Miltogramma (Stephanodactylum) bimaculatum Chao & Zhang, 1988a : 277

Zhang, Dong, Zhang, Ming, Li, Zijuan & Pape, Thomas, 2015, The Sarcophagidae (Insecta: Diptera) described by Chien-ming Chao and Xue-zhong Zhang, Zootaxa 3946 (4), pp. 451-509 : 464-466

Miltogramma (Stephanodactylum) bimaculatum Chao & Zhang, 1988a: 277 . China, Yunnan, Dêqên, East slope of Baimang Snow Mountain.

Originally included specimens: Described from two males.

Name-bearing type: Holotype ♂: Yunnan, Dêqên, East slope of Baimang Snow Mountain/ 3300m / Chinese Academy of Sciences [white label in Chinese, in black print except “Dêqên, East slope of Baimang Snow Mountain/ 3300m ” handwritten in black ink]// 1981. VIII.28 / Collected by X.Z. Zhang [“1981. VIII.28 ” handwritten in black ink, remaining in black print, in Chinese]// HOLOTYPE [red label, in black print]// IOZ(E)216064 [blue label, in black print]// ♂ [white label, in black print]// Miltogramma / (Stephanodactylum) / bimaculatum / Zhao & Zhang [white label, in black print]// Miltogramma / (Stephanodactylum)/ bimaculatum Chao et Zhang / Identified by C.M. Chao [“Identified by C.M. Chao” in black print, in Chinese, remaining handwritten in blue-black ink].

Holotype in good condition except with pollinosity obliterated on part of the abdomen; terminalia in situ.

Current identity: Miltogramma bimaculata Chao & Zhang, 1988 , as correctly listed by Pape (1996) and as treated by Xue & Chao (1998, as M. (Stephanodactylum) bimaculatum), but see further under remarks.

Additional type specimen: Paratype 1♂: Yunnan, Dêqên, East slope of Baimang Snow Mountain, alt. 3300m, 28.VIII.1981, Coll. by X.Z. Zhang. Specimen in NZMC.

Remarks: According to Chao & Zhang (1988a) and Fan (1992), this species resembles M. asiatica Rohdendorf in general appearance, but can be distinguished from it by having two lateral black spots on each of tergites 3 and 4, the length of tarsomere 5 longer than tarsomeres 3+4, frontal bristles denser and thinner in upper part, parafacial with slender black setae, and head reddish yellow, covered with yellow pollinosity. As mentioned under M. albifrons above, there is no modern revisionary work on the genus Miltogramma , and there is in particular a strong need for high-quality documentation (photos, SEM) of the male fore tarsus from different angles to show the often highly diagnostic, species-specific setal configuration. Males in the group of species often separated as subgenus Stephanodactylum Rohdendorf have a tuft of particularly long setae on the fourth tarsomere, but illustrations currently available in the literature are few and inconclusive. In M. varia Verves , this tuft appears to be dorsal ( Verves, 1984, fig. 9), not lateral as in M. bimaculata ( Fig. 8 F) and M. punctata ( Rohdendorf, 1930, fig. 39; Séguy, 1941, fig. 382; Pape, 1987, fig. 26; Povolný & Verves, 1997, fig. 35). Unfortunately, the male fore tarsus of other members of this species group has never been documented, and specimens of all species except M. punctata Meigen are rare in collections and have not been available for the present study. Miltogramma bimaculata has sparse setulae in the upper part of the parafacial, while this plate is bare in M. punctata . Also, the abdominal pattern of M. bimaculata with yellow lateral markings is not found in M. punctata . However, the abdominal pattern of M. asiatica was described by Rohdendorf (1930: 35) to be very similar: “Abdomen dunkel, an den Seiten des 2., 3. und 4. Tergits gelblich, 2. Tergit mit deutlichem schwarzen Mittelfleck und mit undeutlich abgegrenzten Seitenflecken von lichtbrauner bis schwarzbrauner Farbe.” [Abdomen dark, laterally on 2nd, 3rd and 4th tergites yellowish, 2nd tergite with distinct black central spot and with indistinctly delimited lateral spots of light brown to blackish brown colour]. We suspect that M. bimaculata is a junior synonym of M. asiatica , but as we consider the present evidence as inconclusive we prefer to keep M. bimaculata as a valid species until thorough comparative studies can be undertaken.

Redescription of Male: Body length 8.0– 8.3 mm ( Fig. 8 A). Eye bare, deep red. Fronto-orbital plate, parafacial yellow, postocular strip yellow with silvery pollinosity; parafacial with slender black bristles, 1.7× as broad as fronto-orbital plate. Frontal vitta yellow, about 2.0× as broad as fronto-orbital plate in median part; frons at vertex 0.35× head width ( Fig. 8 C, D); frontal row of 15 bristles; outer vertical bristle differentiated from postocular bristles, one upper orbital and seven proclinate orbital bristles. Gena ground color yellow, with short bristles, height 0.12× eye height in lateral view ( Fig. 8 B). Antenna black, not reaching the level of vibrissal insertion, first flagellomere 1.7× as long as pedicel; arista bare ( Fig. 8 C), postocular bristles in one row; vibrissa reduced ( Fig. 8 B, C). Palpus yellow, slightly expanded in distal part.

Thorax ground color black with silvery gray pollinosity, without distinct black dorsal vittae. Chaetotaxy: acrostichals 0+1, dorsocentrals 2+3, intra-alars 1+1, supra-alars 1, postalars 2, postpronotals 2 or 3, notopleurals 2, scutellum with 1 marginal, 1 subapical, 1 basal, 1 prebasal, and 1 discal bristles. Pleuron with meropleurals 10 or 11, katepisternal bristles 1: 1, prosternum, proepimeron and proepisternum all bare, postalar wall with short yellow bristles.

Wing hyaline ( Fig. 8 A); subcostal sclerite and basicosta yellow, bare; tegula yellowish brown; costal spine not differentiated; vein R1 bare, two or three dorsal bristles at node of R2+3-R4+5, lower calypter yellowish white.

Legs black with gray pollinosity; fore femur with dense and long bristles along dorsal, posterodorsal, posterior, posteroventral and ventral margins, fore tibia with one median posterior bristle, fore fourth tarsomere with long bristles cluster ( Fig. 8 F); mid femur with one row of anterior bristles in basal half, one row of ventral bristles and one row of posterior bristles, mid tibia with one sub-median ventral, one median posterior, two anerodorsal and two posterodorsal bristles; hind femur with one row of dorsal bristles, hind tibia with one row of anterodorsal bristles (about 12), one row of posterodorsal bristles (about 12) and one row of ventral bristles in distal half.

Abdomen long oval, ground color blackish yellow; tergites 1+2 with large median black spot, yellowish in the lateral part, all tergites with complete row of marginal bristles ( Fig. 8 E), tergites 3 and 4 each with two black spots laterally to the median spot.

Figures

FIGURE 8. Miltogramma (Stephanodactylum) bimaculatum Chao & Zhang, 1988 [= Miltogramma bimaculata Chao & Zhang, 1988], male. A. Body, lateral view, holotype. B. Head, lateral view, holotype. C. Head, anterior view, holotype. D. Head, anterolateral view, holotype. E. Abdomen, dorsal view, holotype. F. Right fore tarsus, anterodorsal view, paratype. G. Labels, holotype. H. Labels, paratype. Scales: A & E = 2.00 mm, B – D & F = 1.00 mm.