Empis (Enoplempis) penicillata Brooks

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 : 435-438

Empis (Enoplempis) penicillata Brooks sp. nov.

( Figs 16 B, 17A, 18B)

Type material. HOLOTYPE, ♂ from Virginia labelled: “Bath Co., VA/ 24 May 2002 / B. Kondratieff/ Blowing Sprgs/ Back Cr.”; “ HOLOTYPE / Empis (Enoplempis) / penicillata / Brooks [red label]” (USNM). PARATYPES: USA. Virginia: Giles Co.: Ripplemead, Rte 460 Bridge, 11–25.v.2008, 37°19'43''N 80°40'48''W, M. Zhang, ex. feeding on mayfly (1 ♂, DEBU); New River at highway 605, 625 intersection, 17.v.1997, D.C. Caloren (1 ♂, DEBU).

Diagnosis. This species can be recognized by the following combination of features: hind trochanter of males bearing a tight cluster of strong setae confined to distinct spot, not raised on tubercle; hind tibia of males with widely spaced setae, at most slightly longer than tibial width; hypandrium lacking setae.

Description. Wing length 6.7–7.6 mm. Male. Head entirely dark in ground-colour, with dense grey pruinescence. Dichoptic, eye with ommatidia of similar size. Frons below ocellar triangle as wide as or slightly wider than anterior ocellus, bearing short setulae along inner margin of eye; parallel-sided dorsally, sides diverging towards antennae. Face divergent towards mouthparts; bare, with oral margin dark, shinining. Ocellar triangle grey pruinose, with pair of short, parallel, proclinate ocellar setae and 1-4 shorter posterior setulae. Occiput bearing 2–3 strong, black upper postocular setae with remainder of postocular row comprised of short black setae dorsally, ventrally with fine hairs; occipital setae black, similar in size to strong upper postoculars. Antenna entirely dark. Scape about 2× longer than pedicel; postpedicel about 4× longer than basal width, about 2.7× longer than stylus. Palpus pale yellow, with dark setulae. Proboscis light brownish, infuscated laterally; apex and base of labrum darkened; labellum with dark setae.

Thorax dark in ground-colour with dense grey pruinescence; posterior margin of postpronotum, postalar ridge, and posterior margin of scutellum yellowish brown. Scutum grey pruinose with pair of distinct blackish grey vittae between acr and dc rows. Pleura entirely grey pruinose. Proepisternum with 2–3 fine dark setae; prosternum bare. Antepronotum with row of short dark setae. Postpronotum with several short dark setae anteriorly and 1 slightly longer posterior seta. Scutum with inconspicuous, uniserial row of fine acr setulae; dc row uniserial, similar to acr; 1 strong posterior npl, with 2–4 weak anterior npl setae; 1–2 fine presut spal similar to acr; 1 short psut spal; 1 strong pal with adjacent short pale pal. Scutellum with pair of short sctl, similar to pal, 1–2 marginal setulae. Laterotergite with 2–3 long dark setae and 0–3 setula. Anterior and posterior spiracles pale.

Legs long, coxae, trochanters femora and tibia entirely yellow, except for dark ring at trochanter-femur junction and apices of femora; tarsi entirely dark. Coxae with scattered dark lateral and apical setae, setae longer and stouter along apical anterior margins, hind coxa with sparse patch of fine brown setae anteriorly. Hind trochanter of males bearing a tight cluster of strong setae confined to distinct spot ( Fig. 16 B), not raised on tubercle. Femora clothed in short dark setae, setae longer at apex, mid and hind femora with distinct anterior preapical seta. Hind femur slender, slightly swollen in apical half. Fore tibia clothed in dark setae, shorter than width of tibia, setae dense and shorter along anterior surface; 0–3 posterodorsal, 2–3 posteroventral, 0–4 posterior, and 5 preapical setae. Mid tibia clothed in dark setae, shorter than width of tibia; 0–2 dorsal, 2–5 anterodorsal, 2–6 anteroventral, 0–2 posterodorsal, 2–3 posteroventral, 0–2 ventral, and 6 preapical setae. Hind tibia clothed in dark setae, shorter than width of tibia ( Fig. 16 B); 3–6 anterior, 4–6 dorsal, 1–3 anterodorsal, 0–3 anteroventral, 1–3 ventral and 4–5 preapical setae. Tarsomeres 1–5 of all legs with rows of antero- and posteroventral spine-like setae; fore tarsomere 1 slender, not swollen.

Wing clear with brownish veins; all veins complete (except Sc), well sclerotized. Basal costal seta indistinct from surrounding costal setae. R5 and M1 parallel near wing margin; R5 ending beyond wing tip; radial fork acute. Halter yellow.

Abdomen concolorous with thorax, densely grey pruinose; setae pale except on segment 8 with dark marginal setae on tergite and sternite. Segment 8 with tergite and sternite closely approximate laterally; marginal setae longer than preceding segment, not weakly sclerotized dorsally. Pregenital segments unmodified. Terminalia ( Fig.

17A) largely yellow. Cercus narrow, appressed to dorsal margin of epandrium, linear, slightly broader at anterior end; dorsal margin with tooth-like projection at inner apex; posterior end rounded in lateral view with medially projecting tooth-like projection on ventral margin. Hypoproct with several long setae. Epandrial lamella largely clothed with setae; posterodorsal margin with small process, bacilliform sclerite extending to base of process; posterior margin below process rounded. Hypandrium prolonged posteriorly with shallow notch on apical margin, about 0.33× as long as epandrium; lacking setae. Phallus with broad base, apical portion sharply bent upwards; apex just emerging beyond cercus; ejaculatory apodeme slightly shorter than length of epandrium; inverted Yshaped, with short median keel.

Female. Unknown.

Geographical distribution and seasonal occurrence ( Fig. 18 B). Empis (En.) penicillata is known from the Allegheny Mountains in western Virginia. Adults have been collected in May.

Etymology. The specific epithet is Latin for paint brush and refers to the setal cluster on the male hind trochanter.

Nuptial gift presentation. A male specimen from Ripplemead (see “ Type material”) included the observation “feeding on mayfly”. This probably indicates that males of this species present unwrapped prey to females as nuptial gifts.

Remarks. Empis (En.) penicillata is most similar to E. (En.) nuda . Both species have a similarly modified male trochanter; however, in E. (En.) nuda the setal cluster is raised onto a short tubercle unlike E. (En.) penicillata (compare Figs 12 D and 16B).

Figures

FIGURE 12. Male legs of E. (Enoplempis). A, E. montywoodi, apex of hind femur and base of hind tibia, anterior view; B, E. montywoodi, apex of hind femur and base of hind tibia, posterior view; C, E. nodipoplitea, apex of hind femur and base of hind tibia, anterior view; D, E. nuda, hind trochanters; E, E. nuda, hindleg, anterior view.

FIGURE 16. Male legs of E. (Enoplempis). A, E. pectinata, hindleg, anterior view; B, E. penicillata, hindleg, anterior view; C, E. prodigiosa, hindleg, anterior view; D, E. prodigiosa, apex of hind femur and base of hind tibia, anterior view; E, E. prodigiosa, apex of hind femur and base of hind tibia, posterior view.

FIGURE 17. Male terminalia, lateral view of E. (Enoplempis). A, E. pencillata; B, E. prodigiosa.

FIGURE 18. Distribution of E. (Enoplempis). A, E. nuda and E. prodigiosa; B, E. enodis, E. montywoodi, E. pectinata, and E. penicillata.