Empis (Leptempis) rhodopensis Bartak

Kanavalova, Liliana, Kubik, Stepan & Bartak, Miroslav, 2018, Empidinae (Diptera, Empididae) from Bulgaria with new records and descriptions of three new species, ZooKeys 785, pp. 145-161 : 145

Empis (Leptempis) rhodopensis Bartak sp. n. Figs 1, 2

Type material.

HOLOTYPE ♂, Bulgaria, Rhodopes Mountains, Pamporovo env., meadow, 41.65N, 24.73E, 1600 m, Barták, Kubík, 22.-24.vi.2016 (CULSP). PARATYPES: 4♂, 2♀, same data as holotype; 1♂ Bulgaria, Rhodopes Mountains, Sniezhanka peak, 1900m, hilltop, 41.637N, 24.680E, Barták, Kubík, 24.-25.vi.2016 (CULSP).

Diagnosis.

Large species of the E. (L.) rustica group with yellow coxae, very long labrum (2.5 –2.6× head height), grey abdomen incl. venter, brownish yellow epandrial lamella, and spinose ventral part of hind femur.

Etymology.

The species epithet, rhodopensis, is derived from mountain range (Rhodopes Mountains) where the type material was collected.

Description.

Male (Figure 1). Head black, rather light grey microtrichose, holoptic, eyes meeting over long distance. Frons withsmall triangles just above antennae and below front ocellus without setae. Dorsal half of eye with distinctly larger facets than ventral half. Ocellar setae black, broken in all male specimens. Occiput with two rows of long setae dorsally, ventral part with irregularly arranged, long and fine yellow setae. Face approx. 0.35 mm broad ventrally, microtrichose with shiny narrow ventral margin, without setae. Clypeus shiny, gena very narrow, microtrichose. Palpus yellow, with several short black setae, subapical seta longest. Labrum yellow with brown base and apex, 2.5 –2.6× longer than head height. Antenna black, both basal segments short setose; length of antennal segments (scape: pedicel: postpedicel: basal joint of stylus: last joint of stylus) = 0.18-0.21 mm: 0.1-0.11 mm: 0.39-0.43 mm: 0.04-0.05 mm: 0.21-0.3 mm.

Thorax black, light grey microtrichose; mesoscutum with three stripes down rows of acrostichal and dorsocentral setae brown in anterior view and almost velvety blackish-brown in posterior view, postalar callus yellowish. Chaetotaxy: antepronotum with row of 4-6 black setae and several pale setulae laterally, proepisternum with many fine pale setae, prosternum bare; acrostichals biserial and approx. 0.20 mm long (subequally long as distance between rows of acrostichals and dorsocentrals); dorsocentrals longer and stronger, irregularly 2-3-serial (in some specimens almost uniserial anteriorly) ending in 2-4 longer prescutellar pairs; 1 long postpronotal and several smaller setulae; one long posthumeral (presutural supraalar), 1-2 long intrahumeral(s) (presutural intraalars); notopleuron with 2-3 long and strong setae and with several additional setae anteriorly (sometimes one of them equally strong as posterior ones); two postsutural supraalars (and 0-2 finer setae in prealar position); one long postalar (and several very small black setulae); two pairs of long scutellars (outer pair smaller); laterotergite in some specimens with yellow setae, in others mixed with black setae (on anterior part of laterotergite). Legs including coxae yellow, tips of all femora and tibiae, and whole tarsi (except sometimes basal part of hind basitarsus) black, all setae black except some pale setulae anteriorly on fore coxa. Fore femur very short setose, with rows of antero- and posteroventral very fine setulae shorter than half of femur depth. Fore tibia short setose, in some specimens with one to several setulae dorsally shorter than tibia depth, posterior setosity rather dense. Mid femur with fine and medium dense anterodorsal setosity shorter than femur depth, posterodorsal setulae much shorter, anteroventral row of setae slightly shorter than femur depth, posteroventral setae slightly longer. Mid tibia with two ventral rows of setae slightly longer than tibia depth, dorsally with two rows of 4-5 setae up to twice longer than tibia depth. Hind femur short setose dorsally except several somewhat longer fine anterodorsal setae on apical part, posteriorly and posteroventrally rather densely covered with fine setae slightly longer than femur depth, anteroventrally and ventrally with irregularly arranged short spine-like setae. Hind tibia with short ventral ciliation, two rows of 4-5 setae dorsally slightly longer than tibia depth. Basitarsi of all legs slender and short setose, hind one with short spine-like setae ventrally. Comb at tip of hind tibia without longer seta. Wing membrane distinctly brown clouded, veins yellowish to blackish brown, axillary angle slightly acute; costal seta present, fine and rather short. Measurements: M2/d ratio = 1.0-1.2, CuA1 ratio = 1.4-1.6, lw:ww ratio = 3.2-3.5. Halter yellow, calypter light brownish with yellow margin and yellow fringes.

Abdomen black, light grey microtrichose, lower part of cercus and epandrial lamellae brownish yellow. Tergites dorsally mostly with black setae and lateral parts of tergites and venter mostly with yellow setae. Lateral marginal setae on tergites 2-8 almost as long as segments, discal setae on dorsum of abdomen very short, venter sparsely short setose, with fine hind marginal setae best developed on segments 4-6. Genitalia (Fig. 2): hypandrium small, bare; epandrium subovate, long setose, with slightly swollen dorsoapical part; cercus trilobate with broadly U-shaped dorsal incision; phallus long and thin, slightly undulating apically.

Length. body 7.8-8.7 mm, wing 8.5-8.8 mm.

Female. Dichoptic, all facets equal in size, frons approx. 0.25 mm broad with approx. 10 short black setae on each side. Labrum 2.8 –3.2× longer than head height. Fore femur very short setose. Fore tibia short setose, anterodorsally and posteroventrally with several setae shorter than tibia depth. Mid femur short setose, anteroventrally with extremely short setae (0.03 mm), posteroventrally with row of setae approx. 1/3 of femur depth. Mid tibia with several anterodorsal, posterodorsal and posteroventral setae shorter than tibia depth and with rather dense row of slightly shorter anteroventral setae. Hind femur short setose, ventral setae equally extremely short as those on anteroventral side of mid femur.Hind tibia with several antero- and posterodorsal and anteroventral setae shorter than tibia depth. Tarsi of all legs narrow and short setose, basitarsi with short ventral spines. Abdomen with setae mostly black, yellow ones confined to lateral parts of basal segments.

Remarks.

Empis (Leptempis) rhodopensis sp. n. is a member of the E. (L.) rustica group close to E. (L.) trunca Daugeron (subsequently abbreviated ET). However, the newly described species has longer labrum (1.7 × head height in ET), brownish wing membrane (clear in ET), mesoscutum with three narrow not very distinct brown stripes along lines of setae (two broad stripes on dorsocentrals in ET), hind femur with strong and short irregularly arranged spines ventrally (absent in ET), epandrial lamellae brownish yellow (brown to black in ET) and phallus longer and thinner (compare figure 8 by Daugeron 1999 with Figure 2). Another species, with which the newly described species should be compared, is E. (L.) lindneri Oldenberg due to similarly very long labrum, however, E. (L.) lindneri has basally undulating phallus and different shape of the cercus. Spinose hind femur is also present in Empis (Leptempis) tenuis Bahid & Daugeron, 2017 however, this species differs from ER in many characters, especially it has quite different genitalia (see Bahid et al. 2017). Interestingly, in CULSP collections there is another still undescribed species of this group close to ET from Turkey, differing chiefly from both all above mentioned species by yellow tarsi.