Stevenia etrusca, 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 : 35-38

Stevenia etrusca sp. nov.

Type material. Holotype ɗ: ITALY – Toscana (Grosseto prov.) / Scarlino, Cala di Terra Rossa [42°52'25.13''N 10°46'28.42''E] / 02.VI.2004 (hand net) / P. Cerretti, D. Birtele, M. Tisato, D. Whitmore leg. [ MZUR]. Paratypes: 3 ΨΨ, same data as holotype [ CNBF, CPC].

Etymology. From the Latin “ Etruscus, Etrusca , Etruscum ” meaning Etruscan, the ancient people of Etruria (= Tyrrhēnia) an area that covered part of what now are Emilia-Romagna, Tuscany, Umbria and Latium, and containing the type locality. The name should be treated as a Latin adjective.

Diagnosis. Male frons relatively broad and with proclinate orbital setae ( Fig. 11 ); three katepisternal setae; abdomen black with a very narrow brownish rim on posterior margin of tergites 1+2 and 3 in males ( Figs. 12, 13 ); syntergite 1+2 with a pair of median marginal and median discal setae ( Fig. 13 ). Abdominal tergites 1+2–4 with transverse bands of microtrichosity on anterior 1/2–5/6, interrupted medio-dorsally by a broad longitudinal black stripe; tergite 5 microtrichose on anterior 1/3–1/2 ( Fig. 12 ).

Description [character states shared by S. etrusca and S. palermitana are omitted in the following description]

Male:

Length: 10.4 mm.

Colour. Head black with grey microtrichosity; area between gena and parafacial reddish-yellow; scape and pedicel black or dark brown, postpedicel black; palpus yellowish to dark-brown. Thorax and legs black; scutum with three broad longitudinal dark vittae. Upper and lower calypters whitish. Wing hyaline or slightly infuscate; tegula black, basicosta yellow, veins light brown to dark brown. Abdomen ( Figs. 12, 13 ) black, brownish at most on posterior rim of tergites 2 and 3; tergites 2–4 with transverse bands of white microtrichosity on anterior 1/2–5/6, interrupted medio-dorsally by a broad longitudinal black stripe; tergite 5 microtrichose on anterior 1/3–1/2. Epandrium black. Sternite 5 black.

Head ( Figs. 10, 11 ). Postpedicel about 1.3 times as long as pedicel. Frons at its narrowest point 0.77 times as wide as an eye in dorsal view. Ocellar setae short and weak (much shorter than the posterior frontal setae). Lateral vertical setae not differentiated from the postocular setae. One reclinate and 1 lateroclinate upper orbital setae ( Figs. 10, 11 ); 1 proclinate orbital seta ( Figs. 10, 11 ). Frontal setae descending to the level of proximal third of pedicel or slightly lower. Fronto-orbital plate with a row of short and stout proclinate setulae. Lower half of parafacial with a row of 5–7 long and stout medioclinate setae and several short proclinate setulae ( Fig. 10 ). Parafacial at its narrowest point about as wide as the postpedicel. Lower facial margin slightly visible in lateral view. Vibrissa well developed and differentiated from sub-vibrissal setae. Gena in profile 0.47 times the vertical height of eye (height measured in the same vertical plane as height of head). Prementum about 3.5 times as long as wide.

Thorax. Three to 4 katepisternal setae. Scutellum with 3 pairs (basal, lateral and apical) of marginal setae; basal setae very short and weak, less than 1/2 as long as laterals; lateral setae longer than the crossed apicals.

Legs. Fore leg: tibia with 3 anterodorsal setae. – Mid leg: tibia with 3–4 anterodorsal setae, 3–4 posterodorsal setae, usually 1 posterior seta; 1 ventral seta. – Hind leg: tibia with 3–4 long, robust anterodorsal and posterodorsal setae; with 3 dorsal preapical setae.

Abdomen ( Figs 12, 13 ). Syntergite 1+2 with 1 pair of median marginal and median discal setae and one or more lateral marginals. Tergite 3 with 1–2 pairs of median marginal and 1 pair of median discal setae. Tergite 4 with a row of marginal setae, 1–5 medio-discal setae. Tergite 5 with rows of marginal and discal setae.

Terminalia. Epandrial complex, sternite 5 and aedeagus very similar to those of S. palermitana , the only remarkable difference being the more strongly sclerotized dorsal sclerite of distiphallus.

Female, differs from male as follows:

Length: 8.7–9.7 mm.

Colour. Abdomen darker and with basal band of microtrichosity much weaker and sometimes indistinct and without a posterior rim.

Head. Frons wider, at its narrowest point 0.86–0.92 times as wide as an eye in dorsal view. Fronto-orbital plate with 1–2 proclinate orbital setae (the posterior one usually lateroclinate). Parafacial (in lateral view) at its narrowest point 1.26–1.50 times as wide as the postpedicel. Gena in profile 0.41–0.51 times the vertical height of eye.

Abdomen. Tergite 5 very short and triangular. Distribution. Palaearctic – mainland Italy. Biology. Unknown.

Figures

FIGURES 10 – 13. Stevenia etrusca sp. nov. (holotype). 10. Head and anterior half of thorax in lateral view. 11. Detail of fronto-orbital plate, with proclinate orbital seta. 12. Abdomen in dorsal view. 13. Abdomen in lateral view.