Empis (Enoplempis) teres Melander

Sinclair, Bradley J., Brooks, Scott E. & Cumming, Jeffrey M., 2025, Revision of the western Nearctic species of Empis subgenus Enoplempis (Diptera: Empididae), Zootaxa 5615 (1), pp. 1-200 : 117-120

Empis (Enoplempis) teres Melander

( Figs 227–229 , 235 , 238 )

Empis teres Melander, 1902: 315 . Type locality: Juliaetta , Idaho ( USA), by lectotype designation.

Empis (Enoplempis) teres : Melander, 1928: 142 (assigned to subgenus Enoplempis ).

Empis teres : Melander, 1965: 461 (catalogue); Yang et al., 2007: 141 (catalogue).

Type material examined. LECTOTYPE (here designated in order to fix identity of the species) ♂, labelled: “Juliaetta [46°34′N 116°42′W]/ Idaho ”; “May 12,02”; “Cotype/ No. 41828/ U.S.N.M. [red label]”; “ LECTOTYPE / Empis teres Melander / des. Sinclair, Brooks &/ Cumming 2025 [red label]” ( USNM) . PARALECTOTYPES: USA. Idaho: Same data as lectotype (3♂, 2♀, AMNH; 3♂, 3♀, USNM). Latah County: Moscow [46°48ʹN 116°52ʹW], J.M. Aldrich (1♂, USNM = E. scutica sp. nov.) .

Notes on type specimens. This species was based on nineteen male and female specimens from Idaho. Seven male syntypes and five female syntypes were located .

Additional material examined. USA. Idaho: Idaho County: Clearwater NF , Hwy 12, Apgar Ck , 13.vi.2014, 46°12.858′N 115°32.179′W, 495 m, BJS (1♂, CNC); Clearwater NF , Hwy 12, 3 Devils Picnic Area , 2–3 mi. W Lowell , 13.vi. 2014, 450 m, 46°08.155′N 115°38.681′W, small str., BJS (1♂, CNC). Latah County: Lost Ck , 12 mi. ENE Potlatch [46°57′N 116°41′W], 2700 ft, 22.vi.1979, sweep, WJT (14♂, 6♀, WSU) . Nez Perce County: Lk. Waha, Flate Iron Rd , 46°12.412′N 116°49.027′W, 1040 m, 15.iv.2014, W Fk Sweetwater Ck, BJS (1♂, 1♀, CNC) . Oregon: Baker County: L. Goose Ck, 36 mi. SE Union [44°56′N 117°25′W], Wallowa-Whitman NF , 4000 ft, 9.vi.1976, sweeping, WJT (2♂, 1♀, WSU) ; same data except, 9–12.vi.1976, MT baited with CO 2, E.J. Davis (1♂, USNM); same data except, 24–25.vi.1976, sweeping, WJT (1♂, WSU) ; U. Goose Ck, 34 mi. SE Union [44°56′N 117°25′W], 28.vi.1975, 4160 ft, MT baited with CO 2, E.J. Davis (1♀, WSU); same data except, 9–12.vi.1976 (3♂, WSU; 1♀, USNM); same data except, 24–25.1977, sweeping Anaphalis flowers, WJT (1♀, WSU) . Umatilla County: Athena ( Wild Horse Mtn ) [45°48′N 118°29′W], 14.v.1938, Schuh & Gray (1♂, CUIC) . Washington: Columbia County: Umatilla NF , Touchet R on Forest Rd 64, 46.157°N 117.808°W, 940 m, 8.vi.2009, I.S. Winkler, E09-56a (1♂, CNC); Tucannon Fish Hatch ., 20 mi. E Dayton [46°19′N 117°39′W], 2650 ft, 15.v.1979, MT, WJT (1♂, 2♀, WFBM) ; same data except, 12.v.1979, sweeping (2♂, 1♀, WFBM). Grant County: Soap Lk. [47°23′N 119°29′W], 27.vii.1940, C.B. Philip (2♂, CAS). Whitman County : Almocli Ck, nr Almota [46°42′N 117°28′W], 15.v.1975, D.M. Jackson (1♂, WSU) ; 8 mi. SW Pullman [46°43′N 117°11ʹW], Lyle Grove Biol. Area , 2100 ft, 26.v.1979, sweep, WJT (1♀, WSU) ; same data except, 28.v.1979, MT , S. Woods (1♂, 1♀, WSU); same data except, 30.v.1979 (1♂, WSU); same data except, 1.vi.1979 (1♂, 2♀, WSU); same data except, 4.vi.1979 (1♂, WSU); same data except, 8–13.vi.1979 (1♂, WSU); same data except, 16.vi.1979 (1♀, WSU); same data except, 20–22.vi.1979 (1♂, WSU) .

