Empis (Enoplempis) aeripes Melander

Empis (Enoplempis) aeripes Melander View in CoL

( Figs 250–254 View FIGURES 249–250 View FIGURES 251–256 , 262 View FIGURES 262–265 )

Empis aeripes Melander, 1902: 328 View in CoL . Type locality (by lectotype designation): Moscow, Idaho ( USA).

E. (Enoplempis) aeripes View in CoL : Melander, 1928: 142 (assigned to subgenus Enoplempis ).

Empis aeripes View in CoL : Melander, 1965: 458 (catalogue); Yang et al. (2007): 130 (catalogue).

Type material examined. LECTOTYPE (here designated in order to fix identity of the species) ♂, labelled:“ Moscow [46°48ʹN 116°52ʹW]/ Idaho ”; “ E. aeripes / TYPE Mel.”; “ALMelander/ Collection / 1965”; “ LECTOTYPE / Empis aeripes Melander / des. Sinclair , Brooks &/ Cumming 2025 [red label]” ( USNM) . PARALECTOTYPES: USA. Idaho: same data as lectotype (2♂, 2♀, AMNH; 3♂, 1♀, USNM). Latah County: Juliaetta [46°34′N 116°42′W], J.M. Aldrich (2♀, USNM) GoogleMaps .

Notes on type specimens. This species was described from an unspecified number of male and female specimens collected by J.M.Aldrich. Six syntypes (3 males, 3 females) were found in the USNM.There are additional specimens with similar locality labels and red “Type” labels but labelled “W.M. Wheeler collection”. Despite the latter label, they are also assumed to be syntypes. In addition, there are a number of specimens in the USNM labelled as “types” but are not viewed as from the original type series since they were collected after 1902 (publication date). One male and one female paralectotype are also present in OUMNH.

