Empis (Enoplempis), 1880

Empis (Enoplempis) View in CoL clava sp. nov.

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( Figs 131–134 View FIGURES 131–134 , 140, 141 View FIGURES 140–142 , 152 View FIGURES 152–153 )

Type material. HOLOTYPE ♂ ( Figs 131–134 View FIGURES 131–134 ), labelled: “USA: CALIF.: TulareCo. [? Kern Co.]/ Kern River , Campgrd. [35°26′N 118°52′W]/ No.3, alt. ca. 2900’/ 11-V-1971 / P. H. & M. Arnaud ”; “COLLECTION OF/ PAUL H. ARNAUD JR [green label]”; “ HOLOTYPE / Empis (Enoplempis) / clava Sinclair,/ Brooks & Cumming [red label]” ( USNM) GoogleMaps . PARATYPES: USA. California: Same data as holotype (1♂, USNM) GoogleMaps ; same data as holotype, except 10.v.1971 (1♀, USNM) GoogleMaps .

Diagnosis. This species is distinguished from other species in the E. (En.) clava group by the two pairs of brown vittae on the scutum ( Fig. 131 View FIGURES 131–134 ), long, thickened and wavy posterior preapical setae on the male hind femur, longer than apical width of femur and long fine, slender ventral setae on the male hind femur, slightly shorter than width of femur ( Figs 132–134 View FIGURES 131–134 ).

Description. Wing length 4.3–4.7 mm. Male. Head dark in ground-colour, with greyish pruinescence. Eyes narrowly separated on frons; frons slightly narrower than width of anterior ocellus; short setulae along inner margin of eye. Face without setae; short, slightly divergent towards mouthparts, with oral margin dark and shiny. Ocellar triangle elevated, with thin greyish pruinescence, with pair of parallel ocellar setae, longer than occipital setae and several pairs of short posterior setulae. Occiput bearing single row of setae, as strong as upper 2–3 postocular setae; lower postocular setae slender, shorter than occipital row; postocellar region without setae. Antenna dark brown; scape 2× longer than pedicel, with short, black setae; pedicel with ring of apical setae; postpedicel long, slightly tapered, 4× longer than basal width; stylus length 1.5× basal width of postpedicel. Palpus yellowish brown, with dark setulae. Proboscis reddish brown, length less than 2× head height; labellum with short, dark setae.

Thorax dark brown in ground-colour, densely grey pruinescent. Scutum with 2 pairs of brown vittae; median narrower pair between acr and dc rows, ending at prescutellar depression; broader outer vittae extending to postalar ridge; postpronotal lobe with shiny orange-brown apex. Proepisternum with several pairs of short pale setae on lower section; upper proepisternum in front of spiracle without setae. Prosternum bare. Antepronotum with row of pale setae. Postpronotum with 1 long seta and several short setae. Scutum apparently without row(s) of acr; dc uniserial, increasing in size posteriorly; 1 posterior npl, with upper setula, 1–2 slender anterior npl; 1 presut spal; 1 psut spal, with anterior setula; 1 pal, with anterior setula. Scutellum with pair of long apical sctl, with pair of outer, shorter marginal setae; disc bare. Laterotergite with cluster of pale setae. Anterior and posterior spiracles pale.

