Rhamphomyia (Pararhamphomyia) simplex Zetterstedt

Rhamphomyia (Pararhamphomyia) simplex Zetterstedt

(Figs 46, 47)

Rhamphomyia simplex Zetterstedt, 1849: 3035. Type-locality: Copenhagen (Denmark).

Other references: Melander, 1928: 205 (catalogue); Nielsen et al., 1954: 52 (Iceland); Gorodkov & Kovalev, 1969: 624 (key); Messersmith, 1982: 37 [Iceland records]; Barták & Danielson, 2007: 112 (♂ lectotype designation).

Rhamphomyia (Pararhamphomyia) simplex Zetterstedt: Frey, 1922: 39 [key]; Frey, 1955b: 495 (revision); Collin, 1961: 372 (British empidids); Chvála & Wagner, 1989: 305 (catalogue); Yang et al., 2007: 176 (catalogue); Meyer & Stark, 2015: 204 (checklist); Shamshev, 2016: 70 (checklist).

Type material. Not examined.

Additional material examined. ICELAND. Breddalsvik, moist Luzula Empetrum moss pocket, 1360/1/1 -, 7.vii.1981, J.A. Downes (11 ♂, 2 ♀, CNC); nr. Breddalsvik, 1360/3/1 -, 7.vii.1981, J.A. Downes (2 ♂, CNC); 10 km E Hals, 3.vii.1962, B. V. Peterson & E. Bond (4 ♂, 9 ♀, CNC); 5 km S Möðrudalur, 4.vii.1962, B. V. Peterson & E. Bond (1 ♂, CNC) Myvatn, road to Skutustadir, 1357/2/15 -, 3.vii.1981, J.A. Downes (1 ♂, 3 ♀, CNC); Laxa River, Myvata, 1357/1/11 -, 3.vii.1981, J.A. Downes (10 ♂, 5 ♀, CNC).

Diagnosis. This darkly setose species is distinguished from other species of Pararhamphomyia by the shiny reddish brown legs, male tergite 7 shorter than tergite 8, male tergite 8 partially overlapping terminalia, and the phallus is rather short, broad basally, angulately curved, and partly concealed within the epandrium.

Redescription. Wing length 3.5–4 mm. Male. Head dark in ground-colour, with dense greyish-silvery pruinescence on face, frons, postgena and occiput. Holoptic, eye with ommatidia larger on upper half, smaller on lower half. Frons represented by very small triangular space below ocellar tubercle and larger subtriangular space above antennae, bare; face slightly divergent towards mouthparts; bare with oral margin reddish-brown. Ocellar triangle with greyish-silvery pruinescence; anterior pair of setae long, dark; 2 pairs of shorter setae posteriorly; postocellar setae finer and slightly shorter than posterior ocellar setae. Upper half of occiput bearing row of long, dark postocular setae; remaining occipital setae black, shorter and stouter than postocular setae; postgena setae subequal to postocular setae, finer than occipitals.Antenna with postpedicel and stylus darker than scape and pedicel; scape only slightly longer than pedicel; postpedicel about 3X longer than basal width; stylus subequal to scape length. Palpus dark reddish-brown, with dark setulae, some stouter. Clypeus pruinescent; labrum lustrous and dark reddish-brown; labellum grey with dark setae.

Thorax silvery grey pruinescence; postalar callus yellow-brown. Scutum with 2 very faint vittae between acr and dc rows. Proepisternum with 2–3 long, stout, dark setae; upper proepisternum in front of spiracle bare; prosternum bare. Antepronotum with row of dark, stout setae. Postpronotum with 1 pprn and several short, stout dark setae. Scutum with biserial dark acr, increasing in length posteriorly; dc biserial, slightly longer than acr, increasing in length posteriorly; 1 presut spal (= posthumeral) with several additional setae; 2–3 npl, with several shorter setae anteriorly; 1 prealar seta; 3 psut spal; 1 pal; 3–4 pairs of sctl. Laterotergite with cluster of long, stout and fine setae all of different lengths. Anterior and posterior spiracles brownish.

Legs reddish brown, shiny; coxae with grey pruinescence. Coxae with simple dark setae. Femora with 1 anteroventral and 1 posteroventral row of dark setae, shorter than width of femora, setae finer on fore femur, longer on mid and hind femora; hind femur with white ventral pile. Fore tibia with 3 anterodorsal setae; 4–5 posterodorsal setae with shorter setae intermixed; with circlet of stout preapical setae. Mid tibia with rows of dark, stout anterodorsal and posterodorsal setae, about as long as 2X tibial width. Hind tibia with row of long dorsal setae 2X longer than tibial width; row of posteroventral setae longer than tibial width (Fig. 46A); 1 long seta in posteroapical comb. Hind and mid tarsomere 1 with stout anteroventral and posteroventral setae, with circlet of preapical setae stouter and longer; hind tarsomere 1 slightly broader than fore and midlegs; setae of fore tarsomere 1 more slender than mid and hindlegs.

Wing faintly infuscate; basal costal seta present; pterostigma dark and distinct; all veins complete (except Sc); CuA+CuP faint extending to wing margin as fold; anal lobe well-developed; axillary excision obtuse. Halter knob white to yellowish white, base of stem darker brown.

Abdomen paler than thorax, mostly brownish-grey, with silvery pruinescence, posterior margin of tergites pale. Tergites covered in long dark setae; sternites with shorter setae. Sclerites of segments 6–8 thickened; posterolateral corner of tergites 6 and 7 slightly produced; sternite 7 slightly inflated laterally. Tergite 7 shorter than tergite 8; tergite 8 slightly produced into shield overlapping anterior margin of cerci (Fig. 46B), laterally divided into triangular sclerite, closely appressed with lateral margin of sternite 8; sternite 8 swollen, anterior corner enlarged and rounded.

Terminalia (Figs 46B) largely dark reddish-brown. Epandrium pruinose, swollen and rounded, ending with squared knob-like projection, and sharp, slim, finger-like epandrial lobe converging medially; epandrium margins bearing dark setae, decreasing in length and stoutness from base to dorsal margin. Cercus small, thinly sclerotized, 3X longer than broad, rounded, pruinose, dorsal margin bearing fine, erect setae, shorter than cercus length; subepandrial lobe 2X longer than cercus, more heavily sclerotized than cercus, dorsal margin bearing many long, fine, hair-like setae, ending in sharp spine-like projection at apex. Hypandrium rectangular, short. Phallus sharply curved basally, V-shaped; apical half angulate, bent nearly 90° towards cercus; partially concealed within epan- drium. Ejaculatory apodeme longer than high, almost as large as epandrium, tear-drop-shaped, lateral wings shorter than vertical wing.

Female. Similar to male; face with short lateral setulae; legs without pennate setae.

Distribution. In this study R. simplex is only recorded from Iceland (Fig. 47) and is unknown from the Nearctic Region. Rhamphomyia simplex is recorded from Iceland, northern Europe and northwestern Russia (Chvála & Wagner 1989; Shamshev 2016). Collin (1961) considered R. simplex a salt-marsh species confined to coastal regions, whereas in Iceland it occurs on vegetation in meadows and bogs inland, even in highlands (Nielsen et al. 1954).

Remarks. Rhamphomyia simplex keys to the R. breviventris species group in Barták & Kubík (2009).