Rhamphomyia (Holoclera) richterae, Shamshev & Barták, 2024

Shamshev, Igor V. & Barták, Miroslav, 2024, New species and records of the Rhamphomyia subgenus Holoclera (Diptera, Empididae) from the Palaearctic Region, Zootaxa 5512 (4), pp. 512-530 : 517-519

Rhamphomyia (Holoclera) richterae sp. nov.

( Fig. 1 )

Type material. HOLOTYPE ♂, labelled: [ RUSSIA. Krasnodarskiy Terr.] Lasarevskoe [43°54′N 39°19′E], Carpinus / Castanea forest, 11.ix.1984, Richter ( ZISP, INS _DIP_0000849). PARATYPES. RUSSIA. Krasnodarskiy Terr.: same locality as holotype, 23.ix.1982, Gorodkov (2 ♀, ZISP). Sochi, mountain Akhun [43°33′N 39°50′E], 24,27. x.2006, N. Vikhrev (2 ♀, ZMMU). Adygea: Dakhovskaya env., E slope of Azish-Tau, Fagus forest, 44.22N 40.1E, ~ 950 m, 26–29.viii.2009, coll. K. Tomkovich (1 ♂, ZMMU).

Diagnosis. A species of the R. (H.) flava group; acrostichal setae absent; thorax and abdomen entirely yellow, male mesoscutum and abdominal tergites with some brownish tinge. Male: halter with brown knob and yellow stem.

Description. Male ( Fig. 1A ). Body length 5.1 mm, wing length 5.5 mm (holotype). Head with greyish, dense pruinescence on ocellar triangle, occiput and postgena; frons above antennae brownish, face and clypeus brownish yellow; black setose (except noted). Eyes holoptic, with upper ommatidia enlarged. Frons represented by very small, subtriangular space just below ocellar triangle and slightly larger space just above antennae. Face moderately broad, almost parallel-sided, bare. Ocellar triangle with 2 long, thin anterior setae and two pairs of minute setulae posteriorly. Occiput with moderately long strong postoculars and almost regular rows of similar setae laterally; postgena with some short, black and longer pale hair-like setae. Antenna with scape and pedicel yellowish brown, postpedicel (except yellowish brown extreme base) and stylus dark brown; scape short, slightly longer than pedicel, both with short setulae; postpedicel elongate-conical, with narrow base, nearly 3X as long as basal width; stylus short, 2.8X shorter than postpedicel. Proboscis short, with labrum only slightly longer than head height (1.3X in holotype); palpus yellow, with black, scattered setulae.

Thorax almost uniformly yellow, only mesoscutum somewhat darker, with some brownish tinge; faintly pruinose, mesoscutum rather matt; black setose. Proepisternum with 7–10 minute setulae on lower part, 1 similar setula on upper part. Prosternum bare. Antepronotum with 8–9 short, strong setae on each side. Postpronotal lobe with 1 strong, long and 4–5 short, fine setae. Mesonotal setae well-differentiated; acrostichals absent; dorsocentrals uniserial, 9 setae per row, 7 presutural setae subequally moderately long, 2 postsutural setae longer (prescutellar longest); 0 presutural intra-alar, 1 long presutural supra-alar, 3 notopleurals (middle seta longest; additionally, with 2 setulae anteriorly), 1 postsutural supra-alar (with 1–2 setulae anteriorly), 1 long and 1 minute postalars, 4 scutellars (apical setae longer and stronger). Laterotergite with 4–5 long fine setae and numerous minute setulae. Anterior and posterior spiracles yellow.

Legs long, slender, podomeres unmodified; extensively yellow and subshiny (including coxae); trochanters with brownish subapical spot, tibiae brownish yellow on extreme apex, basitarsus of all legs brownish on apex, fore and mid tarsomeres 2–5 almost uniformly brownish (tarsomere 2 somewhat paler near base), hind tarsomere 2 brownish at apex and hind tarsomeres 3–5 brownish. Coxae and trochanters with simple setae. Fore femur with simple setulae anteriorly; bare ventrally, with mostly minute anteroventral and posteroventral setae (somewhat longer near apex) and short, strong subapical setae. Fore tibia with 3 moderately long dorsal setae (besides circlet of subapicals). Mid femur covered with mostly uniform minute setulae ventrally; short, strong anteroventral and posteroventral setae on about apical 1/4; subapical circlet of setae of different robustness (1 anterior seta strongest). Mid tibia with 2 moderately long anterodorsal, 3–4 similar posterodorsal, 1 short anteroventral and 2 short posteroventral setae (position somewhat variable even on right and left legs). Hind femur slightly narrower on about basal half, with similar setation to mid femur. Hind tibia slightly evenly thickened on subapical part; with 4 anterodorsal and 4 posterodorsal setae; 1 short seta in posteroapical comb. Basitarsus of all legs with short spine-like setae ventrally; tarsomeres 3–4 with longer setae of subapical circlet than those on tarsomeres 1–2.