Diagnosis. This species is distinguished from other species of the E. (En.) teres species group by the pair of dark scutal vittae, male hind femur with ventral knob-like process without tuft of whip-like setae ( Figs 228, 229 ), epandrium with short, straight setae, and dorsal margin of male cercus with angled projection.

Redescription. Wing length 4.8–5.5 mm. Male. Head dark in ground-colour, with greyish pruinescence ( Fig. 227 ). Dichoptic, upper ommatidia not enlarged. Frons divergent towards antennae; below ocellar triangle subequal to width of anterior ocellus; without short setulae along inner margin of eye. Face without setae; slightly divergent towards mouthparts, with oral margin dark and shiny. Ocellar triangle elevated, with thin greyish pruinescence, with pair of parallel ocellar setae, slightly longer than ocellar triangle and several pairs of short setulae. Occiput bearing single row of setae, similar in size to ocellar setae, longer and finer ventrally; postocular setae similar to occipital setae; postocellar region without setae. Antenna dark; scape 2× longer than pedicel, with short, black setae; pedicel with ring of apical setae; postpedicel long and tapered, 4× longer than basal width; stylus 1.5× longer than basal width of postpedicel. Palpus pale yellowish-brown, with dark setulae. Proboscis reddish brown, less than twice head height; labellum with short, dark setae.

Thorax dark brown in ground-colour, densely grey pruinescent ( Fig. 227 ). Scutum with pair of narrow dark vittae between setal rows; outer pair of vittae broader, very faint or absent. Proepisternum with pale setae on lower section; upper proepisternum in front of spiracle without setae. Prosternum bare. Antepronotum with row of slender setae. Postpronotum with 1 long seta and some 10 short, dark setae. Scutum with short, fine uniserial acr; dc slightly longer, stronger than acr, increasing in length posteriorly; 1 posterior npl, with 2 shorter anterior npl; 1 presut spal; 1 psut spal; 1 pal. Scutellum with 1 pair of long sctl, with 1 pair of marginal setulae; disc bare. Laterotergite with narrow patch of strong, dark setae. Anterior and posterior spiracles pale.

Legs slender, orange brown, including coxae, apex of tibiae darker, tarsi brown; coxae often with thin greyish pruinescence ( Fig. 227 ). Coxae with stiff, black setae. Hind trochanter with short setae. Fore femur without white ventral pile. Fore tibia with several long anterodorsal and posterodorsal setae on apical third, twice longer than width of tibia; anterior face with short appressed setae; apex with long posterior and ventral preapical setae. Fore tarsomere 1 somewhat swollen; without spine-like ventral setae; tarsomeres 1–3 with long dorsal setae, longer than width of tarsomere; tarsomeres 2–5 with biserial row of spine-like ventral setae; tarsomeres 1–4 with apicolateral pair of spine-like setae, longer than width of segment. Mid femur with white ventral pile; row of short posteroventral setae, shorter that femur width. Mid tibia with 3–4 anteroventral and posteroventral setae, longer than width of tibia; 3–4 short anterodorsal and posterodorsal setae, similar to ventral setae. Mid tarsus with all tarsomeres with biserial row of spine-like ventral setae; tarsomeres 1–4 with apicolateral pair of spine-like setae, longer than width of segment. Hind femur with white ventral pile on basal three-quarters; apical fourth slightly bent with oval, knob-like ventral process without tuft of black whip-like setae; tuft of appressed setae on short swelling anteromedially to knob-like process; flattened, triangular process with narrow posterior appendix posterior to knob-like process, without setae; preapical posterior swelling with strong posteroventral setae; apex without preapical row of posterior setae; without strong preapical anterior seta ( Figs 228, 229 ). Hind tibia greatly narrowed and slightly twisted at base; anteroventral digitiform process reduced to short swelling with oblique row of appressed setae, as long as process; posteroventral process short, bifid with tufts of apical setae; ventral setae distal to processes thickened with apex of some setae bent apically; seta in posteroapical comb; long anterodorsal and posterodorsal setae on apical half, twice as long as width of tibia ( Figs 227–229 ). Hind tarsus similar to fore tarsus with long dorsal setae and slightly swollen tarsomere 1.

