Eumerus antennalis Mutin, 2025

Eumerus antennalis Mutin , sp. n.

https://zoobank.org/NomenclaturalActs/ 2B4DDE17-1E58-475F-BE57-087671EEA3DD 0

Figs 1‒5 View Figs 1‒5

TYPE MATERIAL. Holotype – ♂, Russia: Amurskaya Oblast , Khingansky Nature Reserve, 29 km SW Kundur village, Gryaznaya River, floodplain meadow, 48°54'10"N 130°30'28"E, 5‒6.VIII 2023, leg. D.N. Kochetkov ( FCBV). GoogleMaps

DESCRIPTION. Male. Body length 6.1 mm, wing length 4.2 mm. Face and frons with white pile and dense pruinosity hiding the main background. Vertex and occiput shining black, with rare pale pile. Ocellar triangle equilateral. Eyes dichoptic, rather bare; very short rare pile barely visible. Distance between eyes a little less than that between the posterior ocelli ( Fig. 3 View Figs 1‒5 ). Antennae mainly orange except for the blackish scape, basal pedicel and dorso-apical postpedicel. Postpedicel elongated oval, almost rectangular; ratio of width to length is 1: 1.6. Arista orange basally and darkened apically, a little longer than postpedicel.

Scutum shining black, with short erect yellowish pile, without visible pruinose vittae. Scutellum shining black, with yellowish pile, which is longer apically. Pleuron weakly pruinose, with yellowish pile. Coxae and trochanters black. Femora mainly black except yellow apex, with pale yellow pile, longest on postero-ventral surface and very short and adpressed on antero-dorsal surface of pro- and mesofemur. Metafemur with a pair of setose carinae; anterior row with 4 setae, posterior row with 7 setae. Pro- and mesotibia mainly yellow, with subapical diffused blackish annulus, yellowish pilose. Metatibia yellow on basal 2/5 and black on apical 3/5, yellow pilose. Pro- and mesotarsus white, with argento-white pile. Metatarsus strongly flattened, with snowy-white pile dorsally and yellowish-white pilose ventrally; basitarsomere 1.5x longer than second tarsomere, and ratio of its length to width is 7: 3. Wing hyaline, pterostigma yellow.

Abdomen black, with a pair of large oblique trapezoid yellow maculae on tergum II and narrow oblique pruinose maculae on terga III-IV. Terga II-III with yellow pile; tergum IV mainly pale pilose except black short pile on postero-medial surface. Tergum VIII black pilose. Sterna II-III brownish, narrow rectangular. Sternum IV sub-trapezoid; posterior margin moderately concave, with a pair of lateral tufts of long strong pile, without spines or laminae.

Posterior surstylar lobe short, with an apex bevelled forward ( Fig 4 View Figs 1‒5 ). Hamus gradually curved and tapered towards the top ( Fig 5 View Figs 1‒5 ). Cerci globular brownish.

Female is unknown.

DIAGNOSIS. The male of this new species clearly differs from all other congeners with the snow-white pile on the metatarsus and yellow maculae on tergum II by the following combination of characters: elongated postpedicel, which is 1.6 times longer than wide; dichoptic eyes with short, barely noticeable pile; ratio of basimetatarsomere to the second metatarsomere is 1,5: 1, ratio of basimetatarsomere length to its width is 7: 3.

DISTRIBUTION. Russia: Amurskaya Oblast (Khinganskii Nature Reserve).

BIOLOGY. The holotype of the new species was caught in floodplain meadow.

ETYMOLOGY. The specific name refers to elongated postpedicel atypical for congeneric species.

I thank Dr. V.M. Loktionov (Federal Scientific Center of East Asia Terrestrial Biodiversity, Vladivostok) for help with preparing photos, D.N. Kochetkov (Khingansky Nature Reserve) for collected material, as well as Pr. Francis Gilbert ( UK, Lincolnshire, Grantham) for his help in translating the article into English.