Eumacronychia persolla (Reinhard, 1965)

Xu, Wen-tian, Zhang, Dong & Pape, Thomas, 2018, Biology of Eumacronychia Townsend, with a redescription of E. persolla Reinhard, 1965 (Diptera, Sarcophagidae), ZooKeys 783, pp. 55-65 : 58-61

Eumacronychia persolla (Reinhard, 1965) Figs 1, 2, 3, 4

Eumacronychia persolla Reinhard, 1965: 349. Type locality: USA, California, Contra Costa County, Antioch. HT ♂, CAS.

E. personella : Lopes (1969: 3), incorrect subsequent spelling of persolla Reinhard, 1965.

E. persola : Lopes (1982: 427), incorrect subsequent spelling of persolla Reinhard, 1965.

Redescription.

Male (Figs 1, 3, 4). Body length 8.0 mm (Fig. 1A). Head almost entirely yellowish, including gena, postgena, occipital bridge and median occipital sclerite. Occiput greyish black. Eyes bare. Fronto-orbital and parafacial plates with whitish or silvery grey pollinosity, parafacial about 1.5 × as broad as fronto-orbital plate at its narrowest point, bare or with some very small, black setulae forming an ill-defined brown colour antero-ventrally (i.e., along lower margin close to genal groove). Frontal vitta reddish yellow, wide, about 1.8 × as wide as fronto-orbital plate in median part, sparsely pollinose in upper part. Frons at vertex 0.3 × head width, with rows of 10 or 11 frontal setae. Outer vertical seta well differentiated from postocular setae. Inner vertical seta strong and more than 2.0 × as long as outer vertical seta. Two proclinate and one reclinate fronto-orbital setae. Fronto-orbital plate otherwise with only a few setulae at vertex. One pair of strong ocellar setae directed antero-laterally. Gena silvery pollinose on pale ground colour, with sparse and short black setae, 0.3 × eye height in lateral view. Antenna orange (postpedicel may be dirty orange). Arista entirely brown or with third aristomere orange in proximal part (up to 0.4 of length), 1.4 × as long as postpedicel, thickened in proximal half, with micropubescence (most distinct just distal to middle). Postpedicel about as long as palpus. Vibrissa well developed, with a few supravibrissal setulae. Proboscis brown. Palpus orange or dark yellowish.

Thorax black in ground colour; scutum with grey pollinosity and with three black dorsal vittae. Chaetotaxy: acrostichals 0+1, dorsocentrals 2+3, intra-alars 0, supra-alars 2, postalars 2, postpronotals 2, notopleurals 2; scutellum with two pairs of lateral, one pair of discal, and one pair of apical setae. Wing hyaline, subcostal sclerite and basicosta yellow; colour of tegula with at least the distal margin orangish or light brown; costal spine not differentiated; node of R2+3-R4+5 with 5-6 setae dorsally. Legs blackish. Fore femur with rows of postero-ventral and postero-dorsal setae; fore tibia with a row of six antero-dorsal setae and 1 sub-median posterior seta. Mid femur with 4 ventral setae and 2 posterior setae; mid tibia with a row of antero-dorsal setae, 2 postero-dorsal setae and 1 ventral seta. Hind femur with a row of 5 antero-dorsal setae and a row of 6 ventral setae in basal half; hind tibia with a row of antero-dorsal setae, 1 sub-median antero-ventral and 2 postero-dorsal setae.

Abdomen long oval, ground colour usually blackish except for tergite 5, which is reddish (dark or ‘dirty’ reddish anteriorly, although specimens with an almost entirely reddish abdomen are known (Fig. 1C), possibly a result of bleaching from storage in ethanol), tergites 3-5 each with a broad band of silvery pollinosity anteriorly, covering about 75% of tergite 3, 50% of tergite 4 and 30% of tergite 5. Tergite 3 with a pair of median marginal setae, tergites 4 and 5 with a complete row of strong marginal setae. Terminalia reddish to orange. Syntergosternite 7+8 bare. Epandrium with scattered short setae, especially in dorsal part. Cercus gently curved anteriorly in profile, tapering, basal third with long dense setae dorsally. Surstylus broad in proximal 0.8, narrowing to a truncated apex with postero-apical ‘corner’ slightly twisted laterally (Fig. 3B). Pregonite long and pointed; postgonite with a fine seta close to apex. Distiphallus elongate and sickle-shaped, with a small subapi cal constriction before the lightly sclerotised tip, ventro-median sclerotisation running the full length of distiphallus. Dorsal part of distiphallus entirely membranous, armed with small cuticular spines on most of its surface (Fig. 3A). Epiphallus short, tapering and slightly curved, with a pointed apex and slanting at an angle of about 45° (Fig. 3C).

Female (Fig. 2). Body length 6.0 mm. Similar to male but with frontal vitta narrower and about 1.1 × as broad as fronto-orbital plate at its narrowest point. Abdomen broadly ovate, median marginal setae on tergite 3 absent.

Material examined.

Holotype male [examined from photographs]: USA, California, Contra Costa County, Antioch, 3.X. 1985, J Powell leg. (CAS); 1 male, 1 female: USA, California, Imperial County, Algodones Dunes, 33°02'N 115°08'W, 17-22.IX.2008, RB Kimsey & TJ Zavortink leg., Malaise trap (NHMD); 1 male: USA, California, Davis, 20.VII.1953, EC Carlson leg., "Fish meal bait" (NHMD); 1 male: USA, California, Sacramento, 31.VII.1952, PH Arnaud leg. (NHMD); 1 male: USA, Oregon, Josephine County, Whisky Creek, 27.VI.2002, W Reeves leg. (NHMD).

Remarks.

The almost entirely reddish abdomen in both males and females from the Algodones Dunes (Figs 1, 2) is noteworthy, but the available material is insufficient to decide whether this is a natural condition or an artifact from being preserved in ethanol. Differences in the male terminalia between the holotype (Fig. 4D) and the male from Algodones Dunes (Fig. 3) are here considered to be due to differences in preservation as well as minor differences in orientation. The distiphallus of the dry-mounted holotype has the membranous lateral and dorsal parts of the distiphallus mostly collapsed against the ventro-median sclerotisation, while the KOH-treated phallus stored in glycerine and examined for the present study has the distiphallic membrane fully expanded (Fig. 3A). The slightly skewed cerci in Fig. 4D make them appear more slender than in the perfectly aligned and strict lateral view (Fig. 3B).

Distribution.

Nearctic - Mexico (Baja California Norte, Baja California Sur, Sonora), USA (Arizona, California, Idaho, Nevada, Oregon [new record], Utah, Washington).