Chersodromia mohican, Maeda, Takuya, 2011

Maeda, Takuya, 2011, New species of Chersodromia from the Russian Far East (Diptera: Empidoidea: Hybotidae: Tachydromiinae), Zootaxa 2979, pp. 1-24 : 11-14

publication ID	https://doi.org/ 10.5281/zenodo.202911
DOI	https://doi.org/10.5281/zenodo.6191956
persistent identifier	https://treatment.plazi.org/id/6B3487F7-FFF0-7152-979B-9A9B0757FDC4
treatment provided by	Plazi
scientific name	Chersodromia mohican
status	sp. nov.

Treatment

Chersodromia mohican View in CoL sp. nov.

( Figs. 8 View FIGURES 6 – 12 , 15 View FIGURES 13 – 19 , 34–40 View FIGURES 34 – 36 View FIGURES 37 – 40 )

Diagnosis. A somewhat large species measuring more than 1.5 mm, with wide gena. Katepisternum largely polished. Vein R1 meeting costa after midway of wing. Fore tibial gland distinct. Male terminalia heavily sclerotized, with right surstylus composed of 3 distinct lobes, right epandrial lamella on right lateral side with incomplete row of brown setae, and oval left cercus. Vertical setae (2 pairs) and supra-alar setae present; posthumeral setae absent. Hind femur with anteroventral row of setae mainly in apical half.

Description. Male ( Fig. 8 View FIGURES 6 – 12 ). Body length 1.80–1.95 mm; head width 0.38–0.42 mm; wing length 2.10–2.20 mm. Head ( Fig. 34 View FIGURES 34 – 36 ) black in ground-colour and greyish pollinose; palpus dark brown in ground-colour and greyish pollinose; proboscis brown, slightly shining; antenna dark brown; all setae and setulae on head black. Frons moderate in width; in frontal view face below antennal sockets slightly wider than frons. Ocellar setae (2 pairs) somewhat long, as long as scape, pedicel and postpedicel combined. Vertical setae (2 pairs) slightly longer than ocellar setae. In frontal view gena wide, 1/3 as wide as maximum eye height. Occiput sparsely with setulae. Antenna ( Fig. 35 View FIGURES 34 – 36 ): postpedicel round in lateral view, bearing setulae on anterior margin; extension of postpedicel present dorsoapically; stylus long, ca. 2.5 times as long as pedicel and postpedicel combined. Palpus with ca. 10 setulae (apical one longest) and sensory pit visible in wet specimens without preparation on slide.

Thorax ( Fig. 36 View FIGURES 34 – 36 ) black in ground-colour and greyish pollinose; katepisternum largely polished; all setae and setulae black. Vestiture on thorax: 1 or 2 setulae on each proepisternum; 1 pair of postpronotal setae; no posthumeral setae; 3–4 pairs of notopleural setae; 1 pair of supra-alar setae; 1 pair of long postalar setae; 2–3 pairs of dorsocentral setae near median line; many dorsocentral setulae in multiple rows; 1 pair of incomplete rows acrostichal setulae; 1 pair of inflected apically scutellar setae; 1 pair of tiny subapical scutellar setulae.

Wing ( Fig. 15 View FIGURES 13 – 19 ) normally developed, somewhat narrow, clear, with pale brown veins. Basicosta with 1 or 2 dark brown setae and some black setulae; costa with small, brown setulae along anterior margin, ending at connection with vein M1+2; subcosta absent; R1 meeting costa after midway of wing; radial sector moderate in length; CuA1 indistinctly connected to wing margin; anal vein reduced to pale, fold-like line. Calypter greyish entirely and whitish partially. Halter dark brown.

Legs brown, stout; all setae black; setulae black/brown. Fore femur covered with setulae, with anteroventral row of setae, 1 anterior preapical seta, 1 anteroventral preapical seta and 1 posterior preapical seta. Fore tibia covered with setulae (especially dense on anterior surface), with 1 anteroventral preapical seta and 1 posteroventral preapical seta. Fore tibial gland distinct. Mid femur covered with setulae, with 1 anterior preapical seta. Mid tibia covered with setulae, with anteroventral row of many tiny, black spinulae, 1 posterior preapical seta, 1 posteroventral preapical seta and 1 posteroventral seta. Hind femur covered with setulae, with ventral row of 1 or 2 setae near base, anteroventral row of ca. 5 setae mainly in apical half and 1 anterior seta near apex. Hind tibia covered with setulae (strong, short setulae present on ventral surface in apical part), with anterodorsal row of 3 setae, anterior row of 2 setae, 1 anterior preapical seta, anteroventral row of 2 setae and 1 anteroventral preapical seta. Fore, mid and hind tarsomeres densely covered with setulae.

Preabdomen sparsely covered with brown setulae; tergites and sternites brown in ground-colour, sparsely whitish pollinose; membrane pale brown. Tergites 1–7 each with 2 plaques laterally and 1 pair of small shiny pits dorsolaterally. Tergite 7 with some black setae along posterior margin. Eighth segment hidden, with some black setae along posterior margin.

Terminalia ( Figs. 37–40 View FIGURES 37 – 40 ). Coloration: right epandrial lamella brown in ground-colour and greyish pollinose; right cercus shiny pale brown; left cercus brown; left surstylus shiny brown; left epandrial lamella and hypandrium shiny brown (apical part of hypandrium light brown). Right surstylus composed of 3 lobes; apical lobe shiny dark brown, small and relatively complicated, boundary line between it and right epandrial lamella relatively obscure ( Fig. 37 View FIGURES 37 – 40 ); median lobe shiny pale brown, flattened and somewhat triangular with 2 long setulae at apex, boundary line between apical lobes obscure ( Figs. 37, 39 View FIGURES 37 – 40 ); basalmost lobe shiny brown, flattened, and looks like leaf of ginkgo ( Fig. 39 View FIGURES 37 – 40 ). Right epandrial lamella with incomplete row of brown setae on right lateral side ( Figs. 37, 40 View FIGURES 37 – 40 ). Left surstylus consisting of several lobes; outermost lobe large, composed of 2 main projections, of which bigger one somewhat round ( Fig. 38 View FIGURES 37 – 40 ). Right cercus small, sclerotized and elongate; left cercus large, heavily sclerotized and oval, with setae ( Fig. 40 View FIGURES 37 – 40 ).

Female. Body length 1.65–1.70 mm; head width 0.43–0.49 mm; wing length 2.23–2.36 mm. Resembling males except in structures of mid leg and terminalia. Mid tibia without anteroventral row of spinulae, but with 1 anteroventral seta on median part. Cercus brown.

Type material. HOLOTYPE 3, labelled: Russian Far East, S. Primorye, Nazimov Cape, 28.viii.2010, leg. T. Maeda ( USNM). Paratypes: 20 3, 20 Ƥ (dried specimens), same data as holotype. Other specimens examined (in alc.): 1 Ƥ, Gamov Pen., Astaf’ev Bay (bare sands), 26.viii.2010; 2 3, 7 Ƥ, Gamov Pen., Telyakovskiy Bay, 24.viii.2010; 23 3, 72 Ƥ, Nazimov Cape, 28.viii.2010.

Type depository. Some paratypes (males and females) are deposited in IBSS, NIAES, OUMNH, TMC and USNM.

Etymology. The specific epithet “ mohican ” derives from an English word, “ mohican ” meaning a kind of human hair style. The incomplete row of brown erect setae on the right epandrial lamella of this species looks like Mohican style pattern.

Distribution. Russian Far East: southern part of Primorsk Territory.

Remarks. This species was not collected on the shores along bays. The adults were found only on sandy shores facing the open sea ( Fig. 5 View FIGURES 2 – 5 ), running about on washed up debris consisting mainly of seaweeds.

Chersodromia mohican slightly resembles C. nubifera , both belonging to the hirta -group established by Chvála (1978). They have a wide gena, distinct fore tibial glands and a prominent basalmost lobe of the right epandrial lamella. In body size, however, C. mohican is smaller than C. nubifera . The size of the polished area on the katepisternum of C. mohican is larger than that of C. nubifera . The male terminalia of the former also differs from that of the latter in detail (see key to species).