Usia forcipata Brullé, 1833

Gibbs, David, 2011, 2960, Zootaxa 2960, pp. 1-77 : 45-48

publication ID

1175­5334

persistent identifier

https://treatment.plazi.org/id/856BCF60-C818-FFD9-DDCF-C962FD1EFC83

treatment provided by

Felipe

scientific name

Usia forcipata Brullé, 1833
status

 

Usia forcipata Brullé, 1833 View in CoL

(Plate XI)

Usia forcipata Brullé, 1833: 300 . PLATE XI. Usia forcipata Brullé, 1833 ; 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.

Type material examined. Not seen. Type Locality Greece. The type depository is unknown (Evenhuis & Greathead 1999) and it has not been located during this study so would seem to be lost .

Other material examined. Greece, Athens , Acropolis, iv 1971, leg. W. Parker [♂ in PCDG]; Delphi, iv 1971, leg. W. Parker [♀ in PCDG ); Fokida , Itea, N38º25'52" E22º23'53" s.l. 24 March 1997, leg. J. Dils [♂ in PCJD]; Galaxidi, s.l. N38º25'40" E22º24'04" 19 March 1997, leg. J. Dils [♀ in PCJD]; Arkadia, Sapounakaika 50m N37º16'14" E22º16'14" 25 April 1996, leg. J. Dils [2♀ in PCJD]; Neohori, 25m N37º24'23" E22º44'48" 20 March 1997, leg. J. Dils [♀ in PCJD]; Korinthia, 7km S of Zemeno, 100m N38º03'57" E22º37'59" 23 April 1996, leg. J. Dils [3♂ 2♀ in PCJD]; Ahaia, Katarraktis 400m N38º05'49" E21º48'30" 5 May 1996, leg. J. Dils [2♂ in PCJD]; Atiki, Ino, 600m N38º11'39" E23º20'51" 27 April 1996, leg. J. Dils [2♂ in PCJD]; Ag. Sotiri, 300m N38º06'04" E23º26'54" 27 April 1996, leg. J. Dils [♀ in PCJD] GoogleMaps .

Etymology. The name derives from the Latin “forceps” referring to the prongs on the epandrium.

Diagnosis. A small shining black Balkan endemic, rather robustly built and long-haired. Hind femora with long hairs, scutellum with marginal hairs longer than median length of scutellum, wing with base infuscated in most individuals. Male genitalia very large, epandrium with long, parallel-sided elongations just before the tip that stick out conspicuously in most individuals, occasionally reduced to small points. Most females identifiable by dark wing base but in many cases reliable determination requires examination of genitalia (Plate XI).

Redescription. Measurements. Body length. 2.5–3.5mm Wing length. 2.8–3.7mm.

