Dexia rustica ( Fabricius, 1775 )

Zhang, Chun-Tian, Shima, Hiroshi & Chen, Xiao-Lin, 2010, A review of the genus Dexia Meigen in the Palearctic and Oriental Regions (Diptera: Tachinidae) 2705, Zootaxa 2705, pp. 1-81 : 59-61

Dexia rustica ( Fabricius, 1775)

Figs. 69−72

Musca rustica Fabricius, 1775: 777 .

Dexia rustica: Robineau-Desvoidy 1830: 311 . — Macquart 1834: 190, 1835: 211. — Zetterstedt 1844: 1264, 1859: 6172. — Schiner 1861: 560 (key). — Rondani 1862: 75. — Robineau- Desvoidy 1863b: 389. — Brauer & Bergenstamm 1893: 174 (key). — Pandellé 1896: 160 (key). — Bezzi & Stein 1907: 445 (catalog). — Stein 1924: 238. — Lundbeck 1927: 269. — Emden 1954: 30 (key). — Sabrosky & Arnaud 1965: 982 (catalog). — Kolomiets 1970: 59, 64 (key and redescription). — Crosskey 1976: 45, 177. — Crosskey 1977: 601 (catalog). — Dear & Crosskey 1982: 831 (catalog). — Mesnil 1980: 41 (redescription). — Richter & Farinets 1983: 818 (1st instar larva). — Herting 1984: 143 (catalog). — Crosskey et al. 1986: 282 (proposed type species designation). — ICZN 1988 (type species). — Herting & Dely-Draskovits 1993: 366 (catalog). — Tschorsnig & Herting 1994: 80, 156. — Ziegler 1998: 29, 101, 164−165, 185 (larvae and puparia). — O’Hara et al. 2009: 29 (catalog).

Musca provenio Harris, 1780: 142 . — Herting 1984: 143 (as junior syn. of D. rustica ).

Dexia flavicornis Meigen, 1826: 42 . — Herting 1972: 7 (as junior syn. of D. rustica ).

Dinera fulvipes Robineau-Desvoidy, 1830: 308 . — Herting 1974: 39 (as syn. of D. rustica ).

Dexia grisea Robineau-Desvoidy, 1830: 314 . — Macquart 1834: 191, 1835: 212. — Rondani 1862: 75. — Robineau- Desvoidy 1863b: 389 (as syn. of rustica ). — Bezzi & Stein 1907: 445 (as syn. of D. rustica ). — Herting 1974: 40 (as syn. of D. rustica ).

Dexia testacea Macquart, 1834: 191 — Macquart 1835: 212. — Herting 1976: 9 (as syn. of D. rustica ).

Ida petiolata Robineau-Desvoidy, 1863b: 389 . — Bezzi & Stein 1907: 445 (catalog, as syn of D. rustica ). — Herting 1974: 40 (as syn. of D. rustica ).

Dinera grisesescens Robineau-Desvoidy, 1863b: 356 . — Herting 1974: 39 (as syn. of D. rustica ). — Mesnil 1980: 41.

Diagnosis. Thoracic dorsum with 4 longitudinal vittae; lower calypter with short fringe; thorax and abdomen wholly covered with yellowish pruinosity; 3−4 katepisternal setae; tegula reddish yellow; legs reddish yellow.

Description. Mesnil (1980) redescribed this species in detail. Here we give additional measurements and some diagnostic characters.

Body length. Male & female: 8.4−12.7 mm.

