Piezura shanxiensis Xue, Wang & Wu, 1998

Wang, Ming-Fu, Zhang, Dong & Ao, Hu, 2010, Phylogeny and biogeography of the genus Piezura Rondani (Diptera: Fanniidae), Zootaxa 2412, pp. 53-62 : 59-60

Piezura shanxiensis Xue, Wang & Wu, 1998 . New status.

Figs. 8–10.

Piezura graminicola shanxiensis Wang, Wu, Cheng, Xue & Liu, 1992: 2 . Unavailable name; published in a separate that does not meet the provisions of a published work (I.C.Z.N. 1999; see Moores & Savage 2005: 56).

Piezura graminicola shanxiensis Xue, Wang & Wu in Xue & Wang, 1998: 811; Wang & Xue, 2002: 55.

Piezura pardalina shanxiensis: Moores & Savage, 2005: 56 .

Redescription: Male: Body length 4.5 mm. Eye bare; fronto-orbital plate, parafacial and gena with silverygrey pruinosity, frons about 1.7 times as wide as width of first flagellomere, frontal vitta black, with thin grayish-white pruinosity, frontal setae 5, the gaps filled with few fine setae, upper orbital setae 1, stout and curved outwards; parafacial narrow, at middle about 1/4–1/3 as wide as width of first flagellomere; antennal scape, pedicel and basal 1/5 of first flagellomere yellow, rest black, first flagellomere 2.0 times as long as wide, arista pubescent, the longest hair about 1/2 of width of first flagellomere; epistoma not projecting beyond vibrissal angle, vibrissal angle behind frontal angle in profile; gena and postcranium with black hairs; palpus yellow, claviform; proboscis short, yellowish brown.

Thoracic postpronotum, lower part of katepisternum and distal 1/2 of scutellum yellow, rest of thorax black; notum with brownish-grey pruinosity, with 1 brown median vitta and 2 pairs of lateral narrow vittae; acr in four irregular rows, only presutural pairs stout, the distance between the two rows slightly wider than the distance between acr and dc rows, dc 2+3, pra short and hair-like, notopleuron without setulae; ventral surface and lateral margin of scutellum bare; basisternum, proepisternum, anepimeron, meron and katepimeron bare; katepisternal setae 1:2, katepisternum without ventral spines; proepisternal setae 2, proepimeral seta about 1/2 of upper proepimeral seta in length. Calypters yellowish.

Wing transparent; tegula brown, basicosta yellowish, costal spine inconspicuous; node of Rs bare on ventral and dorsal surfaces; vein M straight; crossveins without obvious cloud; haltere yellow.

Legs yellow, except tarsi and apical part of femora black; fore femur with a short av row and a stout pv row, fore tibia with 1 median ad; mid coxa without any hooked spines or spine-like setae on lower and outer margins; mid femur with an incomplete a row, apical part with 3 a, av row complete, in distal part becoming 11–13 pectinated setae, pv row becoming biserial in distal 1/2, with 6 or 7 pectinated setae at apex, on ventral to posteroventral surfaces with numerous short seta rows; mid tibia with 1 ad and 1 pd, the distal 1/2 slightly expanded and with slender and dense ventral hairs; hind coxa with 2 or 3 setulae on posterior surface; hind femur with a complete a row, distal 2 setae stout (at least as long as the width of hind femur), pv row stout, with numerous hair rows on ventral surface; hind tibia with 1 median av, 3 or 4 ad and 1 stout median d.

Abdomen long and flattened, ground-color reddish-yellow, with grayish-white pruinosity in lateral part; tergites 3 to 5 each with a median dark vitta, sternite 1 bare; sternite 5 with dense setae, over 30 pairs, apex distinctly indented, base distinctly protruded, about 4 times as wide as long; cercal plate slender and pointed apically and weakly bifurcate.

Female: Unknown.

Remarks: Xue and Wang (1998) described one new subspecies of Piezura , P. graminicola shanxiensis . Moores and Savage (2005), working from the Chinese description and English diagnosis, treated the taxon as a subspecies of Piezura pardalina Rondani, 1866 but questioned whether it was deserving of subspecific status. We have re-examined the holotype of P. graminicola shanxiensis and have provided a comprehensive description of the taxon above. We also undertook a phylogenetic analysis of all Piezura species to make clear the status of this taxon. Our results support a sister-group relationship between P. nearctica and P. shanxiensis and also indicate that the latter is not closely related to Piezura pardalina .

Moores and Savage (2005) provided a key in their work to males of Piezura species and keyed out P. shanxiensis in the last couplet along with P. nearctica . However, the diagnostic characters, i.e., the number of setae on hind tibia and the vitta on abdominal tergites 3–5, are ambiguous. In this work, we find Piezura shanxiensis can be separated from P. nearctica in having the fore femur mostly yellow except for the apical part that is black (not infuscated along most of dorsal surface), and sternite 5 with dense setae (over 30 pairs, not about 10 pairs) and about 4 times (not 3 times) as wide as long. So we can confirm that P. shanxiensis should be given full species status. This species is also different from P. pardalina in having the frons about 1.7 (not 0.9–1.0) times as wide as width of first flagellomere, acr in four (not three) irregular rows, hind tibia with 3 or 4 (not 2) ad, cercal plate slender and pointed apically and weakly bifurcate in ventral view, and sternite 5 with dense setae of over 30 pairs.

Specimens examined: Holotype male, China: Shanxi: Fangshan County: Pangquangou (37°54'N, 111°18'E), 26.vi.1990, Coll. M.F. Wang and Y.X. Wu; paratype, 1 male, 24.vi.1990, other data same as holotype.

Distribution: China (Shanxi).