Wing membrane faintly brownish; veins brownish, well sclerotised; CuA+CuP complete but slightly weakened on about middle; cell dm short, with elongate apex. Pterostigma absent. Basal costal seta absent. Anal lobe well-developed; axillary incision acute. Squama yellow, brown fringed. Halter with brown knob and yellow stem.

Abdomen extensively yellow, faintly pruinose, black setose; tergites rather brownish yellow dorsally, with long posteromarginal setae. Pregenital segments unmodified; segment 8 with fused tergite and sternite; tergite 8 entire.

Hypopygium ( Fig. 1 B-D) small, black setose; cercus and most part of epandrium brownish; basal part of epandrium, hypandrium and visible part of phallus brownish yellow. Epandrial lamellae narrowly connected dorsally ( Fig. 1B, C ); epandrial lamella subtriangular (lateral view); covered with moderately long to short, fine setae on apical part and along upper margin. Hypandrium separated from epandrium; subtriangular in ventral view, elongate, with rounded apex, well-sclerotised, bearing 2 spinule-like subapical setae; gonocoxal apodeme inconspicuous. Hypoproct weakly sclerotised, bare. Phallus short, almost entirely hidden, slightly extending beyond cerci, gently curved; almost uniformly thick, slightly thicker closer to apex, in lateral view dorsal margin of apex slightly longer than ventral margin; with pair of rod-like, stronger sclerotised spaces on about apical 1/3 forming partly ventral margin of phallotrema; phallotrema large. Ejaculatory apodeme moderately large, without lateral wings, only extending beyond basal curvature of phallus. Cerci separated from epandrium and from each other; cercus broadly deeply concave on upper part posteriorly forming two lobes; upper lobe invisible in lateral view, in dorsal view small ( Fig. 1D ); lower lobe in lateral view subtriangular and short, apex reaching nearly middle of upper margin of epandrial lamella, produced ventrally forming additional internal subglobular cercal lobe; visible part of cercus covered with simple setulae of different lengths, internal lobe with similar marginal setulae.

Female. Similar to male, except as follows: Dichoptic; frons below ocellar triangle nearly as broad as anterior ocellus, broadened toward antennae on about lower half, bearing minute marginal setulae; wing hyaline; halter yellow; mesoscutum yellow, with shorter presutural dorsocentral setae; abdomen with shorter setae; abdominal tergites 1–7 with indistinct, brownish yellow, small, subtriangular spots anteriorly; tergite 8, syntergite 9+10 and cerci brownish, rather densely greyish pruinose; cercus long, slender, with minute setulae.

Etymology. The species epithet, “ richterae ”, is a Latin genitive matronym to memory of Russian dipterist Vera Andreevna Richter (1936–2015), who collected part of the type material.

Remarks. The new species belongs to the R. (H.) flava group and is similar to R. (H.) variabilis (Fallén) and R. (H.) subvariabilis Barták & Kubík , because these three species lack acrostichal setae. The new species can be readily distinguished from these two species by entirely yellow thorax and abdomen. One more species assigned very recently to R. ( Holoclera ), R. (H.) daugeroni Barták & Kokan differs from R. (H.) variabilis , R. (H.) subvariabilis and R. (H.) richteri sp. nov. primarily by pale setose abdomen ( Daugeron & Lefebvre 2015 —as Rhamphomyia (Lundstroemiella) brevis , preoccupied; Barták & Kokan 2021). The new species is more similar to R. (H.) subvariabilis sharing the absence of anteroventral setae on mid and hind tibiae and the presence of two very short apical setae on the hypandrium. Besides the colour of the thorax and abdomen, the male of the new species differs from the male of R. (H.) subvariabilis by mostly brown halteres and deeply brownish infuscate wings. The female of the new species has yellow halteres and almost hyaline wings. However, it differs from R. (H.) subvariabilis primarily by shorter stylus (about 1/3 of postpedicel length versus more than half length of postpedicel). It should be noted that the new species has a shorter seta in the posteroapical comb of hind tibia than R. (H.) variabilis and R. (H.) subvariabilis .

Distribution. Russia. Known only from the North Caucasus (Adygea, Krasnodarskiy Terr.).

Habitat and seasonal occurrence. According to label data, the new species appears to inhabit mountain slopes covered with broad-leafed forests ( Carpinus , Castanea , Fagus ), occurring unusually late around the end of August until the end of October.

Figures

FIGURE 1. Rhamphomyia (Holoclera) richterae sp. nov., male. A. Habitus, lateral view. B. Hypopygium, lateral view. C. Outline of hypopygium, lateral view (setae omitted). D. Cerci, dorsal view. Abbreviations: cerc—cercus; ej apod—ejaculatory apodeme; epand—epandrium; hypd—hypandrium; ph—phallus. Scale bar 1 mm.