Piezura graminicola (Zetterstedt, 1846)

Moores, Amy & Savage, Jade, 2005, A taxonomic revision of Piezura Rondani (Diptera: Fanniidae), Zootaxa 1096 (1), pp. 41-59 : 47-49

Piezura graminicola (Zetterstedt, 1846)

Figs. 1A–D

Anthomyza graminicola Zetterstedt, 1845: 1361 . Nomen nudum.

Anthomyza graminicola Zetterstedt, 1846: 1747

Mycophaga boletorum Rondani, 1866: 188

Platycoenosia mikii Strobl, 1894: 72

Choristomma pokornyi Stein, 1895: 138

Coenosia externa Pandellé, 1899: 152

Diagnosis: Distance between eyes at narrowest point 3.1–3.5x width of first flagellomere, aristal hairs plumose, as long as width of first flagellomere, postpronotum dark brownishgray to brownish­black, costal spine well developed, hind tibia with one av on apical half.

Type material examined: Holotype ♂ labeled: [with red and light blue tag = Skåne, Tranås, Esperöd, where Zetterstedt spent the summer of 1820]; A. gramini/ cola. Z.; Anthomyza / graminicola/ Zett/ det. A.C. Pont 1980; ZML 2004/ 352; Type No. 2995:1/ Fanniidae (MZLU) .

Other material examined: Over 40 ♂ and ♀. NEARCTIC: Canada: Ontario: Griffith, Marmora, Metcalfe , North Gower , Ottawa , Point Pelee , Rondeau Nat. Pk , St. Lawrence Island Nat. Pk. ; Quebec: Mont St. Hilaire ; USA: Maryland, Washington DC, Tennessee. PALAEARCTIC : Germany: Berlin ; England: Kent (Abbey Woods), Oxfordshire (Taynton Fen); Hungary: Csévharaszt. ( BMNH, CAS, CNC, LEM, USNM)

Description:

Male: body length 5.0–6.0 mm.

Head: Background color dark brownish­gray; clearly dichoptic, with frons at narrowest point 3.1–3.5x width of first flagellomere; frontal vitta dark­grayish brown to orange­brown; anterior fronto­orbital plate with 2–4 medioclinate fr and with a few setulae; 1 reclinate upper orb, 1 latero­reclinate lower orb; parafacial grayish­brown pollinose; fronto­orbital plate grayish­brown pollinose; first flagellomere 1.8–2.0x as long as wide; scape, pedicel and base of first flagellomere yellow, distal half of first flagellomere dark grayish­brown; arista plumose, with longest hair as long as width of first flagellomere.

Thorax: Background color brownish­gray to brownish­black; three faint and narrow dorsal vittae present, often more pronounced in chemically dried specimens; anterior presutural dc one­half length of posterior dc; pre­sutural acr triserial, postsutural acr triserial or irregular; scutellum with 1 strong ap sctl, 2 weak ds sctl, 2 b sctl, the anterior one weaker, and 2–3 accessory discal setulae; postpronotum brownish­gray to brownishblack with edges usually yellowish.

Legs: Yellow; t3 with one av on apical half, 2 ad on apical half, lower one much weaker, 1 d, and often with a few erect pd setulae on apical third; f3 with a row of short av on basal half and 3–4 stronger av on apical half, 1 row of ad, stronger on apical half, 1 preapical d, 1 preapical ad and 1 row of short pv with 2–4 stronger pv on apical third.

Wings: Costal spine strong, 2.0–3.0x as long as surrounding costal setulae.

Abdomen: Tergites 3 and 4 laterally darkened; without dark median vitta.

Postabdomen: Mesolobus approximately 1.3x as high as wide with apex weakly bifurcate ( Fig. 1A ); sternite 5 longer than in other species, 1.3x as wide as long ( Fig. 1B ).

Female: body length 4.5–5.0 mm.

Head: As in male except frons occasionally slightly wider.

Thorax: As in male, but with dorsal vittae usually more pronounced.

Legs: As in generic description except; t3 with 1 ad on apical half, 1 pre­apical ad, 1 av on apical half, 2 distinct d on apical half.

Wings: As in male.

Abdomen: Pale yellow with lateral margins of tergites 2–5 strongly infuscated (visible only in ventral view).

Postabdomen: See generic description and illustrations ( Figs 1C, 1D ).

Distribution: PALAEARCTIC – Europe (see Remarks): Albania, Austria, Corsica, Czech Republic, Denmark, Estonia, Finland, France, Germany, Great Britain, Hungary, Italy, Netherlands, Norway, Poland, Slovakia, Spain, Sweden, Switzerland; Asia: China (see Remarks), Japan. NEARCTIC – Canada: Ontario, Quebec; USA: Washington, Oregon, Wisconsin to Maine, Washington DC to Tennessee and Louisiana.

Remarks: Due to the taxonomic confusion regarding the identity of P. graminicola and P. pardalina (see Introduction), most material determined as P. graminicola in European collections is in fact P. pardalina . No Chinese material of this species was examined, but it was recently recorded from Palaearctic China (as P. boletorum ) by Xue & Wang (1999).

Figures

FIGURE 1. Piezura graminicola (Zetterstedt). A. Male genitalia external structures, posterior. B. Male sternite 5, ventral. C. Female spermatheca. D. Female genitalia, ventral. Abbreviations: epand, epandrium; meso, mesolobus; sur, surstyli; S6, sternite 6; S7, sternite 7; S8, sternite 8; S10, sternite 10.