Rhamphomyia (Pararhamphomyia) nudiscutellata, Bartak, Miroslav & Kubik, Stepan, 2015

Bartak, Miroslav & Kubik, Stepan, 2015, Palaearctic species of Rhamphomyia (Pararhamphomyia) anfractuosa group (Diptera, Empididae), ZooKeys 514, pp. 111-127 : 118-119

Taxon classification Animalia Diptera Empididae

Rhamphomyia (Pararhamphomyia) nudiscutellata sp. n. Figs 5, 11, 15

Type material.

Holotype male: Russia, Amurskaja oblast, g. (gorod = city) Zeja, 14.ix.1981, A. Shatalkin, deposited in ZMMU; Paratypes: 2 males, same data as holotype; 4 males, Tuva, okr. (=region) Baj-Chaaka, Berezovka, 5.ix.1973, V. Kovalev; 2 males, same locality, 3.ix.1973, V. Kovalev; 2 males, same locality, 7.ix.1973, V. Kovalev; 2 males, Tuva, okr. Saryg Sep, listvennicznik na granice lesa (= larch on forest boundary), 28.viii.1973, V. Kovalev; 1 male Chitin, r. (=river) Kuenga, vyche (= above) Chernyshevska, 24.viii.1977, V. Kovalev. Paratypes depositories: ZMMU, CULSP.

Additional material examined

(excluded from type series): 2 females, Chitin, r. (reka = river) Kuenga, vyche Chernyshevska, 26.viii.1977, V. Kovalev; 1 female, Tuva, okr. (= region) Baj-Chaaka, Berezovka, 5.ix.1973, V. Kovalev; 1 female, same locality, 2.ix.1973, V. Kovalev; 2 females, Tuva, okr. (= region) Shagonar, Ishtii-Khem, 21.viii.1973, V. Kovalev; 1 female, same locality, 24.viii.1973, V. Kovalev; (ZMMU and CULSP).

Diagnosis.

Species of the subgenus Pararhamphomyia with phallus forming loops in space, light grey mesoscutum and uniserial dorsocentrals. Female front femur with two rows of ventral setae longer than depth of femur, hind tibia not pennate, wing light brownish and tergites 6 and 7 lustrous.

Etymology.

The name of the species is derived from the relatively naked scutellum bearing only four setae (nudus, Latin = naked).

Description.

Male. Head holoptic, facets in dorsal half of eye enlarged. Frons blackish brown, light grey microtrichose, without setae. Ocellar setae one third as long as frons, black, ocellar triangle with 1-2 pairs of additional setae. Face blackish brown, light grey microtrichose, 0.20 mm broad ventrally and 0.25 mm long, without setae. Occiput brownish black, rather light grey microtrichose, black setose. Antenna black, scape and pedicel brown, length of antennal segments = 15-16: 11: 45-50: 12-14, setae on basal two segments about 0.10 mm long. Labrum brown, lustrous, slightly shorter than head is high. Palpus brown, short, covered with several rather long setae (0.20 mm long), preapical seta poorly differentiated. Gena narrow and lustrous, clypeus microtrichose.

Thorax brownish-black, rather light grey microtrichose, scutum without stripes, only in immature specimens with poorly visible darker stripes below rows of acrostichals and dorsocentrals. All setae black. Chaetotaxy: proepisternum with 5-8 setae, both propleural depression and prosternum bare; 6-10 biserial, short and fine acrostichals (about 0.15 mm long); 7-10 regularly uniserial dorsocentrals (about 0.25 mm in middle of rows), ending in 2 long prescutellars, 1-2 fine and long intrahumerals, 1 strong posthumeral; postpronotum with 2-3 long and 6-10 gradually shorter setae; 3 notopleurals (0-2 long setae on anterior part of notopleuron); 1 long supraalar, prealar absent; 1 long and 1 shorter postalar; 2 pairs of scutellars; laterotergite with black setae.

