Nysson arabicus Gadallah & Edmardash 2023, sp. nov.

Nysson arabicus Gadallah & Edmardash sp. nov. Figs 3A–D, 4A, B, 5A–C Type material: SAUDI ARABIA. Holotype (♁), Sala Mountain, 1186 m [17°04’10.5”N 43°07’43.3”E] (Abdul Rahman Al Jabri farm), 15.xi.2022, Malaise trap, on Coffea arabica, collector Usama Abu El-Ghiet. Description of male holotype: body length: 6.0 mm. Colouration (Figs 3A–C, 5A–C): Head and thorax black (except posterior margin of pronotum, tegula, and basal area of scutellum dark ferruginous), antenna with scape (except yellow ventrally), pedicel and the following 4–5 flagellomeres dark reddish brown, rest dark brown; mandible ferruginous with dark tip; abdomen: T 1 mostly dark ferruginous, with two yellow postero-lateral oval markings, posterior margin black; T 2 with thin, medially interrupted yellow band posteriorly; T 3 with broad band posteriorly, narrowly interrupted medially; T 4 and T 5 with complete broad yellow bands posteriorly, T 6 and T 7 entirely reddish; metasomal sterna mostly ferruginous, but S 1 mostly black, ferruginous at base; legs all ferruginous, with some yellow at tip of fore femur, and along whole length of hind tibia dorsally, hind tibia reddish ventrally, with black spurs. Fore wing slightly darkened, fumigated at apex, with dark brown veins. Head (Figs 3C, D, 4A). In dorsal view as broad as mesoscutum, densely rugulose-lacunose, with dense fine silvery pubescence laterally; vertex thin and sharp; frons densely foveolate, with sharp carina between antennal bases, with coarser silvery setae; clypeus with dense silvery setae, with about 4–5 rounded teeth at apex; antennae placed at an elevated tubercle, scape longer than wide, distinctly notched apically, pedicle cup-shape, all flagellomeres transverse, wider than long, last flagellomere longer than wide, 1.5× as long as its basal width, obliquely truncate at apex. Thorax (Figs 3A, B, 4B). Pronotum distinctly angulate antero-laterally, posterior margin coarsely punctate along ferruginous area; mesoscutum densely areolate, scutellum and metanotum densely areolate (except scutellum basally nearly smooth and shiny); scutellum with two indistinct teeth laterally, hardly seen because of the coarse foveolation of the integument; propodeum broadly strigate dorsally, with two pale sharp teeth postero-laterally; tegula with dense fine and shallow punctures; mesopleuron densely foveate, metapleuron transversely strigate, shiny; mesosternum densely foveolate. Legs normal, simple. Wings as in other Nysson species. Gaster (Figs 3A, B, 5B, C). Terga double-edged, T 1 irregularly punctate, with distinct spaces between punctures, punctures coarser and larger in the yellow areas; T 2 and T 3 with dense shallow punctures, alutaceous in between punctures; T 3 slightly elevated and smooth at base, together with the following two terga with punctures more distinct along yellow bands; terga narrowed towards apex; T 6 and T 7 densely foveolate along their whole areas, T 7 with two short spine-like processes, with rounded area in between; S 1 densely punctate with large spaces between punctures, sparsely setose; S 2 with large rounded hump (not tubercle) near to the middle, posterior margins of S 2–4 with fine punctures arranged in two or three rows; S 5 with dense coarse punctures throughout. Female: Unknown. Etymology. This species is named after the Arabian area where the specimen was collected. Distribution: Saudi Arabia (Alridah, Jazan). Comments. On the generic level, the double-edged gastral terga of the new species agree with Synnevrus A. Costa, 1859 (Guichard 1986; Nemkov 2001), however, in a cladistic analysis of the subfamily Bembicinae (based on morphological characters) carried out by Nemkov & Lelej (2013), this genus was synonymized with Nysson Latreille.Another opinion was that of W. Pulawski (pers. comm.), who attributed this to the presence of intermediate cases in some species. The genus is a new record to the Saudi Arabian fauna. The new species agrees with N. barrei (= Synnevrus barrei) in Nemkov’s key (2001: 4, couplet 4) in having two lateral small teeth on scutellum; pronotum sharply angulate antero-laterally (Fig. 4A, B); however, it differs from N. barrei in having thorax mainly black, with few areas ferruginous (Figs 3A, 4B) (thorax mainly ferruginous in N. barrei). Based on Radoszkowski (1893: 71), our male specimen differs from the male N. barrei in having posterior margin of prothorax dark ferruginous, not interrupted medially (Fig. 4A) (with ivory white band, interrupted medially in N. barrei); mesoscutum, scutellum (except ferruginous at base) entirely black (Fig. 4B) (reddish in N. barrei); T 1 with two postero-lateral oval yellow spots, posterior margins of T 2–5 with yellow bands, interrupted medially on T 2 (Figs 3A, 5C) (posterior margins of T 1–4 with ivory-white bands, interrupted medially in N. barrei); gaster ventrally mostly dark ferruginous, except basal two thirds of S 1 black (Fig. 5B) (S 2 reddish in N. barrei); fore wing slightly darkened, fumigated at apex (Fig. 5A) (transparent in N. barrei); only hind tibia along its whole dorsal side (all tibiae ivory white dorsally in N. barrei). On the other hand, the male N. arabicus somewhat agrees with the male N. ohli (Schmid-Egger 2011: 592) in having the sharply angulate antero-lateral sides of pronotum (Fig. 4A); the same body sculpturing (Fig. 3A); the presence of a median bulge between spines at apex of T 7 (Fig. 5C). However, it differs from N. ohli in the following combination of characters: body length 6.0 mm (4.0 mm in N. ohli); antenna with scape yellow ventrally (Fig. 3C) (whole antenna reddish, darkened apically in N. ohli); pronotum dark ferruginous posteriorly reaching dark ferruginous pronotal lobes (Fig. 4A) (light yellow in N. ohli reaching the dark reddish pronotal lobe); scutellum dark ferruginous at base (Fig. 4B) (clear yellow in N. ohli); T 2–5 with yellow bands posteriorly that is interrupted medially on T 2 (Figs 3A, 5C) (T 2 & T 3 with narrower lateral yellow spots, rest of terga black in N. ohli); sternal colour differs in the two species; terga medially without medial bulges (with small medial bulges in N. ohli); S 2 with a distinct, large rounded hump near to middle (absent in N. ohli); hind tibia broadly yellow dorsally (Fig. 3A) (all tibia with narrow light yellow over whole length dorsally in N. ohli). T 6 & T 7 entirely reddish (Fig. 5C) (T 6 partly and T 7 reddish in N. ohli).Published as part of Abu El-Ghiet, Usama M., Gadallah, Neveen S., Gasib, Abdulmajeed M., Al-Fifi, Zarrag I. A. & Edmardash, Yusuf A., 2023, Further addition to the crabronid fauna of Saudi Arabia (Hymenoptera: Apoidea (Spheciformes): Crabronidae), with new genera and species records, and the description of two new species, pp. 151-177 in Zootaxa 5319 (2) on pages 155-159, DOI: 10.11646/zootaxa.5319.2.1, http://zenodo.org/record/818230