Empis (Enoplempis) snoddyi Steyskal

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 : 439-443

Empis (Enoplempis) snoddyi Steyskal

( Figs 1 D, 19A, 20A, 22A)

Empis snoddyi Steyskal, 1969: 292 . Type locality: Clayton, Georgia, USA.

Type material examined. HOLOTYPE, ♂ labelled: “Rabun Co. Ga. & Macon Co. [NC], N. Cou. Line/ 10 mi. N. Clayton, Ga. Hwy 441 N. / 5-17-67 Coll. E.L. Snoddy”; “ HOLOTYPE / Empis / snoddyi / Steyskal/ 69701 [red label]” (USNM). PARATYPES: Same data as holotype (9 ♂ [3 with balloons], 1 ♀ [allotype], USNM). Remaining paratypes in collection of Georgia Experimental Station (not examined).

Additional material examined. USA. Georgia: 10 mi N Clayton, [Rabun] Co., Hwy 441 N, 17.v.1967, E.L. Snoddy (8 ♂, 1 ♀, USNM); Pine Mt., Rabun Co., 1400 ft., 15.v.1957, H.C. Huckett (1 ♀, CNC). North Carolina: 5 mi N Arrow Springs, 31.v.1965, J.G. Chillcott (8 ♂, 7 with balloons, CNC); Blue Ridge Pkwy, Pauls Gap, 2 mi E, 4700 ft., GSMNP, 8.vi.1965, J.G. Chillcott (5 ♂, CNC); Blue Ridge Pkwy, Waterrock Knob, 6 mi E, 3500 ft., mi 445, Aruncus blossoms, 9.vi.1965, J.G. Chillcott (2 ♂, 1 ♀, CNC); Buncombe Co., 4 km SW Black Mtn, MT, 21– 27.vi.1986, W.E. Steiner (2 ♂, USNM); Cherokee-Newfound Gap, GSMNP, 4200 ft., 4.vi.1962, J.R. Vockeroth (1 ♀, CNC); GSMNP, Noland Divide Tr., 1700 m, 35°33'58''N 83°28'37''W, 30.v.–4.vi.2001, J. Skevington & J.M. Cumming (1 ♀, CNC); GSMNP, Noland Divide Tr., 1700 m, 35°33'58''N 83°28'37''W, 2, 4.vi.2001, J.M. Cumming (1 ♂, 1 ♀, CNC); Haywood Co., GSMNP, Purchase Knob, 1463 m, 11.vi.2008, B.J. Sinclair (1 ♂, 6 ♀, CNC); Highlands, 13, 22, 26, 29.v.1957, W.R.M. Mason (3 ♂, 6 ♀, CNC); Highlands, 16, 29.v., 7, 10, 20.vi.1957, at light, J.R. Vockeroth (3 ♂, 33 ♀, CNC); Highlands, Shortoff Mt., 4200–4800 ft., 23.v.1957, J.R. Vockeroth (4 ♀, CNC); Haywood Co., Soco Gap, 4337 ft., Aruncus blossoms, 4.vi.1962, J.G. Chillcott (1 ♂, 4 ♀, CNC); Macon Co., Wayah Bald, 20.v.1970, ROM Field Party (6 ♂, ROM); Macon Co., Highlands Bio Sta, MT, 27.v.–1.vi.1984, J.K. Liebherr (4 ♂, 4 ♀, CUIC); Macon Co., Coweeta Hydro. Lab, 35°03'N 83°26'W, MT, 11–15.v.1998, G.W. Courtney (1 ♂, 3 ♀, CNC); Swain Co., GSMNP, Clingmans Dome, Forney Ridge Tr., 1830 m, 12.vi.2008, A. Freidberg (1 ♂, 2 ♀, CNC); Swain Co., Indian Gap, Clingmans Dome Rd, 1 mi W, Newfound Gap, 3.vi.1995, J. Sadowski (1 ♂, USNM). Tennessee: Beech Gap, 5500 ft., with balloon, 23.vi.1947, R.H. Whittaker (3 ♂, 1 ♀, USNM); 10 mi W Bry[i]ceville, 27.v.1965 (1 ♀, CNC); Green Brier Cove, GSMNP, 12.vi.1946, R.R. Dreisbach (2 ♀, CNC). NC/TN: Indian Gap, 5200 ft, GSMNP, 28.v., 18.vi., 8.vii.1957, W.R.M. Mason (2 ♂, 3 ♀, CNC). Virginia: Amherst Co., summit, Cold Mtn, nr Hog Camp Gap, Appalachian Tr., 1256 m, 37°45'8''N 79°12'12''W, 7.vi.2001, J. Skevington (2 ♂, CNC); Blue Ridge Pkwy, Apple Orchard Mtn., 3600 ft., mi 38, blossoms of Aruncus , 19.vi.1965, J.G. Chillcott (1 ♂, CNC); Patrick Co., Vesta, 2800 ft., 30.v.1962, J.G. Chillcott (3 ♀, CNC); Smyth Co., Mt. Rogers, 4700–5300 ft., 1.vi.1962, J.R. Vockeroth (2 ♀, CNC).

