Empis (Empis) demissa Collin

Shamshev, Igor V., 2020, Empis s. str. (Diptera: Empididae) from Egypt, Israel and Syria: notes on some species described by J. E. Collin and a key to species, Zootaxa 4743 (2), pp. 266-274 : 267-269

Empis (Empis) demissa Collin

( Figs 1–5 )

Collin, 1949: 184, fig. 9. Type locality (by lectotype designation): Mariout, Egypt.

Other references: Chvála & Wagner, 1989: 265 (catalogue); Pont, 1995: 57 (type data); Yang et al., 2007: 101 (catalogue).

Note on the type-series. Collin (1949) listed four males and two females in his original description of E. demissa . I did not examine two males and one female syntype that should be housed in Cairo University, Egypt.

Type material examined. LECTOTYPE (here designated in order to fix identity of the species): ♂ ( Fig. 1 ), labelled ( Fig. 2 ): “MARIOUT/ 23.2.[19]22”; “ Coll. Efflatoun / EGYPTE ”; “VC-TYPE 697/ Empis ♂ / demissa/ Col- lin”; “ Lectotypus / Empis / demissa Collin, 1949 / design. Shamshev, 2019 [red label]” ( OUMNH).

PARALECTOTYPES. 1 ♂, 1 ♀, same data as lectotype except red label “ Paralectotypus, Empis demissa Collin, 1949 , design. Shamshev, 2019” ( OUMNH) .

Diagnosis. Mid-sized (body about 4.5 mm) greyish flies having yellow halteres, pale setose abdomen, moderately long labrum, scutum with three vittae, wings faintly infuscate, anal vein complete. Male: phallus short, thick. Female: legs with only simple setae.

Re-description. Male ( Fig. 1 ). Lectotype wing length 4.6 mm. Head with dense light greyish pruinescence on face, frons, postgena, ocellar triangle and occiput. Holoptic, eye with upper ommatidia enlarged. Frons represented by very small triangular space below ocellar tubercle and larger subtriangular space above antennae, bare. Ocellar triangle with 2 long and some short fine setae. Occiput with numerous black setae on upper part and pale setae on lower part. Antenna black (sometimes scape and pedicel slightly paler); scape and pedicel short, scape slightly longer, both with short setulae; postpedicel conical, about 2X longer than wide; stylus long, nearly as long as postpedicel. Palpus dark; with numerous long, dark fine setae. Proboscis with labrum nearly 1.5X head height.

Thorax densely greyish pruinescent; scutum viewed dorsally with brownish vittae along rows of dorsocentrals and narrower dark vitta along rows of acrostichal setae. Prosternum bare. Proepisternum with numerous pale hairlike setae on lower portion and similar setae on upper portion opposite anterior spiracle. Antepronotum with several dark to pale setae on each side (in lectotype dark setae dorsally and pale setae laterally). Postpronotal lobe with 1 long strong black and numerous short fine pale and dark setae. Mesonotum with black well differentiated setation; 1 long presutural intra-alar (flanked with 2–3 setulae), 1 long presutural supra-alar (with some additional setulae anteriorly and posteriorly), 3 notopleurals with several additional setulae anteriorly, 2 postsutural supra-alars of different lengths (posterior seta longer; with several additional setulae anteriorly), 1 postalar and 4 long scutellars (sometimes with 1 or 2 shorter setae); acrostichals arranged in 2 irregular rows, long, lacking on prescutellar depression; presutural dorsocentrals arranged in 2–3 irregular rows, nearly as long as acrostichals, postsutural dorsocentrals 1–2-serial, becoming longer toward scutellum, 3–4 prescutellar pairs longest (nearly as long as scutellars). Laterotergite with numerous pale setae. Anterior and posterior spiracles yellow.