Male. Head. Fronto-orbital plate and parafacial with grayish white pruinosity; antennae and palpus reddish yellow. Frons 1/6−1/7 times as wide as head width; facial carina developed, ridge pointed; parafacial 2−3 times as wide as 1st flagellomere; gena about 3/7 times as wide as eye height; 10−12 inclinate frontal setae; inner vertical seta about 1/2 eye height, twice as long as hair-like outer vertical seta. 1st flagellomere about twice as long as pedicel; total width of arista including plumosity 2−3 times as wide as 1st flagellomere; prementum 2.5−3 times as long as wide; palpus about as long as prementum or 1st flagellomere. Thorax black, with grayish yellow pruinosity, with 4 longitudinal black vittae on dorsum, inner vitta about 1/6 as wide as pruinose portion between inner and outer vittae and 1/3−1/4 as wide as outer vitta on presutural scutum. 2 presutural and 2 postsutural acrostichal setae; 3 presutural and 3 postsutural dorsocentral setae; 3 postsutural intra-alar setae; 3 supra-alar setae, anterior one fine, 1/2−1/3 as long as posterior two; 4 postpronotal setae, inner 2 weak; prosternum about 3 times as long as wide; proepisternum bare; 3−4 katepisternal setae. Wing hyaline; tegula reddish yellow; basicosta dark brown; costal spine about as long as crossvein r-m; relative lengths of 2nd, 3rd and 4th sectors of costa about 9:16:9; vein M from dm-cu crossvein to its bend about 2.5 times distance between the bend and wing margin. Lower calypter with short fringe on outer margins. Legs reddish yellow; fore tarsi reddish to brown, mid and hind tarsi dark; mid tibia with 2 posterodorsal setae; hind tibia with 2−3 anterodorsal, 2 posterodorsal and 2−3 ventral setae. Abdomen yellow, weakly dark brown on mid-dorsal longitudinal portion of tergites, with whitish yellow, somewhat grayish, pruinosity on tergites; syntergite 1+2 with 2 lateral marginal setae, without median marginal setae; tergite 3 with a pair of median discal, 1 pair of median marginal and 1 lateral marginal setae; tergite 4 with 2 pairs of discal and a row of marginal setae; tergite 5 with some irregular discal and a row of marginal setae. Male terminalia. V-shaped median cleft of sternite 5 deep, posterior lobe blunt apically; cerci long and pointed at apex; surstylus narrow, apex bluntly rounded; distiphallus long, apical membranous portion about 1/4 as long as basal sclerotized portion; postgonite shorter than basiphallus.

Female. Frons about 2/5 as wide as head width; parafacial about 3 times as wide as 1st flagellomere at middle height; gena 2/3−3/4 eye height. 7−8 inclinate frontal setae; 2 proclinate orbital setae; 1 outwardly directed prevertical seta; strong inner vertical seta 3 times as long as outer vertical seta. Claw and pulvillus shorter than tarsomere 5. Vein M from dm-cu crossvein to its bend 1.7−2 times distance between the bend and wing margin. Abdomen ovate, without discal setae. Other characters as in male.

Type material. Musca rustica Fabricius was described from Copenhagen , Denmark, from an unknown number of specimens of unspecified sex (1 specimen in ZMUC, only thorax remaining) ( O’Hara et al., 2009: 29) (not examined) .

Additional material examined. FRANCE. 1 male, Chavena S. & O., 10.viii.1961, J. U. MeGuire, det. Woodley, 1996 ( USNM) . SWEDEN. 1 male, 1 female, no record, det. C. Bergström, 2001 . 2 males, Dornbach , 4.viii.1905 and 21.viii.1909 ( SMNH) . POLAND. 2 males, Tykocin , Lipnicka, Kepa, UTM: FD29, 19.vii.2001 . 2 females, Tykocin , Broniszewo, UTM: FD19, 14.vii.2001, collected and determined by C. Bystrowski ( SNU) .

Distribution. China (Sichuan, Xizang); Europe (northwards to England, Sweden); Russia (North European territory, West Siberia).

Remarks. This species is similar to D. vacua , but is distinguished from it in having shorter antenna and prementum, thorax and abdomen densely covered with yellowish pruinosity, and 3 katepisternal setae. There are some varied shape between cerci from Kolomiets (1970: 60) and our cerci here. It has been recorded from Xizang and Sichuan ( O’Hara et al. 2009: 29), but it may have been misidentified from China and its occurrence there needs to be confirmed.

Host. Scarabaeidae : Amphimallon solstitialis L., Melolontha spp. , Phyllopertha borticola L., Rhizotrogus aequinoctialis Herbst and R. marginipes Muls ( Tschorsnig & Herting 1994: 156).