Stevenia palermitana, Cerretti, Pierfilippo & Pape, Thomas, 2007

Cerretti, Pierfilippo & Pape, Thomas, 2007, Two new species of European Stevenia Robineau-Desvoidy (Diptera: Rhinophoridae) and a key to the Palaearctic species, Zootaxa 1624, pp. 31-41 : 32-35

Stevenia palermitana sp. nov.

Type material. Holotype ɗ: ITALY – Sicily (Palermo prov.) / Bosco della Ficuzza 600–1000 m / Torretta Torre / hand net on low vegetation / 18.V.2004 / P. Cerretti, D. Birtele, G. Nardi, D. Whitmore leg. [ MZUR]. Paratypes: ITALY – Sicily (Palermo prov.): 2 ɗɗ 1 Ψ, same data as holotype [ ZMUC]; 1 ɗ 1 Ψ, Bosco della Ficuzza 600–1000 m / Torretta Torre / hand net on low vegetation / 18.V.2004 / P. Cerretti, D. Birtele, G. Nardi, D. Whitmore leg. [ CPC, ZMUC]; 2 ɗɗ Bosco della Ficuzza 600–1000 m / Torretta Torre / hand net on low vegetation / 05.V.2004, [same collectors] [ CPC]; 1 ɗ 2 ΨΨ, Bosco della Ficuzza 600–1000 m / (on Ferula communis ) [ Apiaceae ] / 14.V.2004, [same collectors] [ CPC, ZMUC]; 1 Ψ, Bosco della Ficuzza 600–1000 m / (on Elaeoselinum asclepium ) [ Apiaceae ] / 29.VII.2003 (hand net) / P. Cerretti, M. Tisato leg. [ CPC]; 1 Ψ, Bosco della Ficuzza 600–1000 m / Laghetti Coda di Riccio / N37.52329 E13.24032 / 19.V.2004 (hand net), [same collectors] [ CPC]; 5 ɗɗ 7 ΨΨ, Bosco della Ficuzza 885 m / Pulpito del Re / N37.53174 E13.23768 / (on Ferula communis ) / 15.V.2004, [same collectors] [ CNBF, CPC]; 1 Ψ, Madonie – Piano Zucchi 1238 m, 21.V.2004, [same collectors] [ ZMUC].

Etymology. The name refers to the province of the type locality (Palermo) and should be treated as a Latin adjective.

Diagnosis. Male with narrow frons and without proclinate orbital setae. Body entirely black except for the reddish or orangish posterior 1/2–1/4 of abdominal tergite 5; all abdominal tergites with dense microtrichosity.

Description. Male (measurements in square brackets refer to the holotype):

Length: 6.3–7.7 mm.

Colour. Head black with grey microtrichosity; area between gena and parafacial reddish; scape and pedicel black or dark brown, postpedicel black; palpus brown to dark-brown, sometimes yellowish apically. Thorax and legs black; presutural area with three broad longitudinal dark vittae. Upper and lower calypters whitish. Wing hyaline or slightly infuscate; tegula black, basicosta yellow, veins black or dark brown. Abdomen ( Fig. 3 ) mainly black except for posterior 1/2–1/4 of tergite 5, which is red; tergites 2–4 each with a transverse band of white microtrichosity on anterior 1/2–3/4, interrupted medio-dorsally by a broad, longitudinal black stripe; tergite 5 with a non-interrupted band of microtrichosity on anterior 1/3–1/2. Epandrium black. Sternite 5 mainly yellow.

Head ( Figs. 1, 2 ). Eye bare. Arista, thickened on about basal 1/5, covered with hairs at most as long as its basal diameter. First and second aristomere not longer than wide. Postpedicel about 0.9–[1.2] times as long as pedicel. Frons at its narrowest point 0.56–[0.69] times as wide as an eye in dorsal view. Ocellar setae well developed (usually shorter than the posterior frontal setae), proclinate. Medial (= inner) vertical setae strong, reclinate, sub-parallel to each other. Lateral (= outer) vertical setae not differentiated from the postocular setae. One or 2 reclinate upper orbital setae; no proclinate orbital setae. Eight to 9 frontal setae descending to the level of the middle of pedicel or slightly lower. Fronto-orbital plate with scattered, short, proclinate setulae. Parafacial with a row of 5–7 long and stout medioclinate setae on lower 3/4–4/5, and several short proclinate setulae ( Figs 1, 2 ). Parafacial at its narrowest point 1.15–[1.38] times as wide as the postpedicel. Face and lower facial margin not visible in lateral view. Vibrissa usually well developed (sometimes not differentiated from sub-vibrissal setae), arising at level of lower facial margin. Facial ridge concave with robust setulae on lower 1/6–1/5. Genal dilation well developed. Gena in profile about 0.28–[0.40] times the vertical height of eye (height measured in the same vertical plane as height of head). Postocular setae relatively short, slightly bent forwards. Occiput convex, only with black setulae behind the postocular row. Prementum about 2.0–2.5 times as long as wide. Palpus sub-cylindrical with some setulae ventrally, dorsally and apically.

