Eumerus pilosus Barkalov et Mutin, 2024

Barkalov, A. V. & Mutin, V. A., 2024, TWO NEW HOVERFLY SPECIES OF THE GENUS EUMERUS MEIGEN, 1822 (DIPTERA: SYRPHIDAE) FROM RUSSIA, Far Eastern Entomologist 510, pp. 1-6 : 2-4

Eumerus pilosus Barkalov et Mutin sp. n.

https://zoobank.org/NomenclaturalActs/ C88D37E5-6728-4651-8875-0EC59B219840

Figs. 1‒7 , 13‒14

TYPE MATERIAL. Holotype ‒ ♂, Russia: Volgograd Region (=Stalingrad Region), Tinguta , 14.V 1952, G. Victorov leg. [ ZMMU]. Original labels in Russian: “Сталинград. обл., Тингута, 14.V.1952, Г. Викторов” / Eumerus strigatus Flln. ; Л. Зимина det.”.

DESCRIPTION. Male. Body length 7.5 mm, wing length 6.0 mm.

Head ( Fig. 14 ). Face parallel-sided, faintly grey pollinose, with dense silvery pile. Gena very narrow, almost undeveloped. Frons narrow, covered with a silvery tomentum and very dense, hiding the main color, semi-erect silvery pile; angle approximation of eyes distinctly less than 90°. Scapus and pedicel short, dark-brown, shiny, with white pile on dorsal surface of pedicel. Basoflagellomere orange, dense grey pollinose, irregular form with antero-ventral angle, with transverse furrow in basal part, from which four longitudinal furrows extend, and with comparatively small sensory fossa apically ( Fig. 4 ). Eyes holoptic, covered with rare light pile; contiguity of eyes about 4 facets long. Vertex narrow, shiny, black with greenishblue reflection, with silver pile, which dense and semi-erect apically and sparse erect posteriorly. Ocellar triangle isosceles; distance between posterior ocelli is a little bit longer than distance between anterior and posterior ocelli ( Fig. 5 ). Occiput with white pile.

Thorax. Mesonotum shiny, black, with yellow erect moderately long pile, without pollinose marks or stripes. Pleurae shiny, with yellowish pile. Legs. Coxae and trochanters black, without any spurs. Femora black, with narrowly yellow tips. Metafemur distinctly swollen and weakly curved, with apico-ventral carina bearing a row of 6 strong setae ( Fig. 6 ). Meso- and metafemur with yellow pile postero-ventrally, which length approximately equal 2/3 width of femora. Pro- and mesotibia yellow, with black annulus in apical third; metatibia mostly black, except brownish base and yellow tip, with a row of pressed black setulae on postero-ventral surface of basal part. Pro- and mesotarsus brown dorsally and yellow ventrally; segments 1-4 of mesotarsus with a pair of strong black setae ventrally. Length of metabasitarsus approximately equal length of tarsomeres 2-4 put together. Wings hyaline, with brown venae, mostly covered by microtrichia, except bare basal part of anterior and posterior basal cells.

Abdomen. Black dorsally, with yellow pile laterally and black pressed pile medially. Tergites 2-4 with pair of oblique pruinose maculae. Sternum VI with comparatively long black pile. Sternum IV raised, forming a kind of keel, with deep cut on hind margin ( Fig. 7 ), covered with long yellow pile.

Genitalia ( Figs 1-3 ). Posterior surstylar lobe with lateral oblique keel going to the middle of epandrium. Inner side of surstylus with numerous pile. Cercus elongated, curved, with long pile.

Female. Unknown.

DIAGNOSIS. From all species E. pilosus sp. n. differs by the combination of the following characters: the ocellar triangle is shorter in length than in width, the basoflagellomere orange, mesonotum without pruinose vittae and by construction of male genitalia.

DISTRIBUTION. The South of European part of Russia.

ETHYMOLOGY. The species name reflects the character of new species – presence on ventral surface of femora dense long white pile.

Figures

Figs 1‒7. Eumerus pilosus sp. n. 1 – epandrium laterally; 2 – hypandrium laterally; 3 – epandrium ventrally; 4 – 2-3 segments of antenna laterally; 5 – head dorsally; 6 – metaleg laterally; 7 – tip of abdomen ventrally. Scale bars in mm.

Figs 13‒16. Eumerus ssp. 13, 14 ‒ E. pilosus sp. n.; 15, 16 ‒ E. grunini sp. n.; (13, 15 ‒ male laterally; 14, 16 ‒ head dorsally). Scale bars: 13, 15 = 1.0 mm; 14, 16 = 0.5 mm.