Diagnosis. This species is distinguished by nearly holoptic males; unmodified setae on hindlegs; apex of epandrium greatly narrowed; posterior margin of hypandrium truncate, not produced posteriorly; bearing long setae, greater than length of hypandrium; cercus broad apically.

Re-description. Wing length 5.0– 8.4 mm. Male. Head dark in ground-colour, with dense greyish pruinescence on face, frons, postgena and occiput. Very narrowly dichoptic, eye with ommatidia of equal size; short setulae along separation of eyes; frons triangular above antennae. Face slightly divergent towards mouthparts; bare with oral margin shining. Ocellar triangle dark, subshining, with pair of parallel ocellar setae and pair of posterior setulae one-third length of ocellar setae. Occiput bearing row of postocular setae, stout and black on upper section; shorter and more slender on lower section; occipital setae black, longer and stouter than postocular setae. Postpedicel, stylus, pedicel and scape mostly dark; somewhat paler at inner base of postpedicel and inner apex of pedicel. Scape about 2× longer than pedicel; postpedicel more than 6× longer than basal width, 2.5× longer than stylus. Palpus yellow, with setulae dark. Proboscis largely yellowish; apex of labrum reddish brown; labellum with dark setae.

Thorax dark in ground-colour, largely densely grey pruinescent: postpronotum, supra-alar ridge and lower margin of scutellum yellowish orange. Scutum with pair of very faint vittae between dc rows. Pleura grey, with yellowish margins of some sclerites. Proepisternum greyish, with several short, dark setae; prosternum bare with area between coxae yellowish. Antepronotum with row of short setulae. Postpronotum with 1 long, dark setae and 3–4 shorter setae. Scutum lacking acr setulae; 8–10 dc short and slender, 0.5× length of posterior npl, increasing in length somewhat posteriorly; 1 posterior npl, 1 shorter anterior npl and several shorter dark setae; 1 presut spal, subequal in length to anterior npl; 1 psut spal; 1 pal. Scutellum with 2 pairs of sctl, apical pair subequal in length to pal, outer pair shorter than apical pair. Laterotergite with 3–5 long dark setae. Anterior and posterior spiracles pale.

Legs long, entirely yellow, except for dark ring at trochanter-femur junction and apices of femora; tarsi becoming darker apically. Coxae with numerous dark lateral setae, longer and stouter along apical anterior margins. Hind trochanter lacking modifications. Fore femur lacking ventral rows of fine setae; mid and hind femora with multiple rows of short, slender setae; hind femur long and cylindrical, barely swollen subapically ( Fig. 19 A). Fore tibia clothed in long dark setae, shorter than width of tibia; with 4–5 dorsal, 3–4 posterodorsal and several preapical setae. Mid tibia clothed in long dark setae, shorter than width of tibia with few outstanding setae; 2–3 anterodorsal and several preapical setae. Hind tibia clothed in long dark setae, shorter than width of tibia, with row of numerous posterodorsal setae and several preapical setae; dorsal setae mostly distinctly longer than width of tibia ( Fig. 19 A). Tarsomeres 1–5 of all legs with rows of antero- and posteroventral spine-like setae; fore tarsomere 1 slender, not swollen and lacking long outer setae.