Thorax. Prosternum and proepisternum bare. Postpronotum with 4 (rarely 5) setae; the three strongest form a triangle. Scutum with 1–2 + 1–2 acrostichal, 2–3 + 3 dorsocentral, 0–1 + 2–3 intraalar, 2 posthumeral, 1 strong presutural, 2 notopleural, and 3 supraalar setae (first postsutural supraalar seta (= prealar) shorter than notopleural setae), postalar callus with 2 setae. Anatergite with a patch of setulae just below the base of lower calypter. Three katepisternal setae. One anepimeral seta well differentiated from adjacent setulae. Katepimeron bare. Scutellum with 3 pairs (basal, lateral and apical) of marginal setae; basal setae short, about 2/3–3/4 as long as laterals; lateral setae slightly longer than the crossed apicals. A pair of discal scutellar setae. Postmetacoxal area membranous.

Legs. Fore leg: Coxa with bare medial surface; tibia with 3–4 anterodorsal setae, without posterodorsal setae, preapical anterodorsal setae shorter than preapical dorsal one (preapical posterodorsal seta not differentiated); claws longer than tarsomere 5. – Mid leg: tibia with 3–4 anterodorsal setae, 3–6 posterodorsal setae, usually 1 posterior seta; ventral seta on mid tibia present or absent. – Hind leg: Posterior coxal margin bare; tibia with several anterodorsal and posterodorsal setae of irregular length and thickness, with 3 dorsal preapical setae.

Wing ( Fig. 4 ). Costal spine very long, about 1.5–2.0 times as long as crossvein r-m. Second costal portion (CS2) with short setulae ventrally. Base of R4+5 with 1–4 setulae. Section of M between crossveins r-m and dmcu longer than the section between dm-cu and bend of M. Wing cell r4+5 distinctly petiolate, petiole 0.81–1.12 times as long as post-angular portion of M.

Abdomen. Middorsal depression on abdominal syntergite 1+2 confined to anterior 1/3 of that segment. Syntergite 1+2 with 1 pair of median marginal setae and one or more lateral marginals. Tergite 3 with a pair of median marginal and usually 1 pair of median discal setae (rarely absent). Tergite 4 with a row of marginal setae, 1–5 medio-discal setae. Tergite 5 with rows of marginal and discal setae.

Terminalia ( Figs. 5–8 ). Hind margin of sternite 5 with a deep cleft; lateral lobe large; medio-apical margin of lateral lobe with dense microtrichia ( Fig. 5 ). Tergite 6 weakly sclerotized, divided into two hemitergites, joining segment 7+8 by a membrane. Sternite 6 asymmetrical, articulated to segment 7+8 on its left side and attached to it by a large membrane on its right side. Epandrium short and convex. Cerci ( Figs. 7, 8 ) shorter than surstylus, with a dorso-medial suture, apically separated from each other. Surstylus ( Figs 7, 8 ) pointed, long and curved forward in profile. Ejaculatory sclerite large and fan-shaped. Medial plate of hypandrium sub-rectangular in dorsal view; hypandrial arms long and sub-parallel (not encircling the base of the phallus). Bacilliform sclerites long. Pregonite sub-triangular. Postgonite long, narrow and hook-like with one long setula at mid-length. Epiphallus ( Fig. 7 ) straight, well developed and weakly sclerotized. Distiphallus joining basiphallus by a dorsal sclerite and by a ventro-lateral membrane; lateroventral surface of distiphallus strongly sclerotized and covered with scale-like spinules ( Fig. 6 ).

Female, differs from male as follows:

Length: 5.5–6.7 mm.

Colour. Abdomen darker with basal band of microtrichosity much weaker and sometimes indistinct.

Head. Frons slightly wider, at its narrowest point 0.79–0.95 times as wide as an eye in dorsal view. Fronto-orbital plate with 1–2 proclinate orbital setae. Parafacial (in lateral view) at its narrowest point 0.9–1.3 times as wide as the postpedicel. Gena in profile 0.3–0.4 times the vertical height of eye.

Abdomen. Tergite 5 very short and triangular.

Distribution. Palaearctic – Sicily [ Italy].

Biology. Unknown.

Figures

FIGURES 1 – 9. Stevenia spp. 1 – 8. S. palermitana sp. nov. (holotype). 1. Head in lateral view. 2. Detail of head, showing parafacial setae. 3. Abdomen in dorsal view. 4. Left wing in ventral view. 5. Sternite 5 in ventral view. 6. Aedeagus in ventral view, scale bar 0.1 mm. 7. Male genitalia in left lateral view. 8. Epandrial complex in posterior view, scale bar 0.5 mm. 9. S. deceptoria (Italy: Sicily), distiphallus in ventral view, scale bar 0.1 mm.