Male. Head. Frons relatively narrow, about a sixth head width, at narrowest point narrower than length of third antennal segment, eye margins parallel in hind three fifths, widening rather suddenly then parallel sided for front two fifths, in some eye margin distinctly notched. Rather matt medially, finely longitudinally striated, shinier on ocelli with poorly defined grey dust spots anterolaterally. Mouth margin very narrow, shining, linear almost absent. Ocelli equilateral, lateral ocelli separated from the eye by about half their diameter. Longest hairs on ocellar tubercle longer than depth of hind femora, significantly longer than width across vertex at lateral ocelli. Occiput covered with grey dust obscuring ground colour, this dusting considerably 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, fairly elongate, third segment straight dorsally before apical sulcus, convex ventrally at base, narrowing apically to rounded tip, a little more than twice as long as scape and pedicel combined. Dorsally antennae relatively pubescent, third segment with long dark setae on apical half, those immediately before apical sulcus as long as sulcus, almost or quite reaching tip of segment, sensilla brown. Proboscis black, naked, about as long as mesonotum. Palps very small, black to brown, subclavate with a few short, inconspicuous apical setae. Thorax. Entirely black, mesonotum shining and mostly smooth to inconspicuously wrinkled with hair insertions quite visible, often a slightly rougher patch in front of scutellum. Very lightly brownish dusted (more greasy looking) on pronotum, postpronotal lobe, notopleuron close to suture and above wing base. Mesonotum with long, perpendicular black hairs as long as those on ocellar tubercle, acrostichals irregularly biserial, paramedian lines bare slightly more transversely wrinkled than remainder of cuticle, extending back to above wing bases, laterally hairs generally distributed, lateral hairs the longest. Scutellum shining black, slightly brownish dusted along suture, obscurely transversely wrinkled, disc sparsely long haired, hind margin with a very irregular bi- to triserial row of long, black hairs longer than scutellum is long, directed strongly backward. Pleura lightly dusted, shining black on anterior half of anepisternum, anepimeron centrally, katepisternum ventrally and narrowly along posterior margin of meron. Posterodorsal corner of anepisternum with dark hairs distinctly shorter than those on notopleuron. Wing. Distinctly tinged brownish, decidedly infuscated basally and in costal and first basal cell, the veins dark brownish. Anal lobe narrow, shallowly convex hind margin, about two thirds the width of anal cell. Haltere. Yellowish white knob, stem infuscated basally. Legs. Black, shining but with rough texture to cuticle, short semi-erect hairs dorsally, fore femora with a few inconspicuous posteroventral hairs on basal half as long as depth of femora, mid-femora with more and longer posteroventral hairs much longer than femora are deep, hind-femora with a scattering of mid-length, erect black anteroventral hairs, the longest clearly longer than half the depth of the femora. Abdomen. Black, very short, tergites very broad, a distinct surface sculpture of transverse wrinkles, hair insertions traceable. Tergites 1–6 grey dusted in anterolateral corners (viewable from side). Disc of tergites covered with short, semierect black hairs, much longer hairs laterally and apically. Sternites grey dusted with long black hairs along apical margins. Genitalia. Large, sub-globular, almost as large as the remainder of the abdomen, length of epandrium approximately equal to length of sternites. Epandrium apically with distinct angulations and subapically usually with very conspicuous parallel-sided, blunt-ended “prongs” that project at right angles to the epandrium and typi- cally do not fold around the cerci but point backwards parallel or diverging, in some individuals these reduced to mere angulations. Epandrium densely haired on disc, shining and almost bare on “prongs”. Gonocoxite basally bilobed, short and broad with long erect black hairs, in lateral view with a right angled step medially bearing a tuft of short, incurved hairs. Gonostyli often visible, relatively simple, outwardly curved apically. Tip of epiphallus with rounded lateral flanges and topped by narrow spinose structure.

Female. Very similar to the male. The frons of the female a little broader than in males, about one-fifth head width, slightly divergent in hind three-fifths, not expanding so abruptly in anterior two-fifths, hind ocellus separated from eye margin by about the diameter of that ocellus. Hairs generally shorter, most conspicuously so on the disc of the tergites. Anal lobe much wider, hind margin more convex, almost as wide as anal cell. Basal infuscation less intense, especially in tip of first basal cell. Apical sternite trapezoidal, rather flat and long-haired apically, elevated into a narrow boss and grey dusted basally. When macerated a narrow basal part is distinctly separated from the trapezoidal apical part by a translucent band, interrupted medially, apical notch wide and shallow.

Discussion. A very distinctive species, most males easily identified from the epandrium without dissection. Probably most closely related to U. engeli but affinities uncertain.

Although no type specimens were available for study this species has long been well characterised in the literature so there is little doubt that the interpretation here equates to the U. forcipata of Brullé.

Distribution. Greece. Although this species has been widely recorded from Tunisia to Israel (Evenhuis & Greathead 1999), all of the very many specimens seen during this study were from Greece. While it would not be surprising if it was found in other Balkan countries, current data suggests that it is not only endemic to Greece, but is confined to the southern half of that country.

Kingdom

Animalia

Phylum

Arthropoda

Class

Insecta

Order

Diptera

Family

Bombyliidae

Genus

Usia

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