Legs brown, microtrichose, black setose. Coxae blackish-brown, microtrichose (only hind coxa with lustrous spot anteriorly near base), black setose. One long seta present in comb at tip of hind tibia. Fore femur with complete rows of fine antero- and posteroventral setae up to 2/3 as long as long as depth of femur, dorsal setae shorter. Fore tibia short setose, without differentiated setae except preapical. Mid femur with two rows of spiny setae ventrally, anteroventrals up to one-third as long as depth of femur, posteroventrals slightly longer than depth of femur, other setation short. Mid tibia with only two anterodorsal setae (one short subbasal and one long preapical), and 3-4 posterodorsals slightly longer than depth of tibia, two rows of ventral setae somewhat shorter than width of tibia (several posteroventrals may be longer than remaining ones). Hind femur (Fig. 15) with ventral microtrichosity up to 0.05 mm long, with rather fine anteroventral setae about as long as depth of femur in basal half and in some specimens apically, very short to absent on third quarter of femur, posteroventrals present only on extreme base of femur. Hind tibia with 3-4 antero- and 5-6 posterodorsal setae slightly longer than width of tibia, ventral setae short. Basal tarsomeres of fore and mid legs thin and short setose, mid basal tarsomere with several short ventral spines; basal tarsomere of hind leg slightly swollen, with several setae dorsally and spine like setae ventrally up to 2 × longer than diameter of tarsomere.

Wing clear, stigma scarcely darker, veins brown and yellowish in basal part of wing, anal vein indistinct about middle. Costal seta present, axillary angle right. Measurements: M2/d = 1.2-1.7, CuA1 ratio = 1.6-1.9, lw/ww = 2.7-3.3. Halter yellow, calypter yellow with dark fringes.

Abdomen brown, entirely light grey microtrichose (light grey from both lateral and dorsal views), setae all dark. Hind marginal setae on tergites 2-3 somewhat longer and on tergites 4-6 as long as corresponding segments, discal setae shorter. Dorsum of abdomen with short setae. Phallus (Figs 5, 11) with three twists in space.

Length: Body 3.8-4.0 mm, wing 4.5-5.8 mm.

Female. Head dichoptic, frons approximately 0.25 mm long and 0.20 mm wide, subparallel, with two rows of 4-6 relatively long setae on sides. Face approximately 0.20 mm long and subequally wide in middle (strongly divergent ventrally), without setae. Palpus brown as in male. Thorax as in male. Fore femur with both antero- and posteroventral rows of setae as long as depth of femur, posteroventrals mostly thin but in some specimens on one or both legs thickened - almost pennate, dorsal ciliation short and thin. Fore tibia as in male, only posteroventral setae slightly differentiated. Mid femur with both (antero)dorsal and (postero)ventral pennation about as long as depth of femur. Mid tibia short setose, most specimens with several antero- and posteroventral setae and/or several setae dorsally shorter than depth of tibia. Hind femur with long pennate ciliation ventrally in addition to several setae and shorter dorsal subpennate ciliation. Hind tibia slightly flattened, with two rows of dorsal setae slightly longer than width of tibia, ventral setae short, short ciliation slightly subpennate. Wing clear with only indistinct brownish tinge, measurements: M2/d = 1.3-1.6, CuA1 ratio = 1.6-1.8, lw/ww = 2.8-3.0. Abdomen microtrichose, with tergites 6 to 8 and sternites 7 and 8 lustrous. Hind marginal setae on segments 2-4 as long as corresponding segments, on segments 5-7 2/3 as long as corresponding segments.

Length: Body 4.0-4.4 mm, wing 4.6-5.2 mm.

Remarks.

Rhamphomyia (Pararhamphomyia) nudiscutellata sp. n. is closely allied to the remaining three Palaearctic species of the Rhamphomyia anfractuosa group of species with phallus twisted in space, viz Rhamphomyia anfractuosa , Rhamphomyia lineodorsata sp. n. and Rhamphomyia robustior . All four species may be identified according to the key. We excluded females from the type series because of problems with exact identification of females in this group of species and because we had no pairs taken in copula. But we believe we identified them properly. Female differs from Rhamphomyia robustior and Rhamphomyia anfractuosa in lustrous abdominal tergites 6 and 7 (microtrichose in both Rhamphomyia anfractuosa and Rhamphomyia robustior ), from Rhamphomyia lineodorsata by brown palpus (yellowish red in Rhamphomyia lineodorsata ) and from Rhamphomyia anfractuosa also by front femur with two rows of ventral setae longer than depth of femur, hind tibia without broad pennate ciliation and light brownish wing (in Rhamphomyia anfractuosa , front femur has almost no ventral setae, hind tibia is broadly pennate both dorsally and ventrally and wing is deep brown).

Distribution.

Russia (Far East).

Dates of occurrence.

August-September.