Additional material examined. USA. Idaho: Latah County: 3 mi. E Harvard [46.917°N 116.73°W], 17.v.1966, WFB (1♀, WFBM) GoogleMaps ; 3 mi. S Helmer [46°48ʹN 116°28ʹW], along Little Boulder Ck , 10.vi.1984, J. Jenkins (3♂, 5♀, WSU) ; same data except, 10.vi.1984 (1♂, WSU) ; 3 mi. S Helmer [46°48ʹN 116°28ʹW], Potlach R nr Lk. Boulder Cpgd, 2600–2800 ft, 15.vi.1991, P. McLelland (2♂, CUIC) ; 1 mi. W Moscow [46°48ʹN 116°52ʹW], 27.v.1964, E. R. Logan (1♂, WFBM) ; 5 mi. S Moscow [46°48ʹN 116°52ʹW], 18.v.1961 (1♀, WFBM) ; 3 mi. N Moscow [46°48ʹN 116°52ʹW], 24.v.1969 (1♀, WFBM) ; Moscow [46°48ʹN 116°52ʹW], J.M. Aldrich (2♂, WFBM) ; same data except, 21.v.1904 (1♂, 1♂ with Bibionidae prey, 1♀ with Bibionidae prey, USNM) ; same data except, 17.v.1910 (1♀, USNM) ; same data except, 30.v.1911 (1♀, USNM) ; same data except, 24.iv.1912 (2♀, USNM) ; same data except, 30.v.1912 (1♂, USNM) ; same data except, 5.vi.1912 (2♂, 3♀, USNM) ; same data except, 22.v.1913 (3♀, USNM) ; same data except, 5.vi.1912, on flowers of Polygonum (3♂, USNM) ; same data except, 27.v.1964, D.S. Horning, Jr. (2♂, 2♀, WFBM) ; Moscow Mtn [46°48ʹN 116°52ʹW], 4.v.1966, E.J. Allen (1♀, WFBM) ; Paradise Ridge , 46°39′36.7″N 117°22′19.3″W, 7.vi.2022, A. Hawse, ex Lomatium triternatus (1 ♂, CNC) GoogleMaps ; same data except, 24.v.2022 (1♂, 1♀, CNC) GoogleMaps ; same data except, 31.v.2022 (3♀, CNC) GoogleMaps ; same data except, 7.v. i.2022 (1♀, CNC) GoogleMaps ; same data except, 17.v.2022, ex Lithophragma parviflorum (1♂, CNC) GoogleMaps ; same data except, 31.v.2022, ex Balsamorhiza sagittata (2♂, CNC) GoogleMaps ; same data except, 15.vi.2022, ex Geranium vissocossimum (1♂, 1♀, CNC) GoogleMaps . Washington: Whitman County: Almota [46°42ʹN 117°27ʹW], 19.iv.1973, D.L. England (1♂, WSU) ; Pullman [46°43ʹN 117°11ʹW] (1♀, USNM) ; same data except, April 30 (1♀, USNM) ; same data except, May (1♂ CAS; 1♀, CUIC; 3♂, USNM) ; same data except, 30 May (1♂, CUIC; 1♂, USNM) ; same data except, June (2♂, CUIC) ; same data except, June 1 (3♀, USNM) ; same data except 1.vi.1904 (1♂, CAS) ; same data except, 1.v.1907 (1♀, USNM) ; same data except, 7.v.1907 (3♂, USNM) ; same data except, 14.v.1907 (2♂, USNM) ; same data except, 16.v.1907 (2♂, 1♀, USNM) ; same data except, 24.v.1907 (2♂, USNM) ; same data except, 30.v.1913 (3♂, USNM) ; same data except, 23.v.1918, ALM (1♀, USNM) ; same data except, 6.vi.1918 (12♂, 18♀, USNM; 3♂, 3♀, CNC) ; same data except, 4.vi.1964, N.M. Jorgensen (2♀, LACM) ; same data except, 5.vi.1964 (1♀, LACM) ; same data except, 21.v.1971, J.F. MacDonald (1♀, CNC) ; 8 mi. SW Pullman [46°43′N 117°11ʹW], Lyle Grove , 22.v.1973 (1♂, WSU) ; same data except, Lyle Grove Biol. Area , 10.v.1979, E.A. Beck (1♂, 2♀, WSU) ; same data except, 3.vi.1979, S. Woods (1♂, WSU) ; same data except, R. S. Bekey (1♂, WSU) ; same data except, 2.v.1981, R. H. Miller (1♀, MTEC) ; same data except, 14.v.1981 (1♀, MTEC) ; same data except, 2100 ft, MT, 25.v.1979, S. Woods (1♂, 1♀, WSU) ; same data except, 27.v.1979 (1♀, WSU) ; same data except, 28.v.1979 (2♂, WSU) ; same data except, 30.v.1979 (1♀, WSU) ; same data except, 1.vi.1979 (2♂, 1♀, WSU) ; same data except, 4–6.vi.1979 (1♀, WSU) ; same data except, 6.vi.1979 (1♀, WSU) ; same data except, 6–8.vi.1979 (1♀, WSU) ; same data except, sweep, 26.v.1979, WJT (1♀, WFBM) .

Diagnosis. This species is distinguished from other species of the E. (En.) valentis species group by the occiput bearing multiple irregular rows of strong setae, especially dense ventrally ( Fig. 252 View FIGURES 251–256 ), usually six or more marginal scutellar setae, male hind femur with tuft of setae arising directly from inflated anteroventral process and without additional lobes ( Figs 253, 254 View FIGURES 251–256 ), and wing length usually greater than 7 mm.

Redescription. Wing length 6.9–8 mm. Male. Head dark in ground-colour, with greyish pruinescence. Dichoptic, upper ommatidia not enlarged. Frons divergent towards antennae; below ocellar triangle subequal to width of ocellar triangle; with 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 and several pairs of short setulae. Occiput bearing multiple irregular rows of strong setae, similar in size to ocellar setae, rather dense, longer and finer ventrally ( Fig. 252 View FIGURES 251–256 ); postocular setae not differentiated; 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 dark brown, apically orange brown, with dark setulae. Proboscis reddish brown, length 2× or less head height; labellum with short, dark setae.

Thorax dark brown in ground-colour, densely grey pruinescent ( Fig. 251 View FIGURES 251–256 ). Scutum with 2 pairs of brownish vittae, extending beyond transverse suture; lateral pair broader than narrow and darker medial pair of vittae. Proepisternum with long, wavy dark setae on lower section; upper proepisternum in front of spiracle without setae. Prosternum bare. Antepronotum with row of dark setae, longer laterally. 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; 2 posterior npl, with 1–3 shorter anterior npl; 1 presut spal; 1 psut spal; 1 pal. Scutellum usually with 2–3 pairs of long sctl, with 1–2 pairs of marginal setae; disc bare. Laterotergite with narrow patch of strong, dark setae. Anterior and posterior spiracles pale.

