Brachystegus nemkovi Schmid-Egger & Al Jahdhami, 2025

Brachystegus nemkovi Schmid-Egger & Al Jahdhami sp. nov.

( Figs 12–14 View FIGURES 9–16 , 33 View FIGURES 33–36 )

Holotype: SAUDI ARABIA ♂ 01.iii.2024 Asir prov., 10km N Al Habil 18.164 N, 42.246 E, leg. M. Halada ( CSE) GoogleMaps

Diagnosis: Brachystegus nemkovi is unique among Palearctic Brachystegus in having a flat clypeus, with an inconspicuously delimited apical lamella. In remaining species, the clypeus has a conspicuous cross-carina, or is rectangulary stepped apically. The colour pattern of B. nemkovi is also distinctive, with an all yellow clypeus, an all red antenna, and the mesosoma lacking yellow spots. The terga are characterized by a rich yellow color.

Description of male holotype: Body length: 10.2 mm. Color: Clypeus yellow (apart small basal black zone), mandible basally yellow, medially red, apically black. Labrum, antenna and legs light reddish, coxa partly red. Pronotum dark red, remaining mesosoma black. Terga black with yellow spots or bands, lateral spots on T1, medially narrowed band on T2, visible parts of T 3–6 all yellow. T7 reddish. S1 and S7 with some red. Wing venation black, wings somewhat infumate. Lower face, most parts of mesosoma, basal half of T1 and S2 covered with dense, appressed silver pubescence, concealing integument. Femora below with dense silver pubescence. Morphology: Clypeus flat, apically with lamella, with some macro- and many micropunctures, ACM truncate. AS 2 basally narrowed, AS 2–3 and AS 12 as long as wide, AS 4–11 shorter than wide, AS 13 below as long as AS 11+12, conspicuously curved. Lower face with prominent median keel. Lower gena with keel at innerside near mouthparts. Face, upper surface of mesosoma, mesopleuron and T1 with coarse, comb-like sculpture. Remaining terga with dense macropunctation, less than a diameter apart, interspaces microsculptured. Metasoma with cross-carina, medially interrupted. T6 laterally with dentiform keel. T7 tridentate, median tooth larger than lateral tooth. Apical margin of S 2–5 medially with long white bristles, laterally each with a yellow lamella.

Female: Unknown.

Distribution: Asir province in Saudi Arabia ( Fig. 33 View FIGURES 33–36 ).

Etymology: The species is named in honor of the late Pavel G. Nemkov, a Russian expert on Spheciformes, who revised Brachystegus and other genera of Bembicidae . He supported the scientific work of the first author with exchange and identification of specimens.