Swammerdamella spinigera, Haenni, 2009

Haenni, Jean-Paul, 2009, The Scatopsidae (Diptera) of Sardinia, with description of a new species *, Zootaxa 2318, pp. 440-449 : 445-447

11. Swammerdamella spinigera sp. nov.

( Figs 1–9)

Type locality. Italy, Sardinia (province Carbonia-Iglesias), Domusnovas, Sa Duchessa , 371 m, UTM 32S 464990 4358384 .

Type material. Holotype ♂ labelled: “I-Sardegna (Carbonia-Iglesias) / Domusnovas, sa Duchessa, 371 m / UTM WGS 84 32S 464990 4358384 / 3–17.X.2006, Malaise trap S2 / G. Chessa legit / Progetto Sardegna – CNBF” [print], “ Swammerdamella spinigera sp. nov. ♂ / HOLOTYPE / J.-P. Haenni 2007 ” [hand written, red label], in good condition, preserved in alcohol, terminalia dissected ( CNBFVR).

Paratypes: 1 ♀, same data as holotype (dissected) ; 1 ♂, same data as holotype but 17–31.X.2006 . Paratypes preserved in alcohol, in good condition ( CNBFVR) .

Diagnosis. The shape of tergite 6 of male, with posterior margin simple, gently curved ( Fig. 3), not produced posteriorly into a more or less triangular projection, is unique among the European species of Swammerdamella Enderlein. The new species is closely related to S. pediculata ( Duda, 1928) from Central Europe and to the above-mentioned new species from Spain, as may be seen by the long narrow M fork on wing ( Fig. 1) and the shape of the genital capsule, especially the strongly sclerotized aedeagal plate ( Fig. 4). The male genital structures ( Fig. 6), with hardly developed lateral projections and posterior lobes densely beset with short spinulae, allow an easy separation from these species. In the female, the poor knowledge of the genital structures of most species of the genus does not allow to give diagnostic characters for S. spinigera .

Description. Male. 1.5 mm long (in alcohol). Shining black in general colour, with contrasting yellow tarsi. Head shining black, higher than long; antenna longer than head height, clavate, with 8 flagellomeres, gradually shortening and widening towards apex, the penultimate flagellomere more than twice as broad as long, the last one rounded, about 2.5 times longer than preceding one, nearly as broad as long; palpus large, broadly triangular at base, pointed at apex. Thorax. Notum shining black, with irregularly arranged rather coarse dark pilosity, also present on scutellum; margin of scutellum devoid of setae except basally; pleurae shining, largely devoid of pilosity except on elongate triangular spiracular sclerite ( Fig. 2). Wing ( Fig. 1) 1.6 mm long, hyaline, membrane entirely covered with dense, minute, light micropilosity; radial veins short, ending in the vicinity of the middle of wing, light brown; 9 dorsal setae on basal portion of R, 5 dorsal setae on R 4+5, no dorsal setae on R 1; posterior veins translucent; fork of M long and narrow, nearly as long as stem, the branches diverging markedly only near apex of wing. Halter brown, with somewhat lighter brownish stem; legs concolorous with body except tarsi yellow, strongly contrasting; anterior femora with a posteroventral irregular row of elongate setae. Abdomen. Tergites 1–6 shining black, with sparse coarse dark pilosity, denser and longer on posterior tergites; tergite 1 narrow, with a weakly sclerotized median longitudinal line; tergite 6 ( Fig. 3) simple, with posterior margin gently convex; sternites 2–6 present, beset with dark pilosity as tergites; sternite 7 ( Fig. 5) shining, smooth, with complex posterior margin; tergite 7 ( Fig. 5) bearing a pair of elongate acute projections posteriorly; genital capsule with hardly developed lateral projections, yellowish apical lobes densely beset with short spinulae, and heavily sclerotized aedeagal plate and aedeagal complex ( Figs 4, 6). Sperm pump as in Fig. 7.

Female. 1.6 mm long. Wing 1.7 mm long. As male in general colour and morphology except antennae, less clavate apically. Genitalia. Tergite 8 short, incised posteriorly to accommodate the cerci ( Fig. 8); cerci separated on all their length, covered with minute spinose setulae on entire surface and with usual setulae along apical margin only ( Fig. 8); tergite 9 produced posteriorly into 2 lateral lobes encompassing the cerci; sternite 8 more strongly sclerotized on undulated anterior margin, weakly sclerotized posteriorly ( Fig. 9).

Etymology. The name spinigera , a feminine adjective meaning ‘bearing spines’, refers to the unusual spinulation of the ventral lobes of the genital capsule and the acute projections of tergite 7 of the male of the new species.

Chorotype. A possible W-Mediterranean element.

Italian distribution. Presently only known from Sardinia.

Ecology. Unknown.

Notes. This species and the preceding one both belong to the S. pediculata -group of species of Swammerdamella , which are characterized by the 8-segmented flagellomere of antennae, the elongated M fork about as long as M stem, and by the genital structures. Besides the Palaearctic S. pediculata (Duda) and S. genypodis Cook , the group also includes the Nearctic S. pygmaea (Loew) and S. confusa Cook.

Discussion

The present material includes 11 species and thus represents a very significant increase of our knowledge of Sardinian Scatopsidae , which was extremely poor until now. Indeed, no less than 10 species are new records for the island. Little less than half of them are widespread taxa: Coboldia fuscipes and Scatopse notata are cosmopolitan, while Apiloscatopse flavicollis , Reichertella geniculata and Swammerdamella brevicornis are common European (or W-Palaearctic for the latter) species with a wide distribution. It is more difficult to discuss the other taxa, as several of them have been recognized only recently and their distribution is still insufficiently known. Rhegmoclemina lunensis , known elsewhere only from England, may be an up to now overlooked European element. The Mediterranean component is represented by at least 2 species, namely the new Rhexoza Enderlein and the new Swammerdamella Enderlein , that are otherwise known only from Spain. Three taxa, Colobostema sp. , Swammerdamella spinigera sp. nov. and the Anapausis species are possible endemic Sardinian species, although they may well also represent Mediterranean elements with a wider distribution.

Even if based upon a single survey of a limited region only, the fauna of Scatopsidae of Sardinia appears nevertheless to present a very interesting and original assemblage of species. It should however be noticed that the occurrence of several other scatopsid species may be expected on the island. This also highlights the very poor state of our general knowledge of the family in the Mediterranean region. Indeed, Sardinia, with 11 recorded taxa, appears to be much better known when compared with other large islands, e.g. Corsica (5 species), Sicily (2 species) or Crete (2 species) ( Haenni 2004b). In this respect, the fauna of Italy as a whole remains extremely poorly known since only 16 species of Scatopsidae had been recorded until now. The present survey brings this number to 21, which is probably only one third of the real number of expected species.