Legs long, slender, mostly brownish, subshiny and with black setation (except noted); fore tibia near extreme base, mid and hind tibiae tawny (paler closer to base). Coxae densely greyish pruinescent, with numerous pale fine setae. Fore femur with row of long pale anteroventral hair-like setae (longest setae somewhat longer than femur width) and row of similar pale posteroventral setae on basal part, becoming darker toward apex of femur; some hairlike setae closer to apex posteriorly. Mid femur with cluster of several strong black, long setae near extreme base ventrally; anterodorsal row of strong setae, very long and partly pale closer to base, becoming shorter toward apex of femur; anteroventral and posteroventral rows of fine long setae. Hind femur with row of strong, long anterodorsal setae yellowish on basal part; mostly pale (except subapical part) fine, moderately long anteroventral setae; some pale fine setae closer to base ventrally and posteriorly. Fore tibia with numerous moderately long, fine setae posterodorsally and posteriorly. Mid tibia with 3–4 very long, strong and usually 1–2 additional shorter dorsal setae (except 1 similar seta of subapical circlet), 4–5 somewhat shorter posterodorsals, 8–9 very long anteroventrals (similar to longest dorsal setae) and some moderately long posteroventrals. Hind tibia slightly curved and compressed laterally; with numerous moderately long anterodorsal and posterodorsal setae; no seta in posteroapical comb. Fore basitarsus slightly thickened but not broader than fore tibia at apex, with somewhat longer setulae posterodorsally and posteriorly; hind basitarsus slender, with 2–3 moderately long setae dorsally.

Wing membrane faintly infuscate. Basal costal seta present, long. Pterostigma indistinct. Veins brownish, well sclerotised. CuA+CuP (anal vein) complete. Cell dm short, with elongate apex. Anal lobe well-developed; axillary incision acute. Squama pale yellow, pale fringed. Halter yellow.

Abdomen dark in ground-colour, almost entirely densely light grey pruinescent, tergites 7–8 subshiny laterally, sternites 7–8 almost blackish shiny (Collin misinterpreted sternite 8 as sternite 7); almost entirely covered with pale to yellowish setae, tergites with some dark short setae dorsally, sternite 8 with some dark posteromarginal setae. Sternite 8 enlarged, inflated.

Terminalia (not dissected) small ( Figs 3, 4 ). Cercus black, somewhat concave dorsally (lateral view), covered with dark setulae. Epandrial lamella black, mostly faintly pruinescent, subtriangular, subshiny, with some dark setae on upper margin and apex and with longer yellowish setae along lower margin. Hypandrium black, subshiny, subtriangular, bare. Phallus yellow, short, thick.

Female ( Fig. 5 ). Dichoptic, eyes separated by broad frons bearing marginal setulae. Occiput and palpus with sparser and shorter setae than in male. Thorax with shorter setae. Tibiae and tarsi extensively yellowish, only fore tibia brownish yellow closer to apex and tarsomeres 2–4 brownish; fore basitarsus slender. Legs with only simple setae; fore femur covered with minute setulae; fore tibia with somewhat longer setulae posterodorsally; mid femur with short anterodorsal setae on basal 3/4 and anteroventral setae on apical half; hind femur with some stronger short setae anterodorsally and short finer setae anteroventrally; mid and hind tibiae with scattered short anterodorsal and posterodorsal setae (more numerous on hind tibia). Abdomen covered with short setae; tergites 3–5 narrowly subshiny anteriorly, tergites 6–7 broadly shiny, tergite 8 entirely shiny. Cercus long, slender, with dark setulae.

Distribution. Palaearctic: Egypt.

Remarks. In addition to the species keyed below, Empis demissa resembles E. genualis Strobl known from temperate and warm parts of Europe, Caucasus, Azerbaijan and Turkey ( Shamshev 2016). Collin (1949) compared both species in his original description of E. demissa . The male of E. genualis can be distinguished from E. demissa primarily by the subshiny abdomen. The female of E. genualis differs from E. demissa by intensively pennate legs, including the mid and hind coxae ( Syrovátka 2000).

Figures

FIGURES 1–5. Empis (Empis) demissa Collin. 1. male habitus, lectotype, lateral view; 2. lectotype labels; 3. male postabdomen, lectotype, lateral view; 4. male terminalia, lateral view (from Collin, 1949, fig. 9); 5. female habitus, lateral view.