Legs short, fore and midlegs slender, hindleg stocky, reddish brown, with apical tarsomeres darker; coxae with grey pruinescence ( Fig. 131 View FIGURES 131–134 ). Hind trochanter with numerous pale setae. Femora with white ventral pile; less distinct on fore femur. Fore femur with anteroventral and posteroventral row of short setulae. Fore tibia with 3–4 erect dorsal setae, longer than width of tibia; posterior and ventral faces with erect dense pile of setae; with circlet of preapical setae. Fore tarsomere 1 expanded, slightly broader than apex of tibia, with stronger anterior setae; ventrum with dense pile of setulae, without strong setae; tarsomeres 2–3 with biserial row of strong ventral setae; tarsomeres 1–3 with apicolateral pair of strong setae, longer than width of segment. Mid femur with anteroventral and posteroventral row of setae, denser at base. Mid tibia with 1–2 pairs of erect anterodorsal and posterodorsal setae near base; apex with circlet of preapical setae. Mid tarsus slender, with tarsomeres 1–3 with biserial row of strong ventral setae; tarsomeres 1–3 with apicolateral pair of strong setae, longer than width of segment. Hind femur strongly expanded apically, with long, pale, slender ventral setae, slightly shorter than width of femur; apical fourth with row of dark, thicker anteroventral setae; preapex expanded with thumb-like anteroventral process, clothed in short pubescence; preapex with short, nipple-like posteroventral projection, framing concave ventral region between nipple-like and thumb-like processes; preapical posterior face with 3 thickened, wavy setae on broad swellings and several long, slender setae, all longer than width of femur; preapical posterior face with dense setae ( Figs 132–134 View FIGURES 131–134 ). Hind tibia with base narrowed and geniculate; base laterally expanded and flattened opposite concave area on femur; anteroventral edge of expansion with tuft of short setae; inner ventral face of expansion with double transverse row of short, spine-like setae, increasing in length towards posterior face; posteroventral face of expansion with large, flattened sickle-shaped seta; 6–8 erect anterodorsal and posterodorsal setae, slightly longer than width of tibia, with erect pale setae on all faces of tibia; posteroapical comb with seta ( Figs 132, 133 View FIGURES 131–134 ). Hind tarsus with tarsomere 1 slightly swollen; tarsomeres 1–4 with biserial row of strong ventral setae; tarsomeres 1–4 with apicolateral pair of strong setae, longer than width of segment.

Wing lightly infuscate with dark veins; all veins well sclerotized, except CuA+CuP weak, not reaching wing margin. Basal costal seta present. R 5 and M 1 divergent near wing margin; R 5 ending near wing tip; radial fork acute. Halter pale, orange brown.

Abdomen darker than thorax, with thin greyish pruinosity to somewhat shiny; setae pale ( Fig. 131 View FIGURES 131–134 ). Pregenital segments unmodified, except sclerites of segment 8 weakly separated anterolaterally. Terminalia ( Figs 140, 141 View FIGURES 140–142 ): similar colour to abdomen; phallus brownish. Cercus linear, tapered to narrow rounded apex, shorter than epandrium; dorsal margin straight; setae slender, dense, shorter than width of cercus. Subepandrial process with narrow, tapered apex; extending to either side of phallus. Epandrial lamella linear, posterior margin broadly rounded, not expanded dorsally; not fused with cercus anteriorly; evenly clothed in slender setae, shorter than width of epandrium. Hypandrium short, apical margin truncate, without setae. Phallus ( Fig. 141 View FIGURES 140–142 ) expanded on lower half; tapered and sharply bent to expanded apex; pair of short, lateral lobes proximal to bend; apical opening surrounded by row of spicules; apex emerging beyond cerci; ejaculatory apodeme large, more than one-half length of epandrium, Tshaped, with lateral apodemes near lower margin.

Female. Similar to male, except as follows: frons broader, nearly as wide as ocellar triangle; hindleg without modified setae and processes; mid and hind femora with dense ventral setae; abdominal pleural membrane not visible; tergite 7 somewhat shiny; sternite 8 slightly projected.

Geographical distribution and seasonal occurrence ( Fig. 152 View FIGURES 152–153 ). This species is known only from May at the type locality in Tulare County, California .

Etymology. The species name clava is Latin for club, in reference to the club-shaped apex of the hind femur seen in this species.

Nuptial gift presentation. Form unknown.

Remarks. This species is mostly similar to E. (En.) mariposa sp. nov. on the basis of the modified hindleg, including the geniculate tibia.