Legs stocky, orange to reddish brown, apex of tibiae darker, tarsi brown; coxae clothed in dense greyish pruinescence, concolourous with pleura ( Fig. 251 View FIGURES 251–256 ). Coxae with stiff, black setae. Hind trochanter with short setulae. Fore femur clothed in short, black setae. Fore tibia with 3–4 short posteroventral setae, one-third width of femur; one long, ventral preapical seta, slightly longer than apical width of femur. Fore tarsomere 1 slender, not swollen; 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. Mid femur clothed in short, black setae. Mid tibia with 3–4 short posteroventral setae, one-third width of femur; one long, ventral preapical seta, slightly longer than apical width of femur; 3–4 short anterodorsal and posterodorsal setae, similar to ventral setae, one-third width of femur; one long, ventral preapical seta, slightly longer than apical width of femur. Mid tarsus similar to fore tarsus. Hind femur with inflated anteroventral process with tuft of black setae arising directly; inflated process usually with several black, ventral setae; apex with preapical row of 4–5 flattened, black posterior setae; preapical anterior seta strong, shorter than width of femur ( Figs 253, 254 View FIGURES 251–256 ). Hind tibia with narrow, anteroventral digitiform process on basal quarter, slightly proximal to process of femur (when legs folded), with appressed black setae on dorsal half; posteroventrally with broad, triangular process opposite inflated process of femur, with long appressed, black lateral and apical setae, longer than on anteroventral process; without seta in posteroapical comb; 6–7 strong, black anterodorsal and posterodorsal setae, shorter than half width of tibia ( Figs 251, 253, 254 View FIGURES 251–256 ). Hind tarsus similar to fore tarsus.

Wing infuscate with dark veins; all veins complete (except Sc), well sclerotized. Basal costal seta absent. R 5 and M 1 divergent near wing margin; R 5 ending anterior to wing tip; radial fork acute. Halter pale, reddish brown.

Abdomen dark, with dense greyish pruinescence, similar to scutum with long setae on tergites 1 and 2; setae sparse on distal tergites; posterior margin of tergites slightly to distinctly glossy. Pregenital segments unmodified, except sclerites of segment 8 narrowly separated.Terminalia ( Fig. 262 View FIGURES 262–265 ): dark brown with dorsal margin of epandrium and phallus orange brown. Cercus short, rectangular; dorsal margin with distinct notch at mid-length, posteriorly with short, dorsal knob-like projection; setae shorter than width of cercus. Subepandrium without process or setae. Epandrial lamella oval, higher than long; posterior margin with short, knob-like projection, bearing long seta ventrally; setae longer than cercal setae. Hypandrium short, truncate, prolonged laterally; without setae. Phallus with basal half strongly expanded, tapered, mostly straight apically; apex not emerging beyond epandrium; ejaculatory apodeme more than half-length of epandrium, Y-shaped, with ventrally positioned lateral apodemes.

Female. Similar to male, except as follows: frons slightly broader; scutum with bluish pruinescence; vittae narrower, dark grey; hindleg without modified setae and processes; abdominal pleural membrane with darkened, expanded region; tergites 7 and 8 shiny, without pruinescence.

Geographical distribution and seasonal occurrence ( Fig. 250 View FIGURES 249–250 ). Empis (En.) aeripes is known from Idaho and eastern Washington. Adults have been collected from April to June.

Nuptial gift presentation. A male and female specimen listed above were pinned with an unwrapped male Bibio sp. ( Bibionidae ) fly prey item mounted below the specimens. This almost certainly indicates that males of this species present unwrapped prey to females as nuptial gifts.

Remarks. Empis (En.) aeripes is very similar to E. (En.) mixopolia , with male terminalia and male hind legs seemingly identical. The number of scutellar setae that Melander (1902) used appears to generally hold to help distinguish the two species. The multiple rows of occipital setae in E. (En.) aeripes (fewer setae in E. (En.) mixopolia ) and larger size assist to further distinguish this species.

The female abdominal pleural membrane appears to have a darkened, expanded region in less shrunken specimens, which likely indicates that pleural sacs may be inflated during mating ( Table 1).