Wing faintly infuscate with dark veins with base of wing yellowish; all veins complete (except Sc and CuA+CuP), well sclerotized. Basal costal seta absent. R 5 and M 1 parallel near wing margin; R 5 ending posterior to wing tip; radial fork broad. Halter yellowish.

Abdomen dark, with dense grey pruinescence similar to scutum, with long marginal setae, longer on basal tergites; posterior margin of tergites pruinescent; sternites with short setae. Pregenital segments unmodified, except sclerites of segment 8 weakly fused anterolaterally. Terminalia ( Fig. 235 ): brown with dorsal margin of cercus blackish. Cercus short, rectangular, narrowly projecting posteriorly; dorsal margin expanded dorsally near mid-length as subtriangular projection; dense setae basally and on mid-length projection, shorter than width of cercus; base weakly fused to epandrial lamella. Subepandrial process extending on either side of phallus. Epandrial lamella narrow, linear, longer than height; posterior margin strongly upturned; bearing long setae ventrally, subequal to width of lamella. Hypandrium very short, truncate, not prolonged laterally; without setae. Phallus with basal third expanded, tapered, gently arched anteriorly; apex emerging beyond cercus; apex slender and downcurved in lateral view; roughened, spiculate subapically, near dorsal margin of epandrium; ejaculatory apodeme oval, half-length of epandrium, Y-shaped, with ventrally positioned lateral apodemes.

Female. Similar to male, except as follows: frons broader, nearly as wide as ocellar triangle; scutum with 2 pairs of broader brownish vittae; hindleg without modified setae and processes. Abdominal pleural membrane not expanded; tergites 7 and 8 pruinescent.

Geographical distribution and seasonal occurrence ( Fig. 238 ). Empis (En.) teres is known from Washington, eastern Oregon and Idaho. Adults have been collected from April to July.

Nuptial gift presentation. Form unknown.

Remarks. The length of the dorsal setae on fore tarsomere 1 is variable, ranging from subequal to more than twice width of tarsomere.

Figures

FIGURES 227–232. Male habitus and hindleg of the E. (Enoplempis) teres species group. 227, E. (En.) teres Melander, habitus, lateral view; 228, same, hind femur tibia joint, anterior view; 229, same, hind femur tibia joint, posterior view; 230, E. (En.) undulasetosa sp. nov., habitus, lateral view; 231, same, hind femur tibia joint, anterior view; 232, same, hind femur tibia joint, posterior view.

FIGURES 233–236. Male terminalia of the E. (Enoplempis) teres species group, lateral view. 233, E. (En.) scutica sp. nov.; 234, same, phallus; 235, E. (En.) teres Melander; 236, E. (En.) undulasetosa sp. nov.

FIGURES 237–238. Known geographical distribution of the E. (Enoplempis) teres species group. 237, E. (En.) scotti sp. nov. and E. (En.) scutica sp. nov.; 238, E. (En.) teres Melander and E. (En.) undulasetosa sp. nov.