legit”; CNBFVR • 1 ♀; “ Sardegna (Cagliaei), Seulo dintorni Sardali 780 m, UTM 32 S 0523700 4408453, 17 May 2008 retino, G. Nardi P. Audisio, M. Bardiani M. Trizzino leg., Progetto Sardegna”; CNBFVR .

TUNISIA • 1 ♂, 1 ♀; “Fernana oued [valley], meadow 14 May 1995 (leg. M.J. Ebejer)”; PCME .

Redescription

MEASUREMENTS. Body length: 2.8–4.8 mm. Wing length: 2.6–4.6 mm.

Male

HEAD. Gena and mouth margin black or dark brown in ground colour, narrower than the apical breadth of a palp, grey dusted gena narrow, linear, more shining mouth margin a little broader. Frons black or dark brown in ground colour, hind half narrowing distinctly from hind corners to just in front of anterior ocellus where more or less parallel, until eyes diverge fairly abruptly on to anterior part, then narrowing down past antennae. Eyes separated at their narrowest by two to two and a half times the diameter of the front ocellus, frons at narrowest one seventh to one eighth head width, hind ocellus separated from the eye margin less than half diameter of respective ocellus, almost touching in some. Ocellar tubercle shining to subshining, thinly dusted but rather variable, narrow part of frons grey or brownish dusted, but blackish in part from some angles, this colour narrowly continued down gena in some specimens. Anterior part of frons grey-white dusted, often more thinly so medially where dark ground colour shows from some angles. Whitish-yellow hairs on ocellar tubercle relatively short, a little longer than the width of the frons at rear, narrow part of frons bare, anterior part of frons with numerous inconspicuous short white hairs mostly barely longer than scape, inclined at 45°. Occiput dark in ground colour densely covered with grey dust, brownish tinged dorsally, completely obscuring ground colour, thinner and subshining on triangular area behind ocellar tubercle. Yellow to white hairs dorsally not or only just overtopping ocellar tubercle, tips curved anteriorly, hairs rather longer below, silky white, often wavytipped. Ommatidia uniform in size across the eyes. Antennae black, postpedicel variable but relatively long, a little more than 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, baso-laterally on dorsal surface with abundant, semi-erect brown hairs, diminishing in size towards tip. Basoventral membrane murky brown.

THORAX. Black cuticle dulled by dense grey-brown dust, often with a golden tinge, except along well defined paramedian and antehumeral vittae where the dusting is more blackish to brownish, only slightly subshining. Paramedian vittae clear to just behind wings, diverging slightly but hardly widening rearwards, dusted acrostichal stripe approximately same width as paramedian vittae, slightly widening rearwards. Antehumeral vittae interrupted at the thoracic suture, usually completely. Mesonotum covered with moderately long, white to pale yellow hair, the longest hairs longer than those on the ocellar tubercle but rather variable. Scutellum dusted as mesonotum, sparsely haired on the disc, hairs fringing the apical margin longer than those on mesonotum. Pleura dusted as mesonotum laterally, white hairs on pronotum, posterior half of the anepisternum and katepisternum dorsally.

WING. Membrane hyaline, hardly yellow-brown tinged, the veins brown, yellower basally and on subcosta. Crossvein r-m beyond basal third of discal cell, sometimes almost at mid-point 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 dark brown to black, essentially undusted so the shining cuticle is not much 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 blue-grey dusted obscuring the ground colour, most extensive on tergite one where it just extends on to disc which is browner than remaining tergites. Middle tergites with relatively broad, conspicuous and sharply demarcated bright yellow apical margins, can be narrower and duller in smaller individuals, but clear at least laterally. These yellow margins can be narrower on middle tergites, but on average are equally broad throughout on all tergites, laterally tapering away on reflexed margin. Sternites black, grey dusted like sides of tergites, obscuring the ground colour, apical yellow margins while less striking than on tergites, complete and almost as broad. Tergites and sternites all covered with relatively long pale yellow hairs, mostly longer than length of respective tergite, longest on sternites.

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, corners rounded, medially membranous and yellow-brown (often difficult to see in dried material). Gonostylus, short, sharply bent inwards but not quite at a right angle, basal and apical part approximately equal. 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 diameter of hind ocellus. Frons widening more evenly towards the front, hairs more extensive, irregularly uniserial along eye margins to level of front ocellus. Gena and mouth margin conspicuously wider, especially the shining mouth margin, about as wide as palp apically. Thorax very similar, tending to be rather more yellowish-brown dusted, hairing almost identical. Yellow apical margins to the tergite as striking as in male, or even broader especially on apical tergites, continuing broadly onto reflexed margin where abruptly narrow close to edge.Abdominal hairing distinctly shorter. Proximal part of genital fork almost flat, not strongly angled with the arms, broadest closest to base, blunt ended attached to arms by thin, linear unsclerotised strip. Basal spermathecal ducts much expanded relative to apical ducts, short, not extending beyond tip of genital fork.

Remarks

Becker’s (1906) synonymisation of Pru. taeniolata is entirely understandable given that the type is a female and he did not examine the genitalia. However, both male and female genitalia show that this species is quite distinct from Pru. aurata . Perhaps closest to Pru. benoisti gen. et sp. nov. or Pru. cyrenaica gen. et sp. nov., and furthest from the three Iberian species, suggesting it is derived from an ancestor that arrived on the Tyrrhenian Islands from Africa.

The distribution of this species is rather surprising being on both the Tyrrhenian Islands and in northern Tunisia and Algeria. There is no reason to doubt these records, although some are very old, they are numerous, and the two from Tunisia are recent. It appears that having differentiated on the Tyrrhenian Islands, this species has reinvaded North Africa.

Distribution

Algeria, France ( Corsica), Italy (Sardinia), Tunisia.

Excluded species

Most of the following species were included in Usia or Parageron s. lat. by Evenhuis & Greathead (1999) but have been found during the course of this study not, or almost certainly not, to belong here. Included in the following list are notes on other species already recognised as Apolysis but new information worth bringing to light was found while examining types for this review.

Figures

Fig. 67. Parusia taeniolata (Costa, 1883) stat. rev., gen. et comb. nov. a. Epiphallic complex ventral. b. Epiphallic complex lateral. c. Gonocoxite ventral. d. Epandrium dorsal. e. Female genitalia ventral.