Wing clear with yellowish brown veins; all veins complete (except Sc), well sclerotized. Basal costal seta not distinguished. R5 and M1 divergent near wing margin; R5 ending beyond wing tip; radial fork acute. Halter yellow.

Abdominal tergites dark brown, lacking grey pruinescence, paler along apical and posterior margins; marginal setae long and stout on tergites 1–7; sternites pale brown. Marginal setae on tergite 8 longer than length of sclerite. Pregenital segments unmodified; sclerites of segment 8 closely approximated laterally, weakly sclerotized dorsomedially. Terminalia ( Fig. 20 A) largely yellow, except dorsal and apical margins of cerci dark. Cercus separated from dorsal margin of epandrium, divided into quadrate inner lobe and linear outer lobe arising subbasally; apical margin of inner and outer cercus with wavy dark, stout setae. Hypoproct lacking setae; with pair of elongate, slender, sickle-shaped projections, arched ventromedially. Epandrial lamella slender, elongate; slightly longer than cercus; subapical dorsal margin with short triangular projection. Hypandrium short, truncate posteriorly with straight margin, about 0.25× as long as epandrium; clothed with several dark setae, 2× length of hypandrium. Phallus broadly tubular, narrowed subapically with broadly rounded apex and slender, anterior apical filament; ejaculatory apodeme 0.67× length of epandrium; inverted Y-shaped, with median keel.

Female. Similar to male, except as follows: frons more widely separated than male, subequal to width of anterior ocellus; ventral setae on mid and hind femora shorter and not erect; hind femur with strong ventral preapical seta; cercus long and slender, subequal in length to tergite 8.

Geographical distribution and seasonal occurrence ( Fig. 22 A). Empis (En.) snoddyi ranges along the southern Appalachian Mountains from southern Virginia through the Great Smoky Mountains to northern Georgia. Adults have been collected from mid-May to early July.

Nuptial gift presentation. The mating system in E. (En.) snoddyi was described by Sadowski et al. (1999), where males produce and present a cylindrical, empty (prey-less) balloon to females. The balloons used by E. (En.) snoddyi resemble those made by E. (En.) vockerothi (cf. Figs. 1 A, B). The production of balloons has not been observed for any species of E. ( Enoplempis ), but the partially formed balloon held by the male of E. (En.) snoddyi in Figure 1 D appears to be being formed by the male’s mouthparts, presumably with salivary gland secretions. The photograph was taken at 1551 h in Great Smoky Mountains National Park (T. Bentley, pers. comm. 2013). Sadowski et al. (1999) indicated that males of E. (En.) snoddyi form mating swarms over landmarks (i.e., tree stumps, bushes, rocks), for approximately three hours in the morning starting at daybreak, which are visited by females.

Remarks. Steyskal (1969) was not able to assign E. (En.) snoddyi to subgenus using the key by Melander (1928). Despite the unmodified male hindlegs, we confidently assign this species to E. ( Enoplempis ) on the basis of the ventral spine-like tarsal setae present on all legs.

Figures

FIGURE 1. Empis (Enoplempis) species. A, B, E. vockerothi (Hocking Co., OH) male with balloon (photographs by Allen Coovert); C, swarming males of E. vockerothi with balloons shown by arrows (photograph by Allen Coovert); D, E. snoddyi (Sevier, TN) apparently in the process of forming a balloon (photograph by Thomas Bentley, copyright Thomasbentley. com); E, E. vockerothi, male; F, E. appalachicola, male; G, E. tridentata, male. Scale bars = 2 mm.

FIGURE 19. Male legs of E. (Enoplempis). A, E. snoddyi, hindleg, anterior view; B, E. stenoptera, hindleg, anterior view; C, E. stenoptera, hind trochanter, anterior view; D, E. tridentata, hindleg, anterior view; E, E. vockerothi, hindleg, anterior view.

FIGURE 20. Male terminalia, lateral view of E. (Enoplempis). A, E. snoddyi; B, E. stenoptera.

FIGURE 22. Distribution of E. (Enoplempis). A, E. snoddyi and E. stenoptera; B, E. tridentata.