Eumerus chekabicus Gilasian & van Steenis
Gilasian, Ebrahim, Steenis, Jeroen van & Parchami-Araghi, Mehrdad, 2020, Review of the Eumerus tricolor species group (Diptera: Syrphidae) in Iran, with description of six new species, European Journal of Taxonomy 722, pp. 106-152: 117-118
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|Eumerus chekabicus Gilasian & van Steenis|
This species differs from E. grandis Meigen, 1822 , E. ovatus Loew, 1848 and E. sinuatus Loew, 1855 by the following characters: eyes with long brownish pile (with long light brown pile in E. sinuatus and E. ovatus and short white pile in E. grandis ); vertical triangle flat like in E. sinuatus and E. ovatus (bulging vertical triangle in E. grandis ); eyes holoptic, eye contiguity long like in E. grandis and E. ovatus (dichoptic eyes in E. sinuatus ); ocellar triangle isosceles in E. chekabicus sp. nov., E. grandis and E. ovatus , posteriorly rather broad in E. chekabicus sp. nov. (rather narrow in E. grandis and broad in E. ovatus ), ocellar triangle in E. sinuatus equilateral; vertical triangle with mix of black pile posteriorly and yellow pile anteriorly like in E. grandis (entirely black pilose in E. ovatus and E. sinuatus ); scutum shiny metallic, without median vittae like in E. ovatus (shiny bluish in E. sinuatus and shiny black with long median vittae in E. grandis ); scutum with long brownish pile (with short brownish and black pile in E. grandis , long white pile in E. ovatus and long brownish and black pile in E. sinuatus ); tergum IV entirely reddish-orange (mostly black in E. grandis except for narrow red portions anterolaterally; it is black with median dense white pile in E. ovatus and it is black medially, red anterolaterally and posteriorly in E. sinuatus ); metafemur slightly enlarged, with long whitish pile anteriorly (enlarged with long pile posteriorly in E. grandis , slightly enlarged with rather long pile anteriorly in E. ovatus and narrow with long pile anteriorly in E. sinuatus ); metatibia long whitish pilose (with short whitish pilosity in E. sinuatus and short brown to black pilosity in E. grandis and E. ovatus ).
The name ‘ chekabicus ’ [Latin, adjective] refers to the Chekab Valley in the Haftad Qolleh Protected Area, Markazi province, where the holotype was collected.
IRAN • ♂; “ IRAN: Markazi prov., Haftad- / Qolleh Protected Area, / Chekab Valley , 2219 m, / 34°07′0.5″N, 050°16′25.3″E, / 25.v–15.vi.2016, Malaise trap / near pool, E. Gilasian & M. / Parchami- Araghi // HOLOTYPUS ♂ / Eumerus chekabicus / Gilasian & van Steenis / 2020 [red label]”; HMIM.GoogleMaps
MEASUREMENTS. Body length: 10.5 mm; wing length: 7 mm.
HEAD ( Fig. 13 View Fig G–H). Eyes long brownish pilose, holoptic, eyes contiguity almost 0.6 times as long as frontal triangle; face nearly parallel-sided, shiny black and covered with dense and long yellowish pile; frontal triangle shiny black, entirely covered with dense yellowish pile; head in frontal view 3.75 times as wide as face; frontal triangle 1.3 times as long as vertical triangle; vertical triangle shiny black, with yellowish pile; ocellar triangle isosceles; ocellar triangle shiny black, with mix of yellowish and black pile, 1.25 times as long as wide and nearly as long as vertical triangle; distance between posterior ocelli to posterior margin of eye about 0.7 times as long as ocellar triangle; occiput light grey pollinose, with yellowish pile; frontal triangle 1.25 times as wide as ocellar triangle; vertex at posterior corner of eyes 1.3 times as wide as vertex over posterior ocelli; head in dorsal view 5.5 times as wide as vertex at posterior corner of eyes; antennae brownish-black; basoflagellomere almost as long as wide; arista about 2.2 times as long as basoflagellomere ( Fig. 11D View Fig ).
THORAX. Scutum and scutellum shiny metallic, weakly pollinose, with long and dense yellowish pile, without median pollinose vittae; posterolateral part of scutum with two black setulae above base of wing; scutellum with marginal rim; pleurae black; anepisternum, anepiemron and katepisternum with long yellowish pile.
LEGS ( Fig. 9D View Fig ). Legs black; metatrochanter orange at apex; metacoxa with long yellowish-white pile; pro- and mesofemora with long whitish pile posteriorly; mesofemur with short blackish pile anteriorly; metafemur simple, slightly enlarged, about 4 times as long as wide, with long whitish pile anteriorly; anteroventral and posteroventral margins of metafemur each with a row of 9 respectively 6 black setae in about apical half; pro- and mesotibiae with very short dense whitish pile dorsally and with long whitish pile posteriorly; metatibia with dense long whitish pile dorsally; metatarsus with short black pile dorsally and with tuft of dense orange pile ventrally; metasternum with long whitish pile.
WING. Sparsely microtrichose in basal half; vein R 4+5 slightly sinuate; calypters yellowish-white; halter brownish-orange.
ABDOMEN. Tergum I black with whitish pile; terga II–IV long whitish pilose, each with a pair of lunulashaped oblique maculae of white pollinosity; tergum II reddish-orange with a median black ‘pewter chalice’-shaped vitta; tergum III mostly reddish-orange except median narrow black vitta; tergum IV entirely reddish-orange; sterna orange, long yellowish pilose; sternum IV rectangular, with rounded posterolateral corners and with median wide V-shaped incision posteriorly ( Fig. 12C View Fig ).
GENITALIA ( Figs 18C View Fig , 20C View Fig , 22C View Fig ). Hypandrium simple; aedeagal apodeme wide in lateral view; posterior lobe of surstylus in lateral view narrowed toward apex, with a row of short and black setulae posteriorly and in dorsal view uniformly rounded apically with a strong median bend; inner accessory lobe of surstylus with short pile.
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