Empis (Enoplempis) gladiator Melander

Sinclair, Bradley J., Brooks, Scott E. & Cumming, Jeffrey M., 2013, Revision of the Empis subgenus Enoplempis Bigot, east of the Rocky Mountains (Diptera: Empididae), Zootaxa 3736 (5), pp. 401-456 : 418-420

Empis (Enoplempis) gladiator Melander

( Figs 8 B, 9A, B, 11A)

Empis gladiator Melander, 1902: 316 . Type locality: Lawrence, Kansas, USA.

Type material examined. LECTOTYPE (here designated in order to fix identity of the species) ♂, labelled: “ Jun 8 ”; “Lawr/ Kans”; “ E. gladiator / TYPE Mel”; “ALMelander/ Collection/ 1961”; “ LECTOTYPE / Empis gladiator Melander / des. Sinclair, Brooks &/ Cumming 2013 [red label]” (USNM). PARALECTOTYPES: Same data as lectotype (2 ♂, 2 ♀, AMNH, 2 ♂, 4 ♀, USNM).

Additional material examined. USA. Indiana: LaFayette, 10.vi.1916, J.D. Aldrich (1 ♀, USNM). Kansas: Lawrence, 20.v., 4.vi.1922, C.H. Curran (2 ♂, 1 ♀, CNC).

Taxonomic notes. This species was described from “numerous specimens of both sexes” from the type locality. The designation of the lectotype clearly establishes the identity of this species.

Diagnosis. This species is distinguished by the highly modified processes of the hind femur and tibia, with thumb-like process at base of hind tibia clothed with short, fine setae.

Re-description. Wing length 6.0– 6.6 mm. Male. Head dark in ground-colour, with dense grey pruinescence on face, frons and occiput. Dichoptic, eye with ommatidia of similar size. Frons divergent towards antennae; below ocellar triangle slightly wider than anterior ocellus, bearing short setulae along inner margin of eye. Face slightly divergent towards mouthparts; bare with oral margin dark and shining. Ocellar triangle with grey pruinescence, with pair of short parallel ocellar setae; posterior setulae less than 0.5× length of anterior. Occiput bearing row of postocular setae, stout and black on upper section; shorter and more slender on lower section; occipital setae black, long and stout, subequal in length to upper postocular setae. Postpedicel, stylus and scape mostly dark; extreme base of postpedicel and inner face of pedicel slightly paler or orange-brown. Scape more than 2× longer than pedicel; postpedicel more than 4× longer than basal width, less than 3× longer than stylus. Palpus yellow, with setulae dark. Proboscis largely yellow; apex of labrum reddish brown; labellum with dark setae.

Thorax dark in ground-colour, largely densely grey pruinescent: postpronotum, supra-alar ridge and outer margin of scutellum yellowish orange. Scutum with pair of distinct dark vittae between acr and dc rows; distinct pair of vittae lateral to dc and above notopleural depression. Pleura grey, with upper parts of katepisternum, anepimeron, laterotergite and meron paler and yellowish. Proepisternum pale yellowish, with several short, dark setae; prosternum bare. Antepronotum with row of short, stout dark setae. Postpronotum with 2–3 short, dark setae and 1 long seta. Scutum with sparse row of fine acr setulae; dc longer than acr, increasing in length posteriorly; 1 posterior npl, with several short anterior npl setae; 1 short presut spal; 1 psut spal; 1 pal. Scutellum with pair of short sctl, subequal in length to pal, lacking marginal setulae. Laterotergite with 2–4 long dark setae. Anterior and posterior spiracles pale.

Legs long, entirely yellow, except for dark ring at trochanter-femur junction and apices of femora; apex of tarsomere 1 and tarsomeres 2–5 reddish brown. Coxae with numerous dark lateral setae, longer and stouter along apical anterior margins. Hind trochanter lacking setae. Femora lacking distinct posteroventral row of setae; hind femur thickened towards apex and somewhat bent medially. Fore tibia clothed in long dark setae, shorter than width of tibia; with 2–3 anterodorsal, 4 posteroventral and several preapical setae. Mid tibia clothed in long dark setae, shorter than width of tibia; several anterodorsal setae, 4 or more posteroventral, 2 anteroventral setae and several preapical setae. Hind femur lacking preapical anteroventral process, with preapical row of anteroventral setae nearly subequal to width of femur; inner apex with pair of preapical posteroventral hook-shaped processes directed anteroventrally, hook of inner process blackened and anteroventral apex produced as flange ( Figs 9 A, B). Hind tibia somewhat twisted, joint with femur somewhat prolonged; anteroventrally at base with thumb-like process clothed with short, fine setae and with several proximal setae longer than process; inner base with posteroventral pointed knob-like process, with tuft of dark setae on outer base ( Figs 9 A, B); anteroventral and dorsal portions with several rows of black setae of various lengths, some subequal to width of tibia; several preapical setae present. Tarsomeres 1–5 of all legs with rows of antero- and posteroventral spine-like setae; fore tarsomere 1 somewhat swollen, similar to hind tarsomere 1.

Wing clear with brownish veins; all veins complete (except Sc), well sclerotized. Basal costal seta short, mostly inconspicuous, slightly stouter and longer than surrounding costal setae. R5 and M1 somewhat divergent near wing margin; R5 ending beyond wing tip; radial fork acute. Halter yellow.

Abdomen yellow with median area of tergites dark, sternites yellow; long marginal setae on tergites 1–5. Marginal setae on segment 8 subequal to length of tergite. Pregenital segments unmodified; sclerites of segment 8 weakly fused to form complete ring, weakly sclerotized anterodorsally. Terminalia ( Fig. 8 B) largely yellow. Cercus broad, well separated from dorsal margin of epandrium, posterior end prolonged into finger-like setose process arched medially. Hypoproct lacking setae. Epandrial lamella subrectangular, posterodorsal margin produced into hook-like process (lacking pubescence) with bacilliform sclerite extending to base of process; setae short. Hypandrium short, not extended posteriorly with truncate margin, about 0.2× as long as epandrium; lacking setae. Phallus with broad basal 0.25, apical 0.75 gently arched dorsally and gradually tapered; apex emerging beyond cercus; ejaculatory apodeme longer than half length of epandrium; inverted Y-shaped, with median keel reduced.

Female. Similar to male, except as follows: frons slightly broader; hind femur and tibia lacking modified setae and processes; cercus long and slender, slightly shorter than tergite 8.

Geographical distribution and seasonal occurrence ( Fig. 11 A). Empis (En.) gladiator is known from Kansas and Indiana. Adults have been collected from late May to mid-June.

Nuptial gift presentation. Form unknown.

Figures

FIGURE 8. Male terminalia, lateral view of E. (Enoplempis). A, E. enodis; B, E. gladiator.

FIGURE 9. Male legs of E. (Enoplempis). A, E. gladiator, apex of hind femur and base of hind tibia, anterior view; B, E. gladiator, apex of hind femur and base of hind tibia, posterior view; C, E. gulosa, hindleg, anterior view; D, E. gulosa, hind trochanter, anterior view; E, E. loripedis, hindleg, anterior view; F, E. loripedis, apex of hind femur and base of hind tibia, anterior view; G, E. loripedis, apex of hind femur and base of hind tibia, posterior view.

FIGURE 11. Distribution of E. (Enoplempis). A, E. arthritica and E. gladiator